ORAU TEAM

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 ............................................ 46
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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/m3

) for the Building 100 Main Stack, 

applicable 1957 through 1980 ................................................................................................ 36

A-3 Atmospheric dispersion factors (s/m3

) for the Building 100 Main Stack, 

applicable 1981 through 1996 ................................................................................................ 37

A-4 Atmospheric dispersion factors (s/m3

) for the Building 100 Lab Stack, 

applicable 1965 through 1980 ................................................................................................ 38

A-5 Atmospheric dispersion factors (s/m3

) for the Building 100 Lab Stack, 

applicable 1981 through 1995 ................................................................................................ 39

A-6 Atmospheric dispersion factors (s/m3

) 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/m3

) for the east retention pond, 

applicable 1971 through 1997 ................................................................................................ 43

A-10 Atmospheric dispersion factors (s/m3

) for the west retention pond, 

applicable 1973 through 1997 ................................................................................................ 44

A-11 Atmospheric dispersion factors (s/m3

) for the aeration area, applicable 

1973 through 1982.................................................................................................................45

A-12 Atmospheric dispersion factors at the six tritium monitoring station 

locations (s/m3

) ......................................................................................................................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

9
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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 sections
Document 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 causation1

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), 14C, and 

85Kr. 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 14C emit very-low-energy beta particles, whereas 85Kr 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 14C labeled solvents were used in 

a laboratory testing operation in Building 100 from 1979 to 1983 (DOE 1983). Because 14C 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 Monitoring
Document 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 1981b 30.48 [100] 2.44 (8) HT and HTO

Jul 1981–1996b 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 1975–1994d 6.7 [22] 0.41 [1.33] Plutonium oxidee

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 and
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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 85Kr 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 85Kr 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 14C were determined from the volumes of 14C 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 

238Pu and 239/240Pu (IT/Radiological Sciences Laboratory, 1986). The method of plutonium analysis 

consisted of 1) aliquoting a known quantity of 242Pu tracer onto the air filters, 2) introduction and 

chemical equilibration of the 242Pu 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 238Pu and 239/240Pu 

(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. 
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Table 4-2. Radionuclides released from Pinellas Plant 

exhaust stacks (Ci/yr).

a

Year HT HTO Kr-85b C-14c

1957 6,660 140 NRd 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

1980e

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

1989f

44 60 13 NR

1990 62 61 10 NR

1991g

23 88 4 NR

1992 8 32 10 NR

1993 NR 12 19 NR

1994 NR 25 13 NR

1995 NR 26 NR NR
Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 13 of 50

Year HT HTO Kr-85b C-14c

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, 85Kr 

comprised the radiological contents of the exhausts from the Pinellas Plant exhaust stacks. The Plant 

began using 85Kr for leak detection in 1963 (Burkhart 1990). Relatively small contributions of 14C 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

1957–1970b NRc NR NR NRc 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 BDLd 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 NAb 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

1987c NA NA NA NA NA NA NA NA NA NA NA NA

1988 13.3 4.1 152.0d 172.6d 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

1992e 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 14C emitted could have also 

contributed to a worker’s intake. In addition, 85Kr was also released from the Plant’s stacks; however, 

85Kr is not an internal dose concern because it is a noble gas. 

Maximum annual onsite average air concentrations of HT, HTO, and 14C 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 m3

/hr. A breathing rate of 1.2 m3/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 NRb

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

1993b NR 2.68E+02 NR

1994b NR 5.76E+02 NR

1995b NR 6.00E+02 NR

1996b NR 5.03E+02 NR

1997b 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 106 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/m3

). 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 

m3

/hr. A breathing rate of 1.2 m3/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 m3

/hr. A 

breathing rate of 1.2 m3

/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.
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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 85Kr 

emissions from the Plant stacks. Therefore, potential annual environmental external doses were 

assessed for a hypothetical MEE inside the plant boundary using the 85Kr airborne effluent data for 

the stacks. In addition, 14C emissions from the Pinellas Plant stack could have also contributed to the 

environmental external dose. However, the contributions to the environmental external doses from 

14C emissions were negligible compared to the contributions from 85Kr emissions, because 14C 

releases were at least 1/10,000th of the 85Kr releases and because 14C emits much lower energy beta 

particles than 85Kr. 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 85Kr 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 

85Kr, 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 85Kr releases were reported. Because 85Kr was not present at the site until 1963, there 

were no 85Kr 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 stacksb

(Ci)

Total annual

external dose

(mrem)

1957–1962 NRc 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.
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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.

EPA (U.S. Environmental Protection Agency), 1993, External Exposure to Radionuclides in Air, 

Water, and Soil, Federal Guidance Report No.12 (EPA-402-R-93-081), Washington DC. 

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ERDA (Energy Research and Development Administration), 1977, Chapter 0524, Standards for 

Radiation Protection, Washington, D.C., March 30. [SRDB Ref ID: 8083]

GE (General Electric Company), 1957–1973, collection of health physics reports, Neutron Devices

Department, Pinellas Plant, St. Petersburg, Florida. [SRDB Ref ID: 27095]

GE (General Electric Company), 1972, Environmental Monitoring Report 1971, Neutron Devices 

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]

GE (General Electric Company), 1974a, Compilation of Radioactive Effluent/Onsite 

Discharges/Unplanned Releases Reports for 1957–1971, Neutron Devices Department, St. 

Petersburg, Florida, May. [SRDB Ref ID: 12017, pp. 33-116] 

GE (General Electric Company), 1974b, Environmental Monitoring Report 1973, Neutron Devices 

Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12253]

GE (General Electric Company), 1975, Environmental Monitoring Report 1974, Neutron Devices 

Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12258]

GE (General Electric Company), 1976, Environmental Monitoring Report 1975, Neutron Devices 

Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12018, pp. 2-35]

GE (General Electric Company), 1977, Environmental Monitoring Report 1976, GEPP-288, Neutron 

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]
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GE (General Electric Company), 1980, Environmental Monitoring Report 1979, GEPP-EM-484. 

Neutron Devices Department, St. Petersburg, Florida, April. [SRDB Ref ID: 12018, pp. 187-

222]

GE (General Electric Company), 1981, Environmental Monitoring Report 1980, GEPP-EM-570, 

1597A/1598A/1610A-0080A, Neutron Devices Department, St. Petersburg, Florida, March. 

[SRDB Ref ID: 88792] 

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, 

pp. 223-262]

GE (General Electric Company), 1984, Pinellas Plant Environmental Monitoring Report 1983, GEPPEM-806, 8828A-0369A, Neutron Devices Department, St. Petersburg, Florida, April. [SRDB 

Ref ID: 12260]

GE (General Electric Company), 1985, Pinellas Plant Environmental Monitoring Report 1984, GEPPEM-879, 8828A-0115C, Neutron Devices Department, St. Petersburg, Florida, May. [SRDB 

Ref ID: 12261]

GE (General Electric Company), 1986, Pinellas Plant Environmental Monitoring Report 1985, GEPPEM-964, 8828A-0115C, Neutron Devices Department, St. Petersburg, Florida, April. [SRDB 

Ref ID: 12263]

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]

GE (General Electric Company), 1988, 1987 Pinellas Plant Environmental Monitoring Report, GEPPEM-1114, UC-11, Neutron Devices Department, St. Petersburg, Florida, April. [SRDB Ref ID:

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]
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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.
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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]

ORAUT (Oak Ridge Associated Universities Team), 2011h, MS Excel workbook titled Pinellas Plant -

Comparison of Meas to Modeled Air Conc, Rev 0, Oak Ridge, Tennessee, February. [SRDB 

Ref ID: 92636]

ORAUT (Oak Ridge Associated Universities Team), 2011i, MS Excel workbook titled Pinellas Plant –

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.
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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 × 1010) 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., 14C) 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/m3

) for the Building 100 Main Stack, 

applicable 1957 through 1980 ................................................................................................ 36

A-3 Atmospheric dispersion factors (s/m3

) for the Building 100 Main Stack, 

applicable 1981 through 1996 ................................................................................................ 37

A-4 Atmospheric dispersion factors (s/m3

) for the Building 100 Lab Stack, 

applicable 1965 through 1980 ................................................................................................ 38

A-5 Atmospheric dispersion factors (s/m3

) for the Building 100 Lab Stack, 

applicable 1981 through 1995 ................................................................................................ 39

A-6 Atmospheric dispersion factors (s/m3

) 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/m3

) for the east retention pond, 

applicable 1971 through 1997 ................................................................................................ 43

A-10 Atmospheric dispersion factors (s/m3

) for the west retention pond, 

applicable 1973 through 1997 ................................................................................................ 44

A-11 Atmospheric dispersion factors (s/m3

) for the aeration area, applicable 

1973 through 1982.................................................................................................................45

A-12 Atmospheric dispersion factors at the six tritium monitoring station 

locations (s/m3

) ......................................................................................................................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 20
Document 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 

22o

C (72oF) (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 20
Document 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 20
Document 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 2.44b 2.44 1.52b 1.52 0.51

Area (m2)

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 temperaturef 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 26o

C (79oF) 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 20
Document 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/m3

) in Tables A–2 through A–6. These factors are estimates of 

the long-term atmospheric dispersion represented as activity concentration (e.g., Ci/m3

, Bq/m3, 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 20
Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 36 of 50

Table A-2. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

ATTACHMENT A

BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS

Page 6 of 20
Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 37 of 50

Table A-3. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

ATTACHMENT A

BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS

Page 7 of 20
Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 38 of 50

Table A-4. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

ATTACHMENT A

BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS

Page 8 of 20
Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 39 of 50

Table A-5. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

ATTACHMENT A

BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS

Page 9 of 20
Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 40 of 50

Table A-6. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

ATTACHMENT A

BASIS FOR ATMOSPHERIC DISPERSION CALCULATIONS

Page 10 of 20
Document 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/m3)

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 20
Document 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/m3)

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 m2 (≈ 50 m x 125 m) for the east retention pond, 5,080 m2 (≈ 35 m x 145 m) for 

the west retention pond, and 30,800 m2 (≈ 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/m3

). 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 20
Document No. ORAUT-TKBS-0029-4 Revision No. 01 Effective Date: 07/15/2011 Page 43 of 50

Table A-9. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

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Table A-10. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

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Table A-11. Atmospheric dispersion factors (s/m3) 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 (0.0o) 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 (22.5o) 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 (45.0o) 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 (67.5o) 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 (90.0o) 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 (112.5o) 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 (135.0o) 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 (157.5o) 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 (180.0o) 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 (202.5o) 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 (225.0o) 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 (247.5o) 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 (270.0o) 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 (292.5o) 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 (315.0o) 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 (337.5o) 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 0o or 360o

.

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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/m3

).

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

sourcesb

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

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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 

averageb Station 1 Station 2 Station 3 Station 4 Station 5 Station 6

1975 NAc 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

 1982d 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 0.02e 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 NRf 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. 

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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 

averageb Station 1 Station 2 Station 3 Station 4 Station 5 Station 6

1975 NAc 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

 1982d 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 0.01e 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

1992f 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

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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 reasonably effective in predicting 

air concentrations based on the site’s stack releases.

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