ORAU TEAM Dose Reconstruction Project for NIOSH

ORAU TEAM

http://www.cdc.gov/niosh/ocas/pdfs/tbd/pine4-r1.pdf
Dose Reconstruction
Project for NIOSH
Oak Ridge Associated Universities I Dade Moeller I MJW Technical Services
Page 1 of 50
DOE Review Release 07/27/2011
Document Title:
Pinellas Plant – Occupational Environmental
Dose
Document Number: ORAUT-TKBS-0029-4
Revision: 01
Effective Date: 07/15/2011
Type of Document: TBD
Supersedes: Revision 00
Subject Expert(s): Milton Gorden, Amir S. Mosbasheran, Brian P. Gleckler, Tracy A. Ikenberry
Approval: Signature on File Approval Date: 07/13/2011
Brian P. Gleckler, Document Owner
Concurrence: Signature on File Concurrence Date: 07/13/2011
John M. Byrne, Objective 1 Manager
Concurrence: Signature on File Concurrence Date: 07/13/2011
Edward F. Maher, Objective 3 Manager
Concurrence: Vickie S. Short Signature on File for Concurrence Date: 07/14/2011
Kate Kimpan, Project Director
Approval: Signature on File Approval Date: 07/15/2011
James W. Neton, Associate Director for Science
New Total Rewrite Revision Page Change
FOR DOCUMENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR
REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 2 of 50
PUBLICATION RECORD
EFFECTIVE
DATE
REVISION
NUMBER DESCRIPTION
04/05/2005 00 First approved issue. Initiated by Mark D. Notich.
07/15/2011 01 This technical basis document was predominantly revised to address
SC&A’s issues with the document, as identified in SCA-TR-TASK1-
0015. In addition, the bases for the annual environmental intakes
and the annual onsite ambient external doses were redone. This
included redoing the atmospheric dispersion calculations that each of
them were based on. Incorporates formal internal and NIOSH review
comments. Constitutes a total rewrite of the document. Training
required: As determined by the Objective Manager. Initiated by
Brian P. Gleckler.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 3 of 50
TABLE OF CONTENTS
SECTION TITLE PAGE
Acronyms and Abbreviations …………………………………………………………………………………………………5
4.0 Occuupational Environmental Dose ……………………………………………………………………………..6
4.1 Introduction ………………………………………………………………………………………………………………6
4.1.1 Overview ……………………………………………………………………………………………………….7
4.1.2 Purpose…………………………………………………………………………………………………………7
4.1.3 Scope……………………………………………………………………………………………………………7
4.2 Historic Sources of Onsite Environmental Radioactivity…………………………………………………… 8
4.3 Onsite Monitorng Practices …………………………………………………………………………………………8
4.3.1 Employee Monitoring……………………………………………………………………………………….9
4.3.2 Environmental External Dose Monitoring…………………………………………………………..10
4.3.3 Radioactive Airborne Effluent Monitoring…………………………………………………………..10
4.3.3.1 Radioactive Airborne Effluent Discharge Points ……………………………………. 10
4.3.3.2 Monitoring Methods………………………………………………………………………….. 10
4.3.3.3 Historical Radioactive Airborne Effluent Discharges………………………………. 11
4.3.4 Radioactive Liquid Effluent Monitoring………………………………………………………………13
4.3.4.1 Radioactive Liquid Effluent Discharge Points ……………………………………….. 13
4.3.4.2 Monitoring Methods………………………………………………………………………….. 14
4.3.4.3 Historical Radioactive Liquid Effluent Discharges………………………………….. 14
4.3.5 Onsite Environmental Air Monitoring…………………………………………………………………15
4.3.5.1 Onsite Environmental Air Monitoring Locations and Methods………………….. 15
4.3.5.2 Historical Onsite Environmental Air Monitoring Results………………………….. 16
4.4 Potential Exposures ………………………………………………………………………………………………… 18
4.4.1 Potential Internal Exposures and Doses ……………………………………………………………18
4.4.1.1 Potential Intakes Based on Stack Emissions………………………………………… 18
4.4.1.2 Potential Intakes Based on Liquid Effluent Data……………………………………. 19
4.4.1.3 Potential Intakes Based on Onsite Air Monitoring Data ………………………….. 20
4.4.2 Potential External Doses ………………………………………………………………………………..21
4.5 Uncertainty……………………………………………………………………………………………………………..23
4.6 Attributions And Annotations …………………………………………………………………………………….. 23
References ……………………………………………………………………………………………………………………….24
Glossary …………………………………………………………………………………………………………………………..29
ATTACHMENT A, BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS ………………………. 31
A-1 Introduction …………………………………………………………………………………………………………….32
A-2 Computer Model ……………………………………………………………………………………………………..32
A-3 Meteorological Data ………………………………………………………………………………………………… 32
A-4 Atmospheric Dispersion Factors for Stacks…………………………………………………………………. 33
A-5 Atmospheric Dispersion Factors for Area Sources ……………………………………………………….. 42
A-6 Atmospheric Dispersion at Tritium Monitoring Station Locations …………………………………….. 46Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 4 of 50
A-7 Summary and Conclusions ………………………………………………………………………………………. 49
LIST OF TABLES
TABLE TITLE
4-1 Exhaust stacks, their dimensions, and their potential radionuclide
releases …………………………………………………………………………………………………………………
PAGE
10
4-2 Radionuclides released from Pinellas Plant exhaust stacks …………………………………………… 12
4-3 Tritium in the east retention pond………………………………………………………………………………. 15
4-4 Onsite tritium air monitoring results ……………………………………………………………………………. 17
4-5 Annual onsite environmental intakes from stack emissions for a
hypothetical MEE …………………………………………………………………………………………………….19
4-6 Estimated annual tritium intakes based on air monitoring results ……………………………………. 20
4-7 Potential annual onsite environmental external doses…………………………………………………… 22
A-1 Pinellas Plant stack parameters used in the determination of atmospheric
dispersion factors…………………………………………………………………………………………………….34
A-2 Atmospheric dispersion factors (s/m
3
) for the Building 100 Main Stack,
applicable 1957 through 1980 …………………………………………………………………………………… 36
A-3 Atmospheric dispersion factors (s/m
3
) for the Building 100 Main Stack,
applicable 1981 through 1996 …………………………………………………………………………………… 37
A-4 Atmospheric dispersion factors (s/m
3
) for the Building 100 Lab Stack,
applicable 1965 through 1980 …………………………………………………………………………………… 38
A-5 Atmospheric dispersion factors (s/m
3
) for the Building 100 Lab Stack,
applicable 1981 through 1995 …………………………………………………………………………………… 39
A-6 Atmospheric dispersion factors (s/m
3
) for the Building 800 Stack,
applicable 1997……………………………………………………………………………………………………….40
A-7 Summary of maximum atmospheric dispersion factors for Pinellas Plant
stacks…………………………………………………………………………………………………………………….41
A-8 Atmospheric dispersion factors used for Pinellas Plant stack releases…………………………….. 42
A-9 Atmospheric dispersion factors (s/m
3
) for the east retention pond,
applicable 1971 through 1997 …………………………………………………………………………………… 43
A-10 Atmospheric dispersion factors (s/m
3
) for the west retention pond,
applicable 1973 through 1997 …………………………………………………………………………………… 44
A-11 Atmospheric dispersion factors (s/m
3
) for the aeration area, applicable
1973 through 1982…………………………………………………………………………………………………..45
A-12 Atmospheric dispersion factors at the six tritium monitoring station
locations (s/m
3
) ……………………………………………………………………………………………………….46
A-13 Ratio of predicted-to-measured tritium gas (HT) concentrations at tritium
air monitoring stations ……………………………………………………………………………………………… 47
A-14 Ratio of predicted-to-measured tritium oxide (HTO) concentrations at
tritium air monitoring stations ……………………………………………………………………………………. 49
LIST OF FIGURES
FIGURE TITLE
4-1 Environmental monitoring locations………………………………………………………………………………
PAGE
9Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 5 of 50
ACRONYMS AND ABBREVIATIONS
AEC U.S. Atomic Energy Commission
Bq becquerel
CFR Code of Federal Regulations
Ci curie
d day
DOE U.S. Department of Energy
EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000
ft foot, feet
g gram
gal gallon
GE General Electric Company
GEND GE Neutron Devices
GENDD GE Neutron Devices Department
GEPP GE Pinellas Plant
GEXF GE X-ray Division in Florida
H hydrogen (
1
H or protium)
HT tritium gas (also denoted as T2)
HTO tritium oxide (also denoted as T2O)
JFD joint frequency distribution
keV kilovolt-electron, 1,000 electron volts
L liter
m meter
MDL minimum detection level
MEE maximally exposed employee
ml milliliter
mrem millirem
NIOSH National Institute for Occupational Safety and Health
POC probability of causation
POTW Publically Owned Treatment Works
RTG radioisotopically-powered thermoelectric generator
T tritium (
3
H)
TBD technical basis document
U.S.C. United States Code
wk week
yr year
µCi microcurie
§ section or sectionsDocument No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 6 of 50
4.0
4.1 INTRODUCTION
OCCUPATIONAL ENVIRONMENTAL DOSE
Technical basis documents and site profile documents are not official determinations made by the
National Institute for Occupational Safety and Health (NIOSH) but are rather general working
documents that provide historic background information and guidance to assist in the preparation of
dose reconstructions at particular sites or categories of sites. They will be revised in the event
additional relevant information is obtained about the affected site(s). These documents may be used
to assist NIOSH staff in the completion of the individual work required for each dose reconstruction.
In this document the word “facility” is used as a general term for an area, building, or group of
buildings that served a specific purpose at a site. It does not necessarily connote an “atomic weapons
employer facility” or a “Department of Energy [DOE] facility” as defined in the Energy Employees
Occupational Illness Compensation Program Act [EEOICPA; 42 U.S.C. § 7384l(5) and (12)].
EEOICPA defines a DOE facility as “any building, structure, or premise, including the grounds upon
which such building, structure, or premise is located … in which operations are, or have been,
conducted by, or on behalf of, the Department of Energy (except for buildings, structures, premises,
grounds, or operations … pertaining to the Naval Nuclear Propulsion Program)” [42 U.S.C. §
7384l(12)]. Accordingly, except for the exclusion for the Naval Nuclear Propulsion Program noted
above, any facility that performs or performed DOE operations of any nature whatsoever is a DOE
facility encompassed by EEOICPA.
For employees of DOE or its contractors with cancer, the DOE facility definition only determines
eligibility for a dose reconstruction, which is a prerequisite to a compensation decision (except for
members of the Special Exposure Cohort). The compensation decision for cancer claimants is based
on a section of the statute entitled “Exposure in the Performance of Duty.” That provision [42 U.S.C. §
7384n(b)] says that an individual with cancer “shall be determined to have sustained that cancer in the
performance of duty for purposes of the compensation program if, and only if, the cancer … was at
least as likely as not related to employment at the facility [where the employee worked], as
determined in accordance with the POC [probability of causation
1
The statute also includes a definition of a DOE facility that excludes “buildings, structures, premises,
grounds, or operations covered by Executive Order No. 12344, dated February 1, 1982 (42 U.S.C.
7158 note), pertaining to the Naval Nuclear Propulsion Program” [42 U.S.C. § 7384l(12)]. While this
definition excludes Naval Nuclear Propulsion Facilities from being covered under the Act, the section
of EEOICPA that deals with the compensation decision for covered employees with cancer [i.e., 42
U.S.C. § 7384n(b), entitled “Exposure in the Performance of Duty”] does not contain such an
exclusion. Therefore, the statute requires NIOSH to include all occupationally-derived radiation
exposures at covered facilities in its dose reconstructions for employees at DOE facilities, including
radiation exposures related to the Naval Nuclear Propulsion Program. As a result, all internal and
external occupational radiation exposures are considered valid for inclusion in a dose reconstruction.
No efforts are made to determine the eligibility of any fraction of total measured exposure for inclusion
in dose reconstruction. NIOSH, however, does not consider the following exposures to be
occupationally derived (NIOSH 2010):
] guidelines established under
subsection (c) …” [42 U.S.C. § 7384n(b)]. Neither the statute nor the probability of causation
guidelines (nor the dose reconstruction regulation, 42 C.F.R. Pt. 82) define “performance of duty” for
DOE employees with a covered cancer or restrict the “duty” to nuclear weapons work (NIOSH 2010).
• Background radiation, including radiation from naturally occurring radon present in
conventional structures
• Radiation from X-rays received in the diagnosis of injuries or illnesses or for therapeutic
reasons

1
The U.S. Department of Labor (DOL) is ultimately responsible under the EEOICPA for determining the POC.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 7 of 50
4.1.1
This TBD is Part 4 of the Pinellas Plant’s Site Profile. A site profile provides a summary of information
about a site that is relevant to the dose reconstruction process.
Overview
The Pinellas Plant has been known by several names throughout its history. Those names include:
908 Plant, Pinellas Peninsula Plant, GE X-ray Division-Florida (GEXF), GE Neutron Devices
Department (GENDD), GE Neutron Devices (GEND), GE Pinellas Plant (GEPP), and the Pinellas
Plant.
The General Electric Company built and operated the Pinellas Plant for DOE from its initial startup in
January 1957 until June 1992. In June 1992, Martin Marietta Specialty Components, Inc. (MMSC)
took over as the managing and operating contractor for the Pinellas Plant. In 1994, Lockheed merged
with Martin Marietta and the managing and operating contractor for the Pinellas Plant was renamed
Lockheed Martin Specialty Components (LMSC). The Pinellas Plant completed its war reserve
fabrication of neutron generators at the end of September 1994, and began the transition from a
defense mission to an environmental management mission. That transition included a number of
decontamination and decommissioning activities that allowed the Plant to be turned over for
commercial uses. LMSC continued as the managing and operating contractor until decontamination
and decommissioning activities ended in 1997 (ORAUT 2011j).
The Plant was built to manufacture neutron generators, a principal component in nuclear weapons.
The neutron generators consisted of a miniaturized linear ion accelerator assembled with pulsed
electric power supplies. The ion accelerator, or neutron tube, required ultraclean, high-vacuum
technology; hermetic seals between glass, ceramic, glass-ceramic, and metal materials; and highvoltage generation and measurement technology. The Plant manufactured only neutron generators
for its first 10 years of operation. It later manufactured other products including neutron detectors,
radioisotopically-powered thermoelectric generators (RTGs), high-vacuum switch tubes, specialty
capacitors, and specialty batteries (Weaver 1990). As part of its program to promote commercial
uses of the site, DOE sold most of the Plant to the Pinellas County Industry Council in March 1995
and leased back a portion through September 1997 to complete safe shutdown and transition
activities (LMSC 1996b).
4.1.2
This TBD provides the basis for assessing the occupational environmental doses at the Pinellas Plant.
The information in this TBD can be used in dose reconstructions for the EEOICPA.
Purpose
4.1.3
This document provides supporting technical data to evaluate the total Pinellas occupational radiation
dose that can reasonably be associated with the worker’s radiation exposure. Occupational
environmental doses result from exposures to onsite sources of ambient radiation and onsite levels of
environmental airborne radioactivity. Also included are techniques to assess the dose that might have
occurred while an employee was not monitored. Over the years, new and more reliable scientific
methods and protection measures have been deployed. The methods needed to account for these
changes are also identified in this document.
Scope
This TBD describes the radiological conditions in the onsite environment and the environmental
monitoring program at the Pinellas Plant. This includes environmental monitoring data, the practices
and policies at the Plant, and the approaches used for measuring the levels of radiation and/or
radioactivity in the environment at the Plant. The information provided in this TBD is based on the Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 8 of 50
available literature on the site, which consists primarily of environmental monitoring reports and site
environmental reports published between 1971 and 1995.
4.2 HISTORIC SOURCES OF ONSITE ENVIRONMENTAL RADIOACTIVITY
The radionuclides released to the environment at the Pinellas Plant included tritium (
3
H),
14
C, and
85
Kr. Encapsulated sources of plutonium were also present at the Plant in significant quantities, but a
review of the environmental monitoring reports for the site indicates that no plutonium was ever
released to the environment. Tritium and
14
C emit very-low-energy beta particles, whereas
85
Kr emits
high-energy beta particles. The exposure pathways for these radionuclides are explained in the
sections below.
Tritium was the primary radionuclide used at the Pinellas Plant. While it can exist in all compounds
that contain normal hydrogen, two of the more common forms are (1) tritium gas (denoted as HT) and
(2) tritium oxide (denoted as HTO) in either the liquid or the vapor state. With a physical half-life of
12.3 years, tritium emits low-energy beta particles and decays to
3
He. The emitted beta particles
have an average energy of 5.7 keV (Kocher 1981). Because electrons below 15 keV do not have
sufficient energy to penetrate the epidermal layer of the skin (NIOSH 2007), tritium is not considered
an external radiation hazard. Therefore, tritium contributes only to internal dose (LMSC 1995a). In
comparison to tritium oxide (which readily exchanges with the body’s water), the internal dose from an
intake of tritium gas is one ten thousandth the dose of an equivalent intake of tritium oxide (NIOSH
2003).
Krypton-85, which exists only in the gaseous state, has a half-life of 10.72 years. Its most common
decay (99.6%) is by beta particle emission with an average energy of 251.4 keV. Its alternative decay
scheme (0.43%) is by beta particle emission (average energy of 47.5 keV) followed by gamma ray
emission (energy of 514 keV) (Kocher 1981).
A 1983 environmental assessment indicated the small quantities of
14
C labeled solvents were used in
a laboratory testing operation in Building 100 from 1979 to 1983 (DOE 1983). Because
14
C emits a
low-energy beta particle (average energy of 49.5 keV), radiation doses result primarily from internal
deposition (DOE 1983).
4.3 ONSITE MONITORING PRACTICES
Only the onsite monitoring practices that provide an indication of what the unmonitored workers at the
Pinellas Plant were potentially exposed to are included in this section. Onsite monitoring practices
such as vegetation, milk, and groundwater monitoring were not included because radioactivity in
these media would not contribute to worker doses received at the site. The effluent monitoring for
discharges to an offsite location, such as the Publically Owned Treatment Works (POTW), is another
example of a potential source of environmental radioactivity that would not contribute to worker doses
received at the site.
Figure 4-1 identifies the primary onsite environmental monitoring locations for the Pinellas Plant. Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 9 of 50
Figure 4-1. Environmental monitoring locations.
4.3.1
An external dosimetry program was started in 1957 to monitor individual personnel working in the
production areas for the neutron generators. From 1960 to 1973, the U.S. Atomic Energy
Commission (AEC) annual exposure summary reports showed that the Pinellas Plant had 27.5% of its
workers wearing dosimetry. In the 1980s, approximately 10% to 14% of workers were monitored for
radiation dose. This percentage range appears to be representative of the entire history of monitoring
at the Plant (no documentation was found that shows all employees were monitored during any given
period). Only employees who performed activities that could have caused them to receive doses
greater than radiation protection guidelines were monitored. A smaller percentage of employees were
monitored for internal exposures. Therefore, a majority of employees could have received onsite
Employee MonitoringDocument No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 10 of 50
environmental doses that were not monitored because they did not wear external dosimetry or were
not monitored for internal dose.
4.3.2
There is no indication that any environmental external dose monitoring was performed at the Pinellas
Plant. Based on the activities performed at the Plant and the sources of radiation at the site, external
doses outside the Plant buildings were probably too low to warrant monitoring.
Environmental External Dose Monitoring
4.3.3
4.3.3.1 Radioactive Airborne Effluent Discharge Points
Radioactive Airborne Effluent Monitoring
Exhaust stacks were a primary source for radioactive airborne effluent releases to the environment.
Table 4-1 lists the exhaust stacks along with their locations, dimensions, and the nature of their
releases. Figure 4-1 shows the locations of the exhaust stacks with radioactive effluents. The stacks
that accounted for the vast majority of the site’s radioactive airborne effluents were the two Building
100 stacks. Combined, the Building 800 Stack and Building 200 Stack accounted for less than 0.1%
of the site’s total tritium releases through exhaust stacks. Radioactive emissions were never detected
in the Building 400 Stack.
Table 4-1. Exhaust stacks, their dimensions, and their potential radionuclide releases.
a
Stack name
Applicable
Period
Height
(m [ft])
Diameter
(m [ft])
Potential nuclides
in effluent
Bldg. 100 Main Stack 1957–Jun 1981
b
30.48 [100] 2.44 (8) HT and HTO
Jul 1981–1996
b
21.34 [70] 2.44 (8) Kr-85 1963–1994 only
Bldg. 100 Laboratory
Stack
1965–1995 30.48 [100] 1.52 (5) HT and HTO
C-14 1979–1983 only
Bldg. 800 Stack 1980–1989 6.4 [21]
c
0.25 x 0.33 HT and HTO 1980–1997
[0.82 × 1.08] Kr-85 1996 only
c
1990–1997 9.1 [30] 0.51 [1.67]
Bldg. 200 Stack 1989–1994 17.7 [58] 0.30 [0.98] HT and HTO
Bldg. 400 Stack Nov 1975–1994
d
6.7 [22] 0.41 [1.33] Plutonium oxide
e
a. Sources: GE 1972, 1973, 1974a, 1974b, 1975, 1976, 1977, 1978b, 1979, 1980, 1981, 1982, 1983, 1984,
1985, 1986, 1987, 1988, 1989, 1990, 1991; MMSC 1992, 1993, 1994; LMSC 1995b, 1996a, 1997a, 1997b;
ORAUT 2011b.
b. In July 1981, the height of the Main Stack was reduced to provide more stability in the event of hurricaneforce winds (GE 1982).
c. Prior to 1990, this was a rectangular stack with the reported dimensions of 10 in x 13 in (DOE 1983).
d. Even though all plutonium sources were removed from Building 400 by February 1991 (MMSC 1993),
plutonium monitoring on the Building 400 Stack continued until 1994.
e. No plutonium emissions were ever detected from this exhaust stack.
4.3.3.2 Monitoring Methods
Because of the differing physical and radiological properties of radioactive airborne effluents, different
methods were required to determine the quantity of each radionuclide that was discharged from the
Pinellas Plant exhaust stacks.
Until 1974, airborne effluent discharges of tritium gas and tritium oxide were determined using a
combination of continuous stack sampling systems and “real-time” stack monitoring systems. Starting
in 1974, airborne effluent discharges of both tritium gas and tritium oxide were determined using
continuous stack sampling systems. The continuous stack monitoring system used to monitor tritium
gas concentrations consisted of a Kanne-type ionization chamber connected to a picoammeter andDocument No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 11 of 50
recorder. The minimum detection level reported for this type of tritium gas monitoring was 1.3 × 10
-5
μCi/mL in 1971 (GE 1972). To collect and analyze airborne effluent samples for tritium oxide, water
vapor in the sample stream was originally condensed by a refrigeration device, and the water vapor
condensate samples were collected daily (GE 1972). The samples were later analyzed by liquid
scintillation spectrometry (GE 1972). The minimum detection level reported for this type of tritium
oxide sampling was 8.9 × 10
-11
μCi/mL in 1971 (GE 1972).
Starting in 1974, silica gel columns were used to collect both tritium oxide and total tritium samples
initially on a weekly basis and later on a monthly basis (GE 1975, GE 1980). The collected tritium
was then desorbed from the silica columns and analyzed by liquid scintillation counting (GE 1975).
Tritium oxide samples were collected directly by passing a sample stream through a silica gel column.
Total tritium samples (i.e., gas and oxide samples combined) were collected by heating a sample
stream, and converting any tritium gas in the sample stream to tritium oxide using a catalyst. After all
the tritium was converted to tritium oxide, the total tritium samples were collected by passing the
sample stream through a silica gel column. Tritium gas concentrations were calculated by subtracting
the tritium oxide concentrations from the total tritium concentrations (GE 1972, GE 1991,
IT/Radiological Sciences Laboratory, 1986). The minimum detection levels reported for this type of
tritium sampling ranged from 4.2 × 10
-13
to 1.0 × 10
-10
μCi/mL (GE 1972, GE 1975, GE 1991,
IT/Radiological Sciences Laboratory, 1986).
Airborne effluent discharges of
85
Kr were determined using a continuous stack monitoring system on
the Building 100 main stack. The continuous stack monitoring system consisted of a Kanne-type
ionization chamber connected to a picoammeter and recorder. The minimum detection levels
reported for this type of
85
Kr monitoring ranged from 1.3 × 10
-7
to 6.4 × 10
-6
μCi/mL (GE 1972, GE
1975, GE 1991, IT/Radiological Sciences Laboratory, 1986).
Airborne effluent discharges of
14
C were determined from the volumes of
14
C containing solvent used
during each year (GE 1980, GE 1984).
Although there were no reported plutonium releases at the Pinellas Plant, airborne effluents from the
Building 400 stack were sampled for plutonium using a continuous stack sampling system.
Particulate air samples were collected on filters that were exchanged monthly and later analyzed for
238
Pu and
239/240
Pu (IT/Radiological Sciences Laboratory, 1986). The method of plutonium analysis
consisted of 1) aliquoting a known quantity of
242
Pu tracer onto the air filters, 2) introduction and
chemical equilibration of the
242
Pu tracer for recovery efficiency determination, 3) acid digestion of the
combined sample and tracer, 4) plutonium isolation by anion exchange, 5) electrodeposition, and 6)
alpha spectrometric analysis (GE 1991). The minimum detection levels reported for this type of
plutonium sampling ranged from 5.9 × 10
-19
to 3.7 × 10
-18
μCi/mL for
238
Pu and
239/240
Pu
(IT/Radiological Sciences Laboratory, 1986).
4.3.3.3 Historical Radioactive Airborne Effluent Discharges
Table 4-2 provides a summary of the radioactive airborne effluent releases from Pinellas Plant
exhaust stacks. Approximately 82% of the total releases had occurred during the first 4 years of
operation, 1957 through 1960. Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 12 of 50
Table 4-2. Radionuclides released from Pinellas Plant
exhaust stacks (Ci/yr).
a
Year HT HTO Kr-85
b
C-14
c
1957 6,660 140 NR
d
NR
1958 31,920 580 NR NR
1959 41,070 1,330 NR NR
1960 6,265 435 NR NR
1961 504 306 NR NR
1962 611 249 NR NR
1963 179 103 4 NR
1964 233 57 47 NR
1965 50 100 153 NR
1966 325 385 49 NR
1967 1,944 213 70 NR
1968 1,586 215 202 NR
1969 3,275 297 55 NR
1970 587 465 44 NR
1971 694 374 12 NR
1972 111 222 15 NR
1973 74 318 1 NR
1974 155 202 4 NR
1975 154 165 1 NR
1976 101 176 20 NR
1977 129 161 28 NR
1978 132 156 5 NR
1979 127 206 5 1.00E-04
1980
e
140 209 2 2.00E-04
1981 222 195 4 8.46E-05
1982 227 257 8 4.00E-05
1983 259 152 11 1.00E-05
1984 96 206 2 NR
1985 111 149 5 NR
1986 33 161 5 NR
1987 68 138 38 NR
1988 134 124 30 NR
1989
f
44 60 13 NR
1990 62 61 10 NR
1991
g
23 88 4 NR
1992 8 32 10 NR
1993 NR 12 19 NR
1994 NR 25 13 NR
1995 NR 26 NR NRDocument No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 13 of 50
Year HT HTO Kr-85
b
C-14
c
1996 NR 22 6 NR
1997 NR 3 NR NR
a. Sources: GE 1972, 1973, 1974a, 1974b, 1975, 1976, 1977, 1978b,
1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989,
1990, 1991; MMSC 1992, 1993, 1994; LMSC 1995b, 1996a,1996b,
1997a,1997b; ORAUT 2011b.
b. In 1963, the Pinellas Plant began to use Kr-85 for leak detection in
Building 100 (Burkhart 1990). Kr-85 was exhausted through the
Building 100 Main Stack until 1996 when it was exhausted from the
Building 800 stack until all of the Kr-85 was removed from the site in
1996.
c. For the years of 1979–1983, C-14 releases were reported for the
Building 100 Laboratory Stack. Rather than monitoring the C-14
releases, the Pinellas Plant estimated its C-14 released based on
the amount of C-14 labeled solvent that was used during each years.
d. NR = No recorded release.
e. Releases from the Building 800 stack were first reported during this
year.
f. Releases from the Building 200 stack were first reported during this
year.
g. In 1991, two minor point sources (chemical hoods) exhausted tritium
gas and tritium oxide through two roof openings. These were roof
openings 378 (Chemistry Laboratory) and 413 (Environmental
Laboratory).
h. The tritium releases for this year were actually reported as total
tritium released, but have been reported in this table as HTO
released.
As indicated in Table 4-2, mainly tritium gas, tritium oxide and, to a relatively lesser degree,
85
Kr
comprised the radiological contents of the exhausts from the Pinellas Plant exhaust stacks. The Plant
began using
85
Kr for leak detection in 1963 (Burkhart 1990). Relatively small contributions of
14
C to
the overall air releases were reported for 1979 to 1983, as indicated in Table 4-2.
4.3.4
4.3.4.1 Radioactive Liquid Effluent Discharge Points
Radioactive Liquid Effluent Monitoring
From 1957 through 1970 (GE 1974a, 1974b), liquid effluents containing tritium were directed to onsite
holdup/collection tanks. After monitoring, the liquid effluents were released into a county drainage
ditch that was located at the southwest corner of the site. The liquid effluents travelled through a
series of ditches and canals eventually entering Boca Ciega Bay (GE 1974a).
From 1971 through 1972 (GE 1974a, 1974b), drain lines containing liquid industrial effluent were
directed to an onsite acid neutralization facility and from there were sent to the 3,250,000-gal east
retention pond (also known as the northeast lake) (GE 1974a). Discharges from the east retention
pond were made to a county drainage ditch that led to Boca Ciega Bay (GE 1974a).
From 1973 through November 1982 (GE 1974b, 1983), drain lines containing liquid industrial effluent
were directed to an onsite acid neutralization facility and from there were sent to the 2,600,000-gal
west retention pond (also known as the northwest lake), which was equipped with three floating
aerators (GE 1974b). Treated sanitary wastes were also sent to the west retention pond. Water from
the west retention pond was pumped to a 9-acre spray irrigation/aeration field, which was at the north
end of the site. A subsurface drain system under the irrigation/aeration field collected the liquids and
directed them to the 3,250,000-gal east retention pond (also known as the northeast lake) (GE
1974b). Periodic batch discharges from the east retention pond were made to a county drainage ditch Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 14 of 50
that led to Boca Ciega Bay (GE 1974b, 1983). A third retention pond, the south retention pond (also
known as the south lake) was only used for retaining stormwater runoff from the site.
After November 1982, the industrial effluents (after a pH adjustment) were combined with the
untreated sanitary wastes sent to the Pinellas County POTW. Stormwater continued to be diverted to
the retention ponds, where trace quantities of tritium remained (GE 1983).
4.3.4.2 Monitoring Methods
Tritium was the only radionuclide discharged in Pinellas Plant liquid effluents. From 1957 through
1970 (GE 1957–1973, 1974a, 1974b), liquid effluents in the holdup/collection tanks were discharged
into a county drainage ditch after monitoring confirmed that the tritium concentrations were below the
permissible concentrations for release into sanitary sewer systems. During 1971, individual daily grab
samples of the liquid effluents being discharged from the east retention pond were collected and
analyzed for tritium (GE 1972). From 1972 through November 1982, liquid samples were taken from
the east retention pond where the pond discharges to the drainage ditch by a proportional sampling
system (GE 1983). After November 1982, composite samples were collected by proportional
sampling of the discharges to the POTW (GE 1985).
Tritium results through 1982 were referenced to the standards set forth in the Rules of the Florida
State Board of Health, Chapter 170J-1, “Control of Radiation Hazards,” and in AEC Manual Chapter
0524, Standards for Radiation Protection (GE 1973). Sampling results were recorded in the annual
environmental reports in terms of microcuries per milliliter. After 1982, all samples were analyzed in
accordance with the latest edition of Standard Methods for the Examination of Water and Wastewater,
published by the American Public Health Association, American Water Works Association, and Water
Pollution Control Federation (Eaton and Franson 2005; GE 1983).
4.3.4.3 Historical Radioactive Liquid Effluent Discharges
The tritium oxide released to the retention ponds would naturally evaporate into the atmosphere at the
same rate as the water and become a possible internal source of exposure to a worker working
adjacent to a retention pond. Tritium-bearing liquid effluents were discharged to the west and east
retention ponds. The retention ponds were located a short distance away from other Pinellas Plant
facilities and there was no known reason why any workers would be near the retention ponds except
to conduct monitoring of the ponds and perform maintenance on the liquid effluent discharge and
aeration systems.
The tritium concentration in the liquid contained in the east retention pond and discharged to the
drainage ditch was reported in environmental monitoring reports from 1971 through 1994. Table 4-3
summarizes the annual maximum and average concentration of tritium in the retention pond.
Because no data is known for the years prior to 1971, the highest concentration for the subsequent
years was assumed for 1957–1970. The data in Table 4-3 are reflective of results as measured at the
discharge point to the drainage ditch. The actual quantities of tritium sent to the west and east
retention ponds from Pinellas Plant manufacturing processes are not known.
The amount of tritium measured in the east retention pond for all years was less than 1% of the
concentration guide for tritium in water as set forth in Energy Research and Development
Administration Manual Chapter 0524 (ERDA 1977).
After the industrial effluent discharges were rerouted to the POTW in 1982, there was a steady
decline in the tritium concentrations measured in the east retention pond. Beginning in 1986, results
from tritium analyses in water from the west and south retention ponds were reported. By that time,
the reported tritium concentrations in the west and south retention ponds were of the same order of Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 15 of 50
magnitude as the concentrations in the east retention pond.
Table 4-3. Tritium in the east retention pond.
a
Year
Maximum
concentration in
the water
(μCi/mL)
Average
concentration in
the water
(μCi/mL)
Minimum
detection level
(μCi/mL)
Discharge
volume
(liters of water)
Total curies
discharged
from pond
1957–1970
b
NR
c
NR NR NR
c
NR
1971 5.5E-04 4.6E-05 1.0E-05 NR NR
1972 1.5E-04 4.7E-05 1.0E-06 1.32E+08 5.6
1973 3.0E-05 8.6E-06 1.0E-06 NR NR
1974 2.6E-05 9.2E-06 1.0E-06 NR NR
1975 9.8E-06 6.4E-06 1.3E-07 1.23E+08 0.79
1976 6.7E-06 4.1E-06 1.6E-07 3.9E+07 0.16
1977 6.7E-06 5.0E-06 1.4E-07 1.90E+08 0.95
1978 5.2E-06 4.1E-06 1.4E-07 1.27E+08 0.54
1979 1.1E-05 3.6E-06 1.4E-07 8.72E+07 0.31
1980 8.7E-06 6.0E-06 1.4E-07 9.05E+07 0.54
1981 1.4E-05 1.3E-05 1.6E-07 4.69E+07 0.60
1982 1.2E-05 6.7E-06 1.7E-07 1.09E+07 0.73
1983 5.0E-06 1.4E-06 3.0E-07 2.74E+08 0.37
1984 4.8E-06 8.7E-07 1.7E-07 1.73E+08 0.15
1985 3.2E-06 8.9E-07 8.5E-08 NR NR
1986 2.1E-06 9.0E-07 5.5E-07 NR NR
1987 1.05E-06 5.6E-07 7.8E-07 NR NR
1988 1.3E-06 4.4E-07 6.3E-07 NR NR
1989 2.8E-06 4.9E-07 5.1E-07 NR NR
1990 5.1E-07 NR NR NR NR
1991 4.8E-07 NR NR NR NR
1992 2.9E-07 BDL
d
4.5E-07 NR NR
1993 NR BDL 4.8E-07 NR NR
1994 NR BDL 4.3E-07 NR NR
1995 NR BDL 3.3E-07 NR NR
a. GE 1972, 1973, 1974b, 1975, 1976, 1977, 1978b, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988,
1989, 1990, 1991; MMSC 1992, 1993, 1994; LMSC 1995b, 1996b.
b. No monitoring data for the east retention pond was available prior to 1971. Because liquid effluent discharges to the
pond did not begin until 1971, the tritium levels in the pond were likely insignificant prior to 1971.
c. NR = Not reported.
d. BDL = Below Detection Limit.
4.3.5
4.3.5.1 Onsite Environmental Air Monitoring Locations and Methods
Onsite Environmental Air Monitoring
Environmental air monitoring for tritium gas and oxide was performed at the Pinellas Plant from the
very beginning of Plant operations. The earliest background monitoring for radioactivity was
performed in April 1957. Four samples from the areas around the Plant were taken to establish
background counts before the Plant began operations. Before the mid-1970s, the monitoring program
was informal and there were no permanent air monitoring stations. In addition, some monitoring
activities were done on an irregular basis. During the mid-1970s, six permanent onsite air monitoring
stations were installed for monitoring tritium. With the installation of the permanent air monitoring
stations, monitoring was performed on a more regular basis (State of Florida 1994). Starting in 1975,
plutonium monitoring was performed at four locations because of the encapsulated plutonium that
was present at the Plant as part of RTG operations (State of Florida 1994).Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 16 of 50
Figure 4-1 above shows the onsite environmental air monitoring locations at the Pinellas Plant.
4.3.5.2 Historical Onsite Environmental Air Monitoring Results
Table 4-4 provides a summary of the tritium results from the onsite environmental air monitoring
stations for the years of 1975–1992 (State of Florida 1994). Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 17 of 50
Table 4-4. Onsite tritium air monitoring results.
Average Annual Tritium Air Concentrations Measured at Onsite Tritium Air Monitoring Stations (E-12 µCi/mL)
a
Year Station 1 Station 2 Station 3 Station 4 Station 5 Station 6
Gas Oxide Gas Oxide Gas Oxide Gas Oxide Gas Oxide Gas Oxide
1975 NA
b
NA < 5.1 < 8.0 NA NA < 44.2 18.4 < 12.0 < 8.5 15.4 < 11.1
1976 < 4.6 < 6.4 < 6.2 < 3.4 < 18.8 < 4.1 < 5.0 < 3.5 < 87.3 < 5.5 < 4.2 < 5.9
1977 < 7.4 < 7.4 < 5.9 < 6.2 < 8.5 < 6.9 < 26.2 < 8.9 < 12.0 < 11.4 < 9.5 9.8
1978 < 5.2 6.0 4.2 < 5.7 < 1.9 5.3 < 5.0 < 4.4 < 5.8 6.2 < 6.0 9.2
1979 < 3.9 10.2 < 3.6 7.1 < 3.1 6.0 < 2.3 20.9 < 6.0 9.9 < 10.8 15.2
1980 < 4.4 7.1 5.9 7.5 < 4.0 5.2 < 6.2 < 10.2 < 4.2 < 8.5 17.2 9.7
1981 < 5.9 16.5 < 7.2 < 13.1 < 9.3 < 6.9 < 5.4 < 11.2 < 11.4 < 12.4 27.4 19.1
1982 < 10.0 23.7 < 5.0 14.2 < 5.0 < 8.0 < 7.9 19.1 < 5.3 25.4 < 13.2 31.2
1983 < 6.8 9.2 27.1 25.8 < 3.6 < 8.0 < 3.3 6.3 < 22.1 14.6 < 12.2 14.1
1984 < 5.9 14.2 < 11.4 28.2 < 2.1 < 10.0 < 2.5 17.5 3.6 14.9 < 8.5 51.7
1985 < 8.4 9.7 < 5.2 21.5 < 4.1 < 8.4 < 17.7 < 19.3 < 13.6 21.5 < 26.4 29.0
1986 < 7.0 < 17.0 < 6.0 30.0 < 6.0 < 8.0 < 4.0 < 32.0 < 10.0 < 18.0 < 7.0 29.0
1987
c
NA NA NA NA NA NA NA NA NA NA NA NA
1988 13.3 4.1 152.0
d
172.6
d
48.0 29.6 48.0 8.2 18.6 36.9 5.6 2.9
1989 6.1 11.88 0.68 7.06 3.3 11.45 0.64 6.54 32.56 9.29 36.57 16.46
1990 10.39 5.76 6.37 4.13 11.7 7.34 7.13 4.30 22.65 11.26 27.04 16.11
1991 5.42 1.65 3.84 2.64 2.03 1.54 4.12 2.16 10.69 5.46 15.53 12.66
1992
e
2.85 1.09 1.45 3.81 8.72 9.47
a. The values in the table are to be multiplied by 10
-12
μCi/mL (State of Florida 1994).
b. NA – not available.
c. Air concentrations for individual air monitoring stations were not available for 1987.
d. The individual air monitoring results for Station 2 ranged from 0.44 to 708.6 (10
-12
μCi/mL) during 1988, and no explanation was provided in the environmental
monitoring report for 1988 to explain why several air monitoring results from this station were significantly elevated (GE 1989). The environmental monitoring
report for 1988 did indicate that there was no significant difference between the stack emissions for 1988 and the stack emissions from other surrounding years
(GE 1989; State of Florida 1994). Therefore, Station 2 elevated air monitoring results for 1988 were most likely attributable to some unidentified localized event or
activity occurring near this air monitoring station versus a release from one of the site’s stacks.
e. Only total tritium in air results, which include both gas and oxide forms of tritium, were available for 1992.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 18 of 50
4.4 POTENTIAL EXPOSURES
Literature surveys revealed very little occupational environmental dose information. No information
could be found for the first 15 years of plant operation (1957 to 1971) other than the number of curies
released to the environment. For the remaining years (1972 to 1994), the dose to a maximally
exposed individual (member of the public) was estimated using a computational model by the Pinellas
Plant. Depending on the year calculated, the member of the public could be at the Plant boundary or
at a greater distance outside the boundary. Because of the distance from the general Plant work
environment and the fact that calculations included dose from ingestion, the dose to the maximally
exposed member of the public could not be taken to be representative of the environmental dose to a
worker inside the Plant boundary.
4.4.1
Potential onsite environmental internal exposures and subsequent doses to workers at the site were
assessed using airborne effluent data, liquid effluent data, and onsite air monitoring data. Because
the onsite environmental intakes were relatively small, bounding environmental intakes and internal
doses were assessed assuming a 2,600 hour work year versus the standard assumption of a 2,000
hour work year. Bounding potential onsite environmental internal doses were assessed for a
hypothetical worker who was employed at the Pinellas Plant from 1957–1997, using the intake
information and exposure scenarios described in Sections 4.4.1.1 through 4.4.1.3. For each exposure
scenario, the assessment indicated that the total internal dose to all internal organs was <0.001 rem
(ORAUT 2011e, 2011f). Calculated annual environmental internal doses that total less than 0.001
rem for a specific radiation type and energy interval are not required to be included in the Interactive
RadioEpidemiological Program (IREP) input sheet (ORAUT 2004). For such cases, the dose
reconstruction should include appropriate discussions.
Potential Internal Exposures and Doses
4.4.1.1 Potential Intakes Based on Stack Emissions
In this section, the maximum annual radionuclide intakes to a hypothetical maximally exposed
employee (MEE) due to radioactive airborne emissions from the Pinellas Plant stacks are assessed.
While greater than 95% of the radioactivity released during the history of the Plant was from tritium
and therefore potentially contributed to intake, the small amount of
14
C emitted could have also
contributed to a worker’s intake. In addition,
85
Kr was also released from the Plant’s stacks; however,
85
Kr is not an internal dose concern because it is a noble gas.
Maximum annual onsite average air concentrations of HT, HTO, and
14
C were calculated by
multiplying the annual releases in Table 4-2 by the atmospheric dispersion factors in Table A-8. The
basis for the development of the atmospheric dispersion factors is described in detail in Attachment A.
The calculated air concentrations were then used to calculate the annual intakes, assuming a 2,600
hour work-year and a breathing rate of 1.2 m
3
/hr. A breathing rate of 1.2 m
3
/hr is equivalent to the
value in ICRP Report 66 for light work (ICRP 1994). In addition, the HTO intakes were adjusted by a
factor of 1.5, in accordance with the Technical Information Bulletin: Tritium Calculations with IMBA
(ORAUT 2007). The resulting annual intakes are summarized in Table 4-5.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 19 of 50
Table 4-5. Annual onsite environmental intakes from stack
emissions for a hypothetical MEE.
a
Year
Total annual inhalation for each radionuclide
by a hypothetical MEE (Bq)
HT HTO C-14
1957 1.46E+04 4.61E+02 NR
b
1958 7.01E+04 1.91E+03 NR
1959 9.02E+04 4.38E+03 NR
1960 1.38E+04 1.43E+03 NR
1961 1.11E+03 1.01E+03 NR
1962 1.34E+03 8.20E+02 NR
1963 3.93E+02 3.39E+02 NR
1964 5.11E+02 1.89E+02 NR
1965 1.09E+02 3.30E+02 NR
1966 7.14E+02 1.27E+03 NR
1967 4.27E+03 7.03E+02 NR
1968 3.48E+03 7.08E+02 NR
1969 7.19E+03 9.77E+02 NR
1970 1.29E+03 1.53E+03 NR
1971 1.52E+03 1.23E+03 NR
1972 2.43E+02 7.31E+02 NR
1973 1.62E+02 1.05E+03 NR
1974 3.40E+02 6.65E+02 NR
1975 3.37E+02 5.42E+02 NR
1976 2.22E+02 5.80E+02 NR
1977 2.83E+02 5.29E+02 NR
1978 2.89E+02 5.13E+02 NR
1979 2.79E+02 6.77E+02 2.20E-04
1980 3.08E+02 6.89E+02 4.39E-04
1981 3.41E+03 4.50E+03 1.30E-03
1982 3.48E+03 5.93E+03 6.15E-04
1983 3.99E+03 3.51E+03 1.54E-04
1984 1.48E+03 4.75E+03 NR
1985 1.71E+03 3.44E+03 NR
1986 5.14E+02 3.72E+03 NR
1987 1.04E+03 3.19E+03 NR
1988 2.05E+03 2.86E+03 NR
1989 6.73E+02 1.38E+03 NR
1990 9.47E+02 1.40E+03 NR
1991 3.53E+02 2.03E+03 NR
1992 1.25E+02 7.29E+02 NR
1993
b
NR 2.68E+02 NR
1994
b
NR 5.76E+02 NR
1995
b
NR 6.00E+02 NR
1996
b
NR 5.03E+02 NR
1997
b
NR 3.44E+02 NR
a. Source: ORAUT 2011c.
b. NR = no release reported.
c. Because only total tritium releases were reported after 1992, it was
assumed that tritium released was HTO.
4.4.1.2 Potential Intakes Based on Liquid Effluent Data
An approach similar to that described in Section 4.4.1.1 for calculating the intake by a hypothetical
MEE from stack emissions was performed for a hypothetical MEE located near the east retention
pond. However, only annual HTO intakes were calculated because HTO would have been the only Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 20 of 50
emission from the pond. Annual HTO intakes were only estimated for the years of 1971–1992. Prior
to 1971, no tritium monitoring data was available, which was likely because liquid effluents were not
discharged to the east retention pond until 1971. After 1992, the reported tritium concentrations in the
pond were all below the detection limits. Therefore, the tritium levels in the pond and any potential
emissions from the pond were assumed to be negligible during the years of 1957–1970 and 1993–
1997.
Annual HTO releases from the east retention pond were estimated by assuming that 100% of the
tritium inventory in the pond was released for a given year, to ensure that the annual intakes were
overestimated. The annual tritium inventories in the pond were calculated by multiplying the pond’s
reported annual average tritium concentrations by the volume of water in the pond. It was assumed
that the pond had a constant volume of 3.25 x 10
6
gallons. Maximum annual onsite air concentrations
of HTO were calculated by multiplying the annual releases by the maximum onsite atmospheric
dispersion factor in Table A-9 (i.e., 1.3 x 10
-4
s/m
3
). The basis for the development of the atmospheric
dispersion factors is described in detail in Attachment A. The calculated air concentrations were then
used to calculate the annual intakes, assuming a 2,600 hour work-year and a breathing rate of 1.2
m
3
/hr. A breathing rate of 1.2 m
3
/hr is equivalent to the value in ICRP Report 66 for light work (ICRP
1994). The HTO intakes were also adjusted by a factor of 1.5, in accordance with the Technical
Information Bulletin: Tritium Calculations with IMBA (ORAUT 2007). Based on this approach and
these assumptions, the maximum HTO intake attributable to the east retention pond emissions would
be 413 Bq/yr, and would only be applicable for the years of 1971–1992 (ORAUT 2011d).
4.4.1.3 Potential Intakes Based on Onsite Air Monitoring Data
Because stack emissions and emissions from the east retention pond do not account for the tritium
emissions from some other sources (e.g. west retention pond, aeration area, and other fugitive
emissions sources), potential intakes were assessed using the results from the onsite tritium air
monitoring stations, which were at various locations near the property boundary for the Plant.
Potential intakes were calculated using the highest annual tritium air concentrations provided in
Table 4-4 and the inhalation and exposure assumptions used in Section 4.4.1.2. Because the highest
annual air concentrations for Station 2 in 1988 were more than 3 times higher than the next highest
set of annual air concentrations, the 1988 air concentrations for Station 2 were used only to calculate
the intakes for 1988. As a result, tritium gas and oxide intakes for 1988 were calculated based on
concentrations of 152.0 and 172.6 (10
-12
µCi/mL), respectively. For all other years, tritium gas and
oxide intakes were calculated based on concentrations of <8.5 and 51.7 (10
-12
µCi/mL), respectively,
which were measured at Station 6 in 1984. The calculated air concentrations were then used to
calculate the annual intakes, assuming a 2,600 hour work-year and a breathing rate of 1.2 m
3
/hr. A
breathing rate of 1.2 m
3
/hr is equivalent to the value in ICRP Report 66 for light work (ICRP 1994). In
addition, the HTO intakes were adjusted by a factor of 1.5, in accordance with the Technical
Information Bulletin: Tritium Calculations with IMBA (ORAUT 2007). The annual tritium intakes
estimated for each year of operation are summarized in Table 4-6. Given that only the highest annual
concentrations for any tritium air monitoring station were used for the intake estimates and given that
it is unlikely that a worker spent a significant amount of time near the property boundary for the Plant,
this approach overestimates a worker’s potential environmental intakes.
Table 4-6. Estimated annual tritium intakes based on
air monitoring results (Bq).
a
Year H-3 gas intake H-3 oxide intake
1957–1987 < 981 8,952
1988 17,547 29,887
1989–1997 4,222 2,850
a. Source: ORAUT 2011i.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 21 of 50
4.4.2
As indicated in Section 4.3.2, no environmental external dose monitoring appears to have been
performed at the Pinellas Plant, which was most likely due to the low potential for workers to
encounter significant sources of external radiation outdoors at the Plant. However, based on the
available information, small external doses could have been received by workers from the
85
Kr
emissions from the Plant stacks. Therefore, potential annual environmental external doses were
assessed for a hypothetical MEE inside the plant boundary using the
85
Kr airborne effluent data for
the stacks. In addition,
14
C emissions from the Pinellas Plant stack could have also contributed to the
environmental external dose. However, the contributions to the environmental external doses from
14
C emissions were negligible compared to the contributions from
85
Kr emissions, because
14
C
releases were at least 1/10,000th of the
85
Kr releases and because
14
C emits much lower energy beta
particles than
85
Kr. Plutonium could have contributed to the environmental external doses; however,
plutonium was never released to the environment at the Plant. In addition, emissions from the area
sources (i.e., the ponds and aeration area) would not have contributed to the environmental external
doses at the site because tritium was the only emission from the area sources.
Potential External Doses
The annual onsite ambient external doses were calculated in a manner similar to the approach used
for the environmental intake estimates, which was based on airborne effluent data. Maximum air
concentrations were calculated from the annual
85
Kr releases using the atmospheric dispersion
factors in Table A-8 of Attachment A. Dose rates in units of Sv/s were then calculated using the
maximum dose coefficient for air submersion found in Federal Guidance Report 12 (EPA 1993). For
85
Kr, the highest dose coefficient is for the skin, and its use will overestimate the onsite ambient doses
for organs that are not affected by non-penetrating radiation by about two orders of magnitude. The
calculated dose rates were then multiplied by the number of seconds in a 2,600 hour working year to
estimate the bounding annual onsite ambient doses. The onsite ambient external doses that were
calculated using this approach are summarized in Table 4-7. Doses were calculated only for the
years that
85
Kr releases were reported. Because
85
Kr was not present at the site until 1963, there
were no
85
Kr releases prior to 1963.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 22 of 50
Table 4-7. Potential annual onsite environmental external doses.
a
Year
Total Kr-85 released
from stacks
b
(Ci)
Total annual
external dose
(mrem)
1957–1962 NR
c
NR
1963 4 3.48E-05
1964 47 4.09E-04
1965 153 1.33E-03
1966 49 4.26E-04
1967 70.3 6.11E-04
1968 201.7 1.75E-03
1969 55 4.78E-04
1970 44 3.83E-04
1971 11.85 1.03E-04
1972 15.46 1.34E-04
1973 1.36 1.18E-05
1974 3.67 3.19E-05
1975 1.15 1.00E-05
1976 19.92 1.73E-04
1977 27.62 2.40E-04
1978 5.29 4.60E-05
1979 4.66 4.05E-05
1980 1.85 1.61E-05
1981 3.64 2.22E-04
1982 7.77 4.73E-04
1983 11.33 6.90E-04
1984 1.97 1.20E-04
1985 5 3.04E-04
1986 5 3.04E-04
1987 38 2.31E-03
1988 30 1.83E-03
1989 12.9 7.85E-04
1990 10.1 6.15E-04
1991 4 2.44E-04
1992 10 6.09E-04
1993 18.74 1.14E-03
1994 12.9 7.85E-04
1995 NR NR
1996 6 2.96E-03
1997 NR NR
a. Source: ORAUT 2011g.
b. All Kr-85 releases were from the Building 100 Main Stack with the exception
of the 1996 releases, which were from the Building 800 Stack.
c. NR = no release recorded.
The low onsite environmental external doses summarized in Table 4-7 are representative only of
unmonitored external doses that a worker at the Pinellas Plant could have received outdoors.
Because potential unmonitored external doses for Plant workers could have been significantly greater
due to incidental radiation exposures while inside any of the Plant buildings, the unmonitored external
doses for a worker who entered a Plant building should not be limited to the onsite environmental
external doses. Therefore, dose reconstructors should assign the more favorable-to-claimant
unmonitored external doses prescribed for unmonitored workers in the Occupational External Dose
TBD (ORAUT 2011k) in lieu of the onsite environmental external doses.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 23 of 50
4.5 UNCERTAINTY
There are many sources of uncertainty involved in calculation of doses from airborne emissions
sources. The sources of uncertainty range from the magnitude of the emissions, to the amount of
dispersion, to the location and behavior of the receptor. Each individual uncertainty is reflected in
some degree in the uncertainty in the annual intake calculations. To account for those uncertainties,
favorable to claimant values, parameters, and assumptions were used for the atmospheric dispersion
and intake calculations.
Uncertainty in Amount of Effluent Release: The amount of effluent released directly affects the
amount of dose for a given receptor. Assuming all other parameters remain constant, the resultant
dose is proportional to the amount of effluent.
Uncertainty in Amount of Dispersion: The amount of dispersion is dependent on many factors
including the release height above ground, the height of the surrounding buildings, the distance from
the release location to the receptor, and the local meteorological parameters such as wind speed,
frequency of wind direction, and frequency of atmospheric stability. The release height affects the
ground-level concentrations; the higher the release height, the lower the ground-level concentration at
a given location. The distance between the release location and the receptor affects the amount of
dispersion. For an elevated release, the ground-level concentrations initially increase as the distance
from stack increases, until the effluent plume touches the ground; then the ground-level concentration
decreases as the distance from stack increases. To account for some of the uncertainties associated
with atmospheric dispersion calculations, 9-year and 10-year meteorological data sets were used for
the atmospheric dispersion calculations.
Uncertainty in Location and Behavior of the Receptor: The location of the receptor was
determined by selecting the distance and direction that would result in the maximum onsite
concentration. In addition, it was assumed that the receptor was outdoors and exposed to the
maximum on-site environmental air concentrations for 100% of the assumed 2,600 hour work-year.
Furthermore, it was assumed that the same worker was exposed to the maximum air concentrations
calculated from the stack emissions data, onsite ambient air monitoring data, and liquid effluent
monitoring data, which would mean the worker was in three different locations at one time.
4.6 ATTRIBUTIONS AND ANNOTATIONS
All information requiring identification was addressed via references integrated into the reference
section of this document.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 24 of 50
REFERENCES
Burkhart, R. A., 1990, Environmental Health and Safety– Historical Report on Radiation Protection at
GE Neutron Devices, GEPP-EV-1126, UC-707, Largo, Florida, July. [SRDB Ref ID: 12026]
DOE (U.S. Department of Energy), 1983, Environmental Assessment, Pinellas Plant Site, St.
Petersburg, Florida, DOE/EA-0209, U.S. Department of Energy, Assistant Secretary for
Defense Programs, Washington, D.C., July. [SRDB Ref ID: 9971]
Eaton, A. D., and M. A. H. Franson, Standard Methods for the Examination of Water & Wastewater,
American Public Health Association, Washington, D.C.
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Water, and Soil, Federal Guidance Report No.12 (EPA-402-R-93-081), Washington DC.
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Department, Pinellas Plant, St. Petersburg, Florida. [SRDB Ref ID: 27095]
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Department, St. Petersburg, Florida, August. [SRDB Ref ID: 12252, pp. 2-24]
GE (General Electric Company), 1973, Environmental Monitoring Report 1972, Neutron Devices
Department, St. Petersburg, Florida, March. [SRDB Ref ID: 12252, pp. 25-45]
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Discharges/Unplanned Releases Reports for 1957–1971, Neutron Devices Department, St.
Petersburg, Florida, May. [SRDB Ref ID: 12017, pp. 33-116]
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Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12253]
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Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12258]
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Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12018, pp. 2-35]
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Devices Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12259]
GE (General Electric Company), 1978a, Update of the Radioisotopic Thermoelectric Generator Safety
Analysis Report Dated December 15, 1975, Pinellas Plant, Neutron Devices Department, St.
Petersburg, Florida, October 31. [SRDB Ref ID: 12793]
GE (General Electric Company), 1978b, Environmental Monitoring Report 1977, GEPP-363, Neutron
Devices Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12018, pp. 36-72]
GE (General Electric Company), 1979, Environmental Monitoring Report 1978, GEPP-EM-427,
Neutron Devices Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12018, pp. 73-
109]Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 25 of 50
GE (General Electric Company), 1980, Environmental Monitoring Report 1979, GEPP-EM-484.
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1597A/1598A/1610A-0080A, Neutron Devices Department, St. Petersburg, Florida, March.
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GE (General Electric Company), 1982, Environmental Monitoring Report 1981, GEPP-EM-654,
8828A/8842A-0369A, Largo, Florida, March. [SRDB Ref ID: 88793]
GE (General Electric Company), 1983, Pinellas Plant Environmental Monitoring Report 1982, GEPPEM-729, Neutron Devices Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12018,
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GE (General Electric Company), 1987, Pinellas Plant Environmental Monitoring Report 1986, GEPPEM-1017, UC-11, Neutron Devices Department, St. Petersburg, Florida, April. [SRDB Ref ID:
88850]
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12265]
GE (General Electric Company), 1989, Pinellas Plant Site Environmental Report for Calendar Year
1988, GEPP-EV-1193, UC-11, Neutron Devices Department, St. Petersburg, Florida, June.
[SRDB Ref ID: 13252]
GE (General Electric Company), 1990, Pinellas Plant Site Environmental Report for Calendar Year
1989, GEPP-EV-1061, UC-702, Neutron Devices Department, St. Petersburg, Florida, June.
[SRDB Ref ID: 13257]
GE (General Electric Company), 1991, Pinellas Plant Site Environmental Report for Calendar Year
1990, NDPP-OSP-0053, Revision A, Neutron Devices Department, St. Petersburg, Florida,
August. [SRDB Ref ID: 12007]
ICRP (International Commission on Radiological Protection), 1994, Human Respiratory Tract Model
for Radiological Protection, Publication 66, Oxford, United Kingdom.
IT/Radiological Sciences Laboratory, 1986, A Technical Evaluation of the Air Monitoring Systems in
Use for Exhaust Stack Emissions and Environmental Measurements at the Pinellas Plant,
Largo, Florida, Oak Ridge, Tennessee, September 10. [SRDB Ref ID: 13255]Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 26 of 50
Kocher, D. C., 1981, Radioactive Decay Data Tables, DOE/TIC-11026, Health and Safety Research
Division, Oak Ridge National Laboratory, published by the Technical Information Center, U.S.
Department of Energy. [SRDB Ref ID: 32563]
LMSC (Lockheed Martin Specialty Components), 1995a, Pinellas Plant Environmental Baseline
Report, MMSC-EM-95010, Environmental Safety and Health Division, Largo, Florida,
February. [SRDB Ref ID: 13197]
LMSC (Lockheed Martin Specialty Components), 1995b, Environmental Management — Pinellas Plant
Annual Site Environmental Report for Calendar Year 1994, MMSC-EM-95011, Largo, Florida,
June. [SRDB Ref ID: 12027]
LMSC (Lockheed Martin Specialty Components), 1996a, Radionuclide Air Emissions Annual Report
for Calendar Year 1995, MMSC-EM-96031, Pinellas Plant, Largo, Florida, May. [SRDB Ref
ID: 12917, p. 41–132]
LMSC (Lockheed Martin Specialty Components), 1996b, Environmental, Safety and Health Pinellas
Plant Annual Site Environmental Report for Calendar Year 1995, MMSC-EM-96010, Largo,
Florida, July. [SRDB Ref ID: 23003]
LMSC (Lockheed Martin Specialty Components), 1997a, Radionuclide Air Emissions Annual Report
for Calendar Year 1996, MMSC-EM-97006, Pinellas Plant, Largo, Florida, April. [SRDB Ref
ID: 12244]
LMSC (Lockheed Martin Specialty Components), 1997b, Radionuclide Air Emissions Annual Report
for Calendar Year 1997, MMSC-EM-97016, Pinellas Plant, Largo, Florida, August. [SRDB
Ref ID: 12248]
MMSC (Martin Marietta Specialty Components, Inc.), 1992, Pinellas Plant Site Environmental Report
for Calendar Year 1991, MMSC-EM-92047, Largo, Florida, October. [SRDB Ref ID: 12025]
MMSC (Martin Marietta Specialty Components, Inc.), 1993, Pinellas Plant Annual Site Environmental
Report for Calendar Year 1992, MMSC-ESH-93035, UC-702, Largo, Florida, June. [SRDB
Ref ID: 12013]
MMSC (Martin Marietta Specialty Components, Inc.), 1994, Pinellas Plant Annual Site Environmental
Report for Calendar Year 1993, MMSC-ESH-94146, Largo, Florida, June 10. [SRDB Ref ID:
12014]
Napier, B. A., D. L. Strenge, J. V. Ramsdell, Jr., P. W. Eslinger, and C. Fosmire, 2004, GENII
Version 2 Software Design Document, PNNL-14594, Battelle Memorial Institute, Pacific
Northwest National Laboratory, Richland, Washington, November. [SRDB Ref ID: 24168]
Napier, B. A., 2010, GENII Version 2 User’s Guide, PNNL-14583, Rev 3a, Battelle Memorial Institute,
Pacific Northwest National Laboratory, Richland, Washington, June. [SRDB Ref ID: 91665]
NIOSH (National Institute for Occupational Safety and Health), 2003, Technical Information Bulletin:
Tritium Calculations with IMBA, OCAS-TIB-002, Rev. 0, Office of Compensation Analysis and
Support, Cincinnati, Ohio, April 22.
NIOSH (National Institute for Occupational Safety and Health), 2007, External Dose Reconstruction
Implementation Guidelines, OCAS-IG-001, Rev. 03, Office of Compensation Analysis and
Support, Cincinnati, Ohio.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 27 of 50
NIOSH (National Institute for Occupational Safety and Health), 2010, Radiation Exposures Covered
for Dose Reconstructions Under Part B of the Energy Employees Occupational Illness
Compensation Program Act, DCAS-IG-003, Rev. 01, Office of Compensation Analysis and
Support, Cincinnati, Ohio, October 5.
ORAUT (Oak Ridge Associated Universities Team), 2004, Technical Information Bulletin: Assignment
of Environmental Internal Doses for Employees Not Exposed to Airborne Radionuclides in the
Workplace, ORAUT-OTIB-0014, Rev 00, June 22.
ORAUT (Oak Ridge Associated Universities Team), 2007, Site Profile and Technical Basis Document
Development, ORAUT-PROC-0031, Rev 02, August 17.
ORAUT (Oak Ridge Associated Universities Team), 2011a, Meteorological Data: Florida 1960–1990
(http://www.epa.gov/ceampubl/tools/metdata/fl/index.html), Oak Ridge, Tennessee, accessed
January 20. [SRDB Ref ID: 91680]
ORAUT (Oak Ridge Associated Universities Team), 2011b, MS Excel workbook titled Pinellas Plant –
Stack Data, Rev 0, Oak Ridge, Tennessee, February. [SRDB Ref ID: 92639]
ORAUT (Oak Ridge Associated Universities Team), 2011c, MS Excel workbook titled Pinellas Plant –
Annual Env Intakes Based on Stack Releases, Rev 0, Oak Ridge, Tennessee, February.
[SRDB Ref ID: 92634]
ORAUT (Oak Ridge Associated Universities Team), 2011d, MS Excel workbook titled Pinellas Plant –
Annual Env Intakes from E Pond, Rev 0, Oak Ridge, Tennessee, February. [SRDB Ref ID:
92635]
ORAUT (Oak Ridge Associated Universities Team), 2011e, MS Excel workbook titled Pinellas Plant -
Simplified Env Intakes for Dose Estimate, Rev 0, Oak Ridge, Tennessee, February. [SRDB
Ref ID: 92638]
ORAUT (Oak Ridge Associated Universities Team), 2011f, MS Excel workbook titled CAD_000000
(Pinellas – Bounding Env Int Dose Assessment), Rev 0, Oak Ridge, Tennessee, February.
[SRDB Ref ID: 92633]
ORAUT (Oak Ridge Associated Universities Team), 2011g, MS Excel workbook titled Pinellas Plant –
Onsite Ambient Dose Calculations, Rev 0, Oak Ridge, Tennessee, February. [SRDB Ref ID:
92637]
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Comparison of Meas to Modeled Air Conc, Rev 0, Oak Ridge, Tennessee, February. [SRDB
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Annual Env Intakes Based on Measured Air Conc, Rev 0, Oak Ridge, Tennessee, February.
[SRDB Ref ID: 92800]
ORAUT (Oak Ridge Associated Universities Team), 2011j, Pinellas Plant – Site Description, ORAUTTKBS-0029-2, Rev. 02, April 1.
ORAUT (Oak Ridge Associated Universities Team), 2011k, Pinellas Plant – Occupational External
Dose, ORAUT-TKBS-0029-6, Rev. 01, April 28.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 28 of 50
State of Florida, 1994, Pinellas Plant Feasibility Study, Final Report, Florida Department of Health and
Rehabilitative Services, Tallahassee, Florida, September. [SRDB Ref ID: 6501]
Weaver, A. S., 1990, External Dosimetry, HP03, Revision 4.0, General Electric Company, Neutron
Devices Department, St. Petersburg, Florida, May 30. [SRDB Ref ID: 12989, pp. 2-5]
Weaver, A., 1995, “CY 1994 radiological emissions and estimates for CY 1995,” internal
memorandum to C. Biedermann, January 26, Martin Marietta Specialty Components, Inc.,
Largo, Florida. [SRDB Ref ID: 12100]Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 29 of 50
GLOSSARY
background radiation
Radiation from cosmic sources, naturally occurring radioactive materials including naturally
occurring radon, and global fallout from the testing of nuclear explosives. Background
radiation does not include radiation from source, byproduct, or Special Nuclear Materials
regulated by the U.S. Nuclear Regulatory Commission. The average individual exposure from
background radiation is about 360 millirem per year.
becquerel (Bq)
International System unit of radioactivity equal to 1 disintegration per second; 1 curie equals
37 billion (3.7 × 10
10
) Bq.
beta radiation
Charged particle emitted from some radioactive elements with a mass equal to 1/1,837 that of
a proton. A negatively charged beta particle is identical to an electron. A positively charged
beta particle is a positron.
dosimetry
Measurement and calculation of internal and external radiation doses.
exposure
(1) In general, the act of being exposed to ionizing radiation. (2) Measure of the ionization
produced by X- and gamma-ray photons in air in units of roentgens.
gamma radiation
Electromagnetic radiation (photons) of short wavelength and high energy (10 kiloelectron-volts
to 9 megaelectron-volts) that originates in atomic nuclei and accompanies many nuclear
reactions (e.g., fission, radioactive decay, and neutron capture). Gamma photons are identical
to X-ray photons of high energy; the difference is that X-rays do not originate in the nucleus.
neutron
Basic nucleic particle that is electrically neutral with mass slightly greater than that of a proton.
There are neutrons in the nuclei of every atom heavier than normal hydrogen.
radiation
Subatomic particles and electromagnetic rays (photons) with kinetic energy that interact with
matter through various mechanisms that involve energy transfer.
radioactivity
Property possessed by some elements (e.g., uranium) or isotopes (e.g.,
14
C) of spontaneously
emitting energetic particles (electrons or alpha particles) by the disintegration of their atomic
nuclei.
radioisotopically-powered thermoelectric generator (RTG)
Generator that obtains its power from passive (natural) radioactive decay using thermocouples
to convert the heat of decay into electricity.
rem
Traditional unit of radiation dose equivalent that indicates the biological damage caused by
radiation equivalent to that caused by 1 rad of high-penetration X-rays multiplied by a quality
factor. The sievert is the International System unit; 1 rem equals 0.01 sievert. The word
derives from roentgen equivalent in man; rem is also the plural.Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 30 of 50
thermoluminescent dosimeter (TLD)
Device for measuring radiation dose that consists of a holder containing solid chips of material
that, when heated by radiation, release the stored energy as light. The measurement of this
light provides a measurement of absorbed dose. Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 31 of 50
TABLE OF CONTENTS
SECTION TITLE
A-1 Introduction …………………………………………………………………………………………………………….
PAGE
32
A-2 Computer Model ……………………………………………………………………………………………………..32
A-3 Meteorological Data …………………………………………………………………………………………………32
A-4 Atmospheric Dispersion Factors for Stacks…………………………………………………………………. 33
A-5 Atmospheric Dispersion Factors for Area Sources ……………………………………………………….. 42
A-6 Atmospheric Dispersion at Tritium Monitoring Station Locations …………………………………….. 46
A-7 Summary and Conclusions ………………………………………………………………………………………. 49
LIST OF TABLES
TABLE TITLE
A-1 Pinellas Plant stack parameters used in the determination of atmospheric
dispersion factors…………………………………………………………………………………………………….
PAGE
34
A-2 Atmospheric dispersion factors (s/m
3
) for the Building 100 Main Stack,
applicable 1957 through 1980 …………………………………………………………………………………… 36
A-3 Atmospheric dispersion factors (s/m
3
) for the Building 100 Main Stack,
applicable 1981 through 1996 …………………………………………………………………………………… 37
A-4 Atmospheric dispersion factors (s/m
3
) for the Building 100 Lab Stack,
applicable 1965 through 1980 …………………………………………………………………………………… 38
A-5 Atmospheric dispersion factors (s/m
3
) for the Building 100 Lab Stack,
applicable 1981 through 1995 …………………………………………………………………………………… 39
A-6 Atmospheric dispersion factors (s/m
3
) for the Building 800 Stack,
applicable 1997……………………………………………………………………………………………………….40
A-7 Summary of maximum atmospheric dispersion factors for Pinellas Plant
stacks…………………………………………………………………………………………………………………….41
A-8 Atmospheric dispersion factors used for Pinellas Plant stack releases…………………………….. 42
A-9 Atmospheric dispersion factors (s/m
3
) for the east retention pond,
applicable 1971 through 1997 …………………………………………………………………………………… 43
A-10 Atmospheric dispersion factors (s/m
3
) for the west retention pond,
applicable 1973 through 1997 …………………………………………………………………………………… 44
A-11 Atmospheric dispersion factors (s/m
3
) for the aeration area, applicable
1973 through 1982…………………………………………………………………………………………………..45
A-12 Atmospheric dispersion factors at the six tritium monitoring station
locations (s/m
3
) ……………………………………………………………………………………………………….46
A-13 Ratio of predicted-to-measured tritium gas (HT) concentrations at tritium
air monitoring stations ……………………………………………………………………………………………… 47
A-14 Ratio of predicted-to-measured tritium oxide (HTO) concentrations at
tritium air monitoring stations ……………………………………………………………………………………. 49
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 1 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 32 of 50
A-1 Introduction
This attachment describes the methodology and assumptions used to estimate the atmospheric
dispersion of radionuclides released from air emission point sources (stacks) and area sources
(ponds and aeration areas) at the Pinellas Plant during its operation from 1957 through 1997.
Atmospheric dispersion factors can be used to estimate the air concentration of radionuclides around
the Pinellas Plant and to further estimate the potential radiation dose that may have been received
from various applicable exposure pathways such as inhalation of the airborne radionuclide. This
attachment includes a description of the computer model, meteorological data, and the assumptions
made in estimating air dispersion factors that were used to estimate radionuclide intakes and doses
received by a hypothetical maximally exposed employee (MEE) at the Pinellas Plant for Section 4.4 of
this TBD. Dispersion factors were also calculated to estimate atmospheric dispersion at the locations
of six tritium monitoring stations to compare the relative contributions of the various sources to the
measured air monitoring results.
A-2 Computer Model
The GENII computer model (Version 2.10) is a powerful environmental assessment code that can be
used to estimate radiation dose to an exposed individual or a population from a variety of potential
exposure pathways (Napier et al. 2004, Napier 2010). Only a small portion of the GENII capability
was used to develop the atmospheric dispersion factors presented here. GENII allows for input of
site-specific information that affect air emissions, and site-specific Pinellas Plant information was input
into the code where available. Important site-specific data that were available and used included
meteorological data (discussed below), stack parameters including stack area (from given diameters),
height, exhaust velocity (on an annual basis for many years), ambient stack gas temperature, and
ambient site temperature. Annual radionuclide release data from the Plant (given in Table 4-2) were
also considered along with other operational and infrastructure information such as exhaust volume,
exhaust velocity, stack height and stack diameter.
A-3 Meteorological Data
With the exception of the outdoor ambient temperature data, the meteorological data used for the
determination of atmospheric dispersion factors were obtained from the US Environmental Protection
Agency’s Center for Exposure Assessment Modeling (CEAM) website (ORAUT 2011a). The CEAM
website provides hourly meteorological data from 1961 to 1990 for the Tampa International Airport
which is representative of meteorology at the Pinellas Plant. Based on information in the Pinellas
Plant’s 1995–1997 Radionuclide Air Emissions Report, the mean annual temperature is approximately
22
o
C (72
o
F) (LMSC 1996a, 1997a, 1997b).
The data from 1961, 1962, and 1963 were evaluated and it was determined that these data were
structured in such a way that only 15 sectors of a polar grid (rather than 16) were represented.
Therefore, the data from these three years were not used. The GENII Version 2 User’s Guide (Napier
2010) provides information on how to access the CEAM, and the GENII code contains a
meteorological data processor that can be used to convert the CEAM data into a format usable by
GENII. The individual annual files can be combined to provide a longer-term representation of
meteorological data.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 2 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 33 of 50
Because the main stack was shortened from 30.5 m (100-ft) to 21.3 m (70-ft) during the middle of
1981, two sets of atmospheric dispersion factors were generated for each of the Building 100 stacks
(i.e., one set that is applicable to the years prior to 1981 and another set that is applicable to 1981 and
later). As a result, two multi-year meteorological data files were developed to calculate atmospheric
dispersion factors for the Pinellas Plant. One file included hourly data from 1964 through 1973, and
was used to assess the chronic atmospheric releases from 1957 through 1980. The second
meteorological data file included data from 1982 through 1990, and was used to assess the chronic
atmospheric releases from 1981 through 1997.
A-4 Atmospheric Dispersion Factors for Stacks
Atmospheric dispersion factors were calculated using the GENII computer model, the multi-year
meteorological data files discussed above, and building-specific characteristics of the most important
air emission points (stacks) at the Pinellas Plant (i.e., the 100 Building Main Stack, 100 Building Lab
Stack, and 800 Building Stack). As previously indicated, two sets of atmospheric dispersion factors
were generated for each of the Building 100 stacks (i.e., one set that is applicable to the years prior to
1981 and another set that is applicable to 1981 and later), because the main stack was shortened
from 30.5 m (100-ft) to 21.3 m (70-ft) during the middle of 1981.
Average stack emission velocities were calculated for the periods corresponding to the meteorological
data. The majority of the annual average effluent velocities for each stack were calculated by dividing
the annual total volume of air discharged by the total number of seconds in a calendar year. For the
Main Stack and the Lab Stack, flow data from 1964 to 1973 were used to represent the 1957 through
1980 period, and flow data from 1982 to 1990 were used to represent the 1981 through 1996 period.
Although the Building 800 Stack operated from 1980 through 1997, the atmospheric dispersion factors
associated with the Building 800 Stack were only assessed for 1997, because the Building 800 Stack
releases were insignificant compared to Main Stack and Lab Stack releases during earlier years. As
a result, the stack emission velocity reported for 1997 was only used for the Building 800 Stack
dispersion calculations.
The stack parameters used are summarized in Table A-1.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 3 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 34 of 50
Table A-1. Pinellas Plant stack parameters used in the determination of atmospheric dispersion
factors.
Parameter Bldg. 100 Main Stack Bldg. 100 Lab Stack Bldg. 800 Stack
Applicable operating years 1957–1981 1981–1996 1965–1981 1981–1996 1997
Met data years 1964–1973 1982–1990 1964–1973 1982–1990 1982–1990
Diameter (m)
a
2.44
b
2.44 1.52
b
1.52 0.51
Area (m
2
)
c
4.68 4.68 1.81 1.82 0.204
Height (m)
d
30.5 21.3 30.5 nc 9.1
Effluent Velocity (m/s)
d,e
4.16 3.20 7.82 6.65 3.3
Stack gas temperature
f
26ºC, 79ºF 26ºC, 79ºF 26ºC, 79ºF 26ºC, 79ºF 26ºC, 79ºF
a. Sources: LMSC 1996a, 1997a, 1997b.
b. There is no indication that this stack’s diameter ever changed, so the same diameter is applicable for the earlier
years.
c. Calculated using the reported diameter for the stack (ORAUT 2011b).
d. Sources: GE 1972, 1973, 1974a, 1974b, 1975, 1976, 1977, 1978b, 1979, 1980, 1981, 1982, 1983, 1984, 1985,
1986, 1987, 1988, 1989, 1990, 1991; MMSC 1992, 1993, 1994; LMSC 1995b, 1996a, 1997a, 1997b.
e. For the Building 100 stacks, the average effluent velocities were calculated using the 1964–1973 and 1982–1990
flow data for the stacks. For the Building 800 Stack, the reported stack velocity for 1997 was used (ORAUT
2011b).
f. Because effluent temperatures that are close to the average onsite ambient outdoor temperature have little impact
on the dispersion modeling and because of the limited amount of effluent temperature data, an approximate
temperature of 26
o
C (79
o
F) was used for all stacks and all years. The selected temperature is consistent with the
limited effluent temperature data that is available for each stack.
Calculations were performed using GENII for the three stacks and the time periods noted above by
using a 1 Curie per second (Ci/s) unit release of tritium gas (HT) as the basis for determining
atmospheric dispersion. A comparison of the dispersion factors calculated for HT and tritium oxide
(HTO) releases indicated that the differences were negligible, but HT did produce a slightly higher
dispersion factor for some sectors and distances. Therefore, all dispersion factors were calculated
based on HT releases. Plume rise was included in all calculations since stack-specific data were
available. Adjacent buildings were considered and assumed to have a height of 10 m. Releases
were modeled using a chronic Gaussian plume atmospheric dispersion model and several different
sets of dispersion parameters available in GENII to determine which best represented the Pinellas
Plant conditions. The tritium monitoring station data presented in Table 4-5 were used to assist in
selecting the “best” model. Straight Pasquill-Gifford atmospheric stability without enhanced dispersion
from building wake was first evaluated, followed by Pasquill-Gifford and Briggs urban condition
parameters using enhanced dispersion of the Pasquill-Gifford building wake model. Both of the
enhanced dispersion models were better performers than the straight Pasquill-Gifford model, as both
resulted in significantly higher dispersion factors at closer distances from lower stack heights that was
indicated by tritium monitoring station data. Selection of one of these models would also be favorable
to the claimant since near-field concentrations were higher than straight Pasquill-Gifford while the
farther-field concentrations were similar and much lower among all the models. The Pasquill-Gifford
model with enhanced dispersion was selected to develop the atmospheric dispersion factors for this
TBD because it is also used in Version 3 of the Industrial Source Complex computer model (ISC3)
distributed by the US Environmental Protection Agency.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 4 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 35 of 50
Results of the calculations are presented as “Chi over Q” (Χ/Q) atmospheric dispersion factors with
units of seconds per cubic meter (s/m
3
) in Tables A–2 through A–6. These factors are estimates of
the long-term atmospheric dispersion represented as activity concentration (e.g., Ci/m
3
, Bq/m
3
, etc…)
divided by activity release rate (e.g., Ci/s, Bq/s, etc…).
Examination of the calculated atmospheric dispersion factors in Tables A–2 through A–6 shows the
locations of the largest onsite atmospheric dispersion factors (least atmospheric dispersion), which
would result in the highest onsite air concentrations and the highest potential dose to a Pinellas Plant
worker. Table A–7 provides a summary of the maximum atmospheric dispersion factors found in
Tables A–2 through A–6.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 5 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 36 of 50
Table A-2. Atmospheric dispersion factors (s/m
3
) for the Building 100 Main Stack, applicable 1957 through 1980 .
a,b,c
Direction (Deg.)
d
Distance from the Building 100 Main Stack, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 5.7E-09 1.0E-07 2.2E-07 2.9E-07 3.2E-07 3.2E-07 3.0E-07 2.8E-07 2.6E-07 2.4E-07
NNE (22.5
o
) 5.4E-09 1.0E-07 2.2E-07 2.9E-07 3.1E-07 3.1E-07 2.9E-07 2.6E-07 2.4E-07 2.2E-07
NE (45.0
o
) 6.6E-09 1.0E-07 1.9E-07 2.3E-07 2.5E-07 2.4E-07 2.3E-07 2.1E-07 1.9E-07 1.8E-07
ENE (67.5
o
) 7.5E-09 1.4E-07 2.6E-07 3.3E-07 3.4E-07 3.3E-07 3.1E-07 2.8E-07 2.6E-07 2.4E-07
E (90.0
o
) 9.0E-09 1.8E-07 3.7E-07 4.7E-07 4.9E-07 4.8E-07 4.4E-07 4.0E-07 3.6E-07 3.3E-07
ESE (112.5
o
) 2.3E-09 5.9E-08 1.6E-07 2.4E-07 2.8E-07 2.8E-07 2.7E-07 2.5E-07 2.3E-07 2.1E-07
SE (135.0
o
) 1.4E-09 4.0E-08 1.3E-07 2.1E-07 2.5E-07 2.5E-07 2.5E-07 2.3E-07 2.2E-07 2.0E-07
SSE (157.5
o
) 1.5E-09 3.6E-08 1.1E-07 1.7E-07 2.1E-07 2.1E-07 2.0E-07 1.9E-07 1.8E-07 1.7E-07
S (180.0
o
) 1.5E-09 3.8E-08 1.1E-07 1.6E-07 1.9E-07 1.9E-07 1.9E-07 1.8E-07 1.7E-07 1.6E-07
SSW (202.5
o
) 2.0E-09 5.7E-08 1.5E-07 2.2E-07 2.6E-07 2.7E-07 2.6E-07 2.4E-07 2.3E-07 2.1E-07
SW (225.0
o
) 2.7E-09 8.7E-08 2.5E-07 3.6E-07 4.2E-07 4.3E-07 4.1E-07 3.9E-07 3.6E-07 3.4E-07
WSW (247.5
o
) 3.7E-09 1.3E-07 3.4E-07 4.9E-07 5.7E-07 5.8E-07 5.6E-07 5.3E-07 4.9E-07 4.6E-07
W (270.0
o
) 4.5E-09 1.4E-07 3.7E-07 5.3E-07 6.0E-07 6.1E-07 5.9E-07 5.6E-07 5.2E-07 4.8E-07
WNW (292.5
o
) 4.6E-09 1.2E-07 3.0E-07 4.2E-07 4.8E-07 4.9E-07 4.7E-07 4.5E-07 4.2E-07 3.9E-07
NW (315.0
o
) 5.0E-09 1.2E-07 2.7E-07 3.7E-07 4.1E-07 4.1E-07 3.9E-07 3.6E-07 3.3E-07 3.1E-07
NNW (337.5
o
) 5.5E-09 1.1E-07 2.4E-07 3.1E-07 3.4E-07 3.4E-07 3.2E-07 3.0E-07 2.8E-07 2.6E-07
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site or the Building 100 roof.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1964–1973 meteorological data set.
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 6 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 37 of 50
Table A-3. Atmospheric dispersion factors (s/m
3
) for the Building 100 Main Stack, applicable 1981 through 1996 .
a,b,c
Direction (Deg.)
d
Distance from the Building 100 Main Stack, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 1.7E-06 1.2E-06 9.6E-07 7.7E-07 6.3E-07 5.3E-07 4.6E-07 4.0E-07 3.5E-07 3.1E-07
NNE (22.5
o
) 2.0E-06 1.4E-06 1.1E-06 8.4E-07 6.8E-07 5.6E-07 4.7E-07 4.1E-07 3.6E-07 3.2E-07
NE (45.0
o
) 1.7E-06 1.3E-06 9.7E-07 7.7E-07 6.2E-07 5.1E-07 4.3E-07 3.8E-07 3.3E-07 3.0E-07
ENE (67.5
o
) 2.1E-06 1.5E-06 1.1E-06 8.9E-07 7.0E-07 5.7E-07 4.8E-07 4.1E-07 3.6E-07 3.2E-07
E (90.0
o
) 2.6E-06 1.8E-06 1.3E-06 1.0E-06 7.9E-07 6.4E-07 5.3E-07 4.5E-07 3.9E-07 3.4E-07
ESE (112.5
o
) 2.2E-06 1.5E-06 1.1E-06 8.6E-07 7.0E-07 5.8E-07 4.9E-07 4.3E-07 3.8E-07 3.4E-07
SE (135.0
o
) 2.1E-06 1.4E-06 1.0E-06 8.5E-07 7.1E-07 6.0E-07 5.3E-07 4.7E-07 4.3E-07 3.9E-07
SSE (157.5
o
) 1.7E-06 1.1E-06 8.9E-07 7.1E-07 5.9E-07 5.0E-07 4.3E-07 3.8E-07 3.5E-07 3.2E-07
S (180.0
o
) 1.8E-06 1.3E-06 9.9E-07 8.1E-07 6.7E-07 5.7E-07 4.9E-07 4.4E-07 3.9E-07 3.6E-07
SSW (202.5
o
) 1.9E-06 1.4E-06 1.1E-06 8.9E-07 7.4E-07 6.3E-07 5.4E-07 4.8E-07 4.3E-07 3.9E-07
SW (225.0
o
) 3.2E-06 2.3E-06 1.8E-06 1.5E-06 1.2E-06 1.1E-06 9.3E-07 8.2E-07 7.4E-07 6.7E-07
WSW (247.5
o
) 4.2E-06 2.9E-06 2.3E-06 1.8E-06 1.5E-06 1.3E-06 1.1E-06 1.0E-06 9.1E-07 8.3E-07
W (270.0
o
) 3.4E-06 2.4E-06 1.9E-06 1.5E-06 1.3E-06 1.1E-06 9.4E-07 8.3E-07 7.4E-07 6.8E-07
WNW (292.5
o
) 3.0E-06 2.1E-06 1.7E-06 1.4E-06 1.1E-06 9.8E-07 8.5E-07 7.6E-07 6.9E-07 6.3E-07
NW (315.0
o
) 2.9E-06 2.0E-06 1.6E-06 1.3E-06 1.0E-06 8.8E-07 7.6E-07 6.7E-07 5.9E-07 5.4E-07
NNW (337.5
o
) 2.0E-06 1.5E-06 1.1E-06 9.0E-07 7.4E-07 6.2E-07 5.3E-07 4.6E-07 4.1E-07 3.7E-07
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site or the Building 100 roof.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1982–1990 meteorological data set
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 7 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 38 of 50
Table A-4. Atmospheric dispersion factors (s/m
3
) for the Building 100 Lab Stack, applicable 1965 through 1980 .
a,b,c
Direction (Deg.)
d
Distance from the Building 100 Lab Stack, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 9.4E-08 1.1E-07 1.5E-07 2.3E-07 2.5E-07 2.6E-07 2.5E-07 2.4E-07 2.3E-07 2.1E-07
NNE (22.5
o
) 1.8E-07 2.0E-07 1.8E-07 2.0E-07 2.1E-07 2.0E-07 1.9E-07 1.8E-07 1.7E-07 1.9E-07
NE (45.0
o
) 2.2E-07 2.4E-07 2.8E-07 2.9E-07 2.8E-07 2.7E-07 2.5E-07 1.7E-07 1.6E-07 1.5E-07
ENE (67.5
o
) 2.5E-07 3.5E-07 4.0E-07 4.1E-07 2.8E-07 2.6E-07 2.4E-07 2.2E-07 2.1E-07 1.9E-07
E (90.0
o
) 2.7E-07 3.7E-07 4.1E-07 4.1E-07 3.9E-07 3.6E-07 3.3E-07 3.0E-07 2.8E-07 2.5E-07
ESE (112.5
o
) 1.1E-07 1.8E-07 2.2E-07 2.4E-07 2.3E-07 2.2E-07 2.1E-07 1.9E-07 1.8E-07 1.7E-07
SE (135.0
o
) 1.1E-07 1.8E-07 2.2E-07 2.2E-07 2.2E-07 2.1E-07 2.0E-07 1.9E-07 1.8E-07 1.7E-07
SSE (157.5
o
) 9.2E-08 1.4E-07 1.9E-07 2.1E-07 2.2E-07 2.2E-07 2.1E-07 1.6E-07 1.5E-07 1.4E-07
S (180.0
o
) 5.3E-08 1.1E-07 1.4E-07 1.7E-07 1.8E-07 1.8E-07 1.8E-07 1.7E-07 1.6E-07 1.4E-07
SSW (202.5
o
) 3.2E-08 5.8E-08 1.0E-07 1.4E-07 1.6E-07 1.7E-07 1.7E-07 1.7E-07 1.6E-07 1.5E-07
SW (225.0
o
) 1.5E-08 2.4E-08 6.0E-08 1.5E-07 2.0E-07 2.3E-07 2.4E-07 2.4E-07 2.3E-07 3.4E-07
WSW (247.5
o
) 4.7E-09 3.3E-09 2.8E-08 1.4E-07 2.5E-07 3.3E-07 3.7E-07 5.0E-07 4.9E-07 4.7E-07
W (270.0
o
) 1.8E-09 3.6E-14 2.9E-09 9.0E-08 2.8E-07 4.3E-07 5.0E-07 5.3E-07 5.3E-07 5.1E-07
WNW (292.5
o
) 5.0E-09 0.0E+00 1.7E-09 7.7E-08 2.2E-07 3.4E-07 4.0E-07 4.2E-07 4.2E-07 4.1E-07
NW (315.0
o
) 1.8E-08 3.2E-09 3.3E-08 1.2E-07 2.1E-07 2.7E-07 2.9E-07 3.5E-07 3.4E-07 3.2E-07
NNW (337.5
o
) 4.7E-08 5.2E-08 1.1E-07 1.8E-07 2.4E-07 2.7E-07 2.7E-07 2.7E-07 2.6E-07 2.6E-07
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site or the Building 100 roof.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1964–1973 meteorological data set
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 8 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 39 of 50
Table A-5. Atmospheric dispersion factors (s/m
3
) for the Building 100 Lab Stack, applicable 1981 through 1995 .
a,b,c
Direction (Deg.)
d
Distance from the Building 100 Lab Stack, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 1.7E-07 1.9E-07 2.4E-07 2.6E-07 2.8E-07 2.7E-07 2.6E-07 2.4E-07 2.2E-07 2.1E-07
NNE (22.5
o
) 2.1E-07 3.0E-07 2.7E-07 2.8E-07 2.7E-07 2.5E-07 2.3E-07 2.1E-07 1.9E-07 1.9E-07
NE (45.0
o
) 2.6E-07 3.2E-07 3.3E-07 3.2E-07 3.0E-07 2.7E-07 2.5E-07 2.0E-07 1.8E-07 1.7E-07
ENE (67.5
o
) 2.8E-07 3.5E-07 3.6E-07 3.5E-07 2.9E-07 2.6E-07 2.4E-07 2.2E-07 2.0E-07 1.8E-07
E (90.0
o
) 2.9E-07 3.5E-07 3.6E-07 3.5E-07 3.2E-07 2.9E-07 2.6E-07 2.4E-07 2.1E-07 2.0E-07
ESE (112.5
o
) 1.8E-07 2.5E-07 2.7E-07 2.7E-07 2.6E-07 2.4E-07 2.2E-07 2.1E-07 1.9E-07 1.8E-07
SE (135.0
o
) 1.7E-07 2.4E-07 2.7E-07 2.5E-07 2.5E-07 2.4E-07 2.3E-07 2.1E-07 2.0E-07 1.9E-07
SSE (157.5
o
) 1.6E-07 1.9E-07 2.3E-07 2.5E-07 2.5E-07 2.4E-07 2.3E-07 1.9E-07 1.8E-07 1.7E-07
S (180.0
o
) 9.4E-08 1.6E-07 1.9E-07 2.1E-07 2.2E-07 2.2E-07 2.1E-07 1.9E-07 1.8E-07 2.0E-07
SSW (202.5
o
) 6.4E-08 9.8E-08 1.5E-07 2.4E-07 2.6E-07 2.6E-07 2.5E-07 2.4E-07 2.2E-07 2.1E-07
SW (225.0
o
) 3.5E-08 4.8E-08 1.3E-07 2.4E-07 2.9E-07 3.0E-07 3.0E-07 2.8E-07 2.7E-07 4.1E-07
WSW (247.5
o
) 1.3E-08 1.1E-08 6.9E-08 2.7E-07 4.0E-07 4.7E-07 4.9E-07 5.8E-07 5.5E-07 5.2E-07
W (270.0
o
) 5.6E-09 2.8E-13 1.2E-08 1.9E-07 3.6E-07 4.6E-07 5.0E-07 4.9E-07 4.7E-07 4.4E-07
WNW (292.5
o
) 8.3E-09 0.0E+00 5.7E-09 1.4E-07 3.1E-07 4.0E-07 4.3E-07 4.3E-07 4.1E-07 3.9E-07
NW (315.0
o
) 2.7E-08 9.6E-09 5.8E-08 1.8E-07 2.7E-07 3.0E-07 3.0E-07 4.0E-07 3.8E-07 3.5E-07
NNW (337.5
o
) 1.0E-07 1.0E-07 1.6E-07 2.1E-07 2.5E-07 2.6E-07 2.5E-07 2.4E-07 2.3E-07 2.4E-07
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site or the Building 100 roof.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1982–1990 meteorological data set
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 9 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 40 of 50
Table A-6. Atmospheric dispersion factors (s/m
3
) for the Building 800 Stack, applicable 1997 .
a,b,c
Direction (Deg.)
d
Distance from the Building 800 Stack, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 4.6E-06 4.3E-06 3.3E-06 2.4E-06 1.9E-06 1.5E-06 1.3E-06 1.0E-06 9.3E-07 7.9E-07
NNE (22.5
o
) 4.3E-06 3.4E-06 2.7E-06 2.1E-06 1.8E-06 1.5E-06 1.1E-06 1.1E-06 8.7E-07 7.0E-07
NE (45.0
o
) 4.0E-06 2.9E-06 2.5E-06 1.9E-06 1.5E-06 1.3E-06 1.1E-06 8.8E-07 8.6E-07 7.3E-07
ENE (67.5
o
) 3.7E-06 2.7E-06 2.0E-06 1.7E-06 1.4E-06 1.1E-06 1.0E-06 8.8E-07 7.2E-07 6.9E-07
E (90.0
o
) 3.4E-06 2.6E-06 1.9E-06 1.5E-06 1.3E-06 1.0E-06 8.7E-07 8.1E-07 6.6E-07 6.0E-07
ESE (112.5
o
) 4.3E-06 3.4E-06 2.6E-06 2.0E-06 1.9E-06 1.5E-06 1.2E-06 1.2E-06 9.7E-07 8.8E-07
SE (135.0
o
) 4.9E-06 3.5E-06 2.6E-06 3.3E-06 2.9E-06 2.1E-06 2.1E-06 1.8E-06 1.4E-06 1.4E-06
SSE (157.5
o
) 5.2E-06 5.0E-06 4.1E-06 3.6E-06 2.7E-06 2.5E-06 2.2E-06 1.3E-06 1.4E-06 1.2E-06
S (180.0
o
) 7.6E-06 5.5E-06 3.9E-06 2.9E-06 2.6E-06 2.3E-06 1.7E-06 1.7E-06 1.5E-06 1.3E-06
SSW (202.5
o
) 7.3E-06 6.1E-06 4.2E-06 4.2E-06 3.3E-06 2.6E-06 2.4E-06 1.9E-06 1.7E-06 1.6E-06
SW (225.0
o
) 8.5E-06 5.8E-06 6.7E-06 4.9E-06 4.2E-06 3.5E-06 2.6E-06 2.3E-06 2.0E-06 2.6E-06
WSW (247.5
o
) 1.2E-05 1.2E-05 7.9E-06 1.2E-05 8.1E-06 6.6E-06 5.3E-06 5.2E-06 4.3E-06 4.0E-06
W (270.0
o
) 1.0E-05 1.9E-05 2.8E-05 1.5E-05 9.4E-06 7.1E-06 5.4E-06 4.3E-06 4.0E-06 3.1E-06
WNW (292.5
o
) 8.2E-06 1.5E-05 1.6E-05 1.1E-05 9.1E-06 6.5E-06 5.0E-06 4.0E-06 3.6E-06 2.8E-06
NW (315.0
o
) 7.3E-06 7.7E-06 6.0E-06 5.1E-06 3.7E-06 3.0E-06 2.3E-06 2.8E-06 2.3E-06 2.1E-06
NNW (337.5
o
) 5.8E-06 5.2E-06 4.0E-06 3.3E-06 2.6E-06 2.0E-06 1.6E-06 1.4E-06 1.1E-06 1.2E-06
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1982–1990 meteorological data set
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 10 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 41 of 50
Table A-7. Summary of maximum atmospheric dispersion factors for
Pinellas Plant stacks.
a
Stack Id
Applicable
Years
Maximum Dispersion
Factor (s/m
3
)
Bldg. 100 – Main Stack
1957–1980 6.0E-07
1981–1996 4.2E-06
Bldg. 100 – Lab Stack
1965–1980 4.1E-07
1981–1995 3.6E-07
Building 800 Stack 1997 1.9E-05
a. Summarized from Tables A-2 through A-6.
During the years when either of the two Building 100 stacks were operating, the highest atmospheric
dispersion factors amongst the two stacks were selected to represent all of the stacks for a given
period as a favorable to claimant simplification. The Building 100 Main Stack was the only emission
point from 1957 through 1964. The Main Stack also had a larger dispersion factor than the Building
100 Lab Stack during the years that both stacks were operating because of lower stack gas exit
velocities and a larger stack cross-sectional area. The shortening of the 100 Main Stack in 1981 also
contributed to its dispersion factor being greater than the Building 100 Lab Stack after 1980. During
the years of 1980–1996, the Building 800 Stack had higher atmospheric dispersion factors than the
Building 100 stacks. However, releases from the Main Stack and the Lab Stack accounted for over
98% of the total radioactive airborne effluents during the years of 1980–1996, and greater than 99%
of the HTO released (ORAUT 2011b). During the period of 1980–1996, the Building 800 Stack
accounted for less than 2% of total airborne radioactivity released and less than 1% of the total HTO
released (ORAUT 2011b). All other sources of atmospheric releases (i.e., Building 200 and roof
openings) were negligible contributors and accounted for significantly less than 0.1% of the total
radioactivity released during the period of 1980–1996 (ORAUT 2011b). The Building 800 Stack
dispersion is overestimated (i.e., the dispersion factor is underestimated) for the period of 1980–1996
by using the Main Stack dispersion factors. However, use of the Main Stack dispersion factors for
1980–1996 underestimates the overall dispersion (i.e., the dispersion for all stacks) by a factor of
about 1.5 for this period. The underestimate of the dispersion for the Building 100 Lab Stack releases
more than compensates for the overestimate of dispersion for the Building 800 Stack releases, which
are relatively small compared to the Building 100 Lab Stack releases. Table A-8 shows the
atmospheric dispersion factors that were used for the internal and external environmental dose
calculations.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 11 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 42 of 50
Table A-8. Atmospheric dispersion factors
used for Pinellas Plant stack releases.
Applicable
Years
Dispersion Factor
Used (s/m
3
)
1957–1980 6.0E-07
1981–1996 4.2E-06
1997 1.9E-05
A-5 Atmospheric Dispersion Factors for Area Sources
Atmospheric dispersion factors were also calculated for area sources at the Pinellas Plant, namely the
east retention pond, west retention pond, and aeration area located across the northern half of the site
(see Figure 4-1). As discussed in Section 4.3.4, the ponds and aeration area were active from about
1971 through November 1982. After this, the active aeration was discontinued but the plant continued
to use the ponds, which contained trace amounts of tritium for collecting stormwater runoff. The
methods used to calculate the dispersion factors were similar to those described for the stacks. A unit
release of 1 Curie per second (Ci/s) of tritium oxide (HTO) was modeled from an area source of
approximately 6,250 m
2
(≈ 50 m x 125 m) for the east retention pond, 5,080 m
2
(≈ 35 m x 145 m) for
the west retention pond, and 30,800 m
2
(≈ 140 m x 220 m) for the aeration area. Tritium gas was not
considered for these airborne emissions sources because they would have only contained tritiated
water. The area sources were modeled as chronic ground level releases using Pasquill-Gifford
atmospheric stability without enhanced dispersion since no buildings were adjacent to these sources.
Only the 1982–1990 meteorological data file was used to generate dispersion factors for the area
sources because all of the monitoring data was outside of the date range for the other meteorological
data file and because the differences between the atmospheric dispersion factors generated by each
meteorological data set were small.
Results of the area source calculations are presented in Tables A-9 through A-11 as Χ/Q atmospheric
dispersion factors with units of seconds per cubic meter (s/m
3
). Atmospheric dispersion factors were
developed for the west retention pond and aeration area. However, at the time this TBD was issued,
there was no source term information available for the period that these two area sources were used
as part of the site’s liquid effluent discharge system. Therefore, these dispersion factors are not
currently being used for any calculations and were only developed in the event that sufficient
information is found in the future to facilitate their use.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 12 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 43 of 50
Table A-9. Atmospheric dispersion factors (s/m
3
) for the east retention pond, applicable 1971 through 1997 .
a,b,c
Direction (Deg.)
d
Distance from the center of the East Retention Pond, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 3.7E-05 2.0E-05 9.4E-06 5.5E-06 3.6E-06 2.6E-06 1.9E-06 1.4E-06 1.2E-06 1.2E-06
NNE (22.5
o
) 3.2E-05 1.7E-05 8.0E-06 4.8E-06 3.1E-06 2.2E-06 1.6E-06 1.3E-06 1.0E-06 1.0E-06
NE (45.0
o
) 3.7E-05 2.0E-05 9.4E-06 5.5E-06 3.6E-06 2.6E-06 1.9E-06 1.5E-06 1.2E-06 1.2E-06
ENE (67.5
o
) 3.6E-05 1.9E-05 8.5E-06 5.3E-06 3.4E-06 2.5E-06 1.8E-06 1.4E-06 1.2E-06 1.2E-06
E (90.0
o
) 3.3E-05 1.8E-05 8.4E-06 4.9E-06 3.2E-06 2.3E-06 1.7E-06 1.4E-06 1.1E-06 1.1E-06
ESE (112.5
o
) 4.9E-05 2.7E-05 1.3E-05 7.5E-06 4.9E-06 3.5E-06 2.6E-06 2.0E-06 1.6E-06 1.6E-06
SE (135.0
o
) 7.2E-05 4.1E-05 2.0E-05 1.1E-05 7.5E-06 5.3E-06 4.0E-06 3.2E-06 2.6E-06 2.6E-06
SSE (157.5
o
) 5.7E-05 3.2E-05 1.5E-05 9.4E-06 6.0E-06 4.2E-06 3.2E-06 2.5E-06 2.0E-06 2.0E-06
S (180.0
o
) 6.3E-05 3.6E-05 1.7E-05 1.0E-05 6.5E-06 4.6E-06 3.4E-06 2.7E-06 2.2E-06 2.2E-06
SSW (202.5
o
) 6.3E-05 3.5E-05 1.6E-05 9.4E-06 6.4E-06 4.5E-06 3.4E-06 2.6E-06 2.1E-06 2.1E-06
SW (225.0
o
) 1.0E-04 6.0E-05 2.8E-05 1.6E-05 1.1E-05 7.7E-06 5.7E-06 4.5E-06 3.7E-06 3.7E-06
WSW (247.5
o
) 1.3E-04 7.3E-05 3.5E-05 2.0E-05 1.4E-05 9.4E-06 7.2E-06 5.6E-06 4.5E-06 4.5E-06
W (270.0
o
) 1.0E-04 5.7E-05 2.7E-05 1.6E-05 1.0E-05 7.4E-06 5.5E-06 4.3E-06 3.5E-06 3.5E-06
WNW (292.5
o
) 9.4E-05 5.2E-05 2.5E-05 1.4E-05 9.4E-06 6.7E-06 5.0E-06 3.9E-06 3.2E-06 3.2E-06
NW (315.0
o
) 6.6E-05 3.7E-05 1.7E-05 1.0E-05 6.6E-06 4.7E-06 3.5E-06 2.7E-06 2.2E-06 2.2E-06
NNW (337.5
o
) 4.3E-05 2.4E-05 1.1E-05 6.5E-06 4.3E-06 3.0E-06 2.2E-06 1.8E-06 1.4E-06 1.4E-06
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site. Cross-hatched areas are portions of the sector that are
completely obstructed by Building 100, and the onsite dispersion factors in those areas are likely significant overestimates.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1982–1990 meteorological data set. The applicable period for this pond is through 1997 because it
likely contained tritium contaminated water through the end of the site’s covered employment.
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 13 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 44 of 50
Table A-10. Atmospheric dispersion factors (s/m
3
) for the west retention pond, applicable 1973 through 1997 .
a,b,c
Direction (Deg.)
d
Distance from the center of the West Retention Pond, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 4.0E-05 2.0E-05 9.2E-06 5.4E-06 3.6E-06 2.5E-06 1.9E-06 1.5E-06 1.2E-06 9.8E-07
NNE (22.5
o
) 3.5E-05 1.7E-05 8.0E-06 4.7E-06 3.1E-06 2.2E-06 1.6E-06 1.3E-06 1.0E-06 8.5E-07
NE (45.0
o
) 4.1E-05 2.0E-05 9.3E-06 5.5E-06 3.6E-06 2.5E-06 1.9E-06 1.5E-06 1.2E-06 9.9E-07
ENE (67.5
o
) 4.0E-05 1.9E-05 8.9E-06 5.3E-06 3.4E-06 2.4E-06 1.8E-06 1.4E-06 1.2E-06 9.5E-07
E (90.0
o
) 3.7E-05 1.8E-05 8.4E-06 5.0E-06 3.2E-06 2.3E-06 1.7E-06 1.4E-06 1.1E-06 9.0E-07
ESE (112.5
o
) 5.3E-05 2.7E-05 1.3E-05 7.5E-06 4.9E-06 3.5E-06 2.6E-06 2.0E-06 1.6E-06 1.4E-06
SE (135.0
o
) 7.9E-05 4.1E-05 1.9E-05 1.1E-05 7.4E-06 5.3E-06 4.0E-06 3.1E-06 2.5E-06 2.1E-06
SSE (157.5
o
) 6.3E-05 3.2E-05 1.5E-05 9.0E-06 5.9E-06 4.2E-06 3.1E-06 2.5E-06 2.0E-06 1.6E-06
S (180.0
o
) 6.9E-05 3.5E-05 1.7E-05 9.8E-06 6.4E-06 4.6E-06 3.4E-06 2.7E-06 2.2E-06 1.8E-06
SSW (202.5
o
) 6.9E-05 3.5E-05 1.7E-05 9.7E-06 6.4E-06 4.5E-06 3.4E-06 2.7E-06 2.1E-06 1.8E-06
SW (225.0
o
) 1.2E-04 5.9E-05 2.8E-05 1.6E-05 1.1E-05 7.6E-06 5.7E-06 4.5E-06 3.6E-06 3.0E-06
WSW (247.5
o
) 1.4E-04 7.3E-05 3.5E-05 2.0E-05 1.3E-05 9.5E-06 7.1E-06 5.6E-06 4.5E-06 3.7E-06
W (270.0
o
) 1.1E-04 5.7E-05 2.7E-05 1.6E-05 1.0E-05 7.4E-06 5.5E-06 4.3E-06 3.5E-06 2.9E-06
WNW (292.5
o
) 1.0E-04 5.2E-05 2.4E-05 1.4E-05 9.4E-06 6.7E-06 5.0E-06 3.9E-06 3.2E-06 2.6E-06
NW (315.0
o
) 7.3E-05 3.6E-05 1.7E-05 1.0E-05 6.6E-06 4.7E-06 3.5E-06 2.7E-06 2.2E-06 1.8E-06
NNW (337.5
o
) 4.8E-05 2.3E-05 1.1E-05 6.5E-06 4.2E-06 3.0E-06 2.2E-06 1.8E-06 1.4E-06 1.2E-06
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site. Cross-hatched areas are portions of the sector that are
completely obstructed by Building 100, and the onsite dispersion factors in those areas are likely significant overestimates.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1982–1990 meteorological data set. The applicable period for this pond is through 1997 because it
likely contained tritium contaminated water through the end of the site’s covered employment.
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 14 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 45 of 50
Table A-11. Atmospheric dispersion factors (s/m
3
) for the aeration area, applicable 1973 through 1982.
a,b,c
Direction (Deg.)
d
Distance from the center of the Aeration Area, m
100 200 300 400 500 600 700 800 900 1000
N (0.0
o
) 1.8E-05 9.7E-06 6.8E-06 5.4E-06 3.8E-06 2.7E-06 2.0E-06 1.6E-06 1.3E-06 1.0E-06
NNE (22.5
o
) 1.6E-05 8.5E-06 5.9E-06 4.6E-06 3.3E-06 2.3E-06 1.7E-06 1.4E-06 1.1E-06 9.0E-07
NE (45.0
o
) 1.8E-05 9.8E-06 6.9E-06 5.4E-06 3.8E-06 2.7E-06 2.0E-06 1.6E-06 1.3E-06 1.1E-06
ENE (67.5
o
) 1.8E-05 9.5E-06 6.6E-06 5.2E-06 3.7E-06 2.6E-06 1.9E-06 1.5E-06 1.2E-06 1.0E-06
E (90.0
o
) 1.7E-05 8.9E-06 6.2E-06 4.9E-06 3.4E-06 2.4E-06 1.8E-06 1.4E-06 1.2E-06 9.5E-07
ESE (112.5
o
) 2.4E-05 1.3E-05 9.2E-06 7.3E-06 5.3E-06 3.7E-06 2.8E-06 2.2E-06 1.8E-06 1.5E-06
SE (135.0
o
) 3.4E-05 2.0E-05 1.4E-05 1.1E-05 8.0E-06 5.7E-06 4.3E-06 3.3E-06 2.7E-06 2.2E-06
SSE (157.5
o
) 2.7E-05 1.6E-05 1.1E-05 8.8E-06 6.4E-06 4.5E-06 3.4E-06 2.6E-06 2.1E-06 1.8E-06
S (180.0
o
) 3.0E-05 1.7E-05 1.2E-05 9.5E-06 6.9E-06 4.9E-06 3.7E-06 2.9E-06 2.3E-06 1.9E-06
SSW (202.5
o
) 3.1E-05 1.7E-05 1.2E-05 9.5E-06 6.8E-06 4.9E-06 3.6E-06 2.8E-06 2.3E-06 1.9E-06
SW (225.0
o
) 5.2E-05 2.9E-05 2.0E-05 1.6E-05 1.2E-05 8.2E-06 6.1E-06 4.8E-06 3.9E-06 3.2E-06
WSW (247.5
o
) 6.4E-05 3.5E-05 2.5E-05 2.0E-05 1.4E-05 1.0E-05 7.6E-06 6.0E-06 4.8E-06 4.0E-06
W (270.0
o
) 5.0E-05 2.8E-05 2.0E-05 1.5E-05 1.1E-05 7.9E-06 5.9E-06 4.7E-06 3.8E-06 3.1E-06
WNW (292.5
o
) 4.5E-05 2.5E-05 1.8E-05 1.4E-05 1.0E-05 7.2E-06 5.4E-06 4.2E-06 3.4E-06 2.8E-06
NW (315.0
o
) 3.3E-05 1.8E-05 1.3E-05 9.9E-06 7.1E-06 5.0E-06 3.8E-06 2.9E-06 2.4E-06 2.0E-06
NNW (337.5
o
) 2.2E-05 1.2E-05 8.1E-06 6.4E-06 4.5E-06 3.2E-06 2.4E-06 1.9E-06 1.5E-06 1.2E-06
a. Shaded areas represent areas outside the boundary of the Pinellas Plant site. Cross-hatched areas are portions of the sector that are
completely obstructed by Building 100, and the onsite dispersion factors in those areas are likely significant overestimates.
b. Bold box represents the onsite location with the highest dispersion factor.
c. Dispersion factors are based on the 1982–1990 meteorological data set. Also, the applicable years of the aeration area are limited through
1982, because the source term only existed as potentially contaminated soil after 1982 and because structures were later placed over
portions of this source term (see Figure 4-1).
d. The direction in degrees is for the center of each sector with north starting at 0
o
or 360
o
.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 15 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 46 of 50
A-6 Atmospheric Dispersion at Tritium Monitoring Station Locations
The summarized annual tritium monitoring data presented in Table 4-5 for the period of 1975–1992
provided an opportunity to compare the tritium air concentrations predicted by the atmospheric
dispersion modeling to the annual average tritium air concentrations that were measured at several
locations on the site. To do this comparison, separate sets of atmospheric dispersion factors were
calculated for the distances and directions from each source term to each tritium air monitoring station
(i.e., Stations 1–6 in Figure 4-1). Table A-12 presents the calculated atmospheric dispersion factors
associated with each source term for each of the six tritium air monitoring stations. The dispersion
factors from the area sources have been reduced by a factor of 10 to qualitatively account for building
wake effects as the plumes travel through the plant to the monitoring station locations.
Table A-12. Atmospheric dispersion factors at the six tritium monitoring station locations (s/m
3
).
a
Type of
source
Source
name
Tritium Air Monitoring Stations
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6
Point
sources
Bldg. 100 Main Stack 9.4E-07 7.8E-07 8.0E-07 1.2E-06 1.6E-06 2.1E-06
Bldg. 100 Lab Stack 1.7E-07 2.6E-07 3.0E-07 3.5E-07 2.7E-07 3.6E-08
Bldg. 800 Stack 4.0E-06 3.0E-06 1.4E-06 1.4E-06 2.8E-06 7.2E-06
Area
sources
b
east retention pond 8.5E-06 1.9E-05 9.4 E-05 2.6E-05 7.5E-07 8.3E-07
west retention pond 9.8 E-05 1.1E-05 2.2E-06 3.0E-06 4.5E-07 9.6E-07
aeration area 2.70E-05 2.9E-05 4.9E-06 6.4E-06 5.9E-07 9.5E-07
a. Dispersion factors are based on the 1982–1990 meteorological data set.
b. The shaded areas identify area source dispersion factors that have been reduced by a factor of 10 to qualitatively
account for building wake effects during plume transport.
The release of tritium from the effluent ponds and aeration area represent a confounding factor for the
period of their operation (until November 1982) and for an unknown period afterward, as tritium levels
in the ponds were gradually reduced due to natural removal mechanisms (e.g. radioactive decay,
evaporation, dilution by rain and stormwater run-off, etc…) and discharges from the ponds. The
dispersion factors in Table A-12 indicate that the area sources could be a significant contributor to the
onsite tritium air concentrations. However, at the time this TBD was issued, there was not enough
information available to develop a reasonable estimate of the tritium release rates for the area
sources. Therefore, the contributions of the area sources to the tritium air concentrations have not
been factored into the predicted air concentrations that were calculated. Because the tritium
associated with the area sources would have been limited to HTO, the HT concentrations should not
have been influenced by the area sources. As a result, the HT concentrations should only be
attributable to the stack releases.
Annual average HT and HTO air concentrations were predicted for each calendar year and for each
air monitoring station location by multiplying each stack’s annual HT and HTO releases by the
appropriate dispersion factors. The annual air concentrations produced by each stack were then
summed into the predicted HT and HTO air concentrations for each air monitoring station location.
Ratios of the predicted air concentrations to the measured air concentrations were then calculated for
each calendar year and each air monitoring station location. When the measured tritium results were
reported as being less than, “<”, a certain value, the “<” symbol was disregarded. This approach for
dealing with the less than values potentially causes the predicted-to-measured ratios to be lower than
they actually were. For example, when the predicted air concentration is 4 x 10
-12
µCi/mL and the
measured air concentration is < 8 x 10
-12
µCi/mL, a ratio of 0.5 would be calculated even though the
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 16 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 47 of 50
ratio is potentially 1.0. Because the predicted value is below the reported less than value, the two
numbers are still potentially in agreement. The closer that a predicted-to-measured ratio is to 1.00 the
better the predicted air concentrations agree with the measured air concentrations. Ratios that are
less than 1.00 indicate that the predicted air concentrations are being underestimated and ratios
greater than 1.00 indicate that the predicted air concentrations are being overestimated.
Table A-13 shows the annual average ratio of predicted to measured HT concentrations at the six
monitoring stations for the years 1975 through 1992. The monitoring station statistics are shown at
the bottom of the table.
Table A-13. Ratio of predicted-to-measured tritium gas (HT) concentrations at the tritium air
monitoring stations .
a
Year
Tritium Air Monitoring Stations
Yearly
average
b
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6
1975 NA
c
0.51 NA 0.09 0.39 0.35 0.34
1976 0.55 0.35 0.12 0.66 0.05 1.28 0.50
1977 0.35 0.39 0.29 0.13 0.36 0.54 0.34
1978 0.62 0.66 1.52 0.85 0.94 1.15 0.96
1979 0.66 0.65 0.79 1.53 0.73 0.49 0.81
1980 0.80 0.51 0.76 0.72 1.37 0.43 0.77
1981 0.79 0.58 0.46 1.12 0.66 0.34 0.66
1982
d
0.50 0.88 0.91 0.84 1.58 0.78 0.91
1983 1.00 0.21 1.66 2.67 0.52 1.21 1.21
1984 0.31 0.15 0.84 1.00 0.86 0.43 0.60
1985 0.40 0.54 0.60 0.19 0.33 0.25 0.39
1986 0.11 0.11 0.11 0.24 0.12 0.21 0.15
1987 NA NA NA NA NA NA —
1988 0.23 0.02
e
0.06 0.08 0.26 1.11 0.29
1989 0.18 1.41 0.29 2.22 0.06 0.06 0.71
1990 0.16 0.22 0.12 0.30 0.12 0.14 0.18
1991 0.09 0.11 0.21 0.15 0.07 0.06 0.11
1992 NR
f
NR NR NR NR NR —
Average 0.45 0.46 0.58 0.80 0.53 0.55 0.56
Std. dev. 0.28 0.35 0.50 0.78 0.47 0.42 0.32
Minimum 0.09 0.02 0.06 0.08 0.05 0.06
Maximum 1.00 1.41 1.66 2.67 1.58 1.28
a. Source: ORAUT 2011h; The underlined ratios indicate that the annual average air concentration was
reported as a less than value, and that the predicted-to-measured ratio may be underestimated. Sixty-three
of the ninety-four HT results (67%) in Table 4-5 were reported as less than values.
b. The yearly average is the average ratio for all monitoring stations for a given year.
c. NA – not available, no air monitoring data was available for either this location or this year.
d. After 1982, liquid effluent discharges to the area sources ceased, and the contribution to the airborne HTO
concentrations attributable to the areas sources would be expected to decrease after 1982.
e. Significant data outlier.
f. NR – not reported, only total tritium air concentrations were reported for this year and all tritium was assumed
to be HTO.
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These statistics indicate that the predicted HT air concentrations at the various stations are
underestimated by somewhat less than a factor of 1.79 (1/0.56), across the entire period. The main
difference for HT during these years was that the stack releases of HT were significantly higher from
1975 through 1985. Prediction of HT concentrations would be expected to be better when higher
activities of HT were released, resulting in greater concentrations to be detected at the monitoring
stations. In addition, the underestimate of the HT air concentrations is likely smaller than a factor of
1.79 and much closer to a factor of 1.00, if the less than values for the measured results were
accounted for in the comparison. Regardless of this unfavorable bias, the comparison indicates that
the model is reasonably effective in predicting HT air concentrations.
Table A-14 presents the same type of predicted-to-measured ratios for HTO air concentrations.
Overall, the statistics indicate that the predicted HTO air concentrations at the various stations are
underestimated by somewhat less than a factor of 2.33 (1/0.43), across the entire period. The
emissions from the area sources during 1975–1982 were expected to contribute significantly to
measured HTO air concentrations. However, the average predicted-to-measured ratio is actually
better during these years than during later years when the ponds and aeration area were no longer
being used as part of the site’s liquid effluent system. This is counterintuitive, because the predictedto-measured ratios were expected to increase to values closer to 1.00 after 1982. Apparently the
area sources were not as significant contributors to the onsite HTO air concentrations as originally
hypothesized. Based on this analysis, the onsite tritium air concentrations appear to be dominated by
the annual tritium releases from the stacks. As was the case for HT, the stack releases of HTO were
much higher from 1975 through 1986, and prediction of HTO concentrations would be expected to be
better when higher activities of HTO were released. In addition, the underestimate of the HT air
concentrations is likely smaller than a factor of 2.33 and much closer to a factor of 1.00 if the less than
values for the measured results were accounted for in the comparison. Regardless of this
unfavorable bias, the comparison indicates that the model is reasonably effective in predicting HTO
air concentrations.
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 18 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 49 of 50
Table A-14. Ratio of predicted-to-measured tritium oxide (HTO) concentrations at the tritium
air monitoring stations .
a
Year
Tritium Air Monitoring Stations
Yearly
average
b
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6
1975 NA
c
0.31 NA 0.20 0.50 0.41 0.35
1976 0.58 0.98 0.85 1.44 1.15 1.30 1.05
1977 0.39 0.43 0.41 0.45 0.43 0.57 0.45
1978 0.50 0.48 0.54 0.93 0.81 0.64 0.65
1979 0.39 0.51 0.64 0.26 0.68 0.52 0.50
1980 0.71 0.58 0.85 0.63 0.97 1.08 0.80
1981 0.27 0.30 0.56 0.48 0.56 0.46 0.44
1982
d
0.21 0.32 0.58 0.34 0.31 0.30 0.34
1983 0.29 0.10 0.33 0.58 0.30 0.36 0.32
1984 0.29 0.13 0.39 0.31 0.46 0.16 0.29
1985 0.33 0.13 0.35 0.22 0.24 0.22 0.25
1986 0.22 0.11 0.42 0.15 0.34 0.26 0.25
1987 NA NA NA NA NA NA —
1988 0.36 0.01
e
0.06 0.27 0.07 0.78 0.26
1989 0.12 0.18 0.11 0.30 0.27 0.19 0.20
1990 0.30 0.35 0.20 0.51 0.26 0.24 0.31
1991 0.72 0.46 0.84 0.81 0.36 0.16 0.56
1992
f
0.24 0.55 0.43 0.24 0.13 0.15 0.29
Average 0.37 0.35 0.47 0.48 0.46 0.46 0.43
Std. dev. 0.17 0.24 0.24 0.33 0.29 0.33 0.23
Minimum 0.12 0.01 0.06 0.15 0.07 0.15
Maximum 0.72 0.98 0.85 1.44 1.15 1.30
a. Source: ORAUT 2011h; The underlined ratios indicate that the annual average air concentration was
reported as a less than value, and that the predicted-to-measured ratio may be underestimated. Thirty-one of
the 100 HTO results (31%) in Table 4-5 were reported as less than values.
b. The yearly average is the average ratio for all monitoring stations for a given year.
c. NA – not available, no air monitoring data was available for either this location or this year.
d. After 1982, liquid effluent discharges to the area sources ceased, and the contribution to the airborne HTO
concentrations attributable to the areas sources would be expected to decrease after 1982.
e. Significant data outlier.
f. Only total tritium air concentrations were reported for this year and all tritium was assumed to be HTO.
A-7 Summary and Conclusions
Hourly meteorological data and Pinellas Plant-specific stack parameters were used to develop
atmospheric dispersion factors for the Pinellas Plant. Knowledge of the type, time, and magnitude of
the Pinellas Plant radionuclide releases was also used to determine a favorable to claimant set of
three atmospheric dispersion factors that cover the entire operating period from 1957 through 1997.
Release-point-specific information was not considered for minor release points as these would have
ATTACHMENT A
BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS
Page 19 of 20Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 50 of 50
negligible impact on overall employee doses. Potential atmospheric contributions from surface water
area sources were also considered.
Measured HT and HTO concentrations from six onsite tritium monitoring stations were used to
validate the calculated atmospheric dispersion factors from stack releases. In general, the
atmospheric dispersion factors were underestimated by less than a factor of 2.33, even though data
presented as “less than” values and contributions from the surface water area sources were
confounding factors. The comparisons indicated that the model is reasona

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