Draft

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH

National Institute for Occupational Safety and Health

REVIEW OF REMAINING INTERNAL DOSE TOPICS 

RELATED TO THE EVALUATION OF SEC-00235 AT THE 

SANTA SUSANA FIELD LABORATORY

Contract No. 211-2014-58081 

SCA-TR-2019-SEC002, Revision 0 

Prepared by 

Milton Gorden

Bob Barton, CHP 

SC&A, Inc.

2200 Wilson Boulevard, Suite 300 

Arlington, VA 22201-3324 

Saliant, Inc.

5579 Catholic Church Road 

Jefferson, Maryland 21755 

February 20, 2019 

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 U.S.C. § 552a and has been cleared for distribution. 
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SC&A, INC.: Technical Support for the Advisory Board on Radiation and 

Worker Health Review of NIOSH Dose Reconstruction Program

DOCUMENT TITLE: Review of Remaining Internal Dose Topics Related to the 

Evaluation of SEC-00235 at the Santa Susana Field Laboratory

DOCUMENT NUMBER/

DESCRIPTION:

SCA-TR-2019-SEC002

REVISION NO.: 0 (Draft)

SUPERSEDES: N/A

EFFECTIVE DATE: February 20, 2019

TASK MANAGER John Stiver, MS, CHP [signature on file]

PROJECT MANAGER: John Stiver, MS, CHP [signature on file]

DOCUMENT 

REVIEWER(S): John Stiver, MS, CHP [signature on file]

Record of Revisions

Revision 

Number

Effective 

Date

Description of Revision

0 (Draft) 2/20/2019 Initial issue
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TABLE OF CONTENTS

Abbreviations and Acronyms ......................................................................................................... 4

1 Introduction and Background ................................................................................................. 6

1.1 Description of Issue 1 Presence of Thorium and Americium Post-1988 ....................... 7

1.2 Evaluation and Comparison of Available Air Sampling Data during the SEC 

Evaluation Period............................................................................................................ 8

2 Summary of SC&A Review.................................................................................................... 9

2.1 SRDB Documentation Review....................................................................................... 9

2.2 Review of Boeing Incident Database ............................................................................ 14

2.3 Comparison of General Air Sampling Results ............................................................. 17

3 Discussion ............................................................................................................................. 21

3.1 Presence of Thorium and Americium Post-1988 .......................................................... 21

3.2 Comparison of Radiological Conditions during Operational and CEP Period ............. 22

4 Summary Conclusion ............................................................................................................ 23

5 References............................................................................................................................. 24
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ABBREVIATIONS AND ACRONYMS

ABRWH Advisory Board on Radiation Worker Health 

Am americium

BZ breathing zone 

CAM continuous air monitor 

Ce cerium

CEP Controls for Environmental Pollution 

Ci curie

Co cobalt 

cpm counts per minute

Cs cesium

D&D decontamination and decommissioning 

DAC derived air concentration 

DOE U.S. Department of Energy 

dpm disintegrations per minute

EE energy employee 

ETEC Energy Technology Engineering Center 

Eu europium 

GA general air

GM Geiger Muller

HEPA high-efficiency particulate air

HPGe high-purity germanium

MPC maximum permissible concentration 

mrem millirem

μCi microcurie

μR micro roentgen 

NIOSH National Institute for Occupational Safety and Health

pCi picocurie 

Pu plutonium 

RIHL Rockwell International Hot Laboratory

RMDF Radioactive Material Disposal Facility

RMHF Radioactive Materials Handling Facility
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SEC Special Exposure Cohort 

SNAP Systems for Nuclear Auxiliary Power

Sr strontium 

SRDB Site Research Database

SSFL Santa Susana Field Laboratory 

Th thorium 

TRUMP-S Transuranic Management by Pyropartitioning-Separation 

USEPA United States Environmental Protection Agency 

WBC whole body count 
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1 INTRODUCTION AND BACKGROUND

In May 2017, the National Institute for Occupational Safety and Health (NIOSH) issued an 

evaluation report for Special Exposure Cohort ((SEC) Petition SEC-00235 for Area IV of the 

Santa Susana Field Laboratory (SSFL) for the period of August 1, 1991, to June 30, 1993 

(NIOSH 2017). SEC-00235 qualified for evaluation because of compromised bioassay samples 

from the vendor laboratory, Controls for Environmental Pollution (CEP), during this time period 

(the evaluated period is referred to as the “CEP period” in this report). NIOSH did not use the 

bioassay results from CEP because they were implicated in data falsification at another site (not 

SSFL affiliated). NIOSH found that, despite the lack of roughly 2 years’ worth of in vitro 

bioassay data, there was no dose reconstruction infeasibility for the evaluated period and did not 

recommend that a class be added to the SEC. To perform internal dose reconstruction during this 

period, NIOSH recommended use of the coworker models developed for Area IV and 

documented in ORAUT-OTIB-0080, Revision 00, Internal Coworker Dosimetry Data for Area 

IV of the Santa Susana Field Laboratory and the De Soto Avenue Facility (NIOSH 2014). 

However, two SEC-related issues subsequently arose: 

• Issue 1: The possible presence of thorium and americium isotopes that could potentially

represent a significant internal exposure hazard.

• Issue 2: The evaluation and comparison of air sampling data during the operational 

period and CEP period to demonstrate that the general radiological conditions during the 

CEP period are sufficiently bounded by the operational conditions. 

These two issues were discussed during the Area IV SSFL Work Group meeting held on 

December 4, 2017, at which time NIOSH was tasked with evaluating both concerns (ABRWH 

2017). NIOSH delivered two separate white papers on these subjects to the Area IV SSFL on 

November 6, 2018 (NIOSH 2018a, 2018b). This report represents SC&A’s review of those two 

white papers1

 based on currently available documentation. On January 28, 2019, the SEC-00235 

petitioner informed NIOSH that approximately 1,463 boxes of U.S. Department of Energy 

(DOE) records related to SSFL are scheduled to be made available no later than fall 2019. 

Therefore, this report may be considered an interim review contingent on future work group 

deliberations and potential actions in the evaluation of SEC-00235. 

1 Although NIOSH issued two separate white papers on these subjects, due to the general overlap of these two 

issues, SC&A elected to combine its review into this single report.

Sections 1.1 and 1.2 of this report describe the original work group discussion of these issues and 

give a summary of the NIOSH white paper conclusions for the two remaining SEC issues, 

respectively. Section 2 presents the results of SC&A’s interim review, and Section 3 discusses

these results in the context of the individual SEC issues. SC&A’s summary conclusion is 

presented in Section 4. 

 
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1.1 DESCRIPTION OF ISSUE 1 PRESENCE OF THORIUM AND AMERICIUM POST-1988

During the work group discussion on December 4, 2017, the work group noted that thorium and 

americium were not discussed as possible source terms for worker exposures for the residual 

period (post-1988) (ABRWH 2017). For the previous SEC evaluation (SEC-00234), a class was 

recommended to be added to the SEC because NIOSH found an infeasibility to reconstruct 

internal doses from thorium and americium radionuclides for the operational period of 1965–

1988 (NIOSH 2016). NIOSH was tasked by the work group to provide more detail and relevant 

references on the nature of the source term for thorium and americium after 1988 at Area IV 

SSFL (ABRWH 2017). Upon further research and evaluation of additional data, NIOSH 

prepared the white paper, Status of Operations involving Thorium and Americium at Area IV 

SSFL during the Remediation Period (1988 – present) (NIOSH 2018a). NIOSH presented this 

white paper to the Area IV SSFL Work Group on December 3, 2018 (ABRWH 2018a) and the 

Advisory Board on Radiation Worker Health (ABRWH) on December 12, 2018 (ABRWH 

2018b).

NIOSH concluded that by the end of the operational period, all of the highly radioactive fuel had 

been removed from the site, thus removing fission products and transuranics in the reactor fuel 

from SSFL by 1988. The NIOSH review noted that the SSFL facilities under remediation after 

1988 did not pose a “radiation exposure potential similar to the operational period” (NIOSH 

2018a, p. 7), and that the remaining radionuclides of concern at Area IV during the evaluated 

SEC period were cesium-137 (Cs-137), strontium-90 (Sr-90), cobalt-60 (Co-60), and 

plutonium-239 (Pu-239). NIOSH further concluded that “only Cs-137 and Sr-90 were present in 

sufficient quantity to be readily dispersed for inhalation by workers, and Cs-137 was considered 

the most important radionuclide of concern during this period” (NIOSH 2018a, p. 7). NIOSH 

2018a also stated that, “it is believed that the facility had at that point a state-of-the-art radiation 

protection program that was capable of detecting relevant radionuclides, and that those data are 

available for dose reconstruction” (NIOSH 2018a, p. 7). NIOSH, therefore, does not believe that 

the exposure potential to thorium-232 (Th-232) and americium-241 (Am-241) outlined in the 

SEC-00234 evaluation report continued during the remediation period (1989–present) (NIOSH 

2018a).

In this evaluation, SC&A addressed this conclusion in terms of whether it is possible that 

thorium and americium could be present during the remediation period (1989–present) and pose 

a potential internal exposure hazard to workers that may present a similar dose reconstruction 

infeasibility as the operational period. To accomplish this task, SC&A screened over 2,000 

records to determine their potential relevance to this issue and reviewed in detail hundreds of 

records contained in the Site Research Database (SRDB) for Area IV of the Santa Susana Field 

Laboratory – Ventura County, CA. SC&A reviewed a number of different types of records, dated

1988 and later, including air sampling results, contamination survey results, general air (GA) and 

breathing zone (BZ) data, air emission reports, environmental reports, accident/incident reports, 

engineering evaluations of facilities undergoing decontamination and decommissioning, and

other relevant planning/occurrence reports. SC&A reviewed this relevant documentation for 

evidence of thorium and americium to determine the extent of the presence of these 

radionuclides and their potential impact on dose reconstruction. 
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1.2 EVALUATION AND COMPARISON OF AVAILABLE AIR SAMPLING DATA DURING THE SEC

EVALUATION PERIOD

During the work group discussion on Area IV SSFL pertaining to SEC-00235 on December 4, 

2017, NIOSH was tasked by the work group to provide more information on the available air 

sample data for the period where in vitro bioassay data cannot be used (ABRWH 2017). The 

purpose of evaluating the air sampling data is to provide a meaningful comparison of the 

radiological conditions experienced by workers in both the operational period and CEP period. 

This comparison aids in establishing that the coworker intakes developed in ORAUT-OTIB0080 are sufficiently representative and/or bounding of the potential intakes experienced during 

the CEP period. Upon further research and evaluation of additional data, NIOSH prepared the 

white paper, Air Sample Data at Area IV SSFL in Support of SEC-00235 (NIOSH 2018b). 

NIOSH presented this white paper to the Advisory Board Work Group on Area IV of the SSFL 

on December 3, 2018 (ABRWH 2018a) and to the ABRWH on December 12, 2018 (ABRWH 

2018b). 

NIOSH found some additional BZ and GA data for Area IV during the period of August 1, 1991, 

to June 30, 1993, but no complete data sets for all quarters. NIOSH stated that data for the 

Rockwell International Hot Laboratory (RIHL) is available and can be considered bounding for 

the other facilities being decommissioned during this time period (the Systems for Nuclear 

Auxiliary Power (SNAP) reactor facility (T059) and the Radioactive Material Disposal Facility 

(RMDF)). Regarding the additional data that were found, NIOSH concluded that: 

There is no clear evidence that the general air and breathing zone data are in any 

way unusual, given the operational status of the facilities at the time. Elevated air 

samples and whole body count results are in line with the work that was being 

completed then. There were a few localized elevated samples observed during the 

1993 period, when bioassay are not useable for the first half of the year, but there 

is no indication that between the WBC and the bioassay sampling taking place in 

August would have led to significant missed exposures. Whole body counts and 

BZ samples were collected for workers in locations likely to receive an intake. 

Not all air and BZ data is available for all quarters and facilities, but it is believed 

this is because it has not been captured, not because it does not exist. There is no 

evidence that additional data capture for remaining quarters and facilities will lead 

to a different conclusion on the status of the air data or the feasibility to assess 

internal doses for Area IV SSFL using available data or the coworker model.

[NIOSH 2018b, p. 15] 

NIOSH reiterated during the December 3, 2018, meeting of the work group that there are 

sufficient data available to conduct dose reconstructions (ABRWH 2018a).

In this evaluation, SC&A addresses this conclusion in terms of whether the available air 

sampling data demonstrate that radiological conditions are sufficiently representative or 

bounding to allow for the appropriate application of operational coworker data to the CEP 

period. Sections 2.1 and 2.2 of this report provide an overview of documentation relevant to 

exposure conditions after the operational period and include specific references during the CEP 

period. Section 2.3 presents SC&A’s evaluation and comparison of the available air sampling 
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data for RIHL, which had the most complete dataset for comparison and was undergoing 

significant decontamination and decommissioning (D&D) activities during the CEP period.

2 SUMMARY OF SC&A REVIEW 

This section presents the results of SC&A’s review of the two currently outstanding SEC issues 

for SEC-00235. Section 2.1 describes SC&A’s review of available documentation found in the 

SRDB. Section 2.2 evaluates the incident/accident reports found in the petitioner-supplied 

Boeing Database. Section 2.3 presents SC&A’s evaluation and comparison of the GA sampling 

data for the occupational period and CEP period. 

2.1 SRDB DOCUMENTATION REVIEW

SC&A used the documentation review summarized in this section for both SEC issue 

evaluations. Specifically, SC&A reviewed the SRDB documentation to determine if the presence 

of thorium and americium post-1988 represents a significant internal exposure hazard such that it 

represents an infeasibility similar to the operational period (Issue 1). SC&A also reviewed source 

documentation to determine if significant radiological conditions were likely to exist such that 

use of operational coworker data would not bound internal dose potential during the CEP period 

(Issue 2). In the context of Issue 2, and given the nature of the D&D work occurring during the 

CEP period, SC&A focused on noted incidents of contamination. Table 1 summarizes the results 

of SC&A’s document review. 

Table 1 Summary of Document Reviews on the Site Research Database

SRDB 

No. Title Summary of Contents Related to Thorium and Americium

SRDB 

22140 

Energy Technology 

Engineering Center – 

Site Description

(NIOSH 2006) 

P. 24: “As a result of the work in the Hot Lab, the interior 

of the Hot Cells and the equipment they contain have been 

contaminated by small amounts of uranium, plutonium, 

thorium, and fission and activation products.... This

radioactivity will be removed when the Hot Lab is 

decontaminated and decommissioned.” The only mention 

of americium is associated with the TRUMP-S program, 

but these materials were transported offsite prior to 1988

(p. 26). It should be noted that Am-241 was also present 

in sealed sources as well as contained in industrial smoke 

detectors at multiple facilities at the Energy Technology 

Engineering Center (ETEC). 
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SRDB 

No. Title Summary of Contents Related to Thorium and Americium

SRDB 

157608

Radioactive Materials 

Handling Facility 

Decontamination and 

Decommissioning 

Engineering 

Evaluation/Cost 

Analysis

(Boeing 2007)

Section 2.1, page 7, states that Th-232 and Am-241 have 

the potential to be present at the Radioactive Materials 

Handling Facility (RMHF).

SRDB 

166494

Estimation of 

Radioactive Contents 

of RIHL Liquid Waste 

Tank Sludge

(Rockwell 1994)

The report describes the measured activity of the sludge 

contained inside an onsite tank. Th-232 activity 

concentration was within background. Am-241 total 

activity in the sludge was 2.14 μCi out of a total of 

1,026.324 μCi (or about 1 Ci) for all radionuclides.

SRDB 

73536

U.S. Department of 

Energy Radionuclide 

Air Emissions Annual 

Report for Calendar 

Year 1995

(Rockwell 1996)

RMHF. Annual air emissions (after HEPA filter 99.97% 

efficient): Am-241 = 1.4E-10 Ci.

SRDB 

170399

U.S. Department of 

Energy Radionuclide 

Air Emissions Annual 

Report for Calendar 

Year 1991

(Rockwell 1992a)

Section 2 of the report states that thorium and Am-241 are 

present at the RMDF, but it does not specify if the 

material is in the form of contamination or packaged 

waste material. Section 3, paragraph 9, shows Th-232 and 

Am-241 as both being omitted from the dose evaluation 

because they were less than the detection limit. Th-232 is 

not associated with T059 (SNAP) in the report, but 

Am-241 is associated with SNAP but at less than 

detectable quantities.

However, Section 4 of the report provides calculated 

doses to an offsite receptor and indicates that Th-232 and 

Am-241 represented 2.9% and 0.6% of the total dose, 

respectively.

SRDB 

170364

Radioactive Material 

Handling Facility 

Sample Analyses 

January 1998–April 

2001 

(Teledyne Brown 

1998–2001)

There are results for Th-232 on filter media on the order 

of 0.01 to 4 pCi, but the error was larger than the values 

except for five instances when the values were about 

1 pCi. For Am-241, the majority of filter sample results 

were less than detectable, with one smear reading of 

130 pCi.
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SRDB 

No. Title Summary of Contents Related to Thorium and Americium

SRDB 

170373 

Radioactive Materials 

Handling Facility 

Reviewed Surveys 

Area and Smear 

Surveys and Air Data 

December 1998, 1999, 

and January 2000 

(Boeing 2000a) 

Radiation surveys of controlled area boundaries included 

investigation for alpha contamination with all surveys 

being less that detectable. Smears for alpha contamination 

on departing transportation vehicles were likewise less 

than detectable. There are some air sampling records 

showing alpha readings on the order of E-14 to E-17 

μCi/cc in the vault, decontamination room, and package 

room. These values are much lower than the DAC for 

Am-241 (3E-12 μCi/cc) and Th-232 (1E-12 μCi/cc).

SRDB 

170375 

Radioactive Materials 

Handling Facility Air 

and BZ Data April – 

May 2000 

(Boeing 2000b) 

Air sampling records showing alpha readings on the order 

of E-14 to E-16 μCi/cc. These values are much lower than 

the DAC for Am-241 (3E-12 μCi/cc) and Th-232 (1E-12 

μCi/cc).

SRDB 

170391 

Decontamination and 

Decommissioning 

T020 CAM, BZ and 

HEPA Exhaust Air 

Sample Logs 

(Boeing 1998a) 

Air sampling records from 1998 showing alpha readings 

on the order of E-13 to E-15 μCi/cc. These values are 

much lower than the DAC for Am-241 (3E-12 μCi/cc) 

and Th-232 (1E-12 μCi/cc).

SRDB 

114216 

Summary Site 

Environmental Report 

Radiological Doses 

and Releases 1990 – 

1994 

(DOE 2001) 

Table 3.1, p. 3-8: Most of the air emissions are from 

fission products (E-5 to E-6 Ci). Total strontium and total 

uranium were measured at levels of E-6 to E-10 Ci. Other 

actinides varied by several orders of magnitude (E-9 and 

E-16 Ci). Table 3.3, p. 3-20: There were no liquid releases 

containing radionuclides. There is no indication in the 

report that these air emissions resulted from activities that 

represented an internal exposure hazard to workers at 

SSFL.

SRDB 

169468 

Radiological Incidents 

in the 1980s 

(Rockwell 1989d) 

PDF p. 213: October 4, 1989. In RIHL (Building 20), an 

employee bumped a “Unistrut” brace with sharp burr and 

punctured 

 in a glovebox for plutonium handling with 

possible Pu-239 contamination. A survey meter and 

smears showed background levels of contamination. 

There is no indication that Am-241 or Th-232 were also 

present in the glovebox, though it is worth noting that the 

puncture incident immediately triggered a 

.
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SRDB 

No. Title Summary of Contents Related to Thorium and Americium

SRDB 

169468 

Radiological Incidents 

in the 1980s 

(Rockwell 1989d) 

PDF pp. 214–216. November 9, 1989. Equipment arrived 

from Stanford University that had radiation levels up to 

60 μR. The contamination was evaluated and determined 

to be Co-60. There was no indication of transuranic 

activity also present on the contaminated equipment. 

SRDB 

169476 

Historical Rad 

Incidents ETEC-SSFL 

1990s 

(Rockwell 2017) 

PDF p. 4: April 18, 1990. RIHL (T020) Cell 2. Incident 

involving a puncture 

 contaminated to 120 pCi, which cut 

. Bioassay was requested but no indication 

of alpha survey measurements was indicated. The 

document notes “see attachment,” but no attachment is 

provided in the file. There was no observed evidence in 

the incident report that indicates transuranic activity might 

have been involved. 

SRDB 

169476 

Historical Rad 

Incidents ETEC-SSFL 

1990s 

(Rockwell 2017) 

PDF p. 7: July 17, 1990. RIHL (T020).

 and was contaminated . 

Nothing other than the 300 cpm exit survey was noted. 

However, a bioassay follow-up was recommended.

SRDB 

169476 

Historical Rad 

Incidents ETEC-SSFL 

1990s 

(Rockwell 2017) 

PDF p. 8: August 9, 1990. Power tool incident involving a 

cut in the RMDF. Only beta-gamma surveys were made, 

which is likely indicative of no alpha/transuranic material 

likely to be present. Report indicates bioassay as “results 

pending,” but it is unclear what type of bioassay. 

However, since the incident occurred within the CEP 

period, any subsequent bioassay would likely be invalid. 

SRDB 

169476 

Historical Rad 

Incidents ETEC-SSFL 

1990s 

(Rockwell 2017) 

PDF p. 21: SNAP (T059) Test Cell l. September 2, 1992. 

Shoe became contaminated during a torching operation; 

only beta-gamma surveys are indicated, which may 

indicate insignificant transuranic/alpha contamination was 

present. 

SRDB 

169476 

Historical Rad 

Incidents ETEC-SSFL 

1990s 

(Rockwell 2017) 

PDF p. 54: T373 roof. August 22, 1995. Radioactive 

filters discovered. It appears only beta surveys were taken, 

and the contamination was determined to be 

predominantly Cs-137. No indication of worker exposures 

was observed in the incident report. 

SRDB 

169476 

Historical Rad 

Incidents ETEC-SSFL 

1990s 

(Rockwell 2017) 

PDF p. 18: SNAP (T059) restricted area. Date redacted. 

Airborne Co-60 detected during “open tent torching in the 

test cell area.” The EEs involved were referred for 

bioassay analysis. There was no indication in the report of 

transuranic activity also being present. 
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SRDB 

No. Title Summary of Contents Related to Thorium and Americium

19124 Rocketdyne Propulsion 

& Power DOE 

Operations Annual Site 

Environmental Report 

1996 (Boeing 1997) 

Refers to thorium only in the context of naturally 

occurring radioactivity. Americium not mentioned. 

19125 Rocketdyne Propulsion 

& Power DOE 

Operations Annual Site 

Environmental Report 

1997 (Boeing 1998b) 

Refers to thorium only in the context of naturally 

occurring radioactivity. Americium not mentioned. 

In addition to the documents described in Table 1, the SRDB contained an interview with a 

former SSFL worker who worked as the beginning in 1992. The EE 

stated the following about the source term of concern at SSFL during D&D operations: 

Our source-term inventory was overwhelmingly Cs-137/Sr-90. Building 59 was 

Co-60 and some other activation products (that had mostly disappeared when we 

started D&D). In most cases, Cs-137 or Co-60 were reliable indicators for the 

overall inventory (i.e., if Cs-137, Co-60 values were in range, one could be 

comfortable that the other possible isotopes were in range as well)... 

As the various ETEC activities were terminated, the potential exposures to alphaemitters reduced significantly. As mentioned above, the primary isotopes of 

concern became Cs-137 and Co-60. While alpha-emitters were also part of the 

source-terms in Building 20 and the RMHF, these were at very low levels and 

were not routinely found in the contamination surveys of these locations. Thus, 

Whole Body Counting became a very viable screening methodology for the site. 

[Documented Communication 2017, pp. 5–7] 

Furthermore, an interview with the former 

D&D and environmental radiation remediation beginning in 1990 stated the following about 

americium and thorium exposure potential: 

It is my opinion that Am-241 and thorium would have been minor contributors, if 

any, to internal dose. It is likely that this rationale is why there were relatively few 

bioassay requests made historically for these radionuclides.

If Am-241 and thorium had been a significant internal dose contributor in the 

workplace of SSFL or De Soto, then it would logically have also been a potential 

environmental contaminant. This is not the case as demonstrated by the USEPA. 

The USEPA Area IV Radiological Study (2009–2012) took 3,735 soil and 

sediment samples at surface and subsurface analyzing all samples for 54 

radionuclides, including Am-241 and thorium isotopes. Only 3 of 3,735 soil 

samples contained americium-241 that exceeded background, by only several 
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hundredths of a picocurie. Only 5 of 3,735 soil samples had thorium-232 and 228 

that exceeded background (at only 10% over background). So, neither americium 

nor thorium are or were an environmental issue. One could arguably extrapolate 

back and imply that it was also not a workplace issue at SSFL or at De Soto, or at 

least, less so than uranium, plutonium, and mixed fission products, for which we 

had more than adequate bioassay data. [Documented Communication 2018, 

pp. 5–6] 

2.2 REVIEW OF BOEING INCIDENT DATABASE

In addition to captured documents contained in the SRDB, the petitioner for SSFL supplied 

NIOSH with a number of documents collectively known as the “Boeing Incident Database” 

during the ABRWH meeting on December 13, 2018.2 There are approximately 1,500 files 

contained in the database, a portion of which are relevant to the period after 1988. SC&A 

reviewed the relevant files to determine if there are any indications of accidents/incidents that 

were related to inhalation or contamination involving americium and/or thorium. In addition, 

SC&A evaluated the available incident files to characterize the health physics oversight program 

in place during the CEP period. Table 2 summarizes the contents of these accident and incident 

reports. Note that all files in the Boeing Database described as “occurrence reports” were related 

to non-radiological incidents and thus are not discussed further in this report.

2 NIOSH subsequently made these accident and occurrence reports available to SC&A and the work group. They

can be found on the Division of Compensation Analysis and Support internal server at aspp-dcas-files\ABRWH\AB 

Document Review\Santa Susana\Boeing_FlashDrive.

Table 2 Summary of Accident and Occurrence Reports Pertaining to Environmental and 

Personnel Contamination

ID No. Title Summary of Relevant Contents 

A0665 Radiological Incident 

Report 

(Rockwell 1995a) 

August 29, 1995: Contaminated soil at Area IV G Street. 

Radiation levels from the two hottest spots were 

244 μR/hr contact, 40 μR/hr at 1 meter; and 73 μR/hr 

contact, 31 μR/hr at 1 meter. The report determined there 

was no impact on personnel at SSFL. 

A0663 Radiological Incident 

Report 

(Rockwell 1995b) 

August 8, 1995: Page 1 of the file. Soil contamination 

found in T064 side yard. Identified as Cs-137 

(271 pCi/g). Spot is scheduled for remediation. The 

report determined there were no safety concerns, as the 

surface radiation is only 3 times background and the 

Cs-137 concentration is too low to be an inhalation 

concern. 

A0580 Radiological Safety 

Report 

(Rockwell 1993a) 

August 6, 1993. In the RMDF T021 laundry room, 

Cs-134, Cs-137, and Co-60 contamination was found on 

the room intake grill associated with the air conditioner.

A survey of the room indicated no detectable activity. 

 
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ID No. Title Summary of Relevant Contents 

A0575 Radiological Safety 

Report 

(Rockwell 1993b) 

September 15, 1993. In RIHL T020, 

 drain piping found dosimeter off 

scale. in a High Radiation Area. 

measured dose from the dosimeter was calculated to be 

182 mrem. The source of radiation was not specified; 

however, no indications of alpha contamination were 

observed in the incident report. 

A0571 Radiological Safety 

Report 

(Rockwell 1993c) 

June 17, 1993. In Building 20 basement (RIHL).

Contamination found on 

 from a vent duct that had serviced Cell 3. 

Contamination found on . HP found 1,000–

2,000 cpm using a survey meter. A bioassay was 

requested; however, since this incident occurred during 

the CEP period, any such bioassay would likely be 

invalid. The nature of the contamination was not 

specified, so it is not known if any transuranic material 

might have been present. 

A0307 Radiological Safety 

Report 

(Rockwell 1992b) 

December 3, 1992. In SNAP (T059), a worker discovered 

 dosimeter was off scale 

 in test cell L. The report indicates the 

exposure was potentially due to exposure of activated 

steel behind the wall being removed. The dose rate at the 

wall was about 300 μCi/hr. No bioassay was performed; 

however, activated steel contained in a facility wall 

would not contain transuranic material but rather would 

consist of fission and activation products. 

A0217 Radiological Safety 

Report 

(Rockwell n.d.-b) 

Date redacted. A radiological survey of the internal 

Respirator Lab washer at Building T100 in Room 130 

using a GM survey meter that showed no detectable 

activity. A smear wipe was taken and counted on a 

Tennelec 5100 counter, showing 173 dpm/100 cm2 beta.

Gamma spectrometry indicated 254 dpm/100 cm2 of 

Cs-137. Report recommends better decontamination 

practices and routine surveying of the respirators. No 

indication of alpha or transuranic contamination was 

indicated in the report.

A0212 Radiological Safety 

Report 

(Rockwell 1991) 

January 17, 1991. In SNAP electrical room, floor 

sweepings found with a trace of Co-60 (0.85 pCi/g). No 

worker exposures were identified. As a result, the 

penetrations into the high bay were taped over to prevent 

possible migration of radionuclides into the room. 
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ID No. Title Summary of Relevant Contents 

A0211 Radiological Safety 

Report 

(Rockwell n.d.-a)

November 15, 1990. In the RMDF, found contaminated 

 at about 30,000 dpm beta/gamma 

direct reading. Gamma spectroscopy of Ce-144, Cs-137, 

and Co-60. A bioassay was recommended for the EE. 

A0209 Radiological Safety 

Report 

(Rockwell 1990a) 

October 2, 1990. In the T021 Decon Room, a worker 

detected contamination on up to 

2,000 cpm on an exit survey after unloading equipment 

from a storage box. Cause was from handling cables and 

body perspiration from working in a full-face respirator.

Radionuclides included Co-57, Cs-137, Cs-134, and Co58. A bioassay was recommended for the EE. 

A0206 Radiological Safety 

Report 

(Rockwell 1990b) 

May 8, 1990. In T059 (SNAP),

. Fixed 

contamination of 300 cpm was found, and the were 

disposed of. decontaminating 

vacuum equipment room shield blocks. The 

contamination was identified as Co-60. A bioassay was 

recommended for the EE. 

A0199 Radiological Safety 

Report 

(Rockwell 1989a) 

June 29, 1989. In Building 20 (RIHL) Cell #2 and Decon 

#I, (7,000 

cpm and 1,000 cpm) while electropolishing. Believed the 

contamination came from the red line laundry. 

. No 

bioassays were recommended. The report does not 

specify the type of contamination. 

A0198 Radiological Safety 

Incident Report 

(Rockwell 1989b) 

June 6, 1989. In Building 20 (RIHL) Cell #1, two 

workers were contaminated during decontamination and 

decommissioning operations. 

. A survey meter 

measured 6,000 cpm and 12,000 cpm beta/gamma for the 

two workers, respectively. No bioassays were 

recommended. There is no indication of measurable alpha 

contamination indicated in the report. 

A0197 Radiological Safety 

Incident Report 

(Rockwell 1989c) 

April 6, 1989. In the lower level of SNAP (T059), during 

the changing of exhaust filters, a worker noticed a cloud 

of dust from the box of filters when it fell to the ground. 

 (4,350 dpm) and (5,800 dpm) were 

decontaminated. Dust was analyzed on a T100 HPGe 

detector (700 dpm/100 cm2). Nasal smears were taken 

(132 dpm). The report identified Co-60 as the 

radionuclide involved. 
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ID No. Title Summary of Relevant Contents 

A0190 Radiological Safety 

Incident Report 

(Rockwell 1988a) 

September 30, 1988. Building 20 (RIHL) Cell #1. An 

employee found contamination on with a 

maximum of 3,500 dpm beta/gamma using a “T/A pug 

IA.” a No bioassay was recommended. There is no 

indication of measurable alpha contamination mentioned 

in the report.

A0189 Radiological Safety 

Incident Report 

(Rockwell 1988b) 

August 19, 1988. In SNAP (T059), an employee was 

.

. No 

radioactivity from nasal and facial smears. The work area 

air sample indicated 1.5E-11 μCi/cc, below the MPC 

level of 9E-9 μCi/cc for airborne beta/gamma 

contamination. Bioassay was recommended for the 

worker involved. Co-60 is noted as the contaminant of 

interest in the report.

A0188 Radiological Safety 

Incident Report 

(Rockwell 1988c) 

August 15, 1988. In the RMDF (T075), there was an 

accidental release of about 40 grams of radioactivated 

sand from waste drums (24,000 dpm beta/gamma) due to 

a forklift puncturing the drum. No bioassay was 

recommended. There is no indication of measurable alpha 

contamination mentioned in the report. Activated sand is 

not likely to contain transuranic material.

A0187 Radiological Safety 

Incident Report 

(Rockwell 1988d) 

August 12, 1988. In the SNAP (T059) pipe chase room, a 

worker was contaminated with 17,500 dpm 

beta/gamma/100 cm2. Identified radionuclides included 

Co-60, Eu-152, and Eu-154. Bioassay was recommended

for the EE. Nasal smears showed up to 12 dpm. There is 

no indication of measurable alpha contamination 

mentioned in the report.

IR01684 Incident Report 

(Boeing 2003) 

February 26, 2003. Area IV, Building 4057. During a 

routine records search of file cabinet drawer F-25C, a 

package of air samples was discovered that had 

measurable internal contamination using a Ludlum 3 

frisker that indicated approximately 2–3 times 

background. The envelopes had been put in the file 

cabinet in September 1976. The package was transferred 

to the RMHF. a SC&A believes “T/A put IA” to represent the Technical Associates Survey Meter: pug 1A. 

2.3 COMPARISON OF GENERAL AIR SAMPLING RESULTS 

To evaluate the relative internal exposure potential between the operational period (pre-1989) 

and CEP period (approximately 1991–1993), SC&A compiled and analyzed the GA sampling 

reports for RIHL from 1975 through 1993. SC&A chose RIHL due to the relative amount of data 
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available for that location as well as the nature and extent of D&D activities occurring during the 

CEP period.

3

 SC&A examined both the average and maximum quarterly air sampling values for 

gross alpha and gross beta activity, when available, to compare the two periods. Figures 1–4 

show the results of this comparison; Section 3.2 discusses the air sampling analysis.

3 As noted in NIOSH 2006, the radioactive material license for RIHL was modified in 1990 to include only D&D 

activities.

Figure 1. Maximum General Air Beta Air Sampler Results for RIHL (1976–1993) 

 

Source: Rockwell 1980a, p. 18; 1980b, p. 17; 1980c, p. 13; 1980d, p. 13; 1983, p. 13; 1985, 

p. 17; 1984, p. 14; 1986a, p. 20; 1986b, p. 17; 1986c, p. 18; 1988e, p. 17; 1988f, p. 15; 1989e, 

p. 25; 1993d, pp. 18–20, 57–59, 97–98, 146–147, 173–174, 189–197, 246–254, 295–303, 364–

372, 429–437, 483–492, 531–539.
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Figure 2. Average General Air Beta Air Sampler Results for RIHL (1976–1993) 

Source: Rockwell 1980a, p. 18; 1980b, p. 17; 1980c, p. 13; 1980d, p. 13; 1983, p. 13; 1985, 

p. 17; 1984, p. 14; 1986a, p. 20; 1986b, p. 17; 1986c, p. 18; 1988e, p. 17; 1988f, p. 15; 1989e, 

p. 25; 1993d, pp. 18–20, 57–59, 97–98, 146–147, 173–174, 189–197, 246–254, 295–303, 364–

372, 429–437, 483–492, 531–539. 
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Figure 3. Maximum General Air Alpha Air Sampler Results for RIHL (1982–1993) 

Source: Rockwell 1980a, p. 18; 1980b, p. 17; 1980c, p. 13; 1980d, p. 13; 1983, p. 13; 1985, p. 17; 

1984, p. 14; 1986a, p. 20; 1986b, p. 17; 1986c, p. 18; 1988e, p. 17; 1988f, p. 15; 1989e, p. 25; 

1993d, pp. 18–20, 57–59, 97–98, 146–147, 173–174, 189–197, 246–254, 295–303, 364–372, 429–

437, 483–492, 531–539.
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Figure 4. Average General Air Beta Air Sampler Results for RIHL (1982–1993) 

Source: Rockwell 1980a, p. 18; 1980b, p. 17; 1980c, p. 13; 1980d, p. 13; 1983, p. 13; 1985, p. 17; 

1984, p. 14; 1986a, p. 20; 1986b, p. 17; 1986c, p. 18; 1988e, p. 17; 1988f, p. 15; 1989e, p. 25; 

1993d, pp. 18–20, 57–59, 97–98, 146–147, 173–174, 189–197, 246–254, 295–303, 364–372, 429–

437, 483–492, 531–539.

3 DISCUSSION

This section discusses the documentation review and data analysis presented in the previous 

section in the context of the two remaining SEC issues. Specifically, Section 3.1 discusses the 

potential presence of americium and thorium during the D&D period and the implications for 

dose reconstruction feasibility. Section 3.2 discusses the comparison of air sampling data 

between the operational and CEP periods in order to evaluate the relative internal exposure 

potential during the two periods. 

3.1 PRESENCE OF THORIUM AND AMERICIUM POST-1988 

SC&A reviewed the documents shown in Tables 1 and 2 above to determine if there were 

significant quantities of thorium (Th-232) and americium (Am-241) present post-1988 at 

Area IV to determine the feasibility of dose reconstruction to these potential contaminants. 

Boeing 2007 (see Table 1) states that both thorium and americium could be present at RMHF 

based on process history. This conforms to statements in the ETEC site description technical 

basis document (NIOSH 2006) that thorium could be present in RIHL. However, NIOSH 2006 

goes on to state that americium associated with the Transuranic Management by 

Pyropartitioning-Separation (TRUMP-S) program was shipped to SSFL but was later removed to 
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the University of Missouri. It has not been established that TRUMP-S work was ever actually 

undertaken at SSFL; therefore, it is likely the material was only stored at the site. The DOE

radionuclide air emissions annual report for calendar year 1991 (Rockwell 1992a) states that 

thorium and americium are present at the RMDF, but no additional information is provided about 

the form in which these radionuclides would exist (packaged, encapsulated, etc.). Rockwell 

1992a appears to contradict itself in that Section 3 of that report states that americium and 

thorium have been omitted from the offsite receptor dose evaluation because the calculated 

releases were below the level of detection. However, Section 4 of Rockwell 1992a indicates that 

Th-232 and Am-241 contributed 2.9% and 0.6% of the total dose to an offsite receptor (the 

calculated doses were several orders of magnitude less than 1 mrem). Two interviews with 

former workers with technical expertise4 and direct involvement in of 

D&D operations at SSFL did not indicate that significant exposure potential to americium and/or 

thorium during those operations was likely (Documented Communication 2017, 2018). 

4 Interviewees included the during the period of 

interest.

SC&A reviewed radiological surveys, incidents involving area and personnel contamination, and 

process descriptions and could not find thorium or americium mentioned as being present as an 

internal exposure hazard, although other radionuclides were identified (e.g., cesium-137). 

Surveys were predominantly for beta-gamma, although SC&A did find measurements of alpha 

contamination in SRDB 170373, SRDB 170375, and SRDB 170391. However, these measured 

values were much less than the derived air concentration (DAC) for Am-241 and Th-232 

(3×10-12 and 1×10-12 microcuries per cubic centimeter (μCi/cc), respectively). SC&A reviewed 

the incident and accident reports provided by the SSFL petitioner, and none of these reports 

identified thorium or americium as being present in any measurable quantity (see Table 2). The 

only mention of an incident involving alpha activity involved a glovebox that was contaminated 

with plutonium. SC&A identified two annual environmental reports (Boeing 1997, 1998b). Both 

reports referred to thorium as being present in the surrounding environment of Area IV in 

naturally occurring amounts, and neither identified the presence of americium. 

3.2 COMPARISON OF RADIOLOGICAL CONDITIONS DURING OPERATIONAL AND CEP PERIOD

As noted in Section 2.2, several incidents of contamination that may represent an internal 

exposure potential are documented during the post-1988 period. However, in these cases health 

physics follow-up occurred, and in most cases bioassay was recommended. Although follow-up 

bioassay would not be valid during the CEP period, a routine in vivo monitoring program was 

also in place during this period that would detect any intakes of gamma-emitting fission and 

activation products likely to be present at SSFL during the evaluated period. The sole incident 

identified involving alpha contamination was a incident in a plutonium glovebox. Followup bioassay for the incident occurred in 1989 when a viable bioassay program was in place, 

although the results of the bioassay are not known at this time. 

A comparison of GA air samples at both the maximum and average quarterly levels demonstrates 

that the measured values for controlled areas during the CEP period were bounded by the 

operational period for both gross beta and gross alpha measurements. Furthermore, quarterly GA 

air samples during the CEP period were all several orders of magnitude below the maximum 

 
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permissible concentration (MPC) for both alpha and beta airborne contamination. SC&A did not 

identify any evidence in the available air sampling data to suggest that internal exposure 

potential to the radionuclides of concern at SSFL would not be bounded by the operational 

bioassay data.5

 

5 It should be noted that 15 findings and 10 observations from SC&A’s 2014 review of the SSFL coworker model 

remain open (SC&A 2014). However, several of these findings and observations have been obviated by SEC-00234, 

and the remaining issues are not considered items that might preclude dose reconstruction.

4 SUMMARY CONCLUSION

Based on the review of relevant available documentation in the SRDB, as well as relevant 

incident documentation found in the Boeing Incident Database provided by the petitioner, SC&A 

did not identify evidence of internal exposure potential to americium and/or thorium sources that 

would preclude dose reconstruction feasibility. However, the operational history of americium 

and thorium exposure was clearly established in SEC-00234 and then described in Boeing 2007 

as decontamination and decommissioning contaminants of interest. NIOSH 2006 and Rockwell 

1992a indicate that thorium and americium could be present as potential sources of exposure. 

NIOSH 2010 reaffirms americium and thorium as a potential source of exposure and provides 

environmental intakes of both radionuclides based on stack emissions at ETEC. Given the 

uncertainty related to off-normal work conditions associated with decontamination and 

decommissioning activities, NIOSH might consider establishing an occupational exposure 

model, in place of an environmental intake model, that uses available air sampling results (BZ

and GA) or some fraction of the administrative limits in place at the time. This might be 

particularly important if BZ data is not generally provided in a claimant’s dosimetry file. This 

would assure a claimant favorable and bounding dose assignment for thorium and americium. 

With regard to Item 2, SC&A found no evidence in either the available documentation or GA air 

sample data that radiological conditions were significantly different from the operational period 

that would preclude the use of coworker intake models developed for uranium, plutonium, and 

fission/activation products (strontium and cesium) during the CEP Period. Although, there are 

several outstanding findings/observations associated with the SSFL coworker model that are still 

under consideration by the ABRWH (SC&A 2014), SC&A does not consider these outstanding 

findings/observations to be SEC issues at this time. SC&A believes the remaining coworker 

issues can be resolved via the site profile review process. 

Finally, it must be noted that the SEC petitioner notified NIOSH on January 28, 2019, that 

approximately 1,463 boxes of DOE records relevant to SSFL are scheduled to be made available 

no later than fall 2019. Therefore, the analysis and conclusions contained in this report may be 

considered an interim evaluation pending future work group deliberations and/or SEC-00235 

action concerning the discovery of these records. 

 
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5 REFERENCES

ABRWH 2017. Transcript: Meeting of the Advisory Board on Radiation and Worker Health, 

Area IV of the Santa Susana Field Laboratory Work Group. December 4, 2017. [SRDB Ref. ID

174359]

ABRWH 2018a. Transcript: Advisory Board on Radiation and Worker Health, Santa Susana 

Field Laboratory Work Group. December 3, 2018.

ABRWH 2018b. Transcript: 126th Meeting of the Advisory Board on Radiation and Worker 

Health, Redondo Beach, CA. December 12, 2018. 

Boeing 1997. Rocketdyne Propulsion & Power DOE Operations Annual Site Environmental 

Report 1996, RD97-134, Boeing. November 10, 1997. [SRDB Ref. ID 19124]

Boeing 1998a. Decontamination and Decommissioning T020 CAM, BZ and HEPA Exhaust Air 

Sample Logs. [SRDB Ref. ID 170391]

Boeing 1998b. Rocketdyne Propulsion & Power DOE Operations Annual Site Environmental 

Report 1997, A4CM-AR-0012, Boeing North America, Inc. November 23, 1998. [SRDB Ref ID: 

19125]

Boeing 2000a. Radioactive Materials Handling Facility Reviewed Surveys Area and Smear 

Surveys and Air Data December 1998, 1999, and January 2000, Boeing. [SRDB Ref. ID 170373]

Boeing 2000b. Radioactive Materials Handling Facility Air and BZ Data April – May 2000, 

Boeing. [SRDB Ref. ID 170375]

Boeing 2003. Incident Report, IR Number IR01684. 2003.

Boeing 2007, Radioactive Materials Handling Facility Decontamination and Decommissioning 

Engineering Evaluation/Cost Analysis, Boeing Company. June 18, 2007 [SRDB Ref. ID 157608]

DOE 2001. Summary Site Environmental Report Radiological Doses and Releases 1990 – 1994, 

DOE/EH-0644, U.S. Department of Energy Office of Environmental Policy and Guidance.

September 2001. [SRDB Ref. ID 114216]

Documented Communication 2017. Documented Communication SEC-00235 with [Name 

Redacted] on Area IV SSFL. May 10, 2017. [SRDB Ref. ID 166848]

Documented Communication 2018. Documented Communication SEC-00246 with [Name 

Redacted] on Potential Exposure to Americium or Thorium at De Soto Avenue Facility. May 1, 

2018. Interview conducted on May 1, 2018. [SRDB Ref. ID 172299]

NIOSH 2006, Energy Technology Engineering Center – Site Description, ORAUT-TKBS-0038-

2, Revision 00, National Institute for Occupational Safety and Health, Cincinnati, OH. February 

2, 2006 [SRDB Ref. ID 22140]
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NIOSH 2010. Area IV of the Santa Susana Field Laboratory, the Canoga Avenue Facility, the 

Downey Facility, and the De Soto Avenue Facility (sometimes referred to as the Energy 

Technology Engineering Center [ETEC] or Atomics International) – Occupational 

Environmental Dose, ORAUT-TKBS-0038-4, Revision 02, National Institute for Occupational 

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NIOSH 2014. Internal Coworker Dosimetry Data for Area IV of the Santa Susana Field 

Laboratory and the De Soto Avenue Facility, ORAUT-OTIB-0080, Revision 00, National 

Institute for Occupational Safety and Health, Cincinnati, OH. March 14, 2014.

NIOSH 2016. SEC Petition Evaluation Report, Petition SEC-00234, Area IV of the Santa Susana

Field Laboratory, National Institute for Occupational Safety and Health, Cincinnati, OH. October 

11, 2016.

NIOSH 2017. SEC Petition Evaluation Report, Petition SEC-00235, Area IV of the Santa Susana 

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11, 2017. [SRDB Ref. ID 174360]

NIOSH 2018a. Status of Operations involving Thorium and Americium at Area IV SSFL during 

the Remediation Period (1988 – present): White Paper, National Institute for Occupational 

Safety and Health, Cincinnati, OH. November 6, 2018.

NIOSH 2018b. Air Sample Data at Area IV SSFL in Support of SEC-00235: White Paper,

National Institute for Occupational Safety and Health, Cincinnati, OH. November 6, 2018.

Rockwell n.d.-a. Radiological Safety Report, A0211, Rockwell International. Date redacted.

Rockwell n.d.-b. Radiological Safety Report, A0217, Rockwell International. Date redacted.

Rockwell 1980a. Annual Review of Radiological Controls - 1976, Rockwell International.

April 28, 1980. [SRDB Ref. ID 19136]

Rockwell 1980b. Annual Review of Radiological Controls - 1977, Rockwell International.

May 27, 1980. [SRDB Ref. ID 19135]

Rockwell 1980c. Annual Review of Radiological Controls - 1978, Rockwell International.

August 6, 1980. [SRDB Ref. ID 19134]

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Rockwell 1985. Annual Review of Radiological Controls - 1982, Rockwell International. January 

29, 1985. [SRDB Ref. ID 19130]

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February 12, 1986. [SRDB Ref. ID 19129]

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18, 1986. [SRDB Ref. ID 19128]

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July 11, 1986. [SRDB Ref. ID 19142]

Rockwell 1988a. Radiological Safety Incident Report, A0190, Rockwell International. October 

17, 1988.

Rockwell 1988b. Radiological Safety Incident Report, A0189, Rockwell International. August 

24, 1988.

Rockwell 1988c. Radiological Safety Incident Report, A0188, Rockwell International. August 

23, 1988.

Rockwell 1988d. Radiological Safety Incident Report, A0187, Rockwell International. August 

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Effective Date:

2/20/2019

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0 (Draft)

Document No./Description:

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27 of 27

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

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