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SEC Petition Evaluation Report 

Petition SEC-00103

Report Rev #: Addendum 3 Report Submittal Date: November 20, 2012 

Subject Expert(s): Mike Mahathy, Billy Smith, Sam Chu, Jack Beck, Rowena Argall, Pat 

McCloskey

Site Expert(s): N/A

Petition Administrative Summary

Petition Under Evaluation

Petition # Petition 

Type

Petition

Receipt Date

Qualification 

Date

DOE/AWE Facility Name

SEC-00103 83.13 Nov. 19, 2007 March 4, 2008 Savannah River Site (SRS)

Class Evaluated by NIOSH

All workers who worked in any thorium area at the Savannah River Site from October 1, 1972 through December 

31, 2007.

NIOSH-Proposed Class(es) to be Added to the SEC

None

Related Petition Summary Information 

SEC Petition Tracking #(s) Petition Type DOE/AWE Facility Name Petition Status

N/A N/A N/A N/A

Related Evaluation Report Information 

Report Title DOE/AWE Facility Name

SEC Petition Evaluation Report, SEC-00103

Addendum to Savannah River Site SEC Petition Evaluation Report

Addendum 2 to Savannah River Site SEC Petition Evaluation Report

Savannah River Site (SRS)

Savannah River Site (SRS)

Savannah River Site (SRS)

ORAU Lead Technical Evaluator: Mike Mahathy ORAU Peer Review Completed By: Daniel Stempfley

Peer Review Completed By: [Signature on File] 11/20/2012

Timothy Taulbee Date

[Signature on File] 11/20/2012 SEC Petition Evaluation Reviewed By:

J. W. Neton Date

[Signature on File] 11/20/2012 SEC Evaluation Approved By:

Stuart L. Hinnefeld Date
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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This page intentionally left blank 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Addendum 3 to Savannah River Site (SEC-00103) 

Special Exposure Cohort Evaluation Report 

NIOSH presented a Special Exposure Cohort (SEC) evaluation report (NIOSH, 2008) regarding the 

Savannah River Site (SRS) to the Advisory Board on Radiation and Worker Health (Advisory Board) 

during the December 16-18, 2008, Advisory Board meeting. In its report, NIOSH evaluated the 

feasibility of reconstructing radiation doses of construction workers who worked in any area at SRS 

during the time period of January 1, 1950 through December 31, 2007. The feasibility of 

reconstructing doses received from thorium exposure from the start of thorium operations in 1953 

through 1959 was reserved in the evaluation report while NIOSH continued to evaluate approaches for 

bounding doses from thorium exposures during that time period. 

On May 4, 2010, NIOSH issued an addendum to the SEC-00103 Evaluation Report. In that report, 

NIOSH concluded that it can complete dose reconstruction for exposure to all site occupational 

radiation sources for all construction workers who worked in any area at the Savannah River Site 

during the time period from January 1, 1950 through December 31, 2007 (NIOSH, 2010).

NIOSH issued a second addendum to the SEC-00103 Evaluation Report on August 9, 2011. In that 

report, NIOSH proposed an SEC class for some SRS workers that included: “All externally 

monitored employees of the Department of Energy, its predecessor agencies, and their contractors and 

subcontractors who worked at the Savannah River Site from January 1, 1953 through December 31, 

1957, and whose records have dosimetry codes A, G, CMX, or TNX; and all externally monitored 

employees of the Department of Energy, its predecessor agencies, and their contractors and 

subcontractors who worked at the Savannah River Site from January 1, 1958 through September 30, 

1972, and whose records have dosimetry codes 5A, 5C, 6B through 6Z, 12D through 12H, or 12J 

through 12Z for a number of work days aggregating at least 250 work days, occurring either solely 

under this employment or in combination with work days within the parameters established for one or 

more other classes of employees included in the Special Exposure Cohort.” 

The Advisory Board discussed NIOSH’s proposed class during its December 7-8, 2011, meeting in 

Tampa, Florida. The Advisory Board subsequently voted to recommend a revised class definition. 

The Board’s revised class definition was “All employees of the Department of Energy, its predecessor 

agencies, and their contractors and subcontractors who worked at the Savannah River Site from 

January 1, 1953 through September 30, 1972, for a number of work days aggregating at least 250 

work days, occurring either solely under this employment or in combination with work days within 

the parameters established for one or more other classes of employees included in the Special 

Exposure Cohort" (NIOSH, 2011). The class designation became effective on March 3, 2012, as 

provided for under 42 U.S.C. § 7384l (14)(C). 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Since the publication of the second addendum, NIOSH has continued its research, captured additional 

information, and determined that thorium was used in SRS locations and operations from October 

1972 through December 2007. Furthermore, NIOSH has determined that it has the necessary 

monitoring data and source term data needed to adequately bound internal doses received from 

exposures to unencapsulated thorium for SRS workers during this period. This Addendum 3 to the 

SEC-00103 Evaluation Report documents post-September 30, 1972 SRS work performed with 

thorium, locations where these tasks were performed, and exposures that may been received from such 

work.

_________________________________________________________________________________________ 

NOTE: This Evaluation Report Addendum 3 only addresses those sections in the Savannah River 

Site Evaluation Report that require discussion; therefore, the section numbering is not contiguous. 

The sections requiring additional thorium discussion begin below. 

_________________________________________________________________________________________ 

Petition Evaluation Report Addendum 3 Summary 

Class Evaluated by NIOSH (in Addendum 3) 

The feasibility of reconstructing doses received from thorium exposure from October 1, 1972 through 

December 31, 2007 was reserved for further consideration in the original SEC-00103 Evaluation 

Report. During this subsequent review, NIOSH has determined that thorium operations were 

conducted at SRS through 2007, and conducted in locations beyond those considered in the original 

evaluation report (NIOSH, 2008) and the first and second addendums (NIOSH, 2010; NIOSH, 2011); 

therefore, in Addendum 3, NIOSH addressed the feasibility of bounding doses from thorium 

exposures received during the expanded time period from October 1, 1972 through December 31, 

2007.

NIOSH-Proposed Class(es) to be Added to the SEC 

Based on its full research of the class under evaluation, NIOSH has obtained additional process and 

thorium inventory data and has conducted additional interviews with former workers on the use and 

monitoring of thorium. Based on its analysis of these available resources, NIOSH found no part of the 

class under evaluation for which it cannot estimate radiation doses with sufficient accuracy. 

Feasibility of Dose Reconstruction 

Per EEOICPA and 42 C.F.R. § 83.13(c)(1), NIOSH has established that it has access to sufficient 

information to: (1) estimate the maximum radiation dose, for every type of cancer for which radiation 

doses are reconstructed, that could have been incurred in plausible circumstances by any member of 

the class; or (2) estimate radiation doses of members of the class more precisely than an estimate of 

maximum dose. Information available from the site profile and additional resources is sufficient to 

document or estimate the maximum internal and external potential exposure to members of the 

evaluated class under plausible circumstances during the specified period. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Health Endangerment Determination 

Per EEOICPA and 42 C.F.R. § 83.13(c)(3), a health endangerment determination is not required 

because NIOSH has determined that it does have sufficient information to estimate dose for the 

members of the evaluated class. 

3.2 Class Evaluated by NIOSH 

The feasibility of reconstructing doses received from thorium exposure from October 1, 1972 through 

December 31, 2007 was reserved for further consideration in Addendum 2 of the SEC-00103 

Evaluation Report (NIOSH, 2011). That class is further evaluated in this Addendum 3 of the 

SEC-00103 Evaluation Report. 

3.3 NIOSH-Proposed Class(es) to be Added to the SEC 

Based on its research, NIOSH has obtained additional process and thorium inventory data and has 

conducted additional interviews with former workers on the use and monitoring of thorium. These 

resources allow dose reconstruction to be performed with sufficient accuracy. Based on its analysis of 

these available resources, NIOSH found no part of the class under evaluation for which it cannot 

estimate radiation doses with sufficient accuracy. 

4.0 Data Sources Reviewed by NIOSH to Evaluate the Class 

ATTRIBUTION: Section 4.0 and its related subsections were completed by Mike Mahathy, Oak Ridge 

Associated Universities. These conclusions were peer-reviewed by the individuals listed on the cover 

page. The rationales for all conclusions in this document are explained in the associated text. 

NIOSH has obtained additional process data and thorium inventory data for SRS since Addendum 2 to 

the SEC-00103 Evaluation Report was published in August 2011. Some of these data have been 

considered in this Addendum 3 evaluation and will be cited. NIOSH has also conducted additional 

interviews of former workers to obtain specific information on the use and monitoring of thorium. 

4.3 Facility Employees and Experts 

NIOSH interviewed four former SRS employees to learn about thorium work performed at SRS from 

1952 through 1992. 

Personal Communication, 2012a, Personal Communication with Former Nuclear Physicist; 

Telephone Interview by ORAU Team, February 2, 2012, SRDB Ref ID: 107510 

Personal Communication, 2012b, Personal Communication with Former Chemist; Telephone 

Interview by ORAU Team, February 2, 2012, SRDB Ref ID: 107512 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Personal Communication, 2012c, Personal Communication with Former Senior Chemist; 

Telephone Interview by ORAU Team, February 3, 2012, SRDB Ref ID: 107515 

Personal Communication, 2012d, Personal Communication with Former Senior Fellow Scientist; 

Telephone Interview by ORAU Team, February 10, 2012, SRDB Ref ID: 108605 

4.5 NIOSH Site Research Database 

NIOSH has performed additional data captures at SRS since the Addendum 2 was published in 

August 2011. As of May 17, 2012, there were 6,815 documents in the Site Research Database 

(SRDB) pertaining to SRS; thus, approximately 1,600 additional documents have been captured, 

reviewed, and uploaded into the SRDB since August 2011. 

SRDB documents evaluated for relevance to the thorium issue include: historical background on 

thorium operations and thorium material inventories; radiological monitoring data; information on the 

radiological controls program; monthly reports; and incident documentation. Thorium inventory data 

were captured from microfiche at SRS and transcribed to a NIOSH document (Inventory Data, 1976-

1998).

5.0 Radiological Operations Relevant to the Class Evaluated by 

NIOSH 

ATTRIBUTION: Section 5.0 was completed by Mike Mahathy, Oak Ridge Associated Universities. 

These conclusions were peer-reviewed by the individuals listed on the cover page. The rationales for 

all conclusions in this document are explained in the associated text.

The following subsections summarize SRS radiological operations involving thorium from October 1, 

1972 through December 31, 2007, as well as the information available to NIOSH for characterizing 

particular processes and radioactive source materials. From available resources, NIOSH has gathered 

process and source descriptions, information regarding quantities of thorium, and information 

describing both the processes through which radiation exposures to workers may have occurred and 

the physical environment in which they may have occurred. The information NIOSH has included 

within the initial SEC-00103 Evaluation Report and the report’s addenda is intended only to be a 

summary of the available information. 

While the time frame covered by this Addendum 3 begins in October 1972, NIOSH has updated 

inventory data for the THOREX processes conducted in the preceding years to show that THOREX 

operations ended in 1969. There were five major thorium-processing campaigns conducted at SRS, of 

which the last campaign ended in 1970. Table 5-1 summarizes the particulars of the thorium 

campaigns. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Table 5-1: SRS Thorium Processing Campaigns

Started THOREX

Process

Thorium Feed

(T)

Nominal U 

(g/T)

U

(kg)

U-232

(ppm)

U-233 Content 

(%)

3/1964 Interim 23 7.8 metal 2,700 21 50 97

5.7 metal 8,300 48 220 91

12/1964 Interim 23 8.6 metal 2,200 19 38 97

7.8 metal 7,500 64 228 91

9/1965 THOREX 17 metal 1,300 22 2.6-3.9 93-96

77 ThO2 2,000 152 4.3-6.4 98+

5/1968 THOREX 35 ThO2 2,300 80a--- ---

7/1969 THOREX 80 ThO2 2,300 181a--- ---

6/1970 2

nd cyclea N/A N/A 261 6.7 97.9

Source: Thorium Processing, 1970 

a

 Uranium from the last two campaigns was composited and processed through a second uranium cycle and finishing 

 operations in June and July 1970. 

--- means data not available. 

Upon the conclusion of the last campaign in 1970, the separations tanks were flushed many times and 

the targets were stored in the Receiving Basin for Offsite Fuel (RBOF), also known as Building 244H, 

and in reactor basins, mainly the 100 K Basin. The process and flush liquid waste were sent to the 

waste tank farm and eventually transferred to rail cars for shipment to Fernald. Small amounts of 

solid waste from target manufacturing and the Savannah River Laboratory (SRL) were sent to 643-E 

(Old Burial Ground) and 643-7E (New Burial Ground). SRL support to the THOREX IIB campaign 

also diminished upon the conclusion of the campaign in 1970 (Thorium Processing, 1970). Thorium 

inventories available for 1968 through 1971 shows thorium byproduct materials from THOREX 

campaigns had been shipped offsite by 1971. From 1968 through 1971, 138,516 kg thorium was 

shipped to Fernald (Inventories, 1994).

Thorium accountability ledgers for fiscal years 1972 and 1973 provide information on thorium 

inventory and how it was distributed among the SRS Buildings after the last THOREX campaign. 

Thorium ledger data and data from the DOE NMS database were examined to reconstruct thorium 

inventories from 1972 through 2007, as shown in Table 5-2. By 1973, the thorium building inventory 

shows that more than 95% of the site’s thorium inventory, 6679 kg (668 mCi), was stored in the 

RBOF as metal and oxide targets, the majority of it being thorium oxide targets. Approximately 154 

kg (15.4 mCi) of thorium were in Building 773A. About 52 kg (5.2 mCi) of irradiated thorium targets 

were stored in the disassembly area of the K Basin. Other buildings identified with thorium inventory 

include Buildings 305M, Test Pile; 221F/FB Line, Metal Conversion Line; 235F, Plutonium 

Experiment Facility (PEF); 777M, Process Development Pile (PDP); 321M, Fuel Fabrication Facility; 

and 313M/305M, Slug Fabrication and Testing Facilities. Thorium was used in small gram quantities 

in glove boxes as a surrogate for Am-241 in 313M in 1972 (Thorium Impurity, 1972).
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Table 5-2: SRS Thorium Inventory, 1972-2007 (kg)

Year 773A 723A 235-F

772-F

Lab

M 

Area 777M 217-AStorage

100-K

Basin

100-L

Basin RBOF

1972/3 154.01---

2

0.03--- 57.2 6.4 0.0352.0 --- 66791

1974 104.0 --- --- --- --- --- --- 52.0 ---

1975 104.0 0.5 1.1 1.1 43.2 5.4 --- 52.0 --- 6757

1976 89.4 1.1 0.9 0.9 40.7 2.0 0.0 52.0 --- 6757

1977 85.4 1.1 0.9 0.9 25.4 2.0 0.0 52.0 --- 8329

1978 56.6 --- 4.0 4.0 25.2 2.1 0.0 52.0 --- 8729

1979 83.4 --- 4.0 4.0 31.1 2.1 0.0 52.0 --- 8729

1980 108.6 --- 4.5 4.5 31.1 --- 8.0 52.0 3.1 8726

1981 110.9 --- 4.0 4.0 23.1 --- 0.0 55.1 3.1 8726

1982 85.5 --- 4.0 4.0 23.1 --- 0.0 55.1 3.1 8726

1983 32.5 --- 4.0 2.0 --- 0.0 55.1 3.1 8726

1984 21.6 --- 4.0 1.0 2.0 --- --- 55.1 3.1 8726

1985 17.9 --- 4.0 1.0 2.0 --- --- 55.1 3.1 8726

1986 5.4 --- 4.0 1.0 2.0 --- --- 51.9 3.1 8726

1987 4.9 --- 4.0 1.0 2.0 --- --- 51.9 3.2 8726

1988 17.0 --- 4.0 1.0 2.0 --- --- 51.9 3.2 8726

1989 41.6 --- 4.0 1.0 2.0 --- --- 51.9 3.2 8726

1990 207.1 --- 4.0 1.0 2.0 --- --- 51.9 3.2 8726

1991 208.0 --- 4.0 1.0 2.0 --- --- 51.9 3.2 8726

1992 205.9 --- 4.0 1.0 2.0 --- --- 51.9 3.2 8726

1993 167 --- 5 1 --- --- --- 52 3 8727

1994 170 --- 5 1 --- --- --- 52 3 8727

1995 170 --- 5 --- --- --- --- 52 3 8730

1996 170 --- 5 --- --- --- --- 52 3 8730

1997 171 --- 4 --- --- --- --- 52 3 8730

1998 175 --- 4 --- --- --- --- 52 3 8730

1999 175 --- --- --- --- --- --- 52 3 8730

2000 286 --- --- --- --- --- --- 52 3 8730

2001 286 --- --- --- --- --- --- 52 3 8730

2002 399 --- --- --- --- --- --- 52 3 8730

2003 299 --- --- --- --- --- --- 52 3 8730

2004 8 --- --- --- --- --- --- 52 3 8730

2005 7 --- --- --- --- --- --- 52 8785 ---

2006 4 --- --- --- --- --- --- --- 8968 ---

2007 4 --- --- --- --- --- --- --- 8968 ---

Source: DOE NMS database, Inventory Data, 1976-1998, Inventory Reports, 1974-1975, SS Material, 1975, Inventory 

Spreadsheet, 1975a, Inventory Spreadsheet, 1975b 

Notes: 

1

 Data are listed in table as reported. In later years (1993 forward), data were recorded on SRS ledgers as whole 

 numbers. Ledger data for 244-H were rounded off in the table. 

2

 Three hyphens (---) mean no data available. 

3

 0.0 kg means “< 0.099” quantities. 

Reviews of the SRS documents available to NIOSH have not revealed any meaningful thorium 

activities either in production or research during late 1972. Thorium materials were being stored 

rather than processed in 773A and other buildings, other than the very small quantity used as a 

surrogate in a glove box environment in 1972 (Personal Communication, 2012c; Thorium Impurity, 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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1972). The Alpha Materials Laboratory (in 773A) was placed in operation in 1973 and used thorium 

oxide as a surrogate for testing in glove boxes with the Pu-238 fuel form program (Pu-238 Fuel Form, 

Oct1972). In 1973, gram-quantity ThO2 (thorium surrogate) shards were used in 773A hot cells to 

test chemical vapor deposition of molybdenum (Pu-238 Fuel Form, Jul1973); conducting the work in 

hot cells reduced the potential thorium exposures to effectively none. The use of gram quantities of 

thorium as a surrogate continued in 1974. NIOSH has found no significant production and research 

activities involving thorium documented for 1974 and 1975. The thorium inventory in Building 235F 

(that housed the Hot Press Facility for making fuel-forms) was increased to about a kilogram (0.1 

mCi) for use as a surrogate (Pu-238 Fuel Form, Nov1972).

During 1976, nominal use of thorium as a surrogate likely continued with remaining thorium 

inventories being stored or shipped off site. In 1977, thorium contamination (gram quantities) of the 

neptunium product in Mark 16 fuel was successfully removed in H canyon. Thorium was also 

removed from dissolved plutonium scrap (Works Technical, Aug1977, pdf pp. 42, 55, 57-58). 

Thorium (oxalate powder prepared in 773A) was used as a surrogate for plutonium in testing of 

HB-line exchange columns (Works Technical, Aug1977, pdf p. 60). 

In 1977, SRS began work in 773-A as part of the Thorium Fuel Cycle Technology Program (TFCT 

Program) to develop processing technology for spent thorium fuel. The scope of the program 

included broad evaluations to “identify viable thorium/uranium recycle strategies; research and 

development programs to confirm the feasibility of the selected fuel cycle or cycles; a design 

integration study to identify development areas and safeguards and proliferation aspects; and the 

development and testing of key systems, equipment, and components” (SRL History Vol. I, 1984,

pdf, p. 292). Numerous thorium research and testing works were performed from 1977 until the 

TFCT program was terminated in 1980. In November 1980, SRL began stocking thorium nitrate 

crystals in the 773A “Chem Stores” for use in research and as surrogate material with an inventory of 

3.4 kg (0.34 mCi) (Accountability, 1976-1998; Inventory Write-off, 1979). The quantity shown in the 

material accountability ledgers had decreased to 2.9 kg (0.29 mCi) in March 1982, to 2.7 kg (0.27 

mCi) in May 1982, and to 1.2 kg (0.12 mCi) in August 1984. A notation denoted the latter entry as 

“inventory write-off.” A 1979 du Pont memo authorized thorium to be written off inventory as 

purchased from stores (Inventory Write-off, 1979). The inventory was further decreased to 1.0 kg 

(0.1 mCi) in February 1986 and remained at that amount until February 1991 when no further entries 

for thorium were listed for 773A “Chem Stores” (Accountability, 1976-1998).

SRL procured un-irradiated ThO2 and ThO2-UO2 fuel pellets for TFCT analysis (Monthly Status, 

Nov1977). SRS received shipments of spent fuel from SRE, Dresden and Elk River (Monthly Status, 

Nov1977) to support TFCT and the possible future expansion of the program. The fuels were stored 

in the RBOF. NIOSH has found no indication that actual research was conducted with the spent 

thorium fuel. The spent fuel was still being stored in the RBOF through 1998 (Accountability, 1976-

1998).

By 1978, nine cells in the high-level caves of 773A were prepared for the Alternate Fuel Cycle 

Technology Program of which TFCT was a part (SRL History Vol. IV, 1984). Four and one-half kg 

(0.45 mCi) of un-irradiated thorium oxide reflector pellets were received and used to test the effects of 

heat treatment on physical characteristics and dissolution (Monthly Status, Feb1978). This work, 

performed in the high-level caves, involved mechanical grinding of ThO2. Testing of a conceptual 

THOREX process was also evaluated using some of that same thorium oxide inventory (Monthly 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 10 of 45

Status, Feb1978). Testing of the conceptual THOREX flowsheets continued at SRL using irradiated 

thorium and uranium from spent fuels. SRL staff cut sections of irradiation Elk River fuel rods 

(ThO2/UO2 pellets clad in stainless steel) to test off-gas removal characteristics (Monthly Status, 

Apr1978). Laboratory analyses were performed to evaluate alternative chemical reagents in the 

dissolution of thorium oxide (Monthly Status, May1978). SRL continued the investigation of tritium 

removal and retention processes for thorium oxide fuels and the associated evaluation of other volatile 

radioisotopes. Four types of mechanically-blended ThO2-UO2 non-irradiated fuel pellets were 

received from General Electric of Canada for use in thorium oxide experiments (Monthly Status, 

Jul1978). SRL analysis of off-gas removal work continued with simulated voloxidation (heating fuel 

in a furnace under oxidizing conditions) of UO2 fuels in August 1978. Two additional types of ThO2-

UO2 non-irradiated fuel pellets were received from General Electric of Canada (Monthly Status, 

Sep1978). Work at SRL on these types of analyses continued through December 1978 (Monthly 

Report, Dec1978).

In order to test the Plutonium Experimental Facility (PEF), Building 235-F, where Pu-238 heat source 

development was to be done, SRL staff put about 300 grams thorium oxide into the process line in 

March 1978 to functionally test the facility. The cited reference stated that no health physics 

problems were encountered (Works Technical, Mar1978). By April 1978, all PEF equipment except 

for the hot press had been tested using ThO2 as a surrogate in glove boxes (Monthly Status, Apr1978).

In 1979, SRS and Hanford were planning and preparing a small number of 80% ThO2-20% UO2 rod 

assemblies for irradiation in FY 1980, and subsequent post-irradiation characterization (SRL History 

Vol. I., 1984). While thirty fuel rods (of varying thorium and uranium mixtures) were prepared at 

Hanford in 1979 and shipped to SRL, the irradiation was canceled in May 1980 (Program 

Termination, 1980; SRL History Vol. I., 1984).

At CMX, SRL performed long-term flow testing for six months using one of the Hanford fuel rods 

(100% ThO2) (Program Termination, 1980). Thirty rods were prepared by Hanford for SRL flow 

experiments; twelve of the rods were 100% ThO2 and the remainder of the lot was a mixture of 

uranium and thorium. Nine of twelve 100% ThO2 rods were used for the long-term flow test of the 

thoria assembly. During the program through May 1980, all thirty rods were stored in a cage in 773A, 

Room C 070 (Program Termination, 1980). At the end of the flow testing, the unneeded urania was 

transferred to Oak Ridge for reclamation of U-235. The unneeded thoria and thoria/urania materials 

were transferred to SRS waste (Thorium Irradiation, 1981).

SRL continued to use thorium in laboratory analyses in 1981 as a direct reagent and as a surrogate for 

other radionuclides (Bibliography, 1987, pdf pp. 179, 183; Thorium Oxylate, 1981). In 1982, SRL 

conducted bench-scale roasting and dissolution of reactor-grade ceramic fuel (mixtures of ThO2 and 

ThO2/ UO2). This work was done as part of the TFCT to define the specific process conditions and 

equipment required to reprocess the thorium fuel materials (Roasting, 1982).

Beginning in 1980 and continuing into 1981, SRL developed a process for fabrication of general 

purpose heat-source pellets as part of the Pu-238 Fuel Form Program (PuFF). Thorium was used as a 

surrogate for some of the work performed in hot cells in the PuFF Facility, located in Building 235-F. 

Pellet fabrication was tested in the Plutonium Experimental Facility (PEF). Thorium was also used as 

a doping agent of the iridium welding agents. SRS found that some of the pellets made in PuFF were 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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more extensively cracked than those made in PEF, and many were fractured after heat-treating. Pore 

surfaces around the cracks contained unusually high levels of thorium which was used as a doping 

agent. This work continued through 1995 (Cassini, 1995; Fabrication, 1982; Iridium, 1982; Pu-238 

Fuel Form, Jan-Mar1982; SRL History Vol. III, 1984, pdf pp. 118, 162-172).

SRS manufactured Pu-238 heat sources for the Galileo program through 1987 (average about 20 

days per year). As part of this work, SRS workers made numerous welds for about 500 GPHS 

capsules. Manufacturing work was performed in PuFF and PEF while some testing was 

performed by SRL in hot cells, which effectively eliminated the potential for radiological 

exposures. Most of this work did not involve the use of thorium other than its use as a surrogate 

for plutonium during process testing. The actual doping agent was made at ORNL (Cassini, 

2000).

NOTE: The thorium inventory in 773A steadily declined from 1981 (when the TFCT program 

ended) through 1987 with most of the thorium being sent to the burial grounds. Less than 5 kg 

(0.5 mCi) thorium remained in 773A during 1987. 

With the completion of the Galileo project, DOE moved the manufacture of Pu-238 capsules for the 

Cassini probe to Los Alamos Nation Laboratory (LANL) due to restructuring and changing missions; 

Pu-238 fuel was obtained from SRS, which along with ORNL and the Y-12 plant, were assigned by 

DOE to assist in further development and testing of welds and welding inspections (Cassini, 2000; 

Welds, 1998). In July 1989 and April 1990, SRS received significant quantity shipments of thorium 

from ORNL (0.25 mCi) and LANL (0.017 mCi), most likely for use in the effort to assist LANL’s 

production of the Cassini radioisotopic thermoelectric generators. All of the thorium was stored in 

Building 773A; the maximum quantity was 208 kg in February 1991. NIOSH lacks documentation on 

how much of this inventory was used for Cassini program development but, by December 1993, the 

thorium inventory had declined by 0.4 mCi and remained constant until February 1998 when the 

inventoried amount in Building 773A dropped to 0.4 mCi (4 kg). Using the inventory as the source, 

NIOSH concludes that SRS use of thorium in the Cassini program ended by December 1993, which is 

consistent with the SRS role of process development. A weld inspection report states that the 

development worked ended by April 15, 1993 (Welds, 1998).

Separately from the Cassini work, SRS used thoriated-welding electrodes. Health Physics was asked 

to evaluate the need for radiological controls for work with thoriated-welding electrodes (Thorium 

Welding, 1993). Health Physics reported that as long as the SRS welding safety procedure was 

followed no additional controls were required. However, Health Physics also stated that wastes from 

the tapering (grinding) of electrodes should be controlled to limit potential contamination, and that 

Health Physics should review each electrode-grinding location to ensure that adequate contaminationcontrol methods were to be used. Health Physics had to approve new or temporary electrode-grinding 

locations before they could be used for that purpose (Thorium Welding, 1993).

SRL continued to perform laboratory analyses and research using thorium through 1995 

(Bibliography, 1987, pdf pp. 25, 124, 180, 193; SROO, 1996; SRTC, 1995; Waste Glass, 1992; 

Immobilization, 1994). Some of this work involved testing methods for defense waste stabilization 

and immobilization (SROO, 1996; Waste Glass, 1992). Thorium was used as a surrogate for 

plutonium and for other radionuclides, and as an analyte of evaluation (Glass, 2003; Glass, 2006; 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 12 of 45

Neptunium, 1997; Thorium Analyte, 2000). Further work using thorium to test immobilization was 

done through 2010 (Glass, 2003; Waste Processing, 2005; Waste Processing, 2011).

Thorium Waste 

NIOSH also assessed the source term for thorium waste. Thorium wastes (which include spent fuel) 

were stored in underground and above-ground tanks, disposed of in waste trenches in the low-level 

(low-activity) burial ground, and stored in spent-fuel repositories. SRS waste management operations 

have distinguished among low-activity, intermediate-activity, and alpha-contaminated waste products. 

From 1952 through 1964, thorium and other alpha wastes were buried in plastic bags and cardboard 

boxes in earthen trenches and kept separate from other types of waste. Between 1965 and 1974, alpha 

wastes were sorted into two categories. Waste containing less than 0. 1 curie per package was buried 

un-encapsulated in separate trenches. Waste containing greater than 0.1 curie per package was buried 

in concrete containers. When greater than 0.1 curie waste would not fit into prefabricated concrete 

containers, such waste was encapsulated in concrete prior to burial (Disposal Facilities, 1997). 

Between 1952 and 1972, low-level solid and sludge wastes were buried in waste trenches in the Old 

Radioactive Waste Burial Ground (643-E) located in the burial ground complex (E Area). Liquid 

wastes and solvents were stored in some of the twenty-two underground thin-walled steel tanks 

located at E Area. A new burial grounds space, the Low-Level Radioactive Waste Disposal Facility 

(LLRWDF, Building 643-7E) was placed in operation in 1969 (Disposal Facilities, 1997). From 1974 

through 1994, alpha-waste-products containing greater than 10 nCi/g were stored on concrete pads. In 

1994, a new vault facility for defense waste processing was implemented; that facility is known as the 

E Area Vaults Disposal Facility, Building 643-26E (Disposal Facilities, 1997). The EAV Disposal 

Facility currently consists of one low-activity (LAW) vault, one intermediate-activity (IAW) vault, 

one long-lived waste storage building, one set of suspect soil trenches, and one Naval Reactor 

Component disposal area. Waste products disposed of in the suspect soil trenches include soil, debris, 

rubble, and wood. 

Two additional waste treatment and storage facilities were implemented in the 1990s. The Defense 

Waste Processing Facility (DWPF), located in S Area, is a vitrification plant that encapsulates liquid 

high-activity radioactive waste streams from the H Area Extended Sludge Processing facility (sludge 

from H Area waste tanks) and the In-Tank Precipitation facility (liquids from H Area waste tanks) in

glass. Waste glass continues to be blended and is stored in S Area awaiting shipment to a federal 

repository (Disposal Facilities, 1997).

The Saltstone Processing Facility (SPF) and the Saltstone Disposal Facility (SDF) are located in Z 

Area. Decontaminated salt solutions from the Effluent Treatment Facility and the In-Tank 

Precipitation facility are blended with cement, fly ash, and blast-furnace slag to produce saltstone 

grout. The resulting grout is pumped to concrete vaults in the SDF for disposal, where it solidifies 

into stable blocks (Disposal Facilities, 1997).

SRS performed decontamination and decommissioning (D&D) of some of the structures in which 

thorium had been used in 2004 and possibly other years through the end of the period under 

evaluation in this report. Concrete floors and pads were cleaned to remove contamination in 300-M 

buildings, TNX, and 400-D (Air Data, 2004).
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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The primary activities performed with thorium materials from October 1972 through 2007 are listed in 

Table 5-3. Locations where work was performed are assumed to be the same locations where the 

corresponding inventories were noted. The Total Inventory column shows the sum of the various 

location inventories that were available, not including wastes and spent-fuel sources. 

Table 5-3: Thorium Operations (non-waste)

(This table spans two pages)

Year Operation Locations Total Inventory 

(kg)

Activity 

(millicuries)

1972/3 storage, surrogate 773A, M Area (storage) 218 21.8

1974 storage, surrogate 773A, M Area (storage) 104 10.4

1975 storage, surrogate 773A, 235-F, M Area 

(storage)

155 15.5

1976 dissolution studies, storage, surrogate 773A, 235-F, M Area 

(storage)

135 13.5

1977 alternative fuels program, dissolution studies, 

storage, surrogate

773A, 235-F, M Area 

(storage)

116 11.6

1978 alternative fuels program, dissolution studies, 

storage, surrogate

773A, 235-F, M Area 

(storage)

92 9.2

1979 alternative fuels program, tritium studies, 

storage, surrogate

773A, 235-F, M Area 

(storage)

125 12.5

1980 alternative fuels program, tritium studies, 

storage, surrogate

773A, 235-F, M Area 

(storage)

157 15.7

1981 alternative fuels program, welding agent 

studies, storage, surrogate

773A, 235-F, M Area 

(storage)

142 14.2

1982 welding agent studies, storage, surrogate 773A, 235-F, M Area 

(storage)

117 11.7

1983 welding agent studies, storage, surrogate 773A, 235-F 39 3.9

1984 welding agent studies, storage, surrogate 773A, 235-F 29 2.9

1985 welding agent studies, storage, surrogate 773A, 235-F 25 2.5

1986 welding agent studies, storage, surrogate 773A, 235-F 12 1.2

1987 welding agent studies, storage, surrogate 773A, 235-F 12 1.2

1988 welding agent studies, storage, surrogate 773A, 235-F 24 2.4

1989 welding agent studies, storage, surrogate 773A, 235-F 49 4.9

1990 defense waste research, welding agent 

studies, storage, surrogate

773A, 235-F 214 21.4

1991 defense waste research, welding agent 

studies, storage, surrogate

773A, 235-F 215 21.5

1992 defense waste research, welding agent 

studies, storage, surrogate

773A, 235-F 213 21.3

1993 defense waste research, welding agent 

studies, storage, surrogate

773A, 235-F 173 17.3

1994 defense waste research, storage, surrogate 773A, 235-F 176 17.6

1995 defense waste research, storage, surrogate 773A, 235-F 175 17.5

1996 defense waste research, storage, surrogate 773A, 235-F 175 17.5

1997 defense waste research, storage, surrogate 773A, 235-F 175 17.5

1998 defense waste research, storage, surrogate 773A, 235-F 179 17.9
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Table 5-3: Thorium Operations (non-waste)

(This table spans two pages)

Year Operation Locations Total Inventory 

(kg)

Activity 

(millicuries)

1999 defense waste research, storage, surrogate 773A 175 17.5

2000 defense waste research, storage, surrogate 773A 286 28.6

2001 defense waste research, storage, surrogate 773A 286 28.6

2002 defense waste research, storage, surrogate 773A 399 39.9

2003 defense waste research, storage, surrogate, 

D&D

773A 299 29.9

2004 defense waste research, storage, surrogate, 

D&D

773A 8 0.8

2005 defense waste research, storage, surrogate 773A 7 0.7

2006 defense waste research, storage, surrogate 773A 4 0.4

2007 defense waste research, storage, surrogate 773A 4 0.4

Source: The above data were compiled from all inventory-related sources called out in this section of this Addendum 3 

evaluation. 

As of June 25, 1991, 194 kg (19.4 mCi) of thorium was buried in 643-E, 94.4 kg (9.4 mCi) of mixed 

wastes with thorium was buried in 643-28E, and 67.7 kg of thorium wastes was buried in the newer 

low-level facility, 963-G. Due to work performed by SRS to implement the E Area Vaults Disposal 

Facility, inventories of liquids and solids in the solvent tanks and other storage areas were performed 

as part of the SRS COBRA database. A version of this database was available by 1993 and reported 

that about 31,500 kg (3.15 curies) of thorium in liquids were stored in a combination of underground 

waste-storage tanks and ponds, pits, or cribs (Inventories, 1994). Originally stored in the underground 

tanks in 643-E, the liquid wastes were moved from 643-E to double-walled underground tanks (S-33 

through S-36) in H-area by 1997 (Treatment Plan, 1996; Treatment Plan, 1998).

Over the course of the period under evaluation by NIOSH, SRS stored spent fuel containing thorium 

from its reactors, and also received spent fuel containing thorium from other entities for potential use 

with the TFCT Program circa 1978. SRS spent-thorium fuels were stored in K and L basins while the 

externally-supplied fuel was stored in 244-H. Spent fuels were moved from 244-H to L-basin in 2003 

and 2004 (Spent Fuel, 2003; Spent Fuel, 2007). In 2006, a small quantity of spent fuel was prepared 

for shipment to the DOE WIPP facility and to Bettis Lab. In 2006, SRS also moved about 220 kg (22 

mCi) of aluminum-process irradiated thorium wastes to the L-basin. The maximum spent fuel in SRS 

inventories in 2007 was 8968 kg (897 mCi); more than 97% of that was the spent fuel from SRE, 

Dresden and Elk River. Inventory data of spent fuel containing thorium available for SRS is given in 

Table 5-2. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Gibbs compiled the inventories of thorium and other radionuclides through 1993 (Inventories, 1994). 

Using 1993 as a year of reference, the distribution of thorium by research and by waste or storage is 

shown in Figure 5-1. Only 173 kg, or 17.3 mCi, (from Table 5-3) was available for defense waste and 

welding research (or about 1 percent of the total SRS inventory that included 31,500 kg, or 3.15 curies 

of waste) (Inventories, 1994). 

Source: Inventories, 1994 

Figure 5-1: Distribution of Thorium at SRS by Use 

To demonstrate the amount of thorium in comparison to other radionuclides of concern at SRS, 

NIOSH calculated activities (curies) for ten radionuclides detailed in the Gibbs inventories 

(Inventories, 1994). The radionuclides and activities are given in Table 5-4. While the quantity of 

thorium by grams was one of highest amount by gram weight, thorium was the smallest by activity, or 

about 4 curies. By comparison, the activity amount of Pu-238 was calculated to be over 2,000,000 

curies. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Table 5-4: Radionuclide Activities

Isotope Inventory (g) SA (Ci/g) Activity (Ci)

Th-232 4.12E+07 1.10E-07 4.5

Np-237 6.90E+04 6.90E-04 47.6

U-233 1.34E+04 9.50E-03 126.8

Cf-252 2.50E-01 5.40E+02 135.1

Am-243 1.37E+04 1.90E-01 2597.3

Pu-239 5.13E+05 6.20E-02 31806.0

Am-241 7.23E+04 3.20E+00 231360.0

H-3 9.07E+01 9.70E+03 879693.0

Cm-244 1.12E+04 8.20E+01 915940.0

Pu-238 1.49E+05 1.70E+01 2533000.0

Source: Data values derived from reference: Inventories, 1994 

The activities listed above include waste materials. In 1994, there were only 17.6 millicuries of 

Th-232 non-waste (see Table 5-3). 

The activities stated in Table 5-4 were plotted in a bar chart, as shown in Figure 5-2. The activity of 

thorium (4.5 curies) is so small compared to activities of Cm-244 and Pu-238 that the bar for Th-232 

is not noticeable. The activities for Th-232, Np-237, U-233 and Am-243 are shown in the blow-up 

chart. Even in the blow-up, the activity of Th-232 compared to Np-232, U-233, Cf-252 and Am-243 

is still barely noticeable. Table 5-4 and Figure 5-2 demonstrate that the activity of Th-232, and its 

associated radiological hazards, were insignificant compared to other radionuclides used and stored at 

SRS. Almost all of the thorium present was waste or spent fuel being held. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Source: Bar chart values taken from Table 5-4.

Figure 5-2: Comparison of Activities of Various ROCs at SRS 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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6.0 Summary of Available Monitoring Data for the Class Evaluated 

by NIOSH 

The following statements apply to the thorium exposure analysis in this SEC Evaluation Report 

Addendum 3: 

Thorium inventories used in this evaluation were extracted SRS thorium inventory ledgers, SRS 

material accountability documents and in exports from the U. S. Department of Energy (DOE) 

Energy Material Balance Reports, 1998-2011, provided by DOE. 

Thorium personal air sampling data used in this evaluation came from official SRS 

documentation. 

All other documents and data used in this analysis were addressed in the original data pedigree 

analysis provided in SEC Petition Evaluation Report for Savannah River Site (NIOSH, 2008), 

Addendum to Savannah River Site (SEC-00103) Special Exposure Cohort Evaluation Report

(NIOSH, 2010), and Addendum 2 to Savannah River Site (SEC-00103) Special Exposure Cohort 

Evaluation Report (NIOSH 2011).

7.1 Evaluation of Bounding Internal Radiation Doses at Savannah River Site 

7.1.1.8 Thorium (Th-228, Th-232) 

Using Trivalent Bioassay as a Substitute for Thorium Bioassay 

In Determination of Actinides in Biological Samples with Bidentate Organophosphorus Extractant

(Actinides, 1970), the authors reported a new method of analyzing bioassay samples for trivalent 

radioactivity placed into use at SRS in 1970. The authors describe the topic as follows: 

A procedure for the determination of actinides was developed using the bidentate extractant 

dibutyl N, Ndiethylcarbamylphosphonate. Nine actinides were extracted from 12N HN03, backextracted to 2N HN03, and counted in a low-background alpha counter. A procedure was 

developed for sequential extraction of plutonium, neptunium, and uranium with tri-isooctylamine 

(TIOA), followed by extraction of thorium, americium, curium, berkelium, californium, and 

einsteinium with bidentate. Compared with previous methods, the new procedure is simpler, 

requires less analysis time, and gives better recovery. The recovery of Am-Cm-Cf from 250 ml of 

urine or 20 grams of feces was 90%. Sensitivity of analysis is 0.02 ± 0.01 d 1 min /sample. An 

alternative method of exchange of trivalent actinides as oxalate anion complexes with TIOA is 

also described. 

The authors state that all alpha-emitting actinides from thorium through einsteinium were extracted 

giving an excellent gross alpha analytical method. Data from the research showed that, in the analysis 

of americium, curium, and californium, any contaminating plutonium, neptunium, or uranium had to 

be removed. However, SRS found that thorium, berkelium, and einsteinium were not present in 

sufficient quantities to require separation. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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In light of the above information, NIOSH intends to use trivalent americium, curium, and californium 

data to bound potential internal doses received from exposure to thorium remaining at SRS after 

September 1972. NIOSH has already developed co-worker bioassay indices for trivalent 

radionuclides. NIOSH intends to model these data for thorium intakes which will provide bounding 

thorium doses for SRS workers potentially exposed to the low-activity levels of thorium. 

Exotic trivalent radionuclides bioassay results were obtained directly from SRS in the form of an 

electronic database for 1991 through 2007. For the period before 1991, SRS does not have an 

electronic database of bioassay results; however, the bioassay data in NOCTS for SRS employees 

were used to develop a representative database of co-worker bioassay data for the years before 1991 

(ORAUT-OTIB-0075). In addition, neptunium and americium urinalysis bioassay data were obtained 

from SRS laboratory notebooks (DuPont 1963–1970; DuPont 1969; DuPont 1969–1973; DuPont 

1970–1973, DuPont 1973–1978, DuPont 1973–1979, DuPont 1978–1983, DuPont 1979–1980, 

DuPont 1980–1981a, DuPont 1980–1981b, DuPont 1981–1986, DuPont 1986–1989). The data were 

transferred to a spreadsheet and subjected to quality assurance (QA) verification presented in A 

Comparison of Exotic Trivalent Radionuclide Coworker Models at the Savannah River Site (ORAUTRPRT-0055). 

Records showing per-unit-volume were adjusted to “per-1.5L” based on an assumed 1.5 L/d of urinary 

excretion. Volumes greater than 1 L were assumed to represent a full day’s voiding and were not 

adjusted. Volumes less than or equal to 1 L were normalized to 1.5 L. The data in the logbooks 

consisted of one or more corrected activity rate results for each urine sample in units of dpm per disc, 

depending on how many times a sample was counted, and on count-specific results in units of net 

dpm/1.5 L. The result in dpm/1.5 L for each count of a sample was generally recorded as an 

uncensored value (i.e., the calculated result was recorded regardless of its value). In contrast, the 

“reported” values were generally censored (i.e., results less than some level, typically the detection or 

reporting limit were reported as a “less than” result). Some dpm/1.5 L data that were less than zero 

were reported as zero. 

One year of results for each of three individuals in the pool of workers with pre-1991 monitoring data 

were excluded because they were not representative of co-worker inhalation intakes. These included 

an ingestion intake, a plutonium wound intake, and an incident that resulted in the highest-assigned 

intake of Cm-244 in SRS history, respectively. These incidents and intakes were characterized by an 

extremely high number of bioassay results, many of which were orders of magnitude higher than the 

bioassay data for other individuals and were considered unrepresentative of the routine potential 

exposure to thorium for an unmonitored worker. 

Chest Counting Information and Available Data 

SRS identified chest counting as the monitoring method of choice for thorium in the 1990 and 2000 

versions of the internal dosimetry technical basis documents (Internal Dosimetry, 1990; Internal 

Dosimetry, 2001). Th-232 is assumed to be the principal source of thorium intakes. NIOSH has not 

identified claimant results of in vivo analyses performed for thorium. However, the chest counter was 

calibrated to detect photons from the Th-232 progeny, including Th-228 and Pb-212. The chest 

counter, placed in operation in 1989, was configured with an array of four low-energy germanium 

detectors with thin carbide windows capable of measuring 15 to 400 keV photons (Internal Dosimetry, 

2001). That energy range spans the energies of interest for the Th-232 and its progeny. The 84.4 keV 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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gamma energy line of Th-228 and the 238.6 keV energy line of Pb-212 were not normally listed in the 

SRS chest-counter software analysis library. However, if statistically significant activity was present 

in the individual worker examinations, then photo peaks of those energies would have been listed on 

the chest count report as unidentified. These unidentified peaks would have been resolved and 

identified as thorium during the report review process. Depending on the skill of the SRS HP analyst, 

the possibility exists that the association of the unidentified peaks with Th-232 may have been missed. 

However, unresolved unidentified peaks would be listed on the in vivo count reports available to the 

NIOSH dose reconstructor for resolution when reviewing the individual’s dose records. 

The SRS Health Physics Program 

Although Section 7.2 is focused on bounding internal doses, NIOSH also evaluated the entire Health 

Physics program to assess the thoroughness of SRS efforts to minimize all radiation exposure at the 

site, as discussed below. 

From 1972 through 1990, work involving radioactive materials was controlled under Savannah River 

Plant Radiation and Contamination Control, DPSOP-40 (Radiation Control, 1959-1971; Radiation 

Control, 1978), and Radiation Hazards Technical Standards, DPST-RH (Technical Standards, 1974). 

Eight basic policy matters were addressed in DPSOP-40: 

1. Work in regulated areas 

2. Investigating radiation and contamination incidents 

3. Protective clothing 

4. Injury in regulated areas 

5. Disposal of contaminated waste 

6. Fires in regulated areas 

7. Radiation exposure control 

8. Internal radiation exposure control 

The procedure set cited above specified requirements for external and internal worker monitoring, 

surface and air contamination monitoring, protective clothing, transportation of radioactive materials,

and waste disposal of radioactive wastes. The listed bases for SRS personnel monitoring specified in

DPST-RH in 1974 were: published guides in Atomic Energy Commission Manual Chapters 0524 and 

0230; recommendations of the Federal Radiation Council (FRC), the National Committee on 

Radiation Protection (NCRP), and the International Commission on Radiological Protection (ICRP); 

and National Bureau of Standards Handbooks Numbers 42, 48, and 69. SRS implemented a set of 

procedures for its comprehensive radiation protection program in Health Protection Department 

Radiation Survey Procedures, DPSOP-193 (Survey Procedures, 1992).

SRS, in part, limited radiation exposures through the use of zones. SRS defined a Clean Zone as free 

of contamination as determined by smear contamination surveys. Radiological limits for Clean Zones 

are given in the SRS manual, Radiation and Contamination Control (Radiation Control, 1978). A 

Regulated Zone was a delineated area where radioactive materials were handled or where radiation or 

contamination exceeded natural background, but where the radiation level did not exceed 300 mrads 

or 50 mrems/hr and contamination was maintained below levels established by Health Physics. A 

Radiation Danger Zone was a delineated area where radiation or contamination levels exceeded limits 

for a Regulated Zone. (Radiation Control, 1978).
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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In 1990, area designations were changed to Clean Areas, Radiologically Controlled Areas, Radiation 

Areas, High Radiation Areas, Very High Radiation Areas, and Contamination Areas (Survey 

Procedures, 1992). Survey procedures provided the following definitions.

Radiologically Controlled Areas (RCAs) were established where radioactive materials or elevated 

radiation rates might be encountered. RCAs were generally maintained clean (no detectable 

contamination). In areas that were not continuously occupied by personnel, "elevated radiation 

rates" were typically defined as 2 mrem/hr or greater. In areas continuously occupied by 

personnel, any radiation rate above background was considered an "elevated radiation rate." 

Radiation Areas were established where personnel could receive a dose equivalent of 5 mrem (but 

less than 100 mrem) in one hour at 30 centimeters from the radiation source, or any surface 

through which the radiation emanates. Typically, Radiation Areas were established based on a 

dose equivalent rate, i.e., 5 mrem/hr (but less than 100 mrem/hr) at 30 centimeters. 

High Radiation Areas were established where personnel could receive a dose equivalent of 100 

mrem (but less than 5 rem) in one hour at 30 centimeters from the radiation source, or any surface 

through which the radiation emanates. Typically, High Radiation Areas were established based on 

a dose equivalent rate, i.e., 100 mrem/hr (but less than 5 rem/hr) at 30 centimeters. 

Very High Radiation Areas were established where personnel might receive a dose equivalent of 

5 rem or greater in one hour at 30 centimeters from the radiation source or the surface from which 

the radiation emanates. Typically, Very High Radiation Areas were established for dose 

equivalent rates of 5 rem/hr or greater at 30 centimeters. 

Contamination Areas were established where surface contamination levels exceeded the limits of 

DOE Order 5480.11.

Airborne Radioactivity Areas were established where airborne concentrations of radioactive 

material exceeded ten percent of the Derived Air Concentration (DAC), which was 7 x 10-13

μCi/cc for Th-232 in 1990. 

SRS implemented a new radiation control manual in 1991, Radiological Control Manual (WSRC-5Q) 

to comply with DOE Order 5480.11, Radiation Protection for Occupational Workers (December 21, 

1988 and Change 1, July 20, 1989), and updated it for the DOE Radiological Control Manual (1992), 

DOE N 5480.6 (Radiological Control, 1992), DOE Radiological Control Manual (1994), DOE/EH0256T (Radiological Control, 1994), and Occupational Radiation Protection, Final Rule (10 C.F.R. 

pt. 835). Health physics procedures provided in DPSOP-193 were updated to reflect this revised DOE 

guidance. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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SRS maintained the practice of maintaining radiation exposures as low as reasonably achievable 

(ALARA) (ALAP, 1975; ALARA, 1992; ALARA Assessment, 1993; ALARA Goals, 1992). 

DPSOP-40 stated the policy as follows: 

It is plant policy to limit radiation exposure to employees to the lowest reasonably achievable 

level. Guides furnished in references listed above shall not be considered as desirable dose 

commitments. We should operate as far below these guides as reasonably achievable. 

With implementation of 10 C.F.R. pt. 835 in 1995, SRS implemented the Radiological Guide for 

Planners (Radiological Guide, 2000). The document was developed to provide consistent guidance to 

SRS personnel responsible for planning tasks involving radiological work. It documented 

responsibilities for work planners, supervisors, and health physics staff with the goal of maintaining 

all radiation exposures as low as reasonably achievable by identifying hazards and radionuclides, and 

required work steps, protective clothing, and monitoring. A flow chart of the planning process is 

provided in the guide. 

Although SRS administered a thorough radiation and contamination control program, which included 

worker training, material spills and other incidents involving radiation did occur (Incidents, 1973-

1977). While no Special Hazards incidents involving the use of thorium have been identified by 

NIOSH, they have identified incidents that occurred in buildings known to have had thorium 

inventories during the period under evaluation for this Addendum 3 (Special Hazards, 1962-1974; 

Special Hazards, 1974-1983; Special Hazards, 1983-1989).

Facility design was an important aspect of exposure control used at SRS (Operational Health Physics, 

1980). The adequacy of shielding was frequently reviewed. Ventilation was designed to provide air 

flow from clean areas into regulated areas. New facility designs or plans for modifications to existing 

facilities were reviewed by HP to assure that adequate consideration had been given to shielding, 

ventilation, containment, personnel traffic patterns, stationary radiation monitors, and effluent 

controls. 

Routine radiation and contamination surveys played important parts in SRS’s assessment of the 

radiation and contamination program effectiveness. Survey frequency depended on the potential 

associated with the specified work area. Work in some areas required constant surveillance while 

work in some other areas only required occasional monitoring. The SRS radiation control manuals 

and procedures gave limits and action levels for fixed and surface contamination, air monitoring 

(including limits for Th-232), and external and internal monitoring of workers; they also described 

measures and controls to limit radiation exposure. Health Physics maintained a rigorous 

contamination survey program. In addition to monitoring areas for contamination, Health Physics 

surveyed workers, laundry, and tools as these were moved throughout the site. Health Physics 

monitored waste as it moved between plant locations and off site. Health Physics radiation limits for 

tools, laundry, and off-plant shipments are listed in Table 7-1. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Table 7-1: Health Physics Radiation Limits for Tools, Laundry, and Off-plant Shipments

Material Type Radiation Limit

Tools: Transferable: Fixed:

- alpha < 500 dpm/ft2 As low as practical

- beta-gamma < 1000 cpm/ft210 mrad/hr at 3 inches

Laundry: Pre-laundry: Post-laundry:

- alpha < 20000 dpm/100 cm2< 1000 dpm/100 cm2

- beta-gamma exposure rate <12 mrad/hr at 3 inches <12 mrad/hr/100 cm2

Off-plant Shipments: Transferable: Fixed:

- alpha < 220 dpm/100 cm2< 220 dpm/100 cm2

- beta-gamma

< 2200 dpm/100 cm2

(except exclusive use) < 2200 dpm/100 cm2

- beta-gamma exposure rate < 0.5 0 mrem/hr at surface

 Source: Radiation Control, 1978 

There was some potential for exposure to small amounts of unencapsulated thorium in SRL (773A 

and TNX), M area, and at 235-F where thorium was used as a stand-in, for sample analysis, and for 

testing of a doping agent for welding of heat sources. As discussed in Addendum 2 (NIOSH, 2011),

and as guided by the SRS radiation and contamination control manuals (Radiation Control, 1959-

1971; Radiation Control, 1978), Health Physics actively monitored locations where thorium 

operations were conducted during the period under review for that evaluation (January 1, 1953 

through December 31, 1972). Health Physics continued to monitor workers and locations for 

radioactive contamination and exposures through 2007. NIOSH captured a sample of the 

contamination survey sheets from survey logs on file at SRS that were completed in areas with 

thorium inventory. A listing of surveys by location and year are provided in Table 7-2. SRS also 

surveyed spent fuel casks and operations routinely at 244-H; sample surveys have been obtained by 

NIOSH (Survey Logs, 1976; Cask Surveys, 1977; Radiation Surveys, 1977).
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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Table 7-2: Samples of Contamination Surveys Available by 

Location and Year

Location Year SRDB Ref ID

M Area 1972 113925

M Area 1973 113836

M Area 1973 113934

M Area 1973 113956

235-F 1974 114646

M Area 1974 113920

235-F 1975 114644

773-A 1975 113930

M Area 1975 113920

M Area 1975 113922

773-A 1980 113886

773-A 1980 113985

773-A 1980 113986

TNX 1980 116641

773-A 1981 113960

773-A 1981 113863

773-A 1981 113987

773-A 1986 116776

773-A 1986 116778

773-A 1987 116774

773-A 1987 116778

TNX 1987 116681

TNX 1987 116681

773-A 1988 113978

SRS Health Physics maintained an air sampling program that used routine fixed-area samplers, 

portable samplers, and personal air samplers. Stationary continuous air monitoring systems (CAMs)

were installed in many facilities to give warning of airborne radioactivity. The Kanne ionization 

chamber served to detect gaseous radioactivity while low-volume or high-volume CAMS provided

early warning of increasing airborne particulate radioactivity. NIOSH captured some SRS air 

monitoring data for the period under evaluation to support the statement that routine, portable 

(special) and personal air sampling were performed. NIOSH captured a sample of the air monitoring 

data on file at SRS that were taken in areas with thorium inventory. While no specific thorium air 

monitoring data has been identified, a listing of air monitoring surveys by location and year are 

provided in Table 7-3. To prevent significant intake of radionuclides, and thus prevent internal 

radiation exposure, respiratory protection was frequently prescribed as a precautionary measure. 

Filter-type respirators used at SRS were NIOSH-approved. SRS required respiratory protection 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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whenever the air concentration exceeded ten percent of the radioactivity concentration guide (RCG) 

based on air sampling data. 

Table 7-3: Samples of Air Monitoring Surveys Available by Location and Year

Location Year Type SRDB Ref ID

235-F 1972 Routine 114645

235-F 1972 Special 114645

244-F 1972 Routine 114712

235-F 1973 Routine 114647

235-F 1973 Special 114647

244-F 1973 Routine 114712

235-F 1974 Routine 114648

235-F 1974 Special 114648

244-F 1974 Routine 114712

235-F 1975 Routine 114643

235-F 1975 Special 114643

244-F 1975 Routine 114712

321-M 1975 Special 113971

244-F 1976 Routine 114712

244-F 1977 Routine 114712

773-A 1984 Routine 108690

773-A 1985 Routine 108643

773-A 1986 Routine 108626

773-A 1987 Routine 116652

773-A 1987 Routine 108585

773-A 1988 Routine 116652

In 1992, with the implementation of the DOE Radiological Control Manual (1992), DOE N 5480.6, 

the SRS dosimetry requirement changed to “personnel dosimetry shall be required for personnel who 

are expected to receive an annual external whole body dose greater than 100 mrem” (Radiological 

Control, 1992). In addition, self-reading dosimeters were required anytime an individual worked in a 

field of 25 mR/hr or greater. NIOSH analyzed EEOICPA claimant data reported by DOE for SRS to 

determine the extent of both external and internal monitoring of claimants during the period from 

October 1972 through December 1998. Data for claimants who worked from October 1992 through 

December 1998 were included in the evaluation (22 claims). Twenty-one of the claimants were 

monitored by bioassay and for external dose by TLD, although some of the claimants were not 

monitored each year for external dose. Ten of the 22 claimants were monitored by TLD each year, 

1972 through 1998. All claimants who self-reported having been construction workers were 

monitored for external and internal exposures during the years employed in a construction craft. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 26 of 45

Examination of data for claimants with some missing periods of monitoring showed that they were 

likely not exposed to sustained radiation exposure at a rate greater than one mrem/hr, or intermittent 

exposures that would accumulate to greater than 25 mrem in one week. Nonetheless, NIOSH has 

collected all external dosimeter data on SRS co-workers in the HPAREH database. For the period 

1973 through 1998, the number of workers monitored by TLD for at least one cycle (quarter) for the 

specified year is shown in Table 7-4. NIOSH has derived co-worker penetrating and shallow doses 

for unmonitored workers (ORAUT-OTIB-0023). With respect to internal radionuclide monitoring, 

NIOSH has obtained thousands of bioassay results from claimant records in NOCTS and from data 

obtained directly from SRS. 

Table 7-4: Workers Monitored by TLD for at Least One Cycle (Quarter)

Year No. Monitored Year No. Monitored

1973 3534 1986 10949

1974 3809 1987 11700

1975 4329 1988 12438

1976 4784 1989 13674

1977 5057 1990 11350

1978 5760 1991 19908

1979 6286 1992 18734

1980 6571 1993 16077

1981 6764 1994 12587

1982 6515 1995 12450

1983 7393 1996 11400

1984 7074 1997 11069

1985 8323 1998 10484

All personnel entering areas in which they would have received a sustained radiation exposure at a 

rate greater than one mrem/hr, or intermittent exposures that would accumulate to greater than 25 

mrem in one week, were required to wear a thermoluminescent dosimeter (TLD) badge somewhere 

between the waist and neck line (Technical Standards, 1974). All regulated areas and radiation zones 

were included in that requirement. Furthermore, dosimeters were assigned through 1988 based on 

work area. NIOSH discussed this SRS monitoring tenet in Addendum 2 of the SRS ER (NIOSH, 

2011). 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 27 of 45

NIOSH has assembled a depth of documents and data that demonstrate the effectiveness of the SRS 

Health Physics monitoring programs and the data that may be used for reconstructing doses received 

from external and internal exposures to most radionuclides used or stored at the site. A matrix of 

these data is presented in Table 7-5. 

Table 7-5: Available SRS Health Physics Program Documentation and Data

(This table spans two pages)

Year

Health 

Physics 

Report SRS

Health 

Physics 

Report 

SRL

Personnel 

External 

Monitoring

Co-worker 

External 

Doses

Bioassay 

Monitoring 

Data

In vivo Data

Co-worker 

Internal 

Doses

1973 Yes No HPAREH Yes Claim files Claim files Yes

1974 Yes No HPAREH Yes Claim files Claim files Yes

1975 Yes No HPAREH Yes Claim files Claim files Yes

1976 Yes No HPAREH Yes Claim files Claim files Yes

1977 Yes Yes HPAREH Yes Claim files Claim files Yes

1978 Yes No HPAREH Yes Claim files Claim files Yes

1979 Yes Yes HPAREH Yes Claim files Claim files Yes

1980 Yes Yes HPAREH Yes Claim files Claim files Yes

1981 Yes Yes HPAREH Yes Claim files Claim files Yes

1982 Yes Yes HPAREH Yes Claim files Claim files Yes

1983 Yes Yes HPAREH Yes Claim files Claim files Yes

1984 Yes Yes HPAREH Yes Claim files Claim files Yes

1985 Yes Yes HPAREH Yes Claim files Claim files Yes

1986 No Yes HPAREH Yes Claim files Claim files Yes

1987 No Yes HPAREH Yes Claim files Claim files Yes

1988 Yes Yes HPAREH Yes Claim files Claim files Yes

1989 No No HPAREH Yes Claim files Claim files Yes

1990 No No HPAREH Yes Claim files Claim files Yes

1991 No No HPAREH Yes SRS data file SRS data file Yes

1992 No No HPAREH Yes SRS data file SRS data file Yes

1993 Yes Yes HPAREH Yes SRS data file SRS data file Yes

1994 No No HPAREH Yes SRS data file SRS data file Yes

1995 No No HPAREH Yes SRS data file SRS data file Yes

1996 No No HPAREH Yes SRS data file SRS data file Yes
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 28 of 45

Table 7-5: Available SRS Health Physics Program Documentation and Data

(This table spans two pages)

Year

Health 

Physics 

Report SRS

Health 

Physics 

Report 

SRL

Personnel 

External 

Monitoring

Co-worker 

External 

Doses

Bioassay 

Monitoring 

Data

In vivo Data

Co-worker 

Internal 

Doses

1997 No No HPAREH Yes SRS data file SRS data file Yes

1998 No No HPAREH Yes SRS data file SRS data file Yes

Bounding Thorium Doses Using Trivalent Bioassay Data (1973 – 1994) 

For the purpose of NIOSH’s evaluation of the SRS class in this report, bioassay data were analyzed by 

year or multi-year span, depending on the amount of data available for each radionuclide during a 

given period as well as the expected biokinetics of each radionuclide. A lognormal distribution was 

assumed. After the data were log-transformed, the 50th and 84th percentiles were determined for each 

period using the method described in ORAUT-OTIB-0019. “Zero” bioassay results, which represent 

a large fraction of the data for every radionuclide, were also retained in the analysis to rank the results 

from lowest to highest. 

ORAUT-OTIB-0075 presents the method of treating a claimant dataset as a simple random sample 

from the population of all monitored workers. One potential conundrum posed by using a claimant 

dataset is that workers involved in incidents usually submit more samples than workers who submit 

only routine (non-incident-related) samples. This is problematic because a small number of workers 

involved in incidents can dominate the claimant sample in a given year through the sheer number of 

samples submitted and because the samples in the dataset are no longer independent of each other. At 

SRS, the small population of workers subject to bioassay testing results in a similar problem. To 

compensate for the unequal number of samples submitted by workers, the “one person, one sample” 

(OPOS) technique is used, in which only one result is used for each person for each radionuclide for a 

given year. The OPOS statistic is calculated using the maximum possible mean methodology 

(ORAUT-RPRT-0053).

Bioassay techniques for americium, curium, and californium varied as a function of time at SRS. Of 

the techniques used, the most significant feature is that differentiation among americium, curium, and 

californium was not possible until the use of alpha spectroscopy began in 1995. Before 1995, 

regardless of the notation placed in an individual’s bioassay record, the analytical technique was the 

same. As discussed in Section 7.1.1.8, the analytical procedure in use for americium, curium, and 

californium would also extract thorium, and any thorium in the urine sample would be included in the 

reported result. Therefore, the actinide results are assessed four separate times, once each for 

americium, curium, californium, and thorium. The nuclide resulting in the largest dose can be used to 

bound a given case. Beginning in 1995, isotopic analysis in the form of alpha spectrometry was 

performed on the urine samples and thorium was not specifically monitored; therefore, this dose 

reconstruction approach based on bioassay data cannot be used to bound thorium intakes beyond 

1994.
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 29 of 45

Statistical analysis of the trivalent dataset was performed in accordance with ORAUT-RPRT-0053 to 

obtain geometric means of the bioassay excretion results for each year. The All Monitored Workers 

(AMW) dataset discussed in Section 3 of ORAUT-RPRT-0053 was used for thorium determination 

through 1989 but the same analysis was applied to all data through 1994. Results for thorium were 

considered equal to the trivalent bioassay results. These geometric means were then used to model a 

chronic intake of Th-232 from 1973 through 1994 using IMBA Expert-ORAU. The source data are 

given in Table 7-6. Each bioassay geometric mean was considered to have been collected on July 1 of 

the respective year. 

Table 7-6: Annual Thorium Bioassay Results

Year GM (dpm/day) GSD Date

1973 8.19E-03 7.78E+00 7/1/1973

1974 9.32E-03 1.03E+01 7/1/1974

1975 1.02E-02 7.38E+00 7/1/1975

1976 1.30E-02 6.27E+00 7/1/1976

1977 3.73E-03 1.12E+01 7/1/1977

1978 2.58E-02 9.96E+00 7/1/1978

1979 2.49E-02 1.09E+01 7/1/1979

1980 9.55E-03 7.36E+00 7/1/1980

1981 2.84E-03 5.48E+00 7/1/1981

1982 2.08E-03 3.91E+00 7/1/1982

1983 5.39E-03 8.39E+00 7/1/1983

1984 6.25E-03 1.10E+01 7/1/1984

1985 1.19E-02 1.01E+01 7/1/1985

1986 3.52E-03 1.14E+01 7/1/1986

1987 1.75E-02 5.05E+00 7/1/1987

1988 1.85E-02 7.65E+00 7/1/1988

1991 1.80E-02 3.16E+00 7/1/1991

1992 2.32E-02 2.62E+00 7/1/1992

1993 1.56E-02 4.15E+00 7/1/1993

1994 3.15E-02 3.02E+00 7/1/1994

Chronic intakes of 0.599 pCi/day (1.33 dpm/day) for Type M material and 8.06 pCi/day (17.89 

dpm/day) for Type S material were derived from the fits of yearly bioassay. The NIOSH CADW tool 

was then used to estimate doses to lungs and to bone for a chronic intake from 1973 through 1994, 

with cancer diagnosis on December 31, 2007, as shown in Table 7-7. Equal activities of Th-228 and 

Ra-228 were used in the dose modeling, with each assigned to the same material type as that of 

Th-232. With Type M material, the larger dose over this 34-year period would be delivered to the 

bone (19.09 rem). For Type S material, the largest dose would be delivered to the lung (72.18 rem). 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 30 of 45

Table 7-7: Estimated Organ Dose from Thorium (Intake: 1973-1994)

Material Type Lung Dose

(rem)

Bone Dose

(rem)

Type M 2.60 18.66

Type S 79.92 23.34

Bounding Thorium Doses Using Chest Count Data (1995 – 2007) 

The NIOSH approach for bounding post-1994 thorium dose at SRS employs the use of chest count 

data. In 2000, a chest-count MDA of 0.15 nCi was given for Th-232 (Pb-212 in equilibrium with 

Th-232) and an MDA of 3.2 nCi was given for the 84.4 keV peak of Th-228 (Internal Dosimetry, 

2001). Although this information was given for the year 2000, the same chest-counting system had 

been used since 1990. Therefore, the MDA information applies to the post-1994 years for this 

bounding analysis. Using the Th-232 peak region to derive an intake of Th-232 assumes secular 

equilibrium of Th-232 with all progeny. Information given in Table 5-1 shows that the last thorium 

separation was performed in1969. Any remaining thorium would have been in equilibrium by 1995 

(Th-228 reaches equilibrium with its progeny in less than one year). 

NIOSH applied this approach of assumed equilibrium by using the Pb-212 MDA to derive an intake 

rate for Th-232 for the period from January 1, 1995 through December 31, 2007. Corrections for 

chest wall thickness would not be significant for the gamma energies associated with Pb-212 and Th228. NIOSH used IMBA to calculate a chronic intake rate for Th-232 assuming a chest count 

measurement obtained on December 31, 2007 with a result of 0.15 nCi. The data were modeled for 

both Type M and Type S materials. The derived chronic intake rate for 1995 through 2007 was 22.67 

pCi/day for Type M and 3.18 pCi/day for Type S. The NIOSH CADW tool was then used to estimate 

doses to lungs and to bone for a chronic intake from 1995 through 2007 with a cancer diagnosis on 

December 31, 2007, as shown in Table 7-8. Equal activities of Th-228 and Ra-228 were used in the 

dose modeling. 

Table 7-8: Estimated Organ Dose from Thorium (1995-2007)

Material Type Lung Dose

(rem)

Bone Dose

(rem)

Type M 56.94 174.3

Type S 15.40 1.75
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 31 of 45

Feasibility of Bounding Thorium Doses 

As demonstrated in this Addendum 3, SRS implemented a thorough radiological safety program that 

managed hazards from an array of radionuclides. NIOSH has shown that SRS thorium inventories 

were much smaller than inventories of other radionuclides. Nonetheless, SRS Health Physics did 

incorporate monitoring capabilities that would detect thorium for use as needed (e.g., when 

decontamination activities warranted). NIOSH concludes that doses received from potential thorium 

exposures can be bounded using in vitro and in vivo bioassay data and the reconstruction methods 

presented in this section. Based on its analysis, NIOSH believes these methods and approaches 

support its ability to provide sufficiently accurate internal thorium dose reconstructions for SRS 

workers during the evaluated period. 

NIOSH would assign monitored and unmonitored dose to SRS workers using a combination of 

available monitoring data and analysis of the trivalent actinide bioassay data for 1973 through 1994. 

Because the analytical method would have included americium, curium, californium, and thorium, the 

nuclide resulting in the largest dose can be assigned to bound the internal dose. The application of 

this method for unmonitored workers for this period would be applied to SRS workers who had the 

potential for exposures to thorium. 

For 1995 through 2007, chest-count data would be used to support bounding thorium dose. Based on 

its analysis of the available radiological program documentation, NIOSH has concluded that by that 

point in the SRS bioassay monitoring program, those who should have been monitored were 

monitored. Therefore, the dose for personnel who have confirmed work in thorium areas or exposure 

to thorium can be bounded by assigning thorium internal doses based on any positive chest-count data 

and assigning missed internal thorium dose as discussed in this ER (i.e., using existing dose 

reconstruction methods). The dose for those personnel who may have worked in a thorium area or 

may have been exposed to thorium can be bounded by assigning missed internal thorium dose, as 

discussed in this ER as unmonitored dose. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 32 of 45

7.6 Summary of Feasibility Findings for Petition SEC-00103

This report addendum evaluates the feasibility for completing dose reconstructions for employees at 

the Savannah River Site from October 1, 1972 through December 31, 2007. NIOSH found that the 

available monitoring records, process descriptions and source term data available are sufficient to 

complete dose reconstructions for the evaluated class of employees. 

Table 7-9 summarizes the results of the feasibility findings at the Savannah River Site for each 

exposure source during the time period October 1, 1972 through December 31, 2007. 

Table 7-9: Summary of Feasibility Findings for SEC-00103

October 1, 1972 through December 31, 2007

Source of Exposure Reconstruction Feasible Reconstruction Not Feasible

Internal X

 - Th X

External X

 - Gamma X

 - Beta X

 - Neutron X

 - Occupational Medical X-ray X

8.0 Evaluation of Health Endangerment for Petition SEC-00103 

The health endangerment determination for the class of employees covered by this evaluation report is 

governed by both EEOICPA and 42 C.F.R. § 83.13(c)(3). Under these requirements, if it is not 

feasible to estimate with sufficient accuracy radiation doses for members of the class, NIOSH must 

also determine that there is a reasonable likelihood that such radiation doses may have endangered the 

health of members of the class. Section 83.13 requires NIOSH to assume that any duration of 

unprotected exposure may have endangered the health of members of a class when it has been 

established that the class may have been exposed to radiation during a discrete incident likely to have 

involved levels of exposure similarly high to those occurring during nuclear criticality incidents. If 

the occurrence of such an exceptionally high-level exposure has not been established, then NIOSH is 

required to specify that health was endangered for those workers who were employed for a number of 

work days aggregating at least 250 work days within the parameters established for the class or in 

combination with work days within the parameters established for one or more other classes of 

employees in the SEC. 

NIOSH’s evaluation determined that it is feasible to estimate radiation dose for members of the 

NIOSH-evaluated class with sufficient accuracy based on the sum of information available from 

available resources. Therefore, a health endangerment determination is not required. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 33 of 45

9.0 Class Conclusion for Petition SEC-00103 

Based on its full research of the class under evaluation, NIOSH found no part of said class for which it 

cannot estimate radiation doses with sufficient accuracy. This class includes all workers who worked 

in any thorium area at the Savannah River Site from October 1, 1972 through December 31, 2007. 

NIOSH has carefully reviewed all material sent in by the petitioner, including the specific assertions 

stated in the petition, and has responded herein (see Section 7.4). NIOSH has also reviewed available 

technical resources and many other references, including the Site Research Database (SRDB), for 

information relevant to SEC-00103. In addition, NIOSH reviewed its NOCTS dose reconstruction 

database to identify EEOICPA-related dose reconstructions that might provide information relevant to 

the petition evaluation. 

These actions are based on existing, approved NIOSH processes used in dose reconstruction for 

claims under EEOICPA. NIOSH’s guiding principle in conducting these dose reconstructions is to 

ensure that the assumptions used are fair, consistent, and well-grounded in the best available science. 

Simultaneously, uncertainties in the science and data must be handled to the advantage, rather than to 

the detriment, of the petitioners. When adequate personal dose monitoring information is not 

available, or is very limited, NIOSH may use the highest reasonably possible radiation dose, based on 

reliable science, documented experience, and relevant data to determine the feasibility of 

reconstructing the dose of an SEC petition class. NIOSH contends that it has complied with these 

standards of performance in determining the feasibility or infeasibility of reconstructing dose for the 

class under evaluation. 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 34 of 45

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SEC-00103 Addendum 3 11-20-12 Savannah River Site 

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10.0 References 

10 C.F.R. pt. 835, Occupational Radiation Protection; Final Rule; Federal Register/Vol. 63, No. 

213/Wednesday, November 4, 1998; SRDB Ref ID: 19390 

42 C.F.R. pt. 81, Guidelines for Determining the Probability of Causation Under the Energy 

Employees Occupational Illness Compensation Program Act of 2000; Final Rule, Federal 

Register/Vol. 67, No. 85/Thursday, p. 22,296; May 2, 2002; SRDB Ref ID: 19391

42 C.F.R. pt. 82, Methods for Radiation Dose Reconstruction Under the Energy Employees 

Occupational Illness Compensation Program Act of 2000; Final Rule; May 2, 2002; SRDB Ref ID: 

19392

42 C.F.R. pt. 83, Procedures for Designating Classes of Employees as Members of the Special 

Exposure Cohort Under the Energy Employees Occupational Illness Compensation Program Act of 

2000; Final Rule; May 28, 2004; SRDB Ref ID: 22001 

42 U.S.C. §§ 7384-7385 [EEOICPA], Energy Employees Occupational Illness Compensation 

Program Act of 2000, as amended 

Accountability, 1976-1998, Thorium and U-233 Accountability Data 1976-1998, Savannah River 

Site; various locations and years from 1976 to 1998; SRDB Ref ID: 110849 

Actinides, 1970, Determination of Actinides in Biological Samples with Bidentate Organophosphorus 

Extractant, F. E. Butler and R. M. Hall; E. I. du Pont de Nemours & Company, Svannah River 

Laboratory; Analytical Chemistry, Vol. 42, No. 9, August 1970; SRDB Ref ID: 119808 

Air Data, 2004, Specific Thorium Personal Air Sampling (PAS) Data Sheets for 2004, Savannah River 

Site; ESH-RPS-2004-00196; various dates in 2004; SRDB Ref ID: 105000 

ALAP, 1975, Control of Radiation Exposures for the AMF, Technical Division, Savannah River 

Laboratory; May 9, 1975; SRDB Ref ID: 114669, pdf p. 18 

ALARA, 1992, Savannah River Site ALARA Program Appraisals, J. R. Johnson; Westinghouse 

Savannah River Company; WSRC-MS-92-135; April 21, 1992; SRDB Ref ID: 112092 

ALARA Assessment, 1993, SRS ALARA Assessment, June 28-July 2, 1993; Defense Nuclear 

Facilities Safety Board; September 21, 1993; SRDB Ref ID: 48950 

ALARA Goals, 1992, Savannah River Site 1992 ALARA Goals, L. S. Smith; Westinghouse Savannah 

River Company; WSRC-MS-92-137; April 21, 1992; SRDB Ref ID: 112096 

Bibliography, 1987, Savannah River Scientific and Technical Documents, 1975-1986, Office of 

Scientific and Technical Information, U.S. Department of Energy; DP-929-A1; August 1987; SRDB 

Ref ID: 49392 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 36 of 45

Cask Surveys, 1977, HIFR Shipment Cask Surveys, survey log sheets for Building 224H, Savannah 

River Site; May-July 1977; SRDB Ref ID: 114691 

Cassini, 1995, Welding Isotopic Heat Sources for the Cassini Mission to Saturn, AWS paper 

presented by E. A. Franco-Ferreira (Westinghouse Savannah River Company) and T. G. George (Los 

Alamos National Laboratory); WSRC-MS-93-316p Conf-9404233-1; March 1995; SRDB Ref ID: 

112068

Cassini, 2000, Characterization of Cassini GPHS Fueled Clad Production Girth Welds, E. A. FrancoFerreira, et al; Engineering Technology Division, Oak Ridge National Laboratory; ORNL/TM2000/84; March 2000; SRDB Ref ID: 116412 

DCAS-PR-004, Internal Procedures for the Evaluation of Special Exposure Cohort Petitions, Rev. 1, 

National Institute for Occupational Safety and Health (NIOSH); Cincinnati, Ohio; April 15, 2011; 

SRDB Ref ID: 94768

Disposal Facilities, 1997, Composite Analysis: E-Area Vaults and Sandstone Disposal Facilities, 

Westinghouse Savannah River Company; WSRC-RP-97-311; September 1997; SRDB Ref ID: 

118093

DuPont, 1969-1973, Pu-Am, Cm Record Book, 5-14-1969 thru 10-19-1973, E. I. du Pont de Nemours 

and Company, Savannah River Plant; 1969–1973; SRDB Ref ID: 53271 

DuPont, 1970-1973, Am., Cm Record Book, 5-27-1970 thru 2-9-1973, E. I. du Pont de Nemours and 

Company, Savannah River Plant; 1970–1973; SRDB Ref ID: 52006 

DuPont, 1973-1978, Am., Cm Record Book, 2-10-1973 thru 4-30-1978, E. I. du Pont de Nemours and 

Company Savannah River Plant; 1973–1978; SRDB Ref ID: 52010 

DuPont, 1973-1979, Pu-Am Record Book, 10-22-1973 thru 2-1-1979, E. I. du Pont de Nemours and 

Company, Savannah River Plant; 1973–1979; SRDB Ref ID: 51970 

DuPont, 1978-1983, Am., Cm Record Book, 5-1-1978 thru 11-29-1983, E. I. du Pont de Nemours and 

Company, Savannah River Plant; 1978–1983; SRDB Ref ID: 52019 

DuPont, 1979-1980, Pu-Am Record Book, 2-2-1979 thru 7-7-1980, E. I. du Pont de Nemours and 

Company, Savannah River Plant; 1979–1980; SRDB Ref ID: 52018 

DuPont, 1980-1981a, Am-Cm #5 Record Book, 8-12-1980 thru 6-9-1981, E. I. du Pont de Nemours 

and Company, Savannah River Plant; 1980–1981a; SRDB Ref ID: 52012 

DuPont, 1980-1981b, PU-Am #3 Record Book, 8-3-80 thru 8-22-81, E. I. du Pont de Nemours and 

Company, Savannah River Plant; 1980–1981b; SRDB Ref ID: 52015 

DuPont, 1981–1986, Pu-Am Record Book, 10-23-1981 thru 6-9-1986, E. I. du Pont de Nemours and 

Company, Savannah River Plant; 1981–1986; SRDB Ref ID: 53283 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 37 of 45

DuPont, 1986–1989, Pu-Am Record Book, 6-25-1986 thru 8-9-1989, E. I. du Pont de Nemours and 

Company, Savannah River Site; 1986–1989; SRDB Ref ID: 52022 

Fabrication, 1982, Direct Fabrication of 238PuO2 Fuel Forms, G. A. Burnery and J. W. Congdon; E. I. 

du Pont de Nemours and Company, Savannah River Laboratory; DP-1621; July 1982; SRDB Ref ID: 

112070

Glass, 2003, The Impact of Higher Waste Loading on Glass Properties: The Effects of Uranium and 

Thorium, D. K. Peeler and T. B. Edwards; Westinghouse Savannah River Company, Savannah River 

Technology Center; WSRC-TR-2003-00386, Rev. 0; September 15, 2003; SRDB Ref ID: 116414 

Glass, 2006, Development of an Alternative Glass Formulation for Vitrification of Excess Plutonium, 

J. C. Marra, et al; Savannah River National Laboratory; WSRC-TR-2006-00031 Rev. 0; January 

2006; SRDB Ref ID: 118099 

Immobilization, 1994, Compositions and Durabilities of Glasses for Immobilization of Plutonium and 

Uranium (U), W. G. Ramsey; Westinghouse Savannah River Company; WSRC-MS-94-0550; 

October 13, 1994; SRDB Ref ID: 119582 

Incidents, 1973-1977, Analytical Chemistry Incidents, 1973-77; Savannah River Site; BLD-M-6-4-1; 

document date unknown; SRDB Ref ID: 113899 

Internal Dosimetry, 1990, Internal Dosimetry Technical Basis Manual, Westinghouse Savannah River 

Company; WSRC-IM-90-139, Rev. 1; December 20, 1990; SRDB Ref ID: 11266 

Internal Dosimetry, 2001, The Savannah River Site Internal Dosimetry Technical Basis Manual, 

Westinghouse Savannah River Company; WSRC-IM-90139, Rev. 8; December 31, 2001; SRDB Ref 

ID: 722 

Inventories, 1994, Uranium, Thorium, and TRU Inventories at SRS (U), A. Gibbs, Westinghouse 

Savannah River Company; WCRC-TR-940255; May 23, 1994; SRDB Ref ID: 49576 

Inventory Data, 1976-1998, Savannah River Site Thorium and U-233 Inventory Data Printouts 1976-

1998, Savannah River Site; various dates from 1976-1998; SRDB Ref ID: 110833 

Inventory Reports, 1974-1975, SRS Inventory Reports for July 1974 – June 1975, Savannah River 

Site; various date from July 1974 to June 1975; SRDB Ref ID: 113897 

Inventory Spreadsheet, 1975a, Spreadsheet: “Export NIOSH Thorium Inventory Data of Interest” 

with Th-232 inventory Data for 1975 from NMMSS for the Savannah River Site, National Institute for 

Occupational Safety and Health; generated in 2012; SRDB Ref ID: 115577 

Inventory Spreadsheet, 1975b, Spreadsheet: “Export NIOSH Thorium Inventory Data of Interest” 

with Th-232 inventory Data for 1975 from NMMSS for the Savannah River Site, National Institute for 

Occupational Safety and Health; generated in 2012; SRDB Ref ID: 115579 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 38 of 45

Inventory Write-off, 1979, Inventory Write-off Thorium, memo from W. T. Dickenson (du Pont) to N. 

Stetson (DOE-SROO); November 12, 1979; SRDB Ref ID: 108716 

Iridium, 1982, Welding Iridium Heat-Source Capsules for Space Missions, W. R. Kanne, Jr.; E. I. du 

Pont de Nemours and Company, Savannah River Plant; DPSPU 81-30-18; March 1982; SRDB Ref 

ID: 111458 

Monthly Report, Dec1978, Savannah River Laboratory Monthly Report, December 1978, E. I. du 

Pont de Nemours and Company, Savannah River Plant; DP-78-1-12; December 1978; SRDB Ref ID: 

104954

Monthly Status, Oct1977, Monthly Status and Progress Report, October 1977, U.S. Department of 

Energy, Savannah River Operations Office; October 1977; SRDB Ref ID: 104971 

Monthly Status, Nov1977, Monthly Status and Progress Report, November 1977, U.S. Department of 

Energy, Savannah River Operations Office; November 1977; SRDB Ref ID: 104974 

Monthly Status, Feb1978, Monthly Status and Progress Report, February 1978, U.S. Department of 

Energy, Savannah River Operations Office; February 1978; SRDB Ref ID: 104981 

Monthly Status, Apr1978, Monthly Status and Progress Report, April 1978, U.S. Department of 

Energy, Savannah River Operations Office; April 1978; SRDB Ref ID: 104983 

Monthly Status, May1978, Monthly Status and Progress Report, May 1978, U.S. Department of 

Energy, Savannah River Operations Office; May 1978; SRDB Ref ID: 104984 

Monthly Status, Jul1978, Monthly Status and Progress Report, July 1978, U.S. Department of Energy, 

Savannah River Operations Office; July 1978; SRDB Ref ID: 104986

Monthly Status, Aug1978, Monthly Status and Progress Report, August 1978, U.S. Department of 

Energy, Savannah River Operations Office; August 1978; SRDB Ref ID: 104987 

Monthly Status, Sep1978, Monthly Status and Progress Report, September 1978, U.S. Department of 

Energy, Savannah River Operations Office; September 1978; SRDB Ref ID: 104989 

Neptunium, 1997, Neptunium Immobilizations and Recovery Using Phase Separated Glasses, T. F. 

Meaker; Westinghouse Savannah River Company, Savannah River Technology Center; WSRC-TR96-0380 Rev. 1; January 16, 1997; SRDB Ref ID: 111447 

NIOSH, 2008, SEC Petition Evaluation Report for Petition SEC-00103, Savannah River Site; 

National Institute for Occupational Safety and Health (NIOSH); November 14, 2008; SRDB Ref ID: 

90587

NIOSH, 2010, SEC Petition Evaluation Report for Petition SEC-00103, Savannah River SiteAddendum 1; National Institute for Occupational Safety and Health (NIOSH); April 28, 2010; SRDB 

Ref ID: 90588 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 39 of 45

NIOSH, 2011, SEC Petition Evaluation Report for Petition SEC-00103, Savannah River SiteAddendum 2; National Institute for Occupational Safety and Health (NIOSH); September 9, 2011; 

SRDB Ref ID: 118443

Operating Procedure, 1961, Operating Procedure for Radiation and Contamination Control, Rev. 6; 

Technical Procedures Office, E. I. du Pont de Nemours and Company, Savannah River Plant; July 

1961; SRDB Ref ID: 52806 

Operational Health Physics, 1980, Operational Health Physics at the Savannah River Plant, C. H. 

Cofer and G. Hayes; E. I. du Pont de Nemours and Company, Savannah River Plant; April 1980; 

ORAUT-OTIB-0019, Analysis of Coworker Bioassay Data for Internal Dose Assignment, Rev. 01; 

Oak Ridge Associated Universities; October 7, 2005; SRDB Ref ID: 19438 

ORAUT-OTIB-0023, Assignment of Missed Neutron Doses Based on Dosimeter Records, Rev. 01; 

Oak Ridge Associated Universities; March 14, 2008; SRDB Ref ID: 43937 

ORAUT-OTIB-0075, Use of Claimant Datasets for Coworker Modeling, Rev. 00; Oak Ridge 

Associated Universities; May 25, 2009; SRDB Ref ID: 67223

ORAUT-RPRT-0053, Analysis of Stratified Coworker Datasets, Rev. 01; Oak Ridge Associated 

Universities; July 16, 2012; SRDB Ref ID: 116168 

ORAUT-RPRT-0055, A Comparison of Exotic Trivalent Radionuclide Coworker Models at the 

Savannah River Site, Rev. 00; Oak Ridge Associated Universities; July 20, 2012; SRDB Ref ID: 

116358

PAS, 2004, Specific Thorium PAS Data Sheets for 2004, Westinghouse Savannah River Company; 

2004; SRDB Ref ID: 105000 

PAS, 2005, An Update on the Evaluation of Personal Air Monitoring Data at the Savannah River Site, 

Westinghouse Savannah River Company; 2005; SRDB Ref ID: 115493 

Personal Communication, 2012a, Personal Communication with Former Nuclear Physicist; 

Telephone Interview by ORAU Team, February 2, 2012, SRDB Ref ID: 107510

Personal Communication, 2012b, Personal Communication with Former Chemist; Telephone 

Interview by ORAU Team, February 2, 2012, SRDB Ref ID: 107512 

Personal Communication, 2012c, Personal Communication with Former Senior Chemist; Telephone 

Interview by ORAU Team, February 3, 2012, SRDB Ref ID: 107515 

Personal Communication, 2012d, Personal Communication with Former Senior Fellow Scientist; 

Telephone Interview by ORAU Team, February 10, 2012, SRDB Ref ID: 108605 

Physics Studies, 1980, Physics Studies for the ThO2/UO2 Irradiation Program, Technical Division, 

Savannah River Laboratory; May 2, 1980; SRDB Ref ID: 104996 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 40 of 45

Program Termination, 1980, Documentation of Thoria Irradiation Program Termination, Technical 

Division, Savannah River Laboratory; memo to File from J. L. Steimke; December 31, 1980; SRDB 

Ref ID: 104994 

Pu-238 Fuel Form, Oct1972, Savannah River Laboratory Monthly Report, Pu-238 Fuel Form 

Processes, E. I. du Pont de Nemours and Company, Savannah River Laboratory; DPST-72-128-2; 

October 1972; SRDB Ref ID: 112082 

Pu-238 Fuel Form, Nov1972, Savannah River Laboratory Monthly Report, Pu-238 Fuel Form 

Processes, E. I. du Pont de Nemours and Company, Savannah River Laboratory; DPST-72-128-3; 

November 1972; SRDB Ref ID: 112083 

Pu-238 Fuel Form, Jul1973, Savannah River Laboratory Monthly Report, Pu-238 Fuel Form 

Processes, E. I. du Pont de Nemours and Company, Savannah River Laboratory; DPST-73-128-7; 

July 1973; SRDB Ref ID: 45961 

Pu-238 Fuel Form, Jan-Mar1982, Pu-238 Fuel Form Processes Quarterly Report, E. I. du Pont de 

Nemours and Company, Savannah River Laboratory; DPST-82-128-2; July 1982; SRDB Ref ID: 

111464

Quarterly Report Q4, 1959, SRS Dosimetry Quarterly Report for Fourth Quarter 1959, Savannah 

River Site; 1959; SRDB Ref ID: 50543 

Quarterly Report Q2, 1962, SRS Dosimetry Quarterly Report for Second Quarter 1962, Savannah 

River Site; 1962; SRDB Ref ID: 50435 

Quarterly Report Q4, 1963, SRS Dosimetry Quarterly Report for Fourth Quarter 1963, Savannah 

River Site; 1963; SRDB Ref ID: 50421 

Quarterly Report Q4, 1964, SRS Dosimetry Quarterly Report for Fourth Quarter 1964, Savannah 

River Site; 1964; SRDB Ref ID: 50418 

Quarterly Report Q2, 1965, SRS Dosimetry Quarterly Report for Second Quarter 1965, Savannah 

River Site; 1965; SRDB Ref ID: 50457 

Quarterly Report Q3, 1965, SRS Dosimetry Quarterly Report for Third Quarter 1965, Savannah River 

Site; 1965; SRDB Ref ID: 50458 

Quarterly Report Q4, 1965, SRS Dosimetry Quarterly Report for Fourth Quarter 1965, Savannah 

River Site; 1965; SRDB Ref ID: 50459

Quarterly Report Q1, 1966, SRS Dosimetry Quarterly Report for First Quarter 1966, Savannah River 

Site; 1966; SRDB Ref ID: 50442 

Quarterly Report Q2, 1966, SRS Dosimetry Quarterly Report for Second Quarter 1966, Savannah 

River Site; 1966; SRDB Ref ID: 50443
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 41 of 45

Quarterly Report Q3, 1966, SRS Dosimetry Quarterly Report for Third Quarter 1966, Savannah River 

Site; 1966; SRDB Ref ID: 50440 

Quarterly Report Q4, 1966, SRS Dosimetry Quarterly Report for Fourth Quarter 1966, Savannah 

River Site; 1966; SRDB Ref ID: 50441 

Quarterly Report Q1, 1967, SRS Dosimetry Quarterly Report for First Quarter 1967, Savannah River 

Site; 1967; SRDB Ref ID: 50063 

Quarterly Report Q2, 1967, SRS Dosimetry Quarterly Report for Second Quarter 1967, Savannah 

River Site; 1967; SRDB Ref ID: 50064 

Quarterly Report Q3, 1967, SRS Dosimetry Quarterly Report for Third Quarter 1967, Savannah River 

Site; 1967; SRDB Ref ID: 50061 

Quarterly Report Q4, 1967, SRS Dosimetry Quarterly Report for Fourth Quarter 1967, Savannah 

River Site; 1967; SRDB Ref ID: 50062 

Quarterly Report Q1, 1968, SRS Dosimetry Quarterly Report for First Quarter 1968, Savannah River 

Site; 1968; SRDB Ref ID: 50065 

Quarterly Report Q2, 1968, SRS Dosimetry Quarterly Report for Second Quarter 1968, Savannah 

River Site; 1968; SRDB Ref ID: 50066 

Quarterly Report Q3, 1968, SRS Dosimetry Quarterly Report for Third Quarter 1968, Savannah River 

Site; 1968; SRDB Ref ID: 50067 

Quarterly Report Q4, 1969, SRS Dosimetry Quarterly Report for Fourth Quarter 1969, Savannah 

River Site; 1969; SRDB Ref ID: 50072 

Quarterly Report Q2, 1970, SRS Dosimetry Quarterly Report for Second Quarter 1970, Savannah 

River Site; 1970; SRDB Ref ID: 50074 

Quarterly Report Q3, 1970, SRS Dosimetry Quarterly Report for Third Quarter 1970, Savannah River 

Site; 1970; SRDB Ref ID: 50075 

Quarterly Report Q4, 1970, SRS Dosimetry Quarterly Report for Fourth Quarter 1970, Savannah 

River Site; 1970; SRDB Ref ID: 50076 

Quarterly Report Q1, 1971, SRS Dosimetry Quarterly Report for First Quarter 1971, Savannah River 

Site; 1971; SRDB Ref ID: 50079 

Quarterly Report Q2, 1971, SRS Dosimetry Quarterly Report for Second Quarter 1971, Savannah 

River Site; 1971; SRDB Ref ID: 50080 

Quarterly Report Q3, 1971, SRS Dosimetry Quarterly Report for Third Quarter 1971, Savannah River 

Site; 1971; SRDB Ref ID: 50077 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 42 of 45

Quarterly Report Q4, 1971, SRS Dosimetry Quarterly Report for Fourth Quarter 1971, Savannah 

River Site; 1971; SRDB Ref ID: 50078 

Quarterly Report Q1, 1972, SRS Dosimetry Quarterly Report for First Quarter 1972, Savannah River 

Site; 1972; SRDB Ref ID: 50402

Quarterly Report Q2, 1972, SRS Dosimetry Quarterly Report for Second Quarter 1972, Savannah 

River Site; 1972; SRDB Ref ID: 50371 

Quarterly Report Q3, 1972a, SRS Dosimetry Quarterly Report for Third Quarter 1972, Savannah 

River Site; 1972; SRDB Ref ID: 50359 

Quarterly Report Q3, 1972b, SRS Dosimetry Quarterly Report for Third Quarter 1972, Savannah 

River Site; 1972; SRDB Ref ID: 50367 

Quarterly Report Q4, 1972, SRS Dosimetry Quarterly Report for Fourth Quarter 1972, Savannah 

River Site; 1972; SRDB Ref ID: 50363 

Quarterly Tritium Q1, 1989, SRS Quarterly Tritium Contribution for First Quarter 1989, Savannah 

River Site; 1989; SRDB Ref ID: 50539 

Radiation Control, 1959-1971, Radiation and Contamination Control (Historical Revisions 1959-

1971), E. I. du Pont de Nemours and Company, Savannah River Plant, Explosives Department, 

Atomic Energy Division; DPSOP-40; historical page change revisions to SOP manual for 1959-1971; 

SRDB Ref ID: 52805 

Radiation Control, 1978, Savannah River Plant Radiation and Contamination Control, Volume III; E. 

I. du Pont de Nemours and Company, Savannah River Plant, Explosives Department, Atomic Energy 

Division; DPSOP-40, Volume III; latest document date is Rev. 60 page change, April 1978; SRDB 

Ref ID: 86188 

Radiological Control, 1992, Radiological Control Manual, U.S. Department of Energy; DOE N 

5480.6; June 1992; SRDB Ref ID: 11515 

Radiological Control, 1994, Radiological Control Manual, U.S. Department of Energy; DOE/EH0256T, Rev. 1; April 1994; SRDB Ref ID: 14856 

Radiological Guide, 2000, Savannah River Site Radiological Guide for Planners, IM-99-00001, Rev. 

3, Savannah River Site Radiological Protection Department; 2000; SRDB Ref ID: 119270 

Radiation Surveys, 1977, Daily Radiological Control Survey, RBOF Facility (Bldg, 244-45-H), 

Savannah River Site; August 1 to December 30, 1977; SRDB Ref ID: 114686 

Resuspension, 1980, Resuspension Factors and Probabilities of Intake of Material in Process (Or “Is 

1

-6 a Magic Number in Health Physics?”), A. Brodsky, Office of Standards Development, U.S. 

Nuclear Regulatory Commission; Health Physics, Vol. 39, December 1980; SRDB Ref ID: 52086 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 43 of 45

Roasting, 1982, Roasting and Dissolution Studies on Non-irradiated Thorium Dioxide/Uranium 

Dioxide Pellets, J. B. Pickett, et al; E. I. du Pont de Nemours and Company, Savannah River 

Laboratory; DP-1590; January 1982; SRDB Ref ID: 105021 

Special Hazards, 1962-1974, Final Reports of Special Hazards Investigations No. 200-299; Savannah 

River Plant; various incident dates from March 30, 1962 to April 11, 1974; SRDB Ref ID: 45094 

Special Hazards, 1974-1983, Final Reports of Special Hazards Investigations No. 300-399; Savannah 

River Plant; various incident dates from May 23, 1974 to November 15, 1983; SRDB Ref ID: 45096 

Special Hazards, 1983-1989, Final Reports of Special Hazards Investigations No. 400-494; Savannah 

River Plant; various incident dates from December 29, 1983 to November 30, 1989; SRDB Ref ID: 

45098

Spent Fuel, 2003, Spent Fuel Storage at Savannah River Site (October 2003), T. Andes, et al; 

Westinghouse Savannah River Site; WSRC-MS-2003-00567; September 12, 2003; SRDB Ref ID: 

112102

Spent Fuel, 2007, Spent Fuel Management at the Savannah River Site, P. R. Vormelker, et al; 

Westinghouse Savannah River Site; WSRC-STI-2008-00129; November 3, 2007; SRDB Ref ID: 

112105

SRL History Vol. I, 1984, History of the Savannah River Laboratory, Volume I – Production Reactor, 

Fuel, and Target Technology, E. I. du Pont de Nemours and Company, Savannah River Plant; DPST62-200-I; August 1984; SRDB Ref ID: 89232 

SRL History Vol. III, 1984, History of the Savannah River Laboratory, Volume III – Power Reactor 

and Fuel Technology, E. I. du Pont de Nemours and Company, Savannah River Plant; DPST-62-200-

III; June 1984; SRDB Ref ID: 90054

SRL History Vol. IV, 1984, History of the Savannah River Laboratory, Volume IV – General, E. I. du 

Pont de Nemours and Company, Savannah River Plant; DPST-62-200-IV; August 1984; SRDB Ref 

ID: 49497 

SROO, 1996, Savannah River Operations Office; Interim Management of Nuclear Materials at the 

Savannah River Site, U.S. Department of Energy; Federal Register Vol. 61, No. 35, Wednesday, 

February 21, 1996, Notices; SRDB Ref ID: 116410 

SRP History, 1954, SRP History, Volume 2, Health Physics Section; Savannah River Plant; undated, 

but from context, no earlier than 1954; SRDB Ref ID: 51620 

SRTC, 1995, Savannah River Technology Center Monthly Report, Westinghouse Savannah Rover 

Company; WSRC-TR-95-100-5; May 1995; SRDB Ref ID: 112013 

SS Material, 1975, SRS SS Material Monthly Inventory Reports for February-May 1975, Works 

Technical Division, Savannah River Site; February-May 1975; SRDB Ref ID: 113906 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 44 of 45

Survey Logs, Nov1972-Jan1973, Radiation Multi-survey Logsheets, Savannah River Site; various 

dates from November 6, 1972 to January 17, 1973; SRDB Ref ID: 113925 

Survey Logs, Mar-Aug1973, Radiation Multi-survey Logsheets, Savannah River Site; various dates 

from March 22, 1973 through August 31, 1973; SRDB Ref ID: 113956 

Survey Logs, Sep-Dec1973, Radiation Multi-survey Logsheets, Savannah River Site; various dates 

from September 4, 1973 through December 31, 1973; SRDB Ref ID: 113836 

Survey Logs, Jan-May1974, Radiation Multi-survey Logsheets, Savannah River Site; various dates 

from January 3, 1974 through May 31, 1974; SRDB Ref ID: 113920 

Survey Logs, Dec1974-Aug1975, Radiation Multi-survey Logsheets, Savannah River Site; various 

dates from December 30, 1974 through August 31, 1975; SRDB Ref ID: 114644 

Survey Logs, Jan-Mar1975, Radiation Multi-survey Logsheets, Savannah River Site; various dates 

from January 2, 1975 through March 5, 1975; SRDB Ref ID: 113922 

Survey Logs, Mar-Jun1975, Radiation Multi-survey Logsheets, Savannah River Site; various dates 

from March 6, 1975 through June 17, 1975; SRDB Ref ID: 113930 

Survey Logs, 1976, Radiation Survey Log Sheets and Cask Receiving and Shipping Reports for 

Building 244H, Savannah River Site; November 3, 1976 to December 16, 1976; SRDB Ref ID: 

114711

Survey Logs, Mar-Jul1980, Radiation Multi-survey Logsheets, Savannah River Site; various dates 

from March 2, 1980 through March 17, 1980; SRDB Ref ID: 113985 

Survey Procedures, 1992, Health Protection Department Radiation Survey Procedures, E. I. du Pont 

de Nemours and Company, Savannah River Plant, Atomic Energy Division; DPSOP 193; Rev. 77, 

May 1992; SRDB Ref ID: 45958 

Technical Standards, 1974, Radiation Hazards Technical Standards, E. I. du Pont de Nemours and 

Company, Savannah River Plant, Explosives Department, Atomic Energy Division; DPSTS-RH, 

March 1974; SRDB Ref ID: 99467 

Thorium Analyte, 2000, Input to Resin Column Structural Analysis if Autocatalytic Resin reaction 

Occurs in HB-Line Phase II, D. F. Hallman; Westinghouse Savannah River Company; 2000; 

http://sti.srs.gov/fulltext/tr2000511/tr2000511.html; SRDB Ref ID: 119273 

Thorium Impurity, 1972, Source of Thorium Impurity in U-238 Prepared from Am-241, memo to J. A. 

Porter from G. A. Burney; Technical Division, Savannah River Laboratory; August 23, 1972; SRDB 

Ref ID: 49541 

Thorium Irradiation, 1981, The Thorium Irradiation Program, Technical Division, Savannah River 

Laboratory; July 31, 1981; SRDB Ref ID: 49581 
SEC-00103 Addendum 3 11-20-12 Savannah River Site 

Page 45 of 45

Thorium Oxylate, 1981, Thorium Oxylate Solubility and Morphology, P. R Monson and R. Hall; E. I. 

du Pont de Nemours and Company, Savannah River Laboratory; DP-1576; October 1981; SRDB Ref 

ID: 49927 

Thorium Processing, 1970, SRP Thorium Processing Experience, D. A. Orth, E. I. du Pont de 

Nemours and Company, Savannah River Plant; undated, but from context, 1970 but not much later; 

SRDB Ref ID: 44512 

Thorium Result, 1975, Radiation Survey Logsheet – Multi-survey of Thorium Billets, F. M. Wise; 

Savannah River Site; January 13, 1975; SRDB Ref ID: 114644 

Thorium Welding, 1993, Thorium Welding Electrodes, inter-office memorandum to J. F. Jordan from 

W. S. Loring; Westinghouse Savannah River Company; July 30, 1993; SRDB Ref ID: 105006 

Treatment Plan, 1996, Approved Site Treatment Plan (STP) (U), WSRC-TR-94-0608, Rev. 4; 

Savannah River Site Mixed Waste; April 15, 1996; SRDB Ref ID: 119271 

Treatment Plan, 1998, Savannah River Site Approved Site Treatment Plan, 1998 Annual Update (U), 

WSRC-TR-94-0608, Rev. 6; Savannah River Site; March 16, 1998; SRDB Ref ID: 119272 

Waste Processing, 2005, The Impacts of Uranium and Thorium of the Defense Waste Processing 

Facility (DWPF) Viscosity Model (U), C. M. Jantzen; Immobilization Technology Section, Savannah 

River National Laboratory; WSRDC-TR-2004-00311; February 2005; SRDB Ref ID: 116399 

Waste Processing, 2011, Analyses by the Defense Waste Processing Facility Laboratory of Thorium 

Glasses from the Sludge Batch 6 Variability Study, M. T. Feller, et al; Applied Computational 

Engineering and Statistics, Savannah River National Laboratory; SRNL-STI-2011-00074 Rev. 0; 

February 2011; SRDB Ref ID: 116413 

Waste Glass, 1992, Nuclear Waste Glass Product Consistency Test (PCT) – Version 5.0 (U), C. M. 

Jantzen, et al; Westinghouse Savannah River Co.; WSRC-TR-90-539, Rev. 2; January 1992; SRDB 

Ref ID: 116415 

Welds, 1998, Nondestructive Inspection of General Purpose Heat Source (GPHS) Girth Welds, M. A. 

H. Reimus, et al; Los Alamos National Laboratory; LA-UR-97-3286; paper presented January 25-29, 

1998; SRDB Ref ID: 116411 

Works Technical, Aug1977, Works Technical Report for August 1977, E. I. du Pont de Nemours and 

Company, Savannah River Plant; DPSP 77-1-8; August 1977; SRDB Ref ID: 72918 

Works Technical, Mar1978, Works Technical Report for March 1978, E. I. du Pont de Nemours and 

Company, Savannah River Plant; DPSP 78-1-3; March 1978; SRDB Ref ID: 68060 

Works Technical, Aug1978, Works Technical Report for August 1978, E. I. du Pont de Nemours and 

Company, Savannah River Plant; DPSP 78-1-8; August 1978; SRDB Ref ID: 68279