Draft

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH

National Institute for Occupational Safety and Health

SC&A REVIEW OF WHITE PAPER, “NIOSH RESPONSE TO 

SC&A’S REVIEW OF THE SEC-00109 LANL ADDENDUM” 

Contract No. 211-2014-58081 

SCA-TR-2018-SEC005, Revision 2 

Prepared by

Joe Fitzgerald, MS, MPH

SC&A, Inc.

2200 Wilson Boulevard, Suite 300 

Arlington, VA 22201-3324 

Saliant, Inc.

5579 Catholic Church Road 

Jefferson, MD 21755 

January 9, 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: SC&A Review of White Paper, “NIOSH Response to SC&A’s 

Review of the SEC-00109 LANL Addendum”

DOCUMENT NUMBER/

DESCRIPTION:

SCA-TR-2018-SEC005 

REVISION NO.: 2 (Draft)

SUPERSEDES: N/A

EFFECTIVE DATE: January 9, 2019

TASK MANAGER Joseph Fitzgerald, MS, MPH [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) 11/13/2018 Initial issue

1 (Draft) 11/16/2018 Changed some text references to DOE documents at DOE 

request.

2 (Draft) 1/9/2019 Corrected errata in previous draft and updated comments on 

Appendix A.
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TABLE OF CONTENTS

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

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

2 SC&A Responses .................................................................................................................... 7

2.1 SC&A Response to NIOSH Finding of Programmatic Adequacy for Field Monitoring 

and Contamination Control Programs at LANL ............................................................. 7

2.2 SC&A Response to NIOSH Finding of Bioassay Data Adequacy and Completeness . 10

2.3 Specific Issues ............................................................................................................... 12

2.3.1 10 CFR Part 835 as a Paradigm Shift ....................................................................... 12

2.3.2 Technological Limitations of in vivo Capability....................................................... 13

2.3.3 DOE Oversight Finding in 2001 about Mixed Activation Product Monitoring for 

LANSCE and Thorium-232 ...................................................................................... 14

2.3.4 Exposure from Unevaluated Neptunium-237 Sources.............................................. 15

2.3.5 Relevancy of DOELAP Accreditation Milestone ..................................................... 16

2.3.6 Mixed Activation Products and Dose Assessment ................................................... 16

2.4 Appendix A: SEC-00109 LANL Petitioner Issues and Resolutions ............................ 19

3 Conclusions ........................................................................................................................... 20

4 References ............................................................................................................................. 22
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ABBREVIATIONS AND ACRONYMS

Advisory Board or 

ABRWH Advisory Board on Radiation and Worker Health 

AL Albuquerque Operations Office 

Ar argon

CEDE committed effective dose equivalent

CFR Code of Federal Regulations

Ci curie

CsI cesium iodide 

CTW construction trade worker 

DOE U.S. Department of Energy

DOELAP DOE Laboratory Accreditation Program 

ER evaluation report 

G/MAP gaseous mixed activation product 

HPGe high purity germanium 

keV kiloelectron volt 

LAMPF Los Alamos Meson Physics Facility

LANSCE Los Alamos Neutron Science Center

LC critical level

MAP mixed activation product 

MDA minimum detectable activity

MEI maximally exposed individual 

MFP mixed fission product 

mrem millirem

NaI sodium iodide 

NIOSH National Institute for Occupational Safety and Health

NOV Notice of Violation

Np neptunium 

NTS Noncompliance Tracking System

O oxygen

ORAUT Oak Ridge Associated Universities Team

OTIB ORAUT technical information bulletin

PPE personnel protective equipment 

Pu plutonium 
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RPP radiation protection program 

RWP Radiation Work Permit 

SALI stochastic annual limit on intake

SEC Special Exposure Cohort 

SRDB Site Research Database

Sv sievert

TA technical area

Th thorium 

U uranium 
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1 INTRODUCTION AND BACKGROUND

In its September 12, 2018, white paper response (NIOSH 2018) to SC&A’s review (2017) of the 

Los Alamos National Laboratory (LANL) Special Exposure Cohort (SEC)-00109 petition 

evaluation report (ER) Addendum (NIOSH 2017), the National Institute for Occupational Safety 

and Health (NIOSH) agrees that use of a 10 CFR Part 835 compliance milestone beginning on 

January 1, 1996, is not a sufficient basis to presume that “the absence of internal dosimetry 

records indicates that unmonitored workers were deemed unlikely to have received intakes 

resulting in a CEDE 0.1 rem or more from all occupational radionuclide intakes in a year” 

(NIOSH 2017, p. 17), as noted below:

NIOSH concurs with SC&A’s assessment that program compliance may not be 

sufficient for demonstrating implementation of the radiation monitoring program. 

NIOSH also concurs that reliance on oversight findings may not be sufficient for 

validating that LANL had fully implemented 10 CFR Part 835. This appears 

particularly evident in the multiple pertinent findings identified in [a 1999 LANL 

self-assessment], as SC&A points out later in its memorandum. [NIOSH 2018, 

p. 6]

However, in acknowledging this agreement, NIOSH noted that it “does not rely solely on 10 

CFR 835 compliance for the conclusion that unmonitored workers were unlikely to have 

received intakes resulting in greater than 100 mrem CEDE” (NIOSH 2018, p. 6). NIOSH

contends that there are other evidentiary bases upon which this bounding assumption can be 

made. As clarified in this recent NIOSH response, these include the following: 

1. A programmatic basis founded on the conclusion that “the field monitoring and 

contamination control programs at LANL were well-established and formalized by 

January 1, 1996,” and “intended to ensure that unmonitored individuals were unlikely to 

receive intakes of 100 mrem CEDE” (NIOSH 2018, pp. 6, 2). In its review, NIOSH notes 

that “although 10 CFR 835 contains a lot of nuances and implementation guides that may 

have come out too late to impact RPP development by January 1, 1996, the important 

question is not overall implementation and compliance with 100 percent of 10 CFR 835, 

but rather, whether there was a program in place ensuring that unmonitored workers were 

unlikely to receive intakes resulting in 100 mrem CEDE” (NIOSH 2018, pp. 6). To 

support its contention about the adequacy of LANL’s field monitoring program, NIOSH 

provides, in its response, a summary listing of numerous procedures, Radiation Work 

Permits (RWPs), surveys, sampling results, and event reports. 

2. A bioassay data adequacy and completeness basis founded on a review of the primary 

LANL radionuclides—tritium, plutonium isotopes, and uranium isotopes—“for which 

bioassay data are abundant,” that demonstrate ER Addendum intake rates are bounding 

(NIOSH 2018, p. 30). This review was undertaken, in light of “multiple issues regarding 

LANL’s technical ability to monitor for various radionuclides” (p. 22), to answer the 

question: “Is the assignment of 100 mrem CEDE intakes for unmonitored workers likely 

to be bounding?” (p. 22). To support its contention about the adequacy of LANL’s 

capability to monitor for radionuclides for which an exposure potential was present at 

LANL, NIOSH also provides, in its response, a summary of the radionuclide-specific 
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in vivo intake values, by year, for 1969–2005. NIOSH, likewise, does not find any 

“significant technical shortfalls” (NIOSH 2018, p. 30) with regard to LANL’s in vivo

program during the period in question. 

Based on a “weight of evidence” assessment of these two considerations, and its judgment that 

10 CFR Part 835 represented a “paradigm shift” in DOE operations, NIOSH concluded: 

Based upon its review of existing bioassay results, NIOSH finds that workers who 

were monitored for the primary radionuclides (uranium, plutonium, and tritium) 

were unlikely to have received intakes exceeding 2% of the SALI (or intakes that

would have resulted in 100 mrem CEDE). NIOSH also believes that intakes to the 

unmonitored population would have been lower than that of the monitored 

population. NIOSH therefore concludes that unmonitored workers were unlikely 

to have received intakes of 2% of the SALI, and the assignment of 2% SALI 

intakes for unmonitored workers with access to controlled areas is bounding. 

NIOSH further finds no reason to believe that intakes of exotic radionuclides by 

unmonitored workers would be substantially different. In summary, NIOSH 

concludes that the weight of the evidence supports assignment of 2% SALI intakes 

for unmonitored workers, as proposed in the ER Addendum, is sufficiently 

bounding and claimant favorable. [NIOSH 2018, pp. 30–31]

In this evaluation, SC&A addresses this conclusion in terms of its two key supporting bases, with 

more-specific issues addressed separately.

2 SC&A RESPONSES

2.1 SC&A RESPONSE TO NIOSH FINDING OF PROGRAMMATIC ADEQUACY FOR FIELD 

MONITORING AND CONTAMINATION CONTROL PROGRAMS AT LANL

NIOSH’s white paper notes that:

The field monitoring and contamination control programs at LANL were wellestablished and formalized by January 1, 1996. A description of these programs, 

along with a summary of associated data available to NIOSH, was included in 

Section 6.1.1 of the SEC-00109 ER Addendum. [NIOSH 2018, p. 6]

The information provided in support of its finding of programmatic adequacy1

 includes, for 

1996–2005, “hundreds of radiological protection documents” from LANL that include RWPs, 

contamination surveys, area monitoring survey results, air sampling results, and radiological 

protection checklists (NIOSH 2018, p. 18). With respect to the RWPs reviewed, NIOSH noted 

that they tended to include required contamination surveys, personnel protective equipment 

(including respiratory protection), and radiation control technician coverage, but generally, not 

 

1 SC&A uses the term “programmatic adequacy” in this case to mean the adequacy and completeness of the 

bioassay program, both in terms of its definition, scope, and procedures as well as its demonstrably effective field 

implementation. It is recognized that this may not be necessarily the same as the bioassay program being 

“well-established and formalized,” as described by NIOSH. However, the question of how adequacy is defined lies 

at the heart of this particular issue.
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bioassay requirements. NIOSH noted that the RWPs reviewed “appear to have been designed 

to minimize the likelihood of intakes via engineering controls, personnel protective equipment 

(PPE), and respiratory protection,” with elevated surface or airborne contamination presumably 

triggering “an assessment for the need for bioassay” (NIOSH 2018, p. 20). NIOSH provides two 

occurrence reports where this scenario played out, i.e., evidence of contamination triggering an 

assessment that led to bioassays being performed. 

SC&A finds that the NIOSH conclusion that “field monitoring and contamination control 

programs at LANL were well-established and formalized by January 1, 1996” belies whether 

they were, in fact, being adequately carried out by LANL personnel. In its 2017 report, SC&A 

raised a concern on this question based on a self-assessment conducted by a team of health 

physicists in 1999, led by LANL ( ). The assessment team included 

representatives from Savannah River Site and MJW Corporation/Mound (not so incidentally, 

these latter two organizations had just dealt with major U.S. Department of Energy [DOE] 

enforcement actions regarding the implementation of their respective bioassay programs). This 

LANL self-assessment found 10 key findings regarding inadequate implementation of the LANL 

bioassay program, including three that directly impaired LANL’s ability to monitor individuals 

“likely to receive a committed effective dose of 0.1 rem (0.001 Sv) or more from all occupational 

radionuclide intakes in a year” (10 CFR 835.402(c)(1)). These included workers not providing 

bioassays when required by RWPs and the principal construction trade worker (CTW) 

subcontractor at LANL not enrolling all workers who were potentially exposed to radionuclides, 

as required. These findings led to a broad revamp of LANL’s bioassay program procedures and 

processes that was completed in 2000.

NIOSH’s response to what is apparently the only comprehensive validation of LANL bioassay 

program adequacy during 1995–2000 appears not to have been an investigation of whether these 

major programmatic shortfalls would have implications for the adequacy and completeness of 

LANL’s recorded bioassay data in the late 1990s; instead, NIOSH finds that the self-assessment 

results are not “sufficient” for validating that LANL had fully implemented 10 CFR Part 835. 

(NIOSH 2018, p. 6). NIOSH then returns to its apparent thesis that workers were “unlikely to 

receive intakes of 100 mrem CEDE” because “LANL’s field monitoring programs were designed 

and implemented” for that purpose (NIOSH 2018, pp. 2, 6, 9, 30), and that NIOSH has 

considerable dosimetry data for 1996–2005 that show doses for monitored workers were 

generally less than 100 millirem (mrem) committed effective dose equivalent (CEDE) and that 

“intakes for unmonitored workers would likely be even lower” (NIOSH 2018, p. 10). 

SC&A finds this assessment shortsighted, discounting the need to gauge what constituted actual 

field monitoring practice, i.e., the reality of bioassay practice at LANL in terms of whether 

workers were appropriately identified for bioassays, whether those bioassays were actually 

carried out, and to what extent accountability was exercised at the laboratory to ensure such 

procedures were implemented. The 1999 self-assessment results and corrective actions in 2000 

indicate substantial program inadequacies in this regard, undercutting NIOSH’s assertion to the 

otherwise. This is not a question of proving (or not proving) 100 percent compliance with 

10 CFR Part 835 as stated by NIOSH, but following a long-established precedent under the 

Energy Employees Occupational Illness Compensation Program Act to investigate and resolve 

evidence of inadequacy and incompleteness in worker monitoring data. 
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In its white paper, NIOSH indicates that the findings identified in a 1999 LANL self-assessment

( ) should not be relied upon because they “may not be sufficient for validating 

that LANL had fully implemented 10 CFR Part 835”(NIOSH 2018, p. 9), and cites SC&A’s 

support of that position. SC&A disputes that interpretation and finds that NIOSH has taken 

SC&A’s statement out of context. While NIOSH “concurs” with the second part of SC&A’s 

conclusion, below, the qualifying statement that precedes it (regarding the 1999 review) is 

seemingly overlooked: 

SC&A concludes that the 1999 LANL noncompliance notwithstanding (which 

derived from an independent review with outside reviewers), solely relying on 

the lack of Notices of Violation (NOVs) and other recorded nonconformances as a 

benchmark of effective RPP implementation is questionable. [SC&A 2017; 

emphasis added]

It needs to be reemphasized, as SC&A did in its 2017 memorandum, that oversight findings—

particularly those of external regulatory oversight—are a “blunt instrument” for identifying 

“often imbedded culture-based workplace safety program gaps and deficiencies” (SC&A 2017, 

p. 3). However, as SC&A indicated above, LANL’s internal self-assessment was not that form of 

oversight and represents one of the few effective means by which field implementation of health 

physics procedures could be validated. Given the timeframe and team composition of the review, 

it is clear that LANL was concerned about the implementation of its bioassay program and 

wanted to ensure that it was in substantive compliance with 10 CFR Part 835 (including 

§ 835.402(c)(1) governing monitoring for individuals “likely to receive a committed effective 

dose of 0.1 rem (0.001 Sv) or more from all occupational radionuclide intakes in a year).” As an 

internal self-assessment led by LANL health physicists and advised by independent dosimetrists 

from other DOE sites, it was uniquely able to review bioassay program implementation for 

adequacy and completeness. Reporting was done under the aegis of the DOE enforcement 

program because that was incumbent on all DOE sites following the 120-day moratorium on 

enforcement actions for bioassay program noncompliances (as noted by SC&A in its 2017 

report, self-assessment and self-reporting were cornerstones of the DOE enforcement program).

SC&A is not disputing that NIOSH has captured a considerable number of radiological control 

documents that illustrate a functioning field monitoring program, just that the number and scope 

of such documents do not necessarily equate, without some form of validation, to adequate 

implementation in the context of the data completeness necessary for dose reconstruction with 

sufficient accuracy.

SC&A recommends that the Work Group has NIOSH follow up on the 1999 LANL selfassessment results ( ) and substantiate whether and how these reported program 

deficiencies impact the adequacy and completeness of bioassay results for 1995–2000.2 A 

pertinent question is whether bioassay data are sufficiently complete, given evidence of 

incomplete worker bioassay program enrollments, inadequate use of checklists to identify 

radionuclides being handled, and nonparticipation of workers in required bioassays (particularly, 

 

2 At the August 23, 2017, Advisory Board meeting, NIOSH had indicated it would obtain more information on this 

assessment from LANL and make that information available to the Work Group and SC&A, but there is no mention 

of such a follow-up or its results in their white paper (ABRWH 2017, pp. 249–250).
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transient CTWs). This question is particularly relevant given LANL’s apparent reliance on 

engineering controls, PPE, and respiratory protection, backed up by RWP-driven surveillance of 

job contamination levels, to trigger an assessment for the need for bioassay. 

2.2 SC&A RESPONSE TO NIOSH FINDING OF BIOASSAY DATA ADEQUACY AND 

COMPLETENESS

In its response, NIOSH outlines the radiation dosimetry requirements for LANL before

promulgation of 10 CFR Part 835 and notes that they were well-established and included action 

levels for monitoring of workers with a potential to receive 100 mrem CEDE from internal 

sources. However, as emphasized in SC&A’s 2017 response, the DOE validation review in 1995 

of LANL’s radiation protection program (RPP) (DOE/AL 1995) likewise found that the radiation 

protection program, including radiation dosimetry, satisfied all 10 programmatic requirements of 

10 CFR Part 835, including an onsite review of procedural implementation. However, without 

any uniform acceptance criteria3 for what was needed in these procedures and how they were to 

be implemented, their actual use and implementation would remain in question. This was later 

illustrated, for LANL’s bioassay program, in the results of the self-assessment conducted in 1999 

(DOE/AL 2017). 

3 The lack of uniform DOE-wide acceptance criteria was highlighted and referenced in SC&A’s 2017 memorandum.

In response to this concern, NIOSH makes the following point: 

In SC&A’s review of the SEC-00109 LANL ER Addendum, SC&A pointed out 

multiple issues regarding LANL’s technical ability to monitor for various 

radionuclides and example of oversight findings where perhaps workers should 

have been monitored for internal dose according to the 10 CFR 835 rule, but 

apparently were not. NIOSH shares some of the concerns from the oversight 

findings, as discussed above in this document. In light of these concerns, the 

primary question still remains. Is the assignment of 100 mrem CEDE intakes for 

unmonitored workers likely to be bounding? [NIOSH 2018, p. 22]

To answer this question, NIOSH looks to the primary LANL radionuclides—tritium, plutonium, 

and uranium—where there are over 450,000 in vitro records and over 100,000 in vivo records.

Included in NIOSH’s white paper are six tables, excerpted from ORAUT-OTIB-0062, Internal 

Dosimetry Coworker Data for Los Alamos National Laboratory (NIOSH 2009), that give intake 

values to be used in dose reconstruction for unmonitored LANL workers for any given year. 

From these data, NIOSH concludes that 100 mrem CEDE would be bounding of intakes for the 

primary radionuclides. NIOSH also “finds no reason to believe that intakes of exotic 

radionuclides by unmonitored workers would be substantially different” (NIOSH 2018, p. 30). 

However, NIOSH offers no substantiation for this last finding about exotic radionuclides. As 

noted earlier in its white paper:

A class of LANL workers has been added to the Special Exposure Cohort due to a 

lack of available bioassay data for “exotic” radionuclides. This class includes all 

workers from the beginning of site operations in 1942 through 1995. This lack of 

 
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bioassay data for “exotic” radionuclides has continued to persist to the present 

time. [NIOSH 2018, p. 22; emphasis added] 

If bioassay data for exotic radionuclides are lacking and continue to be lacking, and were the 

central basis for the preceding SEC class, it would seem important for NIOSH to provide 

substantiation grounded in actual monitoring data, dose modeling, or even source term 

assessment (using the hierarchy of objective dose reconstruction methods) to demonstrate that 

the acknowledged conditions for the SEC class through December 31, 1995, had clearly changed 

by 1996.4 While there are considerable bioassay data associated with the primary radionuclides, 

particularly plutonium, uranium, and tritium, this has always been the case for LANL and was 

determined by NIOSH and the Work Group not to be a valid consideration in determining the 

adequacy of bounding doses for exotic radionuclides in the SEC years prior to 1996 (ABRWH 

2012a, pp. 5–12; NIOSH 2012, pp. 47–53). 

4 The white paper notes that “the ER Addendum presents a methodology for performing dose reconstructions for 

exotic radionuclides for LANL workers in the absence of bioassay during the 10 CFR 835 era” (NIOSH 2018, 

p. 12). However, as noted by NIOSH, “the primary basis for this proposed method was the legal requirements set 

forth in 10 CFR 835 that went into effect on January 1, 1996” (NIOSH 2018, p. 22). The Addendum also cites 

ORAUT-OTIB-0054 (NIOSH 2015) methodologies that are only applicable to reactor or reactor fuel mixed fission 

product (MFP) and MAP source terms (i.e., not MAPs from accelerators such as the Los Alamos Neutron Science 

Center [LANSCE]). Without a presumption of compliance, these Addendum methodologies would need to be rejustified by NIOSH.

NIOSH recognized, then, that the application or extension of bioassay results for plutonium and 

the other actinides would not be appropriate as a means to bound intakes of exotic radionuclides 

to unmonitored workers at LANL because of the following reasons: 

• Exposure for many exotics might be on an intermittent, experimental basis 

leading to episodic exposures that are not adaptable to chronic-exposure 

models. 

• The controls in place for smaller bench-top-type operations might not have 

been as well-engineered as the controls in place for larger routine operations. 

• The operations involving these exotics might have been of a sufficiently 

different nature as to preclude a direct comparison to those of U and Pu. 

[NIOSH 2012, p. 48]

On this basis, a response to the central question posed in the NIOSH white paper—Is the 

assignment of 100 mrem CEDE intakes for unmonitored workers likely to be bounding?—would 

be clearly affirmative for the primary radionuclides and would remain uncertain for the exotic 

radionuclides. While NIOSH finds that there is no “evidence” suggesting that the exposure 

experience with exotics, in this case (i.e., 100 mrem CEDE), would be otherwise for 

unmonitored workers, such a comparison is flawed for the reasons stated without any new data 

or analysis to the contrary. 

While SC&A acknowledges releases of, and occupational exposures to, airborne radionuclides, 

including exotics, had declined at LANL by the mid-1990s, SC&A does not share NIOSH’s 

apparent support of LANL’s contention that bioassay data are scarce for exotic radionuclides 

 
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because “workers were not required to have been monitored for them” (NIOSH 2018, p. 22). As 

noted in Work Group meetings and reports, LANL responses, and DOE oversight reviews,5

LANL’s in vivo program did not focus on exotic radionuclide monitoring, a circumstance that 

predated 10 CFR Part 835. What heretofore has been lacking is a bounding LANL (or NIOSH) 

dose assessment for exotic radionuclide exposure that shows occupational doses would be below 

the threshold of 100 mrem CEDE per year by 1996. 

5 For example, ABRWH 2012b, NIOSH 2012, LANL 2013, and DOE 2001.

On what is the assumed 100 mrem CEDE bounding dose for exotic radionuclides to be based if 

the following are true: (1) the compliance basis of 10 CFR Part 835 is no longer a sufficient basis 

for benchmarking 100 mrem CEDE, (2) the use of primary radionuclide bioassay results to 

bound or compare those of exotic radionuclides is inappropriate, (3) bioassay data are found to 

be likely incomplete and program implementation inadequate from the 1999 LANL selfassessment, and (4) bioassay data for exotic radionuclides remain unavailable, as acknowledged

in the ER and NIOSH white paper? A NIOSH judgement based solely on what is taken to be 

apparent program improvement in the 1990s would not seem to be enough, considering the 

substantial evidence to the contrary. 

2.3 SPECIFIC ISSUES

2.3.1 10 CFR Part 835 as a Paradigm Shift 

The white paper indicates that “NIOSH believes that the 10 CFR 835 era represents a paradigm 

shift in DOE operations” (NIOSH 2018, p. 6). SC&A agrees that the 10 CFR Part 835 

implementation period brought about greater accountability to safety and health requirements. 

However, as emphasized in SC&A’s 2017 memorandum, that accountability did not necessarily 

begin on January 1, 1996. Self-assessments performed by Los Alamos in 1999 ( 

), SRS in 1998 (Kornacki et al. 1998), and Mound in 1997 (DOE 1998a) for their 

respective sites under the aegis of the Price-Anderson enforcement program found significant 

deficiencies in the implementation of occupational bioassay programs that impaired field 

monitoring, including “ensuring that unmonitored workers were unlikely to receive intakes 

resulting in 100 mrem CEDE” (NIOSH 2018, pp. 6–7). The latter two were of sufficient concern 

to DOE (combined with similar findings at three other DOE sites) to prompt a 120-day 

“moratorium” for DOE-wide enforcement actions related to bioassay program deficiencies 

beginning in December 1998 to enable all DOE operating contractors to self-assess their 

bioassay programs, take necessary corrective actions, and report program status to DOE (DOE 

1998b, DOE 2000). 

As noted in this DOE directive, the need for DOE-wide self-assessments during the moratorium 

was found necessary given the “commonality” of bioassay program deficiencies that included 

lack of formalized and approved procedures, failure to implement program requirements, 

non-collection of and participation in job-specific and special bioassays, and failure to maintain 

accurate worker dose records (DOE 1998b, pp. 1–3). For LANL, it is particularly noteworthy 

that the 1999 bioassay program deficiencies (10 corrective actions to be completed by 2000) 

( ), were preceded by bioassay program deficiencies from another selfassessment in 1997 (10 corrective actions to be completed by 1998) ( ). This 

 
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corroborates DOE’s further finding, as contained in its moratorium directive, that even when 

bioassay program deficiencies were identified by contractor self-assessments, “corrective actions 

taken have been inadequate to prevent recurrence of identical [bioassay and dose assessment] 

problems” (DOE 1998b, p. 3). 

Whether “there was a program in place ensuring that unmonitored workers were unlikely to 

receive intakes resulting in 100 mrem CEDE,” as noted by NIOSH (2018, pp. 6–7), is a 

condition that needs to be critically reviewed and established on a site-by-site basis as a function 

of available information about program adequacy and completeness. It should not be a standing 

assumption, regardless of whether 10 CFR Part 835 compliance is, or is not, its basis. 

2.3.2 Technological Limitations of in vivo Capability

NIOSH does not share many of the concerns identified by SC&A about historical technological 

limitations of the LANL in vivo program, as noted in its white paper response (NIOSH 2018, 

p. 12). The comments summarized by SC&A in its 2017 memorandum regarding these 

technology-based concerns were taken directly from interviews with LANL internal dosimetrists 

and were originally cited in SC&A’s 2010 review of the ER (SC&A 2010). SC&A is, indeed, 

aware of the use of germanium detectors at LANL during the period in question. The following 

is the preface to the same LANL interview comments, as provided in SC&A 2010, which, in 

turn, had been drawn from an earlier edition of ORAUT-TKBS-0010-5, Los Alamos National 

Laboratory – Occupational Internal Dose (NIOSH 2004a):

In 1970, an in-vivo counter capable of measuring four separate regions of the 

body began operation.... Twin Phoswich (CsI and NaI) detectors were placed 

over the lungs. The two layers of the detector were capable of simultaneously, yet 

separately, monitoring chest burdens for 10–250-keV photons (NaI), and 250–

2,000-keV photons (CsI) for a qualitative assessment of a variety of fission and 

activation radionuclides. A planar High Purity Germanium (HPGe) detector 

monitored the region between 10 keV and 250 keV with excellent energy 

resolution, and could be positioned over the liver or thyroid as needed. Finally, 

an HPGe (previously a GeLi) detector was positioned under the prone subject. 

This detector was primarily for whole-body assessment and has good photon 

energy resolution in the range of 10–2,000 keV. This system could both identify 

radionuclides and quantify the body burden. [SC&A 2010, p. 11]

SC&A provided the excerpted comments in its 2010 report (SC&A 2010) based on the LANL 

interviews to illustrate that the technology available to LANL for monitoring exotic 

radionuclides paced the implementation of that technology. This was often dependent on 

judgments about whether mixed activation products (MAPs) or MFPs figured in a worker’s 

exposure potential, whether a dosimetrist was actually focused on source terms beyond the 

primary radionuclides, and whether one could discriminate a corresponding spectrum peak for a 

these exotic radionuclides when available detectors of the time may not have been sufficiently 

sensitive, particularly at the lower energy regions.
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As noted in ORAUT-TKBS-0010-5: 

An in vivo count spectrum is not analyzed for a fission or activation product 

radionuclide unless a peak that is associated with that nuclide is visible in the 

spectrum. When that peak is visible, the suspected nuclide is added to the library 

and the spectrum is reanalyzed. Visual or non-library-driven software recognition 

of a peak can be subjective and not directly correlated to MDA or LC

calculations, especially with the broad peaks that are associated with scintillation 

detectors. For whole-body counts, it is not reasonable to assume that a worker 

was exposed to or is being monitored for all radionuclides potentially reportable 

simply because an MDA was determined and listed on the report. [NIOSH 2013, 

p. 47]

Given NIOSH’s and SC&A’s original concerns about the lack of available in vivo results for 

MAPs and MFPs, despite the availability of state-of-the-art counter technology, SC&A had 

interviewed internal dosimetrists to better ascertain actual practice in this regard. Our summary 

of comments, as presented in SC&A’s 2017 report, was consistent with NIOSH 2013, with one 

clarification needed. 

It needs to be clarified that LANL’s twin Phoswich detectors were replaced by twin threedetector arrays of HPGe detectors in 1999, with the Phoswich and germanium systems being 

operated concurrently during the 1998–1999 period. The HPGe lung counter has 10–300 

kiloelectron volt (keV) and 80–3,000 keV ranges, so a lower sensitivity for certain fission and 

activation products can be obtained (NIOSH 2013). SC&A agrees that Phoswich detectors were 

used in conjunction with germanium detectors, but when the former detectors were replaced with 

HPGe lung counters in 1998, it opened up the lower energy spectrum common for a number of 

MAPs and MFPs to improved peak discrimination and therefore, better detection. 

2.3.3 DOE Oversight Finding in 2001 about Mixed Activation Product Monitoring for 

LANSCE and Thorium-232 

Regarding the 2001 DOE oversight finding, NIOSH indicates that it does not share SC&A’s 

concern over the exclusion of thorium-232 (Th-232) monitoring capability in monitoring 

matrices and the absence of MAPs radionuclides for LANSCE in the in vivo program library. In 

its supporting explanation, it appears that NIOSH is conflating LANL’s in vivo technical 

capability to detect Th-232 and MAPs using germanium detector technology with actual 

practice. While the technology existed at LANL at the time of the DOE audit, an agreement was 

lacking between the in vivo laboratory and the internal dosimetry program to ensure ready 

capabilities to monitor for incident or non-routine exposures. As DOE pointed out, the “in-vivo

monitoring matrices should include the capability to monitor for Th-232” and that “without [the 

library of radionuclides of concern from LANSCE], the in vivo laboratory cannot identify 

monitoring strategies or ensure adequate energy calibrations” for LANSCE emissions (DOE 

2001, p. 9). However, it is also clear that LANL could deploy its in vivo monitoring for Th-232 

for special bioassays, if necessary, as in the case of the international traveler cited by NIOSH 

(NIOSH 2018, p. 16). 
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NIOSH discussed this specific issue at the April 29, 2010, LANL Work Group meeting: 

DR. NETON: Yes. I guess what I’m concerned about in talking to the dosimetrists 

at Los Alamos, anybody you talk to probably, is that, yes, you’re a plutonium lab 

essentially. This is an accelerator over here with a short life... 

I think just walking down and validating whether or not this new robust system 

was actually being applied uniformly, beyond the primaries, to things that 

certainly the HPs may have considered not a big deal would be very important 

because I think it’s possible that because of the nature of the source terms at a 

glance, even though they were an exposure pathway, they might not have been 

sort of front and center to those kinds of controls and that kind of responsiveness. 

And certainly one review as late as 2001 seems to suggest that it took DOE 

whacking the bioassay program and the in vivo program on the head to get their 

attention that they weren’t doing what was prescribed in terms of monitoring 

LANSCE, being able to monitor LANSCE. [ABRWH 2010, pp. 83–84]

With regard to LANL monitoring capabilities for Th-232, the DOE assessment in 2001 indicated 

that a “review of the internal dosimetry monitoring matrices for internal dosimetry evaluation 

program indicated that this program might be required to analyze for thorium-232 (Th-232) on a 

routine basis and for an accident scenario since this source term is present at LANL” (DOE 

2001, p. 9). DOE was clear that “at this time there are no personnel who have been identified as 

requiring routine monitoring for Th-232” (p. 9). However, the issue was the need for LANL to 

include the capability to monitor Th-232 in its in vivo monitoring matrices. As noted by DOE, an 

apparent gap existed in LANL capabilities:

Interviews with the in-vivo laboratory staff indicated that they were not aware of 

the need for this capability. The in-vivo laboratory does have a phantom for 

thorium calibration; however, the in-vivo procedures call for thorium monitoring 

to be performed by the phoswich system. This system is currently not in use. While 

the system could be brought into operation if needed, the in-vivo staff indicated 

that there were no immediate plans to do so. Their plan was to use the newer 

germanium system for all routine analysis. To provide the thorium capability in 

case of incidents, the in-vivo laboratory should maintain the phoswich system 

consistent with this need or update their procedure and/or calibrations to permit 

thorium monitoring on the germanium system. [DOE 2001, p. 9]

On this basis, while SC&A agrees with NIOSH’s claim that LANL had the “technical capability” 

to monitor for Th-232 (and other MAPs), SC&A finds, as did DOE, that the exclusion of Th-232 

from LANL in vivo monitoring matrices and MAPs from the in vivo monitoring library would 

make it problematic for this monitoring to be accomplished adequately. 

2.3.4 Exposure from Unevaluated Neptunium-237 Sources

Despite SC&A’s identification of other neptunium-237 (Np-237) source terms that would bear a 

review for exposure potential, NIOSH contends that LANL would have limited unmonitored 
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doses to 100 mrem CEDE and therefore, NIOSH’s proposed bounding dose would be 

appropriate for any such exposures. SC&A has already addressed its concern about NIOSH 

reliance on the design and implementation of the LANL field monitoring program after 1995 as 

the basis for applying a 100 mrem CEDE bounding dose. NIOSH should evaluate the exposure 

potential for all identified Np-237 sources and show that they can be bounded. 

2.3.5 Relevancy of DOELAP Accreditation Milestone

NIOSH indicates that it “does not agree that DOELAP accreditation is relevant for full 

compliance with 835.402 and 835.702” and notes that “DOELAP is not a dosimetry standard,” 

but rather, a performance standard (NIOSH 2018, p. 7). SC&A believes that NIOSH 

misunderstands its comment, and the context in which it was being made, which is reproduced 

below: 

If anything, core requirements for and change to how DOE internal dosimetry 

programs were implemented did not come until the internal dosimetry technical 

standard of 10 CFR Part 835 was coupled with an accreditation requirement (for 

overall dosimetry program functionality) under DOELAP in the 1998 

amendments to the rule, which required all sites to achieve accreditation by 

January 1, 2002. [SC&A 2017, p. 4; emphasis added]

As noted, SC&A acknowledges that the DOE Laboratory Accreditation Program (DOELAP) 

addresses the functionality of key elements of the dosimetry program, not the dosimetry, itself. 

However, based on experience at other DOE sites (e.g., Sandia National Laboratory and 

Brookhaven National Laboratory), full compliance with 10 CFR Part 835 was not achieved for 

internal dose assessment and recordkeeping for some sites until the DOELAP accreditation 

process was well underway.

In fact, for LANL, in response to an earlier (1997) 10 CFR Part 835-based compliance finding 

regarding bioassay program deficiencies, expedited action was initiated to “meet the 

requirements of the Department of Energy Laboratory Accreditation Program for 

Radiobioassay” (DOELAP)” ( ). LANL noted that “an assessment of 

current operations and the development of a Plan/Program that will meet the DOELAP 

accreditation standards” would be undertaken and that this assessment would be used “to identify 

and eliminate any weakness found in the [bioassay] program.” This additional compliance 

finding of weaknesses in the LANL bioassay program and the 10 action items (including 

DOELAP accreditation) for which LANL made a subsequent, formal commitment to DOE under 

the enforcement program further underscore that the LANL bioassay program was not “wellestablished and formalized” by 1996, and that both LANL and DOE considered DOELAP 

accreditation to be relevant for ensuring 10 CFR Part 835 compliance. 

2.3.6 Mixed Activation Products and Dose Assessment

In response to a NIOSH inquiry, LANL noted that its internal dosimetry monitoring programs 

are established on an “as-needed basis” and that monitoring is only required if a given 

radionuclide “represents a significant internal exposure hazard” and if “workers are likely to 

receive 100 mrem [annually] from internal exposure” (LANL 2013, p. 2). However, as noted 
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elsewhere in this report, and as discussed at length in previous Work Group meetings, LANL had 

the in vivo program and technological capability since the 1970s to monitor for many MAPs and 

MFPs but clearly did not address exotic radionuclides as a priority, instead focusing on 

plutonium, uranium, tritium, and other primary exposure sources. 

The lack of in vivo bioassay results belies the historic presence of airborne exposure pathways 

for workers due to MAPs from sources such as LANSCE (or LAMPF, the Los Alamos Meson 

Physics Facility, as it was originally called). LAMPF/LANSCE has been the dominant source of 

airborne radionuclides at LANL since the late 1970s (NIOSH 2004b, p. 43). In the 1970s–1980s, 

MAPs, while relatively short-lived, historically accounted for the largest boundary dose and 

individual dose from all of LANL operations, with reported doses “among the highest 

nationwide among DOE operations in 1979” (NIOSH 2004b, p. 43). The estimated maximum 

site boundary dose levels varied according to beam energy, operational workload, and stack 

holdup controls, which affected the total MAP emission activity levels. These have declined 

steadily over time with improved emission controls and operational changes from 734,000 curies 

(Ci) in 1984, to 120,000 Ci in 1990, to 50,200 Ci in 1994, to 20,000 Ci in 1997, and to almost 

zero (43 Ci) in 1999 (Bowen et al. 1986, p. 1; NIOSH 2004b, p. 43; LANL 1994, p. 5; LANL 

2002). For 1978, with an annual MAPs radionuclide release of 117,000 Ci from LAMPF (at 40% 

to 50% of design beam time), a maximally exposed individual (MEI) dose of 126 mrem was 

calculated at the site boundary based on “conservative plume diffusion models,” with a 

corresponding measured dose of 14 mrem (NIOSH 2004b, p. 43). 

While it is true that the “use of exotic radionuclides at LANL was relatively rare, not nearly as 

prevalent as the use of the primary radionuclides (plutonium, uranium, and tritium), for which 

there is an abundance of bioassay data” (NIOSH 2018, p. 12), the exposure potential for 

unmonitored workers to intakes of airborne emissions of MAPs was clearly of some significance 

given the historical boundary doses that were modeled and monitored. Without substantiation

that upper-bound doses from these sources did not exceed 100 mrem per year for the maximally 

exposed unmonitored onsite worker after 1995, LANL’s (and NIOSH’s) assertion about 

monitoring appears to have no objective basis. 

To gain some perspective in this regard, SC&A reviewed LANL environmental surveillance 

reports for the period 1990–2000 and found that (as noted previously) total MAPs emissions 

from LANSCE had declined from 120,000 Ci to almost zero by 2000, with a corresponding 

offsite MEI drop of 6 mrem to 0.4 mrem in that same period (LANL 2018). This is shown 

graphically in Figure 1. 
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Figure 1. Annual LANSCE Radionuclide (G/MAPs) Emissions and Offsite MEI, 1990–2002 

(adapted from LANL 2003, 2018) 

SC&A also reviewed the technical basis document for occupational environmental dose, 

ORAUT-TKBS-0010-4, Revision 01 (2010), and found that NIOSH had modeled occupational 

skin and whole-body dose immersion doses for “gaseous/mixed activation products” (G/MAPs) 

for LANSCE (NIOSH 2010, p. 23–24). This was done for Technical Area (TA) 53 (LANSCE), 

and two nearby work locations, TA-21 (Defense Programs East; 2,000 meters south-southeast of 

TA-53) and TA-72 (700 meters south-southeast of TA-53) that were predominantly downwind 

(NIOSH 2010, p. 24). Using Gaussian equations to model dispersion from the LANSCE stack 

(assuming no adjustment for dispersion factors and a ground-level release for claimant 

favorability), the estimated average external dose (immersion) from G/MAPs released from 

LANSCE were as shown in Table 1 for the 1990–2000 period. (NIOSH 2010, p. 47). In Table 1, 

the estimates assume the receptor is at 500 m from the source for 2,000 hr/yr, with no plume 

depletion, and no plume rise (stack height is zero). 
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Table 1. Estimated Average Occupational External Doses from G/MAPs released from 

LANSCE (TA-53) (mrem/yr) (excerpted from NIOSH 2010, Table 4-29) 

Year Skin (a) Whole Body (b)

1990 190 mrem 120 mrem

1991 90 mrem 57 mrem

1992 110 mrem 71 mrem

1993 51 mrem 32 mrem

1994 79 mrem 49 mrem

1995 69 mrem 43 mrem

1996 17 mrem 11 mrem

1997 32 mrem 20 mrem

1998 12 mrem 7.7 mrem

1999 0.047 mrem 0.3 mrem

2000 1.1 mrem 0.68 mrem

a. Calculated using skin dose factor for O-15 from Eckerman and 

Ryman (1993). 

b. Calculated using whole-body dose factor for Ar-41 from 

Eckerman and Ryman (1993). 

As Table 1 shows, average whole-body dose declined from an estimated 120 mrem per year in 

1990 to 0.68 mrem per year by 2000, with a range of 0.3 to 20 mrem during the 1996–2000 

period (of relevance to this SC&A review6). For occupational environmental exposures at the 

adjacent facilities at TA-21 and TA-72, the respective average whole-body dose ranges during 

this same period were 0.02 to 7.6 mrem, and 0.06 to 4.2 mrem (NIOSH 2010, Table 4-30). 

6 SC&A selected this subset of the SEC evaluation period as one of relevance to 10 CFR Part 835 program 

implementation.

While these constituted average estimated occupational doses from G/MAPs emissions for 

workers at LANSCE and nearby facilities, the decline of LANSCE emissions from the 1990–

1995 period through to 1999 is marked and, upon further review, may warrant further attention 

as a starting point to characterize maximum annual occupational exposure to G/MAPs and other 

airborne exotics.

2.4 APPENDIX A: SEC-00109 LANL PETITIONER ISSUES AND RESOLUTIONS

This appendix provides a compilation of all the issues identified over the years by the SEC00109 LANL petitioner, along with corresponding resolutions; this review was requested by the 

Advisory Board on Radiation and Worker Health (Advisory Board) LANL Work Group. This 

compilation is provided in the form of a table that identifies the following for each issue: the 

petitioner issue, the forum or document source, date, supporting documents, and NIOSH 

resolution. SC&A reviewed this Appendix following the initial issuance of the NIOSH response 

(issuance of a revised Appendix was delayed until after issuance of the NIOSH response).

Beyond SC&A’s general comments in its draft report (SC&A 2018) about the assumption of 

100 mrem CEDE/year for any unmonitored exposures after 1995 (an assumption that figures in 

 
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many of the responses in Appendix A), SC&A has one specific comment on Appendix A that 

requests a clarification from NIOSH regarding how it would bound occupational doses from 

mixed activation and fission products for the post-1995 period. As a function of NIOSH’s 

intended reassessment of such exotic internal exposures (ABRWH 2018), this concern may also 

be resolved in the course of that planned review. 

This request for clarification was forwarded to NIOSH and the Work Group in a January 4, 2019, 

transmittal (SC&A 2019).

3 CONCLUSIONS

NIOSH has agreed that compliance alone with 10 CFR Part 835 may not be a sufficient basis for 

validating that unmonitored workers at LANL would not have been likely to receive 100 mrem 

CEDE intakes. In its white paper, NIOSH has provided what it considers additional 

substantiation as it pertains to exposures to both primary and exotic radionuclides (e.g., MAPs 

and MFPs), including a review of bioassay results for primary radionuclides (plutonium, 

uranium, and tritium) monitored at LANL and a summary of available radiological control 

documents that are considered exemplary of the overall strength of the LANL field monitoring 

program. NIOSH also stresses its belief “that the 10 CFR 835 era represents a paradigm shift in 

DOE operations” (NIOSH 2018, p. 6). In its conclusion, NIOSH finds that this “weight of the 

evidence” continues to support the premise that unmonitored LANL workers were unlikely to 

have received intakes greater than 100 mrem CEDE per year.

SC&A respectfully disagrees that NIOSH has provided any new evidence that is sufficiently 

persuasive to contribute to the weight of evidence for this SEC-related evaluation, other than for 

the LANL primary radionuclides. As noted earlier in this response, a comparison of exposure 

results for these primary radionuclides as a means to compare or bound those of exotic 

radionuclides was discussed extensively in Work Group sessions and has already been deemed 

inappropriate. Likewise, any review of LANL field monitoring program performance would 

need to consider the implications of the 1999 LANL self-assessment of its bioassay program, 

which found not only broad noncompliances with 10 CFR Part 835, but also evidence of likely 

bioassay data incompleteness due to improper bioassay enrollments by the principal CTW 

contractor and nonparticipation by workers in the bioassay program. Without objective evidence 

to substantiate it, this assumption of a 100 mrem CEDE intake per year benchmark is no 

different than the former presumption based on regulatory compliance. 

It would seem that two central questions remain to be resolved. First, what is the adequacy and 

completeness of the LANL bioassay program in light of the 1999 findings? Second, can potential 

doses to unmonitored workers be bounded for exposures to exotic radionuclides? 

For the first question, there is a need to follow up on the findings of the 1999 LANL selfassessment and ascertain whether those findings are indicative of a serious programmatic 

deficiency that would impair the completeness of bioassay results and records for workers 

through 2000 (when corrective actions were put into place). If there is evidence that a substantial 

number of workers were not enrolled in bioassay programs as required or that many workers did 

not provide required bioassays, NIOSH would need to consider whether that would render 
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bioassay records inadequate and incomplete for purposes of dose reconstruction with sufficient 

accuracy. 

For the second question, NIOSH has already modeled occupational skin and whole-body 

immersion doses for “gaseous/mixed activation products” from LANSCE, using Gaussian 

dispersion models and conservative dose assessment factors, and found average worker wholebody doses (but not maximum exposed worker doses) to decline from 20 mrem per year to 

0.6 mrem per year during the 1995–2000 period. It would seem that these modeled dose 

estimates may provide a starting point for further review of how potential occupational 

exposures to G/MAPs can be characterized during the time period of interest after January 1, 

1996. It is unclear how the other radionuclide constituents (“exotic alpha-emitters” and “fission 

products”) (NIOSH 2017, p. 3) would be addressed, but similar source-term or air samplingbased modeling estimates would seem feasible.7

7 SC&A provides this additional perspective for the Work Group and NIOSH based on its broader review, in this 

case, of relevant data and documentation not addressed in the ER Addendum or NIOSH’s white paper. However, 

SC&A’s findings and conclusions as contained in this response paper only address the issues, findings, and 

conclusions presented by NIOSH in these two aforementioned evaluation documents for Petition SEC-00109. 

Finally, the fundamental question for the Work Group comes back to the established basis for the 

preceding SEC class for LANL. If compliance with 10 CFR Part 835 is no longer a valid reason 

for applying a 100 mrem CEDE for unmonitored workers, on what basis is the acknowledged 

pre-1996 “inability to bound unmonitored intakes of exotic alpha-emitters, fission products, and 

activation products” (NIOSH 2017, p. 3) to be resolved such that those potential exposures can 

now be bounded in dose reconstruction? The lack of bioassay data for exotic radionuclides 

confounded dose reconstruction before 1996, and there is no new evidence presented by NIOSH 

of any demonstrable changes in field monitoring, in vivo analysis results, or recordkeeping 

beginning on January 1, 1996, that would resolve the issue other than the implementation of 

10 CFR Part 835, which has now been discounted as a sole deciding factor. 

The NIOSH weight-of-evidence conclusion that the same 100 mrem CEDE benchmark can now 

be based on LANL’s “well-established” field monitoring and contamination control programs 

coupled with “state-of-the-art counting equipment...staffed with competent professionals” 

(NIOSH 2018, p. 30) is reminiscent of past Work Group deliberations contrasting LANL’s 

recognized technical capability versus its actual practice, in this regard. These were ultimately 

decided by both NIOSH and the Advisory Board, in terms of recommending an SEC class

through 1995, on actual data unavailability, i.e., the lack of bioassay data for exotic radionuclides 

and lack of applicable dose reconstruction methods, not the extensive bioassay program 

requirements, procedures, technology, and professional expertise that made such field 

monitoring feasible at LANL but ultimately not realized in a way that dose reconstruction could 

be accomplished with sufficient accuracy. 

 
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4 REFERENCES

10 CFR Part 835. Occupational Radiation Protection, U.S. Department of Energy. [SRDB Ref. 

ID 173742] 

ABRWH 2010. Transcript: Meeting of the Advisory Board on Radiation and Worker Health, Los 

Alamos National Laboratory Work Group, Hebron, KY. April 29, 2010. 

ABRWH 2012a. Transcript: Meeting of the Advisory Board on Radiation and Worker Health, 

Los Alamos National Laboratory Work Group, Hebron, KY. September 11, 2012. 

ABRWH 2012b. Transcript: Meeting of the Advisory Board on Radiation and Worker Health, 

Los Alamos National Laboratory Work Group, Hebron, KY. May 14, 2012. 

ABRWH 2017. Transcript: 118th Meeting of the Advisory Board on Radiation and Worker 

Health, Santa Fe, NM. August 23, 2017. 

ABRWH 2018. Meeting of the Advisory Board on Radiation and Worker Health, Redondo 

Beach, CA. December 12–13, 2018. [Transcript pending.] 

Bowen et al. 1986. Brent M., Bowen, William A. Olsen, Donald Van Etten, and I-li Chen, 

Measurement and Modeling of External Radiation during 1984 from LAMPF Atmospheric 

Emissions, LA-10766-MS, UC-11, Los Alamos National Laboratory, Los Alamos, NM. 

July 1986. Available at https://www.osti.gov/servlets/purl/5464930

DOE 1998a. 1997 Annual Report: Price-Anderson Nuclear Safety Enforcement Program, U.S. 

Department of Energy, Office of Enforcement and Investigation, Washington, DC. January 1998. 

[SRDB Ref. ID 167498] 

DOE 1998b. Memorandum from R. Keith Christopher, Director, Office of Enforcement and 

Investigation, U.S. Department of Energy, to DOE and Contractor PAAA Coordinators, Subject: 

Price-Anderson Amendments Act Enforcement Actions Related to Internal Dose Evaluation 

Programs (Radiobioassay and Dose Assessment) for Contractors in the Department of Energy 

Complex, U.S. Department of Energy, Washington, DC. November 24, 1998. [SRDB Ref. 

ID 168448] 

DOE 2000. Letter from R. Keith Christopher, Director, Office of Enforcement and Investigation, 

to Yoon I. Chang, Argonne National Laboratory-East, Subject: Enforcement Letter (NTS-CHAA-ANLE-ANLE-1999-0009). February 24, 2000. [SRDB Ref. ID 129026]

DOE 2001. Programmatic Assessment of the Internal Dosimetry Program at Los Alamos 

National Laboratory, 200-RP-1, U.S. Department of Energy, Los Alamos Area Office, Office of 

Facility Operations, Los Alamos, NM. July 5, 2001. [SRDB Ref. ID 83663] 

DOE/AL 1995. Memorandum from Manager, Albuquerque Operations Office, to Assistant 

Secretaries for Defense Programs and Environmental Management, and Directors of Energy 

Research and Nuclear Energy, U.S. Department of Energy, Subject: Recommendation for the 
Effective Date:

1/9/2019

Revision No.

2 (Draft)

Document No./Description:

SCA-TR-2018-SEC005

Page No.

23 of 24

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. 

Approval of the University of California (UC/LANL) 10 CFR 835 Radiation Protection Program 

(RPP) for the Los Alamos National Laboratory (LANL). May 24, 1995. [SRDB Ref. ID 166022] 

Eckerman and Ryman 1993. K.F. Eckerman and J. C. Ryman, External Exposure to 

Radionuclides in Air, Water, and Soil, Federal Guidance Report No. 12, EPA-402-R-93-081, 

U.S. Environmental Protection Agency, Office of Radiation and Indoor Air, Washington, DC. 

September 1993. [SRDB Ref. ID 11997] 

Kornacki et al. 1998. Interoffice memorandum from J.W. Kornacki, W.L. Hendrix, C.R. 

Morgan, J.L. Gatlin, N.D. Johnson, and E.Z. Parrish, Westinghouse Savannah River Company, 

to C.C. Cabbil, Subject: Root Cause Analysis for Corrective Action Report #97-CAR-07-0001. 

January 19, 1998. [SRDB Ref. ID 167757, PDF pp. 14–28] 

LANL 1994. Environmental Surveillance at Los Alamos during 1994, LA-13047-ENV, UC-902, 

Environmental Assessments and Resource Evaluations Group, Los Alamos National Laboratory, 

Los Alamos, NM. July 1996. Available at 

https://digital.library.unt.edu/ark:/67531/metadc676084/m1/2/

LANL 2000. Environmental Surveillance at Los Alamos during 1999: 30th Anniversary Edition, 

LA-13775-ENV, Los Alamos National Laboratory, Los Alamos, NM. December 2000. 

Available at https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-13775-ENV

LANL 2003. 2002 LANL Radionuclide Air Emissions Report, LA-14058-PR, U.S. Department of 

Energy, Los Alamos National Laboratory, Los Alamos, NM. Available at 

https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-14058_PR

LANL 2013. Response to NIOSH Questions for LANL Staff Regarding 10CFR 835 

Implementation and Unresolved Issues, RP2-HPM-13:002, Los Alamos National Laboratory, 

Radiation Protection Division, Los Alamos, NM. March 19, 2013. [SRDB Ref. ID 166130] 

LANL 2018. Los Alamos National Laboratory, Los Alamos, NM, Annual Environmental 

Reports, 1966–2017. Available at https://www.lanl.gov/environment/environmental-report.php

NIOSH 2004a. Technical Basis Document for the Los Alamos National Laboratory – 

Occupational Internal Dose, ORAUT-TKBS-0010-5, Revision 00, National Institute for 

Occupational Safety and Health, Cincinnati, OH. December 21, 2004. [SRDB Ref. ID 19565] 

NIOSH 2004b. Technical Basis Document for the Los Alamos National Laboratory – Site 

Description, ORAUT-TKBS-0010-2, Revision 00, National Institute for Occupational Safety and 

Health, Cincinnati, OH. April 27, 2004. [SRDB Ref. ID 19561] 
Effective Date:

1/9/2019

Revision No.

2 (Draft)

Document No./Description:

SCA-TR-2018-SEC005

Page No.

24 of 24

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. 

NIOSH 2009. Internal Dosimetry Coworker Data for Los Alamos National Laboratory, 

ORAUT-OTIB-0062, Revision 00, National Institute for Occupational Safety and Health, 

Cincinnati, OH. October 15, 2009. [SRDB Ref. ID 75028] 

NIOSH 2010. Los Alamos National Laboratory – Occupational Environmental Dose, ORAUTTKBS-0010-4, Revision 01, National Institute for Occupational Safety and Health, Cincinnati, 

OH. March 26, 2010. [SRDB Ref. ID 80164] 

NIOSH 2012. SEC Petition Evaluation Report, Petition SEC-00109, Los Alamos National 

Laboratory, Revision 1, National Institute for Occupational Safety and Health, Cincinnati, OH. 

August 13, 2012. [SRDB Ref. ID 165232] 

NIOSH 2013. Los Alamos National Laboratory – Occupational Internal Dose, ORAUT-TKBS0010-5, Revision 02, National Institute for Occupational Safety and Health, Cincinnati, OH. 

April 18, 2013. [SRDB Ref. ID 124166] 

NIOSH 2015. Fission and Activation Product Assignment for Internal Dose-Related Gross Beta 

and Gross Gamma Analyses, ORAUT-OTIB-0054, Revision 04, National Institute for 

Occupational Safety and Health, Cincinnati, OH. August 27, 2015. 

NIOSH 2017. SEC Petition Evaluation Report, Petition SEC-00109, Addendum, National 

Institute for Occupational Safety and Health, Cincinnati, OH. April 24, 2017. [SRDB Ref. 

ID 173741] 

NIOSH 2018. NIOSH Response to SC&A’s Review of the SEC-00109 LANL Addendum: 

Response Paper, National Institute for Occupational Safety and Health, Cincinnati, OH.

September 12, 2018. [SRDB Ref. ID 173861] 

SC&A 2010. SC&A’s Review of NIOSH’s Evaluation Report for Los Alamos National 

Laboratory Special Exposure Cohort Petition SEC-00109: Preliminary Issues – Availability of 

Bioassay Records and Adequacy of In-vivo Dosimetry, SCA-TR-SEC2010-0004, Revision 0, 

SC&A, Inc., Vienna, VA. April 8, 2010. [SRDB Ref. ID 173739] 

SC&A 2017. Review of SEC Petition Evaluation Report Addendum (SEC-00109) for Los Alamos 

National Laboratory, Memorandum report from SC&A, Inc., to Los Alamos Work Group. 

July 27, 2017. [SRDB Ref. ID 173740] 

SC&A 2018. SC&A Review of White Paper, “NIOSH Response to SC&A’s Review of the SEC00109 LANL Addendum,” SCA-TR-2018-SEC005, Revision 1, SC&A, Inc., Arlington, VA. 

November 16, 2018. 

SC&A 2019. Clarification Comments about NIOSH White Paper Response (September 12, 

2018), Appendix A, “SEC-00109 LANL Petitioner Issues and Resolutions,” Memorandum to Los 

Alamos National Laboratory Work Group, SC&A, Inc., Arlington, VA. January 4, 2019.