DISCLAIMER: This is a working document provided by the Centers for Disease Control and Prevention (CDC) 

technical support contractor, SC&A, for use in discussions with the National Institute for Occupational Safety and 

Health (NIOSH) and the Advisory Board on Radiation and Worker Health (ABRWH), including its Working Groups or 

Subcommittees. Documents produced by SC&A, such as memorandum, white paper, draft or working documents are 

not final NIOSH or ABRWH products or positions, unless specifically marked as such. This document prepared by 

SC&A represents its preliminary evaluation on technical issues.

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Memorandum

To: Santa Susana Field Laboratory Work Group

From: SC&A, Inc.

Date: July 25, 2019

Subject: Evaluation of Petitioner-Specific Concerns Regarding SEC-00235

Introduction

On March 25, 2019, CORE Advocacy for Nuclear & Aerospace Workers—the petitioner, 

hereafter “CORE Advocacy,” for Special Exposure Cohort (SEC) petition SEC-00235 at the 

Santa Susana Field Laboratory (SSFL)–submitted two documents for consideration by the SSFL 

work group (WG) related to potential exposures to thorium and americium during the post-1988 

period. 

The two items submitted by CORE Advocacy were described as follows in the transmitting 

email (CORE Advocacy, 2019): 

1. SSFL Area IV Building Numbers where EPA identified Americium and 

Thorium as “Radionuclides of Concern,” during the 2012 Area IV 

Radiological Characterization Study. Dates of building demolition are 

included. There are approximately 50 building locations where EPA identified 

Am / Th.

2. EPA’s description of processes at SSFL Area IV Building 4023, which 

specifically involved TRUMP-S research.

The first item was a 2017 report by CORE Advocacy (CORE Advocacy, 2017) summarizing 

specific information from the 2012 U.S. Environmental Protection Agency (EPA) study 

(referenced as EPA 2012a–2012h in this memorandum). The second item was an excerpt from a 

specific section of the 2012 EPA study. These items were briefly discussed during the March 

2019 SSFL WG teleconference (SSFL WG, 2019, pp. 23–26) and again during the meeting of 

the Advisory Board on Radiation Worker Health (Board) held April 17, 2019, in Pittsburgh, PA 

(ABRWH, 2019, pp. 59–60, 73–96). During the latter discussion, the Board tasked SC&A with 

providing a formal review of the submitted documents in the context of SEC-00235. This 

memorandum presents the results of SC&A’s review of the two petitioner-supplied documents 

and any relevant underlying documentation as necessary. 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 2 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Radionuclides of Concern Identified in 2012 Area IV Radiological Characterization 

Study

The first item submitted by CORE Advocacy summarizes a series of historical site assessments 

(HSAs) that were performed for EPA and finalized in 2012. The purpose of the HSAs was to 

review historical site processes in order to identify the areas and potential contaminants that 

could theoretically be present to aid in future sampling and remediation activities. Specifically, 

the “Introduction” volume to the HSA study states:

The objective of the HSA component of the radiological study was to provide a 

comprehensive investigation that identifies, collects, organizes, and evaluates 

historical information relevant to nuclear research operations as it pertains to 

radiological contamination in the Area IV Study Area. Once these areas were 

identified, potential areas where radiological contamination may exist at the site 

were identified for sampling. [EPA, 2012a, p. 1] 

The HSAs are useful because they provide a retrospective look at the different radiological 

operations at the site and thus indicate the different types of residual contamination that have the 

potential to be present in the various SSFL facilities under consideration. For example, one such 

HSA concerning building 4023 identified the potential for Transuranic Management by 

Pyropartitioning – Separation (TRUMP-S) operations after the currently established SEC period 

(post-1988) (EPA, 2012b). This specific building is the subject of item 2 presented by CORE 

Advocacy in March 2019 and is discussed in detail in the next section. 

As CORE Advocacy points out in their report detailing information in the HSAs and 

correspondence submitted to the SSFL WG, there are approximately 50 buildings/locations 

where americium and thorium were likely to be present for the purposes of remediation sampling 

activities (CORE Advocacy, 2017). The potential for residual contamination (including 

americium and thorium) to have been present at various locations at SSFL is to be expected 

based on the historical radiological operations at the site, in particular, operational research 

related to irradiated fuel elements and use of thorium fuels in reactors such as the Advanced 

Epithermal Thorium Reactor (AETR). 

However, the key question is whether operational activities involving these radionuclides 

occurred after 1988 that may present an exposure scenario that cannot be bounded with sufficient 

accuracy by potential dose reconstruction methods. It should be noted that, based on SC&A’s 

preliminary review of SEC-00235 (SC&A, 2019), it was recommended that the National Institute 

for Occupational Safety and Health (NIOSH) develop dose reconstruction methods for 

decontamination and decommissioning (D&D) workers who may have come in contact with 

residual contamination from americium and thorium. NIOSH agreed with this recommendation 

and methods to reconstruct such doses are currently being evaluated (SSFL WG, 2019, pp. 16–

21). 

The question of continued operational exposures that are independent from D&D activities is 

certainly a potential concern in the context of SEC-00235. Therefore, SC&A reviewed the EPA 

HSAs to ascertain whether such operations may have existed after 1988. Specific comments 

related to the buildings identified by CORE Advocacy are contained in Attachment A. 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 3 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

SC&A did not find evidence that operations involving thorium and americium existed during the 

time period in question. However, SC&A acknowledges that residual amounts of radioactivity 

from americium and thorium were likely (and expected) to exist during this time and must be 

appropriately accounted for during dose reconstruction for former energy employees at SSFL. 

TRUMP-S Activities After 1988

The second item submitted by CORE Advocacy in March 2019 included a specific excerpt from 

the EPA HSA related to potential for TRUMP-S activities in building 4023. The pertinent 

section of the excerpt is as follows:

In 1989, reports appear to indicate that Building 4023 served as a support facility 

for the Transuranic (TRU) Management by Pyropartitioning – Separation 

(TRUMP-S) operations in Building 4020, located in Subarea HSA-5D. Atomics 

International requested DOE’s approval to utilize the facilities for a 2-year period 

beginning July 1988 for the Kawasaki Heavy Industries (KHI) and the Central 

Research Institute of the Electric Power Industry (CRIEPI) of Japan-sponsored 

“pyrochemical partitioning of actinides from PUREX waste” program. . . . The 

material used in this experiment was listed as including uranium, neptunium 

(Np-237), plutonium (Pu-239), and americium (Am-241). [EPA, 2012b, p. 15] 

The underlying documentation for this statement in EPA (2012b) was a safety analysis 

conducted for building T020 (also known as building 4020 and the “hot lab”), revised usage 

applications regarding TRUMP-S materials, and a management plan for the TRUMP-S test 

program. All the documents were dated 1989. 

SC&A identified additional documentation from 1988–1990 related to the proposed TRUMP-S 

project at SSFL, summarized as follows: 

• October 20, 1988: An internal letter describes revisions to the proposed usage 

application for TRUMP-S materials (Rockwell International, 1988). The letter describes 

several internally identified deficiencies in the proposed application and requests 

appropriate revisions.

• July 25, 1989: An internal letter indicates that a planning meeting was held to obtain the 

proper documentation to operate the TRUMP-S glove box in B/020 (the hot lab). The 

document states:

The portion of the license for renewal and to do the work was submitted to 

NRC. [Redacted] is following the license renewal process. At the present 

time we can work with depleted uranium, neptunium and americium. 

[Rockwell International, 1989a, p. 1] 

Although the document does appear to indicate work with americium could have been 

done under the existing license at that time, subsequent documentation (discussed below) 

suggests that the radioactive portion of the TRUMP-S project did not occur at SSFL. 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 4 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

• Undated, probably mid-1989: An undated report that appears to be a regular status 

update on SSFL site operations discusses what to do with the waste that will be generated 

from the TRUMP-S experiment. While undated, the report has a handwritten notation of 

“8/16” and discusses activities to be carried out in late 1989 and early 1990. Therefore, 

SC&A believes it is reasonable to assume the report was from August of 1989. The report 

states: 

A meeting was held with [redacted] to discuss the disposition of the waste 

to be generated from the TRU partitioning tests. Since the waste will 

contain transuranics (Pu, Am, Np) and cadmium, the waste generated in 

late 1989/early 1990 will be TRU/mixed waste. [Redacted] will be in 

contact with [Redacted] to determine what steps are needed to get a head 

start on the planning/disposal process. [Emphasis added.] [Rockwell 

International, n.d., p. 1] 

• October 13, 1989: An internal letter states that a “Test Readiness Review” (Rockwell 

International, 1989b, p. 1) of the TRUMP-S glove box tests was to be held on 

October 13, 1989. Per the Rockwell International test procedures, the object of a “Test 

Readiness Review” is to:

verify technical and operational readiness to conduct the planned tests or 

operations, to identify risks associated with the tests, and to document review 

comments and their resolution. [Rockwell International, 1989b, p. 3] 

• October 21, 1989: An internal letter dated October 21, 1989, describes the meeting 

minutes and action items directly related to the TRUMP-S program. The letter states:

The following action items resulted at the meeting. These action items must be 

completed prior to beginning the radioactive portion of TRUMP-S [emphasis 

added]. [Rockwell International, 1989c, p. 1] 

• February 1, 1990: A letter from Rockwell International to the U.S. Nuclear Regulatory 

Commission (NRC) on February 1, 1990, concerning the license amendment to allow the 

TRUMP-S project to proceed, states: 

This is in reply to your letter . . . regarding our recent transmittal to 

[redacted], wherein we provided additional information regarding the 

TRUMP-S program to be conducted in the RIHL. We understand that a 

license amendment is necessary to reflect this change. [Emphasis added.] 

[Rockwell International, 1990a, p. 1] 

• February 1990: A technical progress report provided by Rockwell International to the 

U.S. Department of Energy (DOE) for the year 1989 describes the progress made in 

electrochemical instrumentation designed for the TRUMP-S experiment. The progress 

report states that the glove box testing for the project had met satisfactory criteria. 

However, the progress report notes: 
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Evaluation of Petitioner Concerns, page 5 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

While Rockwell was awaiting DOE permission to start up the test

pending DOE review of the NEPA Action Description Memorandum, 

Rockwell Management concluded it would be impractical to continue the 

TRUMP-S project beyond Stage 1 activities at the Santa Susana Field 

Laboratories. As a result, an effort was undertaken to locate a facility 

where the TRUMP-S actinide tests could be conducted for both Stage 1 

and Stage 2. [Emphasis added.] [Rockwell International, 1990b, p. 7] 

• February 21, 1990: A newspaper article from February 21, 1990, indicates that seven 

opponents to Rocketdyne’s application to continue operations in the hot lab had filed 

“legal cases with the Nuclear Regulatory Commission judge reviewing the case” 

(Chasen, 1990a). The article goes on to state: 

The cases challenge Rocketdyne’s record of credibility in monitoring 

itself, the company’s described “worst-case scenario” for its planned 

“TRUMP-S” project, its emergency contingency plan, and several other 

aspects of the company’s application. . . . 

[Rocketdyne] is seeking permission to keep the lab open through Oct. 30 

to complete one last experiment called TRUMP-S, for transuranic 

management by pyro-partitioning separation, and has announced plans to 

shut it down afterward.

Originally, Rocketdyne was seeking a 10-year license extension, but cut 

its request to one year last October. [Emphasis added.] [Chasen, 1990a] 

• May 19, 1990: A follow-on newspaper article from The Simi Valley Enterprise, dated 

May 19, 1990, describes the dismantling of the hot lab at SSFL and specifically discusses 

the intended TRUMP-S research as follows:

Rocketdyne announced in April that the “hot lab’s” days were over. One 

last experiment called TRUMP-S, originally scheduled to take place in 

the “hot lab,” was relocated to University of Missouri, at Columbia in the 

heat of public challenges to the company’s request to get the project 

licensed by the U.S. Nuclear Regulatory Commission. 

The experiment would have been in a 4-by-3.5-by-7-foot shielded glove 

box. 

Now the TRUMP-S project — sponsored jointly by Japan and the DOE – 

is facing challenges in Missouri as well. But Rocketdyne officials are 

confident that the project will go forward there. [Emphasis added.] 

[Chasen, 1990b] 

• September 21, 1993: D&D operations for building 4023 were completed by Rockwell 

International; however, specific isotopic analysis is not included in the final report 

(Rockwell International, 1993). 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 6 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

• October 1994: A confirmatory survey of building 4023 was performed for DOE by the 

Oak Ridge Institute for Science and Education (DOE, 1994) and found one small spot of 

beta surface contamination that was above the DOE guidelines. This spot was 

subsequently cleaned up, and DOE (1994) agreed with the assessment by Rockwell 

International that building 4023 met the guidelines for unrestricted release. Soil samples 

appear only to have been taken for uranium isotopes and cesium. 

• February 19, 1998: The State of California Health and Welfare Agency, Department of 

Health Services concurred that building 4023 could be released for use without 

radiological restriction (California DHS, 1998).

Based on the evidence described in the documentation above, it is SC&A’s belief that despite 

significant planning, procedural development, and equipment testing, the TRUMP-S experiments 

planned by Rockwell International to occur after 1988 never actually took place at SSFL. It 

appears the TRUMP-S material and equipment designed for the experiment were transferred to 

the University of Missouri. Therefore, the exposure potential at SSFL to TRUMP-S materials 

appears limited to storage during the time period of interest. 

Summary Conclusion

SC&A does not believe that there is evidence currently available that demonstrates that 

operational exposures involving thorium and americium continued to occur at SSFL after 1988. 

Specific to the TRUMP-S research, SC&A believes that there was clear intent to conduct such 

operations using the hot lab (building 4020) with support from building 4023 (and likely other 

laboratory buildings associated with the hot lab). However, the documentation reviewed 

indicates that the project never reached fruition at SSFL as far as the actual handling and 

processing of the TRUMP-S material. 

Given the historical processes involved in previous campaigns covered by already established

SECs (SEC-0093, SEC-00156, and SEC-00234), it is logical that residual amounts of thorium 

and americium were likely present in existing facilities, equipment, and surrounding areas that 

underwent decontamination and decommissioning during the post-1988 period. NIOSH 

acknowledges as much regarding americium in their 2018 white paper, “Status of Operations 

Involving Thorium and Americium at Area IV SSFL During the Remediation Period (1988 - 

Present)”: 

The majority of the transuranic activity would have been from plutonium-238, 

plutonium-239, plutonium-240, plutonium-241, americium-241, and curium-244. 

. . . Workers who subsequently performed decommissioning and decontamination 

(D&D) procedures on the hot cells could potentially be exposed to residual 

amounts of these radionuclides. [NIOSH, 2018, p. 2] 

As noted previously, SC&A’s review of remaining internal dose issues for SEC-00235 (SC&A, 

2019) recommended that an occupational intake model be developed for D&D workers using 

available air sampling data, administrative limits, or alternate methods to account for exposures 

to residual americium and thorium for the period after 1988. NIOSH and the SSFL WG 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 7 July 25, 2019

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concurred with this recommendation, and dose reconstruction methods for these important 

radionuclides are currently being evaluated by NIOSH. 

References

Advisory Board on Radiation and Worker Health (ABRWH). (2019). Advisory Board on 

Radiation and Worker Health April 17, 2019 128th meeting [Transcript]. Pittsburgh, PA. 

Retrieved from https://www.cdc.gov/niosh/ocas/pdfs/abrwh/2019/tr041719-508.pdf 

Argonne National Laboratory (ANL). (1984). Post remedial action survey report for the Sodium 

Reactor Experiment (SRE) facility Santana Susana Field Laboratories Rockwell International, 

Ventura County, California (DOE/EV-0005-46). Retrieved from 

https://www.etec.energy.gov/Library/Main/Doc._No._24_Post_Remedial_Action_Survey_Repor

t_ANL_SRE_Survey.pdf 

Chasen, S. (1990a, February 21). ‘Hot lab’ opponents file cases with NRC. The Enterprise.

Retrieved from https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP001873756.pdf 

Chasen, S. (1990b, May 19). Hot lab is being dismantled. The Simi Valley Enterprise. Retrieved 

from https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP001873751.pdf 

CORE Advocacy for Nuclear and Aerospace Workers (CORE Advocacy). (2017). Santa Susana 

Field Laboratory Area IV: Locations of americium / thorium / associated progeny and 

approximate dates of building demolition. [SRDB upload pending] 

CORE Advocacy for Nuclear and Aerospace Workers (CORE Advocacy). (2019, March 25). 

SSFL SEC-00235 [Formal email communication to SSFL WG]. [SRDB upload pending] 

National Institute for Occupational Safety and Health (NIOSH). (2018). Status of operations 

involving thorium and americium at Area IV SSFL during the remediation period [White paper]. 

Retrieved from https://www.cdc.gov/niosh/ocas/pdfs/dps/dc-ssflthamremed-110618-508.pdf

Rockwell International. (1988, October 20). Review of TRUMP-S user application [Internal 

letter]. Retrieved from https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP001800248.pdf 

Rockwell International. (1989a, July 25). Documentation required for operation of TRUMP-S 

glovebox in B/020 [Internal letter]. Retrieved from https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP001856975.pdf

Rockwell International. (1989b, October 10). Test readiness review of B/020 TRUMP-S hot 

glove box tests [Internal letter and attached procedure]. Retrieved from https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP001830642.pdf
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Privacy Act 5 USC §552a and has been cleared for distribution. 

Rockwell International. (1989c, October 21). 10/19/89 TRUMP-S environmental issues meeting 

minutes and action items [Internal letter]. Retrieved from https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP001919222.pdf

Rockwell International. (1990a, February 1). Amendment to Rockwell International Hot Lab 

(RIHL) License SNM-21 (Docket 70-25) [Formal correspondence to the NRC]. Retrieved from: 

https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP001873152.pdf

Rockwell International. (1990b). Technical progress report private sector initiatives between the 

United States and Japan January 1989 – December 1989 (RI/RD92-116). Retrieved from SRDB 

Ref. ID 158386 

Rockwell International. (1993). Building 023 D&D operations final report (023-AR-0002). 

Retrieved from SRDB Ref. ID 74943 

Rockwell International. (n.d.). Highlights, page 2 [Undated discussion of TRUMP waste]. 

Retrieved from https://www.dtscssfl.com/files/lib_rcra_soils/group5/historicaldocs/PDF_Files/HDMSP00040707.pdf

Santa Susana Field Laboratory Work Group (SSFL WG). (2019). US Department of Health and 

Human Services Centers for Disease Control National Institute for Occupational Safety and 

Health Advisory Board on Radiation and Worker Health Santa Susana Field Laboratory Work 

Group Monday, March 25, 2019 [Transcript of teleconference meeting]. Retrieved from 

https://www.cdc.gov/niosh/ocas/pdfs/abrwh/2019/wgtr032519_2-508.pdf 

SC&A, Inc. (2019). Review of remaining internal dose topics related to the evaluation of 

SEC-00235 at the Santa Susana Field Laboratory (SCA-TR-2019-SEC002, rev. 0). Arlington, 

VA: SC&A, Inc. Retrieved from SRDB Ref. ID 175490

State of California—Health and Welfare Agency, Department of Health Services (California 

DHS). (1998, February 19). Boeing’s request for concurrence in release for use without 

radiological restriction, Rocketdyne Santa Susana Field Laboratory building T023 [Formal 

correspondence to Rocketdyne Division, Boeing North America, Inc.]. Retrieved from SRDB 

Ref. ID 78237 

U.S. Department of Energy (DOE). (1994). Verification survey of buildings 005, 023, and 064 

Santa Susana Field Laboratory Rockwell International Ventura County, California 

(ORISE 94/K-14). Retrieved from SRDB Ref. ID 157541 

U.S. Environmental Protection Agency (EPA). (2012a). Final historical site assessment Santa 

Susana Field Laboratory site Area IV radiological study Ventura County, California [Redacted 

version]. Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67892_1_Final_HSA_Text_10_201

2_Redacted.pdf 
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Privacy Act 5 USC §552a and has been cleared for distribution. 

U.S. Environmental Protection Agency (EPA). (2012b). Final technical memorandum Subarea 

HSA-5A historical site assessment Santa Susana Field Laboratory site Area IV radiological 

study Ventura County, California [Redacted version]. Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67899_1_Final_HSA5A_TM_Text_10-2012_Redacted.pdf 

U.S. Environmental Protection Agency (EPA). (2012c). Final technical memorandum subarea 

HSA-5B historical site assessment Santa Susana Field Laboratory site Area IV radiological 

study Ventura County, California [Redacted version]. Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67901_1_Final_HSA5B_TM_Text_10-2012_Redacted.pdf 

U.S. Environmental Protection Agency (EPA). (2012d). Final technical memorandum subarea 

HSA-5C historical site assessment Santa Susana Field Laboratory site Area IV radiological 

study Ventura County, California [Redacted version]. Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67904_1_Final_HSA5C_TM_Text_10-2012_Redacted.pdf 

U.S. Environmental Protection Agency (EPA). (2012e). Final technical memorandum subarea 

HSA-5D historical site assessment Santa Susana Field Laboratory site Area IV radiological 

study Ventura County, California [Redacted version]. Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67913_1_Final_HSA5D_TM_Text_10-2012_Redacted.pdf 

U.S. Environmental Protection Agency (EPA). (2012f). Final technical memorandum subarea 

HSA-6 historical site assessment Santa Susana Field Laboratory site Area IV radiological study 

Ventura County, California [Redacted version]. Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67917_1_Final_HSA6_TM_Text_10-2012_Redacted.pdf 

U.S. Environmental Protection Agency (EPA). (2012g). Final technical memorandum subarea 

HSA-7 subarea HSA-3 subarea northern buffer zone historical site assessment Santa Susana 

Field Laboratory site Area IV radiological study Ventura County, California [Redacted version].

Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67919_1_Final_HSA-7-3-

NBZ_TM_Text_10-2012_Redacted.pdf 

U.S. Environmental Protection Agency (EPA). (2012h). Final technical memorandum subarea 

HSA-8 historical site assessment Santa Susana Field Laboratory site Area IV radiological study 

Ventura County, California [Redacted version]. Retrieved from https://www.dtscssfl.com/files/lib_ceqa/ref_draft_peir/Chap3_ProjDesc_vol2/67922_1_Final_HSA8_TM_Text_10-2012_Redacted.pdf 

U.S. Nuclear Regulatory Commission (NRC). (1982). Guidelines for decontamination of 

facilities and equipment prior to release for unrestricted use or termination of licenses for 

byproduct, source, or special nuclear material. Retrieved from 

https://www.nrc.gov/docs/ML1034/ML103430093.pdf 
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Attachment A: Discussion of Specific Buildings Identified in CORE Advocacy 

(2017)

Bldg. SC&A Summary of Pertinent Information from 2012 EPA Historical Site Assessment Ref.

0000 The location is noted in CORE Advocacy 2017 as the Radioactive Materials Disposal Facility

(later known as the Radioactive Materials Handling Facility) Leach Field. This leach field was 

not used after 1961, when the sanitary sewer line was constructed. 

EPA, 

2012g

4003 Atomics International performed D&D of this facility from January 1975 to June 1975, after 

which time it was used as a storage building for excess equipment.

EPA, 

2012f

4005 The radionuclides of concern are listed as Th-234 and Th-231 (both of which are natural decay 

products of U-238 and U-235, respectively) as a result of a uranium carbide fuel manufacturing 

operations occurring in building 4005 during a 9-month period in 1966 and 1967. Other 

operations at building 4005 appear to be non-nuclear.

EPA, 

2012b

4006 Americium was only mentioned as a radionuclide of concern due to the proximity of building 

4006 to the primary buildings housing the Systems for Nuclear Auxiliary Power (SNAP) 

operations.

EPA, 

2012c

4009 Building 4009 housed the Organic Moderated Reactor and Sodium Graphite Reactor operations 

occurring up until 1967. Radiological use authorizations after this time indicate the handling of 

contaminated equipment as part of the in-service inspection project for commercial power 

reactors (1989–1992), use of x-ray tubes (1992–1993), and depleted uranium for the HighEnergy Rate Forging project (date unspecified).

EPA, 

2012h

4010 Building 4010 housed the SNAP Experimental Reactor projects up until 1965. After that, the 

building remained unused for 9 years until it was declared surplus in 1974. D&D work took place 

in 1977 and 1978.

EPA, 

2012c

4011 The north section of the building was used for the calibration and repair of radiation detection 

equipment utilizing sealed and electroplated calibration sources (1984–1996). The south section 

was used for nonradiological activities. 

EPA, 

2012c

4012 This building was part of the SNAP Critical Test Facility and stored clad reactor elements up 

until approximately 1968. Additional criticality experiments were performed in the early 1970s for 

the Heavy Metal Reflected Fast Spectrum Reactor that was sponsored by the National 

Aeronautics and Space Administration (NASA). In 1979, the facility was modified to perform 

quality assurance radiography work, which occurred until 1992.

EPA, 

2012c 

4013 EPA 2012c did not find any evidence of radioactive material being stored or handled in 

building 4013. The building was identified due to its proximity to other SNAP buildings.

EPA, 

2012c 

4019 Also known as the SNAP Flight Systems Facility, this building had all SNAP-related components 

removed in 1970, at which time it was redesignated the Energy Technology Engineering Center 

(ETEC) Construction Staging and Computer Facility.

EPA, 

2012c 

4020 The Fermi Program was the last fuel decladding operation performed at building 4020 (the hot 

lab). The operation actually finished ahead of schedule, and in 1986, all the related materials 

and equipment for decladding operations were removed. The hot cells were also 

decontaminated at this time in preparation for an alternate future project. However, DOE opted 

to begin D&D activities in the hot lab rather than continue radiological operations. Twenty

radiological incidents were reported after 1988 in the hot lab; only one of them involved 

transuranic material (puncture wound occurring in a contaminated plutonium glovebox), and 

none involved thorium.

EPA, 

2012e 

4021 Building 4021 was named the Radioactive Materials Disposal Facility, which later became the 

Radioactive Materials Handling Facility (RMHF). It was built to process low-level radioactive 

waste and after 1988 was used to handle waste associated with D&D activities occurring at 

ETEC. Seven incidents were reported after 1988; however, none indicated the presence of 

transuranic material or thorium.

EPA, 

2012g 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 11 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Bldg. SC&A Summary of Pertinent Information from 2012 EPA Historical Site Assessment Ref.

4023 See discussion in item 2 on p. 3 of this memorandum concerning potential TRUMP-S activities 

in building 4023. However, it is also worth noting that building 4023 served as a design, 

development, and demonstration facility for the Rocky Flats Plutonium Recovery Project that 

occurred in 1987 (plutonium-241 is the parent isotope of americium-241). 

EPA, 

2012b 

4024 Building 4024 was used to test the SNAP reactors in a simulated operational environment; 

subsequent dismantling of the reactors prior to shipment to the hot lab resulted in the 

building 4024 vaults becoming contaminated. Decontamination of the vaults and removal of 

contaminated equipment was completed in 1978. However, a significant amount of activation 

products contained in the facility’s concrete remained per a disposition of the building in 1989.

EPA, 

2012b 

4025 After cancellation of the SNAP program, building 4025 was renamed the ETEC Instrumentation 

and Inventory Building. The building was not known to have handled or stored radioactive 

materials; however, americium and thorium are listed as contaminants of concern due to the 

proximity of the building to the RMHF and the potential for migration. 

EPA, 

2012c 

4027 The building was not known to have handled or stored radioactive materials; however, 

americium and thorium are listed as radionuclides of concern due to the proximity of the building 

to the RMHF and the potential for migration. A 1988 DOE survey concluded that the area

passed the NRC criteria at the time for unrestricted use.

EPA, 

2012b 

4028 In January 1988, it was reported that building 4028 was in very poor condition due to the 

facility’s inactive status. The above-grade portion of the building was demolished down to its 

concrete slab in April 1989.

EPA, 

2012g 

4034 Building 4034 was an office building for the RMHF and was also used for records storage. EPA 

(2012g) concluded that there was no evidence of radioactive materials known to have been 

stored or handled in building 4034. However, americium and thorium are listed as radionuclides 

of concern due to the building’s proximity to the RMHF storage vault.

EPA, 

2012g 

4036 Building 4036 was a non-nuclear office building in support of the SNAP program. Americium 

and thorium are listed as radionuclides of concern due to the building’s proximity to the RMHF.

EPA, 

2012b 

4041 This building was released by DOE for unrestricted use on July 23, 1985, and was subsequently 

used for nonradioactive equipment storage.

EPA, 

2012f 

4044 Building 4044 served as a health physics office, which used calibration sources and performed 

counting measurements on removable contamination samples. Americium and thorium are 

listed as radionuclides of concern due to the building’s proximity to the RMHF storage vault.

EPA, 

2012g 

4048 This building was known as the Plant Development Unit Instrumentation Building, which was a 

non-nuclear operation that occurred from 1978 to 1981. No incidents or radiological surveys 

were identified for the area. The building was included in the assessment due to its proximity to 

building 4005.

EPA, 

2012b 

4055 Also known as the Nuclear Materials Development Facility, this building was designed to house 

plutonium development work. D&D of the building was completed in October 1986, and final 

surveys were completed in March 1987.

EPA, 

2012e 

4057 EPA (2012d) did not find evidence that radioactive material was handled or stored at this 

location. However, because the building was a research laboratory, it is possible that radioactive 

materials may have existed. Americium and thorium are listed as radionuclides of concern due 

to the building’s proximity to building 4059.

EPA, 

2012d 

4059 Building 4059 housed the SNAP 8 prototype reactor, which operated until the end of 1969. The 

reactor and associated equipment were removed in 1970. In 1973, the building was used by the 

Liquid Metal Engineering Center, which tested non-nuclear components related to liquid metals.

EPA, 

2012d 

4064 Building 4064 was built for the repackaging and storing of special nuclear material; however, no 

special nuclear material was handled in this facility after 1980. A radiological use authorization 

(No. 139) from 1989 allowed for the storage of radioactive material and decontamination 

activities at building 4064.

EPA, 

2012f 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 12 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Bldg. SC&A Summary of Pertinent Information from 2012 EPA Historical Site Assessment Ref.

4075 This building was utilized for the storage of radioactive waste awaiting shipment for disposal at 

appropriate offsite locations. These stored wastes include low-level, mixed, and transuranic 

waste. 

EPA, 

2012g 

4100 Building 4100 was the site of the AETR, which utilized thorium as nuclear fuel. However, from 

the 1980s until the late 2000s, the facility was used by NASA for high-energy computer-aided 

tomography. The laboratory portions of the building were also used for instrument calibration 

and contaminated sample counting. Two incidents are reported after 1988: One involved mixed 

fission products, and the other involved a radiography issue.

EPA, 

2012d 

4143 Building 4143 housed the Sodium Reactor Experiment (SRE). Decommissioning began in 1974, 

and the final D&D report was issued in 1983. After this time, the building was used for 

component storage.

EPA, 

2012f 

4153 This building was demolished in 1978 and released for unrestricted use by DOE in July 1985. EPA, 

2012f 

4163 DOE released this area for unrestricted use in July 1985. EPA, 

2012f 

4228 EPA (2012c) did not find evidence that radioactive material was handled or stored in building 

4228. Americium is included as a radionuclide of interest due to the building’s proximity to 

building 4012 (SNAP facility).

EPA, 

2012c 

4273 This building served as the radioactive laundry facility until 1971. The building was demolished 

down to its foundation in 1975 and was cleared for unrestricted use by DOE in July 1985.

EPA, 

2012f 

4373 This building was used as part of the SNAP program. Following a 1988 survey of the building, it 

was reassigned for non-nuclear use. However, it was also reported at the time that the interior 

of the building had become dilapidated. EPA (2012e, p. 110) notes: “As of 1994, the building 

remained abandoned; however, it is unclear whether the condition of the building had been 

improved or changed since the 1988 survey report.” The building was eventually demolished in 

1999.

EPA, 

2012e 

4563 Building 4563 was a storage area for radioactive waste that had already been containerized and 

was awaiting shipment to an offsite disposal facility.

EPA, 

2012g 

4621 This building was RCRA-C permitted for storage of radioactive sources, packaged waste, and 

contaminated equipment. A single incident was documented after 1988 at the facility involving a 

faulty radiation alarm.

EPA, 

2012g 

4622 Building 4622 was used by health physics for sample counting of waste present at the RMHF. 

Therefore, americium and thorium are included as radionuclides of concern, as they were 

present at the RMHF and could have been included in the waste characterizations being 

performed in building 4622.

EPA, 

2012g 

4653 This building was used as an interim radioactive waste vault and was cleared by DOE for 

unrestricted use in July 1985.

EPA, 

2012f 

4654 Building 4654 was demolished in 1985. EPA, 

2012g 

4658 EPA (2012g) could not find evidence of specific radionuclides at building 4658. The site was 

used as the entry and exit point for all fuel and waste shipments. Therefore, it is assumed all 

radionuclides of concern for SSFL could have been present at building 4658.

EPA, 

2012g 

4664 Building 4664 was demolished in the early 1980s. EPA, 

2012g 
SC&A, Inc.

Evaluation of Petitioner Concerns, page 13 July 25, 2019

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Bldg. SC&A Summary of Pertinent Information from 2012 EPA Historical Site Assessment Ref.

4665 This building served as an oxidation facility, equipment and sodium storage for the RMHF. A 

later undated report identified in EPA (2012g, p. 140) noted the building was at one time used to 

store “paper, plastics, paints, filters, and lighting.” The radionuclides of concern for this building 

were developed based on its proximity to the RMHF and storage of materials previously 

contained in the RMHF.

EPA, 

2012g 

4668 Note: SC&A was unable not locate an HSA for “Building 4668” but did locate an HSA for 

“Building 4688” that appears consistent with the CORE Advocacy (2019) entry and is discussed 

below:

Building 4688 was designated as a nonradioactive chemical storage facility (acetone, alcohols, 

various solvents, reagent materials, paints, oils, and gasoline). However, it appears at some 

point in the mid-1970s there was an interim storage yard for the RMHF and SRE operations that 

was located in close vicinity to building 4688. Therefore, radionuclides of concern were 

identified based on the operations of the SRE and RMHF.

EPA, 

2012g 

4686 Building 4686 was demolished prior to 1978. A 1982 verification survey by Argonne National 

Laboratory (ANL, 1984) confirmed that the site area had been decontaminated below limits 

specified in the Draft ANSI Standard No. N13.12 and NRC (1982) guidelines.

EPA, 

2012f 

4689 This building was removed in 1967. A 1982 verification survey by Argonne National Laboratory 

(ANL, 1984) confirmed that the site area had been decontaminated below limits specified in the 

Draft ANSI Standard No. N13.12 and NRC (1982) guidelines. Furthermore, DOE released the 

area for unrestricted use in July 1985.

EPA, 

2012f 

4695 Building 4695 was completely demolished (including below-grade structures) in 1978. The area 

was released for unrestricted use in July 1985.

EPA, 

2012f 

4733 Site 4733 was demolished in the 1970s and was released for unrestricted use by DOE in 

July 1985.

EPA, 

2012f 

4773 This area is actually an 800,000-gallon retention pond. DOE released this area for unrestricted 

use in July 1985, and the pond was demolished sometime in 1988.

EPA, 

2012f 

4886 This area was primarily known as the Sodium Disposal Facility/Sodium Burn Pit. Particularly 

during 1960–1970, this area was used to dispose of combustible materials (kerosene, sodium, 

and sodium-potassium alloys (i.e., NaK)) that were contaminating test components from SRE, 

SNAP, and other nuclear program operations (valves, pumps, etc.). Cleanup of the disposal pit 

began as early as 1978 with the primary contamination related to cesium-137. However, the 

remediation does not appear to have been completed until 1994. 

EPA, 

2012h