Working Draft 

Pantex Plant Site Profile Issues Matrix 

Draft Preliminary SC&A Assessment 

Revision 4 

Contract No. 211-2014-58081 

Prepared by 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, Virginia 22182 

Saliant, Inc. 

5579 Catholic Church Road 

Jefferson, Maryland 21755 

September 2014 

The attached “Pantex Plant SEC Issues Matrix – Draft Preliminary SC&A Assessment” is a 

revision of the previous issues matrix (Revision 3) of October 2013. It reflects deliberations 

conducted at the Work Group meeting held on September 4, 2014. 

Disclaimer 

This document is made available in accordance with the unanimous desire of the Advisory Board on 

Radiation and Worker Health (ABRWH) to maintain all possible openness in its deliberations. However, 

the ABRWH and its contractor, SC&A, caution the reader that at the time of its release, this report is predecisional and has not been reviewed by the Board for factual accuracy or applicability within the 

requirements of 42 CFR 82. This implies that once reviewed by the ABRWH, the Board’s position may 

differ from the report’s conclusions. Thus, the reader should be cautioned that this report is for 

information only and that premature interpretations regarding its conclusions are unwarranted.
Draft Pantex Issues Matrix – Rev. 4 2 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

1 Adequacy of Internal 

Dose Records

 During essentially all years under evaluation, there was no 

Pantex bioassay program for uranium, thorium, or plutonium 

that would be considered “routine.” Instead, bioassay was 

performed for specific events and for known or suspected 

exposure incidents.

 According to both procedures and interviewed employees, 

evidence of potential exposures was always followed by

additional area monitoring/media sampling (as appropriate), 

and also included personnel bioassay monitoring (if deemed 

necessary). 

 The routine bioassay program for radionuclides other than 

tritium was short-lived, occurring mostly in 1991 and 1992. 

Research did not reveal the level of air concentrations or other 

workplace indicators that triggered special bioassays before 

1991. 

 Except for a single measurement made for Pu-239 and Am241 at the Los Alamos Scientific Laboratory in 1978, no 

records of in-vivo measurements made within the 1951 

through 1991 evaluation period are available.

 More than 200 personnel working on a disassembly program 

were monitored by the Helgesen in-vivo counter in 1989; 

however, the results of the in-vivo counts were later 

determined to contain a positive bias and were deemed not 

credible (Helgeson 1989).

 While the quantity of Pantex internal data collected during the 

proposed class time is relatively low, it is consistent with the 

internal exposure potential associated with work conducted at 

the Pantex Plant (pg. 35). 

 Data available for estimating internal doses due to potential 

uranium, plutonium, and thorium exposures are predominantly 

from sampling/analyses performed in 1989 or later (pg. 36).

(1) Although the presence of radioactive material at the site has 

existed since 1952, the bioassay program was limited to 

incident-based sampling for a majority of the Pantex 

operating period in question. Limited routine monitoring for 

tritium was initiated in 1976, although there were a few 

samples prior to that time. Thorium and plutonium bioassay 

began to a minimal extent in 1991 and 1992, respectively. 

No routine internal monitoring data exist for worker intakes 

prior to 1991, and only intermittent data exist for some 

isolated incidents before then (with no documented trigger 

level for monitoring). Operations, work practices, and the 

potential for intakes changed over the 40 years in question 

(1951–1991), making back extrapolation or bounding 

approaches problematic. NIOSH has not demonstrated 

equivalency for use of more current data for the 

extrapolation back through time.

(2) The ER’s reliance on assumed compliance with past 

procedures and employee recollections is not a sufficient 

basis to assume positive uptakes were caught. The 

understood “cleanliness” of the materials and work 

performed do not provide an acceptable basis for overriding 

the wide gaps in bioassay records. The application of 

generalized bounding doses drawn from disparate 

documents that are not necessarily specific to either time or 

place, and post-date the exposure era in question, is neither 

technically coherent nor sufficiently accurate.

(3) Pantex did not have a lung-counting capability for in-vivo 

measurements of plutonium, americium, or uranium in the 

lungs of workers. There is no mention of a routine fecal 

monitoring program. Some consideration needs to be given 

to the inherent difficulties with determining potential acute 

and chronic exposures of insoluble plutonium, americium, 

uranium, and thorium. In addition, the Tiger Team 

assessment indicates that prior to 1989, the plant was not 
Draft Pantex Issues Matrix – Rev. 4 3 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

 Hardcopy air monitoring results applicable to specific 

activities have been documented and are available to NIOSH 

(see Attachment One of the ER).

 Based on the available data and the re-evaluation of the 

hundreds of documents in the SRDB related to Pantex, 

specifically in the area of internal dose, NIOSH concludes that 

the methods described in ORAUT-TKBS-0013-5 provide 

reasonable approaches to conservatively bound doses for all 

members of the class under evaluation. New information 

revealed since the TBD was issued confirms that internal dose 

assessment was performed on an appropriate, as-needed basis. 

As proven based on the available program documentation, the 

Pantex Plant operations were performed under strict 

radiological cleanliness controls and continually performed 

workplace monitoring to determine whether contaminated 

weapons were brought onsite or in the case of an inadvertent 

release of radioactive materials.

conducting baseline bioassay sampling (DOE 1990).

(4) Few air sampling records are available for key areas, such as 

the explosive cell, and gaps exist in the data for 1959–1963, 

1973, 1978, and 1988–1991. Lapel air sampling is available 

for only 1989 and 1991. High volume air sampling is also 

available for some years. There is also air-sampling data for 

the burning grounds and firing sites for a limited number of 

years. Many of the sources cited in the ER are used across 

many years. The preponderance of data is from general area 

air sampling, which may not be representative of the 

workers’ breathing zone. When using air-sampling data, the 

ER recommends applying a factor of 10 (in the case of 

plutonium) for the upper limit of the triangular distribution 

to account for the possibility that the air-sampling system is 

not representative of the workers’ breathing zone. There is 

no information on placement of air monitoring equipment in 

relation to the source term and the employees. An assumed 

bounding factor of 10 may be too low for such an 

adjustment. Further analysis of the air monitoring program 

is necessary to determine its appropriateness for use.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

Prologue statement emphasized how “basic characteristics of the Pantex mission and operations,” “national security assurance requirements” (e.g., “diamond stamped” 

quality assurance), and “comprehensive radiation safety programs” provided “compelling evidence” sufficient to justify its conclusion that “exposure potential during 

the early periods of Pantex were essentially nil, and/or can be adequately bounded for claimant favorability.” Mere “presence of radioactive material at the site” does 

not in and of itself define a credible internal intake potential. There is ample evidence of a comprehensive radiation safety program. Most hazardous radioactive 

materials are contained in sealed vessels, welded barriers, cladding, etc. High degree of “cleanliness,” housekeeping, and order assured in the weapons assembly and 

storage areas. Records provide an extensive listing of “incidents,” and the internal dosimetry data and evaluations are in the claimant dosimetry files and the NIOSH 

records repository. Low internal intake potential was particularly evident during early years of operations.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A submitted its draft assessment of “Data Completeness and Adequacy for the Pantex Plant” (April 2011), which addresses the adequacy of internal dose records. 

In its April 2010 update and both Work Group meetings, SC&A challenged NIOSH’s reliance on “descriptive memos,” a presumed “comprehensive radiation 

protection program,” and so-called “strict requirements” of the nuclear weapons program as a basis for characterizing exposure potential, as opposed to actual and 

demonstrable monitoring or field data of any kind. SC&A pointed out that it finds such reliance inconsistent with the interpretation of 42 CFR 82.17 provided by 

NIOSH at the Advisory Board’s November 2010 meeting, i.e., that “it is incumbent on NIOSH to quantitatively evaluate exposures associated with known source 
Draft Pantex Issues Matrix – Rev. 4 4 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

terms.” At the May 3, 2011, WG meeting, SC&A likewise challenged NIOSH’s statements in its prologue position, noting that program quality and assurance provides 

no “compelling evidence” of little early exposure potential for DU and thorium, that “diamond stamp” is merely an overall quality assurance program, and that many 

outside audits of Pantex have shown the lack of a comprehensive radiation protection program going back to at least 1980. SC&A recommended to the WG that it 

judge dose reconstructability not on subjective program assumptions or health physics professional perspectives, but on the objective merits of whether the available 

quantitative data are sufficient and adequate to support dose reconstruction with sufficient accuracy for all the workers and years defined by the petition class.

SC&A Status Update (10/8/13)

Based on discussions and agreement by the Work Group at its June 18, 2013, meeting, this issue was closed. Closure reflects that there were no SEC-level issues with 

the adequacy and completeness of bioassay data outside of uranium and thorium issues, which were dispositioned as part of the Board’s SEC recommendation at its full 

meeting on July 17, 2013. However, site profile issues remain to be resolved, as identified in SC&A’s Data Completeness and Adequacy for the Pantex Plant (April 

2011).

2 Internal Dose Models 

for the Assignment of 

Internal Dose from 

Uranium

 The only nuclear component involved at Pantex prior to 1957 

was DU. Because DU components were new at the time of 

assembly, there was minimal potential for DU oxide 

contamination (pg. 22).

 All of the unsealed uranium used at the Pantex facility was 

either DU or natural uranium. Enriched uranium was always 

associated with a sealed component with little likelihood of 

release and, therefore, not considered a significant potential 

exposure source for the proposed worker class evaluated 

(pg. 22).

 Some DU was also released at the hydrotest firing sites when 

hydroshots involved DU (pg. 23).

 No bioassay data were found for Pantex workers involved in 

the burning of DU-contaminated high explosives and 

hydroshots; however, the doses can be adequately bounded by 

doses calculated from air-sampling data (pg. 39).

 The DU intake data related to the contamination incident in 

February 1989 can be used for bounding the potential uranium 

doses for assembly/disassembly workers. Isotopic 

determination of uranium alpha activity in urine samples is 

available and the data set contains sufficient data to perform 

statistical analysis (pg. 39).

(1) The ER uses unsupported assumptions for modeling DU 

exposures and makes inappropriate use of the air-sampling 

detection limit for assigning uranium worker exposures. 

The internal DU proposed model for unmonitored workers 

(1980–1993) may be inappropriate and not claimant 

favorable. Given that bioassay data at Pantex are very 

limited and have been event-driven since 1993, NIOSH 

elected to use a worker bioassay dataset that was derived 

from a radiological incident in February 1989. The ER and 

TBD provide no confirmatory information that characterizes 

the “1989 contamination incident” in terms of verifying that 

the 305 assessed workers in fact represent 

assemblers/disassemblers, radiation safety technicians, and 

quality assurance personnel who, moreover, were employed 

for a full 10-year period, as assumed in the model. SC&A 

questions the basis of the assumption that unmonitored 

workers over Pantex’s operating history were no different 

from the 305 workers monitored in 1989. 

(2) Significant quantities of EU were handled at Pantex. The 

ER recognizes that plutonium was handled in a sealed form 

and assigns a potential missed dose from plutonium. EU 

presents the same potential for exposure, yet the ER has not 

addressed potential missed dose from this source.
Draft Pantex Issues Matrix – Rev. 4 5 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

 Internal doses are calculated based on methods outlined in 

ORAUT-TKBS-0013-5 (Hickey et al. 2007, pp. 41–42).

(3) The TBD contains unexplained and implausibly extreme 

changes in sensitivity values for uranium urinalysis and 

minimum detectable activity (MDA), as well as significant 

data gaps. The TBD (Hickey et al. 2007) shows an apparent 

improvement in sensitivity values of 2 orders of magnitude 

between 1960 and 1963, which then diminishes by a factor 

of 50 between 1968 and 1978. Gaps also appear in the data 

with no historical information on sensitivity from 1968–

1978, 1978–1983, and 1983–1990. With these inherent 

uncertainties and wide variations in values, SC&A does not 

believe the ER or the TBD provides a technically valid basis 

for applying uranium bioassay analysis data to coworker 

applications and intake calculations spanning these gaps and 

years.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

NIOSH can back-extrapolate bioassay data collected following the 1989 B-28 disassembly incident, because it is the “most robust set” of uranium urinalysis data,

which generated a “bounding quantity of depleted uranium oxide contamination from weapons disassembly.” It is noted that this operation had occurred in the late 

1980s prior to the complex-wide implementation of 10 CFR 835, and “hence, the bioassay data collected from this bounding contamination exposure potential scenario 

(due to workplace practices, operations, and engineering controls) can be applied to the earlier times as a very conservative, claimant-favorable, scientifically validated 

default.” There are also some “4300+ air sample results from several decades of plant experience, as well as uranium urinalysis sampling beginning in the late 1950s to 

validate the claimant favorability of the overestimation.”

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A agreed at the May 3, 2011, WG meeting to provide a “real-time” response to this issue to expedite resolution on behalf of the work group. However, at this 

meeting, SC&A noted that there were previous weapons disassemblies that involved evident DU contamination for which fewer or no samples were taken, but may 

have involved even greater contamination levels based on recently identified data. If the cited 4,300+ air samples were, in fact, credible and useful, it would seem that 

NIOSH would have already applied them for dose reconstruction purposes or for direct corroboration of its position. However, the vast majority of these samples were 

apparently not taken for dosimetry purposes and were not, in any case, positioned to ensure representative BZ sampling. The same problem holds for the older uranium 

urinalysis samples; if there were enough of them to be statistically reliable, they would be cited as a “quantitative basis” for back extrapolation of the 1989 data. SC&A 

concludes that there is no corroboration of NIOSH’s contention that its back-extrapolation of DU oxide exposure is bounding of all workers previously exposed.

SC&A Status Update (10/8/13)

Based on discussions and agreement by the Work Group at its June 18, 2013, meeting, this issue was closed. Closure reflects that the issue of internal dose models for 

uranium were resolved with NIOSH at the Work Group meeting prior to the full Board’s action on the SEC at its July 17, 2013, meeting.
Draft Pantex Issues Matrix – Rev. 4 6 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

3 Dose Estimate 

Approach for 

Plutonium

 Bounding doses from plutonium can be calculated for Pantex 

employees.

(1) For the period from 1958 (the year that plutonium was 

introduced to Pantex) to 1991 (except 1961, as discussed 

below), air-sample levels that would have triggered 

bioassay are not known; however, fewer disassemblies 

occurred and the plutonium was newer, meaning that 

there was less potential for oxidation and, therefore, 

personnel exposures to plutonium. Assemblies would 

have involved newly sealed plutonium metal. 

Consequently, the possibility of intakes and the severity 

of intakes would have been less. However, because the 

documentation of the number of disassemblies and the 

contamination levels are not available, unmonitored 

workers may be assigned an intake that is the same as the 

intake from the 1991 to 2000 period. (This excludes 

workers involved in the 1961 Cell Incident, which have a 

separate bounding dose.)

(2) Because intakes were rare for the period 1991 to 2000 

(1991 for the evaluated class), the criterion for 

investigation of possible acute intake (including obtaining 

special bioassay) can be used to support establishing 

bounding intake estimates for the proposed worker class 

evaluated in this report. During this period, when the 

number of disassemblies was highest and the plutonium 

was oldest, the criterion for investigation was any 

workplace indicator, indicating that an intake of 40 DAChours (290 pCi) might have occurred. These intakes can 

be assigned to the workers with the highest exposure 

potential as the mode of a triangular distribution with a 

minimum of 0 and a maximum of 10 times the mode. The 

factor of 10 for the upper limit of the distribution is set to 

account for the possibility of more than 1 intake per year 

and the possibility that the air-sampling system is not 

representative. The bounding intake for the period from 

The ER assumes a single acute exposure of 40 DAC-hours per 

year, based on the investigation criteria for the period 1991 to 

2000, and applies the internal dose methodology for plutonium 

outlined in the internal TBD. Intakes of 290 pCi are assigned to 

the workers with the highest potential as the mode of a triangular 

distribution with a minimum of 0 and a maximum of 10 times the 

mode. The 40 DAC-hr per year intake assumes that workplace 

monitoring, in the absence of adequate personal monitoring, was 

representative of the exposure conditions to the worker without 

providing a basis for this assumption. The use of the 40 DAChour annual exposure recommended by the ER, which equates to 

100 mrem total effective dose equivalent (TEDE), may not have 

been detectable, and is not supported by the DOE findings and 

investigation report (DOE 2001), even for workers as late as 

2000, with all the latest sensitivities and air monitoring 

capabilities taken into consideration. For workers that had in fact 

been monitored based on the 40 DAC-hour criterion (but for 

whom no records exist), the assigned value of 40 DAC-hours 

may only represent a lower bound or threshold value. The ER 

and supporting documents have not demonstrated that this 

approach bounds the thorium dose.
Draft Pantex Issues Matrix – Rev. 4 7 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

1991 through 2000, therefore, is 400 DAC-hr (2,900 pCi 

acute intake) per year of employment for high-risk tasks.

 Plutonium at Pantex was in the form of encapsulated pits of 

nuclear weapons. Strict workplace monitoring practices, 

including smears for contamination, were completed during 

assembly and disassembly to ensure the integrity of the 

encapsulation (pg. 23). 

 Internal doses are calculated based on methods outlined in 

ORAUT-TKBS-0013-5.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

NIOSH refers to its Prologue statements regarding program assurance and reliability. It also notes that the design of, and interest in, the integrity of sealed pits would 

have raised concerns if any uncontained Pu would have occurred in their handling. A suggested use of a factor of 10 is applied to an air sampling assumption of 

40 DAC-hours, for a default assignment of 400 DAC-hour intake for routine unmonitored exposures.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

Pending a final data capture being scheduled at Pantex by June 2011, SC&A recommends that this issue be closed. While SC&A still questions the methodology for 

the reasons stated, this issue appears to be moot, given the lack of any historic evidence that routine Pu internal exposures occurred due to lack of integrity of 

components handled.

SC&A Status Update (10/8/13)

Pursuant to SC&A’s 2010 recommendation, and based on additional discussion at its June 18, 2013, meeting, the Work Group closed this issue. 

4 Dose Estimate 

Approach for 

Thorium

 Workers handled thorium compounds during assembly and 

disassembly of certain weapons. Pantex used strict workplace 

monitoring practices, including smears for contamination on 

components to verify the encapsulation of the thorium (pg. 

24).

 It is assumed that workers could have encountered oxidized 

thorium components during disassembly of weapons in the 

mid-1960s (pg. 24).

 Bounding doses from thorium can be evaluated for Pantex 

employees (pg. 40).

 From 1980 to present, the methods for assigning intakes of 

(1) NIOSH has not provided evidence of workplace monitoring 

practices verifying the encapsulation of thorium. 

Furthermore, it is indicated that workers could have 

encountered oxidized thorium. Workers have, in fact, 

confirmed the existence of oxidized metal in thoriumbearing weapons. 

(2) For thorium, the assumption of an acute uptake in 

unmonitored thorium workers during disassembly is 

inconsistent with the argument for chronic exposure to DU 

workers during disassembly, given documented incidents of 

thorium contamination problems as early as the 1960s, 

although the exposure conditions for both types of workers 
Draft Pantex Issues Matrix – Rev. 4 8 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

thorium are the same as for plutonium because of similar 

workplace conditions. Specifically, there were fewer 

disassemblies containing thorium; thus, the plutonium 

methods are claimant favorable for thorium....For workers 

who had the highest possibility of intake for each year from 

1980 to 1991, a single acute intake of 40 DAC-hrs (48 pCi) of 

Th-232 (in equilibrium with progeny) was assumed. For 

Category 2 workers in Table 5-2 of ORAUT-TKBS-0013-5, 

0.1 times the intake was assigned. These intakes are modes of 

triangular distributions with a minimum of 0 and a maximum 

of 10 times the mode to account for the possibility of more 

than 1 intake per year and the possibility that the air-sampling 

system is not representative (Hickey et al. 2007).

 The ER proposes a methodology for assessing a bounding 

dose for thorium using uranium data for time periods before 

1980. Because DU contamination and thorium contamination 

would have been in the oxide form and behaved similarly in 

the workplace on a mass basis, it was assumed that the 

bounding intakes for inhalation of Type S and insoluble 

ingestion of thorium were the same as the bounding intakes for 

DU on a mass basis (pg. 44).

 Internal doses are calculated based on methods outlined in 

ORAUT-TKBS-0013-5 (Hickey et al. 2007).

are similar. 

(3) For the era prior to 1980, the ER recommends a bounding 

uptake the same as the bounding intakes for DU on a mass 

basis (i.e., 5.2 pCi/day). The basis for this is the similar 

behavior of thorium and uranium in the workplace. There 

has been no consideration of the relative quantity of 

materials in these assumptions. The ER and supporting 

documents have not demonstrated that this approach bounds 

the thorium dose.

(4) From 1980 to the present, the same intake (40 DAC-hrs) is 

assigned for thorium-232. The 40 DAC-hr per year intake 

assumes that workplace monitoring, in the absence of 

adequate personal monitoring, was representative of the 

exposure conditions to the worker without providing a basis 

for this assumption. The use of the 40 DAC-hour annual 

exposure recommended by the ER, which equates to 100 

mrem TEDE, may not have been detectable. For workers 

that had, in fact, been monitored based on the 40 DAC-hour 

criterion (but for whom no records exist), the assigned value 

of 40 DAC-hours may only represent a lower bound or 

threshold value. The ER and supporting documents have not 

demonstrated that this approach bounds the thorium dose. 

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

NIOSH’s ER acknowledges the limited amount of bioassay data available for thorium. Thorium dose for Category I workers is assigned based on a triangular 

distribution, with the minimum set at 0, the mode at 48 pCi, and the maximum at 480 pCi, with the modes corresponding to 40 DAC-hours (with the maximum being

set at 10 times the mode to account for possibility of more than one intake per year and non-representativeness of air sampling). Bioassay data and lapel sample results 

from the 1990s can be used to bound historical exposures, given that the source term was “cleaner and lower” in the earlier days (due to fewer disassemblies and less 

time since fabrication), and because engineering controls were largely unchanged. A conservative upper-bound estimate for an oxidized uranium source term 

potentially found during disassembly would be 300 grams; for thorium, an upper bound for the source term mass would be an order of magnitude lower (30 grams). 

NIOSH notes that “ONLY 3-5%” of the filters analyzed contain thorium particulates; in these cases, 95% of the isotopic particulate matter on the filters is uranium. For 

the specific case of W55 disassembly, “worst case equivalent dose” resulting from acute and chronic intakes for those involved in that disassembly showed that 

uranium, not thorium, was the radionuclide of concern. Thorium fecal, urine, and lung counts exist for about 25 employees.
Draft Pantex Issues Matrix – Rev. 4 9 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A agreed at the May 3, 2011, WG meeting to provide a “real-time” response to this issue (in conjunction with depleted uranium) to expedite resolution on behalf 

of the WG. As noted in SC&A’s Data Completeness and Adequacy for the Pantex Plant (April 2011), the largest gaps in incident-based bioassay data exist for thorium 

exposures. There were no thorium bioassay data available for the evaluated population during the SEC period. There were some personnel identified that encountered 

thorium oxide when working with thorium-containing systems, and there were workers identified as working with such systems on the Employee Health Physics 

Checklist for the plant. The NIOSH assumption regarding episodic or acute uptake in unmonitored thorium workers during disassembly is not consistent with the 

known work being performed. No quantitative basis is provided by NIOSH, as required by 42 CFR 82.17, to corroborate its contention that its approach is bounding of 

thorium dose for all workers exposed during disassembly operations.

SC&A Status Update (10/8/13)

Based on discussions and agreement by the Work Group at its June 18, 2013 meeting, this issue was closed. Closure reflects that the issue of an internal dose approach 

for thorium was resolved with NIOSH and the Work Group prior to the full Board’s action on the SEC at its July 17, 2013, meeting. 

5 The Internal Dose 

Approach for Metal 

Tritides

 Tritides were formed as a result of tritium gas reacting with 

metal components of weapons and producing tritiated 

compounds. In addition, tritium compounds were used in 

some weapons programs (pg. 23).

 A Cockcroft Walton neutron generator also produced some 

tritium in the off-gas and tritium particulate contamination 

existed in the target and the area where the target connected 

(pg. 23).

 The assessment of metal tritides revealed that the doses would 

not impact the bounding dose established for tritium in 

ORAUT-TKBS-0013-5 (Hickey et. al. 2007) (ER, pg. 42).

In interviews conducted by SC&A and backed by documents 

reviewed, some of the Pantex workers recognized that tritides 

were present in some of the operations. RSD-TBD-0036, Metal 

Tritides—Technical Basis Document (Jones and Levell 2004), 

addressed some of the concerns and issues regarding tritides and 

the disassembly program types that may have metal tritides 

present. Elemental tritium and tritiated water interact with 

metals and organics over time, producing special tritium 

compounds. In addition, processes at Pantex exposed workers 

directly to metal tritides. The ER indicates that metal tritides 

would not impact the bounding dose for tritium because it 

constitutes such a small percentage of tritium in the workplace. 

However, no formal evaluation is apparent in the ER of the types 

of tritium compounds present and their relative concentrations. 

Compounds such as metal tritides and other insoluble forms of 

tritium would be expected to have substantially longer residence 

times in the body and, therefore, provide a higher dose than what 

is assumed for elemental tritium or tritiated water. Bioassay 

techniques typically implemented for soluble compounds of 

tritium do not work for insoluble compounds, such as some 

metal tritides handled at Pantex.
Draft Pantex Issues Matrix – Rev. 4 10 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

Tritium is contained in sealed reservoirs, whose stainless steel composition mitigates against corrosion effects. Fabrication and application of tritides did not take place 

at Pantex. The only potential exposure pathway existed with “boom box” operations, for which exposure may have occurred during the removal of the debris from the 

firing tube and during cleaning of the boom box. An upper-bound estimate was calculated based on an assumed upper-bound intake rate, a maximum contamination 

level in the box, and use of titanium tritide (absorption Type M) as a source term to calculate a 50-year committed lung equivalent dose of 0.0691 merm, which would 

equate to about 1 mrem, assuming 15 cleanouts.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

Pending a final data capture being scheduled at Pantex by June 2011 to ascertain actual compounds in use, SC&A recommends that this issue be closed. While 

information is lacking regarding actual compounds handled and to what extent diffusion issues may have figured at Pantex, SC&A has found no documented evidence 

of exposure pathways of significance from a dose standpoint.

SC&A Status Update (10/8/13)

Pursuant to SC&A’s 2010 recommendation, and based on additional discussion at its June 18, 2013, meeting, the Work Group closed this issue. No further information 

was found in its data capture to indicate that tritides were implicated with the issue of tritium permeation of reservoirs at Pantex.

6 Interpretation of 

External Dosimetry 

Data

 The nature of the radiation fields a worker could have 

encountered depends on the type of facility in which the work 

occurred. Nuclear weapons components emit alpha, beta, 

x-ray, gamma rays, and neutrons; however, dose to workers 

depends strongly on the configuration (i.e., material and 

shielding) of the source radiation and work performed 

(pg. 24).

 Industrial radiography operations had the potential to expose

some workers to x-ray, gamma, and neutron radiation (pg. 24).

 Americium-241 was an increasingly significant source of 

exposure to workers performing weapons disassembly, which 

often occurred many years after assembly (pg. 25). 

(1) Early recorded deep dose (Hp10) may not be reliable. It is 

clear that for proper assessment of a film dosimeter, 

calibration curves must be used that resemble photon 

energies of the work environment. The dominant photon 

energy for Pantex workers was the 60 keV photon associated 

with Am-241, which is a factor of 10 lower than the 

calibration photon energy for Co-60 and/or Cs-137, which 

had been used historically at the plant. The use of Cs-137 or 

Co-60 as the calibration source for the dominant workplace 

photon energy of 60 keV would lead to an over-response 

for the open window (as a result of photographic film 

containing silver bromide with Z values of 47 and 35, 

respectively) and an under-response for the deep dose, 

which is subject to the attenuation effects of 1,000 

milligrams per centimeter squared (mg/cm2) [or 

0.88 millimeters (mm)] of lead, which has a Z value of 82.

(2) Calibration and dosimeter processing methods by outside 

contractor services cannot be assumed without further 

information. Three contractor services were used between 

1952 and 1973 for processing film dosimeters. While the 
Draft Pantex Issues Matrix – Rev. 4 11 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

competency of these vendors is not questioned, it is without 

basis to assume without further information that each would 

have used the proper calibration curves that matched the 

expected photon energies of the Pantex work environments. 

Given the variability of photon energies to which workers 

may have been exposed and the highly classified nature of 

the Pantex operations, it is reasonable to question whether 

vendor dosimeter services can be expected to have known 

which calibration curves to apply to individual Pantex 

dosimeters. 

(3) Exposures from skin contamination were possible with 

weapons programs involving oxidized metal. External 

exposure from this route should be considered for skin 

cancers. The current methodology of assigning whole-body 

penetrating dose in situations where nonpenetrating dose is 

unavailable may underestimate the dose, particularly in 

situations where uranium is involved.

(4) Derived estimates of the photon and neutron dose for 

unmonitored workers are likely to be too low. Pantex 

worker photon dose statistics, as defined in the ER and TBD 

(Fix et al. 2007), are based solely on dosimeter records for 

monitored workers whose photon dose was equal to or 

greater than 30 mrem per monitoring period. For the 10-

year period of 1952–1962, dosimeters were exchanged 

weekly, which may explain the fact that for the period 1952–

1958, all Pantex recorded doses (for monitored workers) 

were less than 30 mrem. Thus, on the basis of these 

statistics and guidance, all unmonitored workers would also 

not be assigned any photon or neutron doses for the years 

1952–1958. For years 1959 to the present, the exclusion of 

missed photon doses for deriving the median dose of 

monitored workers will also impact the estimated dose for 

unmonitored workers. SC&A does not consider the current 

guidance for dose reconstruction of unmonitored workers 

claimant favorable. For deriving photon and neutron doses 
Draft Pantex Issues Matrix – Rev. 4 12 SC&A – Updated September 29, 2014 

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However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

for unmonitored workers, missed photon doses for 

monitored workers should be included.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

In SC&A’s 2007 site profile review, a series of findings were made regarding the reliability of early recorded deep dose (Hp10), how calibration and dosimeter 

processing were performed by outside vendors, how the current dose estimation methodology assigned exposures from skin contamination, and how missed photon 

doses for monitored workers should be reflected in the derivation of photon and neutron doses for unmonitored workers. It was agreed that the site profile review lays 

out these concerns in detail, including the implications of a 1980 DOE investigation report that cited deficiencies in how the dosimetry program was administered and 

with the credentials of the Pantex personnel responsible for that program. The WG agreed that NIOSH’s response during the May 4, 2010, meeting suggested that these 

concerns were not likely of SEC significance; however, NIOSH agreed to clarify its dose estimation approach keying on the SC&A site profile review findings. The 

work group also tasked SC&A with evaluating the adequacy and completeness of the external and internal dose records being used for dose reconstruction for Pantex.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A noted during the May 2, 2011, WG meeting that while these were site profile issues in nature, some of them involved incorrect adjustment factors or values that 

would affect the accuracy of dose estimates if used as stated. NIOSH agreed to review the external dose findings from SC&A’s site profile review in that context. 

With respect to adequacy and completeness, SC&A has submitted its Data Completeness and Adequacy for the Pantex Plant (April 2011).

SC&A Status Update (10/8/13)

Discussion at the Work Group’s June 18, 2013, meeting clarified that NIOSH provided a response to SC&A’s Data Completeness and Adequacy for the Pantex Plant

(April 2011) white paper (contained in Faust and Ruhter 2011), which addressed a number of the key issues involved. These issues are also addressed in other matrix 

items for which responses have been provided or will be forthcoming (e.g., Items 7, 12, and 16). One issue remains to be clarified based on NIOSH’s white paper

response: For 1976 onward, how would dose reconstructors interpret “zero” entries when these may represent blanks, which could have been either actual zero dose 

monitored or reflect lack of monitoring? In both cases, “missed dose” would presumably be applied; for the latter case (lack of monitoring), this assignment would be 

less than that provided by a coworker dose assignment.

SC&A Status Update (9/4/14)

NIOSH agrees that it needs to clarify how “zero” entries will be interpreted for 1976 onward. A note or memo providing this clarification will be provided to the work 

group within 6 weeks, with subsequent revision of the TBD. Pending this resolution, this issue is held in abeyance.

7 Data do Not Support 

the Assumption that 

the 95th Percentile 

Neutron-to-Photon 

Ratio is Bounding for 

All Exposure 

Scenarios

The ER (pg. 26 states) states the following: 

The TBD neutron-to-photon ratios are based on worker 

dosimeter measurements that were recorded using the 

Panasonic UD-809/UD-812 system and correspond to 

doses in which both the photon and neutron doses of the 

individual exceeded 50 mrem per year. From these data, 

a median neutron-to-photon ratio of 0.8 and a 95th

While the recommended neutron-to-photon ratio method may 

bound some of the Pantex workers’ neutron doses, it cannot be 

assured that it will bound all workers’ neutron doses for 1951–

1992, because of the following issues:

(a) Back-extrapolating to previous 42 years not 

supported. The n/p value of 0.8 and 1.7 was obtained 

from 43 data points taken during the period of 1993–
Draft Pantex Issues Matrix – Rev. 4 13 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

percentile value of 1.7 were calculated. For dose 

reconstruction of monitored workers, NIOSH recommends 

the 95th percentile neutron-to-photon ratio of 1.7.

The ER (pg. 47) states the following:

Neutron doses measured at Pantex since this time [1993] 

with this new system are considered reliable for use in this 

radiological dose reconstruction program, and these 

measurements provide a basis for using neutron-to-photon 

dose ratios to permit estimating worker neutron doses for 

the periods prior to the accreditation. Based on NIOSH’s 

review and evaluation of the weapons systems handled at 

Pantex, and the assembly of the list that permits 

comparison across all times associated with this 

evaluation, NIOSH is able to establish that the neutron-tophoton dose ratios, applied to bounding photon doses, 

result in calculated neutron doses that are considered 

bounding across all time periods. The method used to 

bound neutron doses is addressed in Section 7.3.4.

Section 7.3.4 of the ER (pg. 50) states the following:

Photon doses (with appropriate corrections for lead apron 

use and dosimeter response uncertainty) were reliably 

measured from 1994 forward and can be used with a 

neutron-to-photon dose ratio of 1.7 to calculate neutron 

doses for the years prior to 1994 (ORAUT-TKBS-0013-6; 

Strom unknown date). The average neutron-to-photon dose 

ratio determined from reliable collective neutron and photon 

doses measured since 1994 is only 0.25 (see Table 6.1 in 

ORAUT-TKBS-0013-6). Thus, this method for calculating 

neutron doses prior to 1994 will result in average neutron 

doses to workers that are approximately 6.8 times the 

expected doses, which will be bounding (ORAUT-TKBS0013-6) for the class evaluated in this report.

Typically, there should not be a significant neutron exposure to 

2003. There is no supporting evidence that the 

operating conditions and radiation fields were 

sufficiently similar during this period to the previous 

42-year period, 1951–1992. Benchmark measurements 

would have to have been made to establish this 

relationship. NTA film results cannot be used for this 

purpose, because they have been deemed unreliable.

(b) Examples where n/p of 1.7 is not bounding. There are 

numerous examples over a significant time period (1960–1995) 

that indicate that using a neutron-to-photon ratio value of 1.7 

would not bound the neutron dose. See Attachment 1 for some 

examples where the neutron-to-photon ratio values ranged from 

2.0 to 13.6, with a GM=5.0, when measured during surveys. 

Additionally, if a worker’s recorded NTA film results show a 

dose greater than that calculated using a neutron-to-photon ratio 

value of 1.7, it cannot be used, because the correct neutron dose 

is not known from the NTA film results, which have been 

deemed unreliable. Dose reconstruction cases have used 

neutron-to-photon ratio values ranging from 0.25 to 2.5.

(c) Comparison to collective dose neutron-to-photon ratio 

value not valid. The statement that the recommended neutronto-photon ratio value of 1.7 is 6.8 times the neutron-to-photon 

ratio value of 0.25 derived from collective doses is not a valid 

comparison, because much of the collective photon dose was 

from workers who had only photon doses; hence, the results were 

diluted by photon doses (see ORAUT-TKBS-0013-6, pp. 33 and 

56).

(d) Reliability of recorded photon dose not established. 

While SC&A agrees that the systems used to create and store 

external dose records at Pantex appear to be adequate, we 

question whether the measured photon doses are sufficiently 

reliable for use in assigning photon dose and deriving neutron 

doses, while relying on only one measured parameter—the 

photon dose. An error in photon dose assignment is magnified 
Draft Pantex Issues Matrix – Rev. 4 14 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

unmonitored workers. However, for an unmonitored worker with 

some evidence of potential neutron exposure, neutron doses can be 

estimated by applying a median neutron-to-photon dose ratio of 

0.8, as determined by the log probability analysis of grouped 

Pantex and neutron dosimeter data, as determined by Strom. This 

median value, when applied to the assigned photon dose for 

monitored workers, will yield a bounding neutron dose to 

unmonitored workers.

ER pages 46 states:

Since first used, the film badges and TLDs assigned at 

Pantex have been capable of measuring photon exposures in 

the workplace with sufficient accuracy to permit the 

calculation of bounding photon exposures. There is strong 

evidence that workers who had the highest potential for 

radiation exposure were monitored with state-of-the-art 

dosimeters (National Bureau of Standards 1955) and the 

measured photon doses were reasonably accurate and 

complete (ORAUT-TKBS-0013-6). Dosimetry records 

maintained by the Radiation Safety Department have been 

independently reviewed by the HERS project to verify 

accuracy and to ensure complete documentation (Rawlston 

1991).

The ER (pg. 50) states that an alternate method has been developed 

for conservatively estimating missed neutron doses. Neutron and 

gamma dose rates associated with various weapons configurations 

are available for LANL and LLNL-designed nuclear weapons 

handled at Pantex. Dose rate data for individual weapons have 

been located at Pantex to cover the weapons configurations 

encountered during assembly and disassembly operations. The 

dose rate data, coupled with the exposure times derived from time 

and motion studies of the nuclear explosive operations, allow the 

calculation of exposure time-weighted neutron-to-photon dose

ratios. Using the neutron-to-photon dose ratios, the missed neutron 

doses can be estimated based on the measured photon doses and 

by a factor of 2.7 (i.e., 1 photon + 1.7 neutron-to-photon ratio = 

2.7 total error). SC&A has identified the following areas of 

concern, which have been discussed elsewhere in this matrix and 

are applicable to neutron dose calculations:

 Calibrated using medium to high energy photons (Co-60 

and Cs-137), but major photon fields were 60 keV

 Early photon dosimetry under-response, as well as overresponse, must be considered

 Wide range of photon energies present in work areas

 Three different dosimetry vendors used without access to 

classified photon energy spectra

 Pantex TBD and SEC ER state photon dosimetry was 

correct, while IAAP, for similar operations, states that 

only 37% of 60 keV dose was measured

 DOE investigation board findings are relevant to the 

credibility of photon, and hence, neutron dose 

reconstruction at Pantex
Draft Pantex Issues Matrix – Rev. 4 15 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

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DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

assigned to the personnel performing the nuclear explosive 

operations. These data allow determination of bounding neutron 

doses.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

The current site profile (TBD-6) for Pantex recommends using the following method to assign neutron dose prior to 1994:

 For unmonitored workers who may have had the potential to be exposed to neutrons, multiply the claimant’s photon dose by 0.8 (the 50th percentile n/p value) 

to assign neutron dose.

 For monitored workers, if monitored for neutrons, or had the potential for neutron exposure, multiply the claimant’s photon dose by 1.7 (the 95th percentile n/p 

value) to assign neutron dose.

 For 1994 forward, use the recorded neutron dose with appropriate ICRP-60 adjustments.

In response to concerns that while the recommended neutron-to-photon ratio method may bound some of the Pantex workers’ neutron doses, it cannot be assumed that 

it will bound all workers’ neutron doses for 1951–1993, NIOSH proposed a new approach that mirrors a similar one proposed by NIOSH in the course of the Mound 

WG SEC review proceedings. This approach applies measured doses in place of n/p ratios (with corresponding correction factors for NTA film) and MCNP modeling 

for missed doses at certain energies for the coworker model.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

In response to a WG request that SC&A review the new approach to neutron dose estimation, SC&A provided a review that was forwarded to the WG and NIOSH on 

December 27, 2010. At the May 3, 2011, WG meeting, SC&A also raised the need for NIOSH to demonstrate, in its upcoming response to this SC&A review, how the 

proposed parameters for MCNP are bounding for the range of systems assembled and disassembled for the period 1951–1991 at Pantex. SC&A will clarify this 

implication in a memo report, now that its notes have been cleared by DOE.

SC&A Status Update (10/8/13)

SC&A provided a memo report on May 18, 2011, to the Work Group and NIOSH regarding remaining questions surrounding the application of MCNP in the specific 

setting of Pantex operations. [No NIOSH response to these questions has been located; at about this time, the Work Group turned to remaining SEC issues as its 

priority.] Since then, NIOSH has revisited the neutron monitoring issues and believes it has a “good correction factor for the NTA film period,” but that the “early TLD

period still was an open question, because the TLD had failed DOELAP testing for neutron exposure.” (Pantex Work Group transcripts, June 18, 2013, pp. 118–119). 

NIOSH committed to provide “new” information associated with this most recent analysis to SC&A which, combined with its review of Faust and Ruhter 2011, will 

enable a full response to the Work Group on remaining questions regarding reconstructing Pantex external dose. This issue remains open until pending disposition 

before the Work Group.
Draft Pantex Issues Matrix – Rev. 4 16 SC&A – Updated September 29, 2014 

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DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

SC&A Status Update (9/4/14)

NIOSH originally proposing application of MCNP model as means to correct for NTA film shortcomings in pre-1977 period, use of TLD data as corrected by Stanford 

algorithm for 1977–1993 period, and use of adequate TLD data after 1994. However, NIOSH has observed some substantial anomalies with recorded n/p ratios, 

leading to conclusion that use of full distribution of measured neutron doses preferable. In cases where n/p ratios are skewed, application of the skewed ratio produces 

implausibly high neutron doses. Most of the observed neutron doses at Pantex are relatively low. NIOSH commits to providing a white paper to the work group within 

6 weeks, with a subsequent revision of the TBD once resolution is achieved. Pending this resolution, this issue is held in abeyance.

8. Completeness and 

Interpretation of 

Historic Radiological 

Exposure Sources

(1) The primary sources of internal radiation contamination have 

been depleted uranium oxide and tritium. The primary sources 

of external radiation exposure include plutonium pits and 

depleted uranium or thorium components (Personal 

Communication October 1, 2003).

(2) The burning grounds were used to burn high explosive (HE) 

waste, some of which was contaminated with uranium.

 Data that did not indicate contamination and/or exposures 

(“negative” data) were often not saved for future reference, 

particularly in the earliest years of operations (Personal 

Communication April 8, 2008). This Pantex recordkeeping 

practice, coupled with the relative cleanliness of the materials 

and work performed at Pantex, and the site’s practice of only 

collecting bioassay samples when other monitoring/events 

dictated a need, has resulted in apparent monitoring data gaps 

for many types of internal monitoring data over the years (pg. 

29).

 Exposure records from previous employment at other sites 

were also collected and incorporated into workers’ exposure 

files, as were exposures while employed at Pantex (pg. 35).

(1) There is a need to characterize the types of radiation 

exposure associated with particular weapons programs or 

time periods, including impacts of improvements in 

development technology. Operations, work practices, and 

the potential for intakes changed over the 40 years in 

question (1951–1991). Certain programs are more prone to 

internal contamination and pose a greater internal dose risk 

to disassembly and other workers.

(2) The predominant source of external exposure is during the 

assembly, disassembly, and modification of weapons where 

radioactive material is unshielded and often held close to the 

body. The radiation characteristics vary in energy with the 

different configurations and radiation-generating devices 

used. To further complicate this, there are few gamma and 

neutron radiation surveys available prior to the mid-1970s.

(3) The basis for determining exposure to uranium from burning 

activities was air-sampling activity for the period of 1960-

1967. The default intake rate of DU for the burning ground 

was 130 pCi/day for 1952 to present. No air-sampling data 

were available for 1952-1959 and 1963 (Hickey et al. 2007). 

(See Addendum regarding Burn Area exposures for further 

background.)

(4) The ER indicates that internal monitoring gaps are the result 

of the relative cleanliness of materials and work at Pantex, 

and the site’s practice of collecting bioassay samples based 

on field indicators or incidents. SC&A site expert 
Draft Pantex Issues Matrix – Rev. 4 17 SC&A – Updated September 29, 2014 

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DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

interviews conducted as a part of the site profile review 

indicate routine tritium off-gassing and significant oxidation 

of components (not always the pit) related to particular 

programs. Per the ER, records containing negative exposure 

or contamination data were not retained. In light of the 

opposing opinions of former workers, actual field 

monitoring data are critical to characterizing and 

ascertaining the true potential for internal exposure. 

(5) Pantex workers were involved in offsite operations, such as 

the Tweezer Project at Nevada Test Site (NTS), weapons 

accident recovery, and field modifications of weapons. The 

ER does not address internal and external exposure from 

these offsite and nonroutine operations conducted by Pantex 

employees. Pantex also received and evaluated debris and 

components from joint test assembly operations and 

weapons accidents. This extramural work potentially 

exposed Pantex workers to different source terms while at 

other facilities and while working with damaged weapons 

components. Exposure from these activities is not discussed 

in the ER. 

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

The types and sources of radiation exposure at Pantex Plant, from a historical standpoint, have been fully characterized in both the Pantex Plant TBDs or in the 

Evaluation Report.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A submitted its draft assessment of Data Completeness and Adequacy for the Pantex Plant (April 2011), which addresses the adequacy of internal and external 

dose records, and whether all exposure sources have been sufficiently characterized. As noted at the May 3, 2011, WG meeting, SC&A still awaits information 

regarding offsite exposures to Pantex workers that may have occurred at other DOE facilities.

SC&A Status Update (10/8/13)

NIOSH provided its response to SC&A’s Data Completeness and Adequacy for the Pantex Plant (April 2011) in Faust and Ruhter’s NIOSH Responses to SC&A’s 

Draft Data Completeness and Adequacy for the Pantex Plant (August 5, 2011). At the June 18, 2013, Work Group meeting, SC&A and NIOSH committed to revisit 

SC&A’s April 2011 paper and NIOSH’s August 2011 response, to disposition remaining site profile issues. SC&A’s review of NIOSH’s response on this issue 

indicates that the one remaining question to be resolved is the need for the Pantex site profile to reflect the historic role Pantex personnel played in “work for others” in 

terms of weapons test activities at NTS, weapons accident recoveries, and field modifications of weapons. This matrix item remains open pending that review.
Draft Pantex Issues Matrix – Rev. 4 18 SC&A – Updated September 29, 2014 

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DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

SC&A Status Update (9/4/14)

NIOSH agreed to add information in the TBD, upon revision, to inform dose reconstructors of this history. Pending the revision of the TBD, this issue is in abeyance.

9. Incidents Discussed 

in the ER and TBDs 

are Limited

 To support the incident/suspected exposure-driven internal 

monitoring program, all aspects of work at Pantex have always 

involved procedures and routine contamination checks (e.g., 

smears, air sampling) to assist in identifying work locations 

with potential for internal exposure (pg. 28).

 Documented monitoring data obtained from response work are

available for bounding the doses associated with incidents that 

occurred during the evaluation period (pg. 27).

 A list of Pantex incident/accident report titles applicable to the 

NIOSH evaluated time frame have been reviewed by NIOSH 

(pg. 26).

(1) The ER does not sufficiently discuss incidental internal 

exposures. These incidental situations form the basis for the 

bioassay program prior to 1991. There is no information on 

what defined an incident, how incidents were formally 

communicated, and whether the exposure to the personnel 

involved was integrated into the exposure records. SC&A is 

concerned about radiological incidents not identified in the 

ER and TBD, and for which the personnel files do not 

include bioassay data. The internal dose reconstruction 

assumptions for plutonium and thorium indicate that a single 

acute intake should be assumed. Exposures to these 

radionuclides are usually the result of incidental exposure, 

rather than continuous exposures. The ER should outline 

incidents resulting in exposure to workers to inform the dose 

reconstructor of potential exposure situations. Furthermore, 

the monitoring for incidents and exposure to cleanup 

workers from these incidents should be carefully evaluated 

to determine the completeness and adequacy of monitoring 

data available.

(2) The ER assumes all individuals involved in incidents were 

monitored; however, occurrences considered incidents by 

current standards historically were considered routine in 

some cases. 

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

There are some 100 or more incident reports listed in the SRDB. The treatment of incidents by the operating contractor was consistent with how other site contractors 

[in DOE] performed prompt and thorough investigations, followed by detailed reports. This is evidenced by the number and quality of the Pantex Incident Report files. 

There is no evidence that anything abnormal was considered routine from the very beginning of operation, and that anything abnormal was treated accordingly and 

promptly, which included bioassay and dose assignment, if appropriate.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

This issue is addressed by SC&A in its recent report submitted to the WG and NIOSH, Data Completeness and Adequacy for the Pantex Plant (April 2011). At the 

May 2, 2011, WG meeting, NIOSH indicated that it would review SC&A’s contention that not all incidents resulted in directed bioassays as part of its response to this 
Draft Pantex Issues Matrix – Rev. 4 19 SC&A – Updated September 29, 2014 

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Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

report.

SC&A Status Update (10/8/13)

NIOSH provided its response to SC&A’s Data Completeness and Adequacy for the Pantex Plant (April 2011) in Faust and Ruhter’s NIOSH Responses to SC&A’s 

Draft Data Completeness and Adequacy for the Pantex Plant (August 5, 2011). At the June 18, 2013, Work Group meeting, SC&A and NIOSH committed to revisit 

SC&A’s April 2011 paper and NIOSH’s August 2011 response, to disposition remaining site profile issues, including conduct of event-driven bioassays. SC&A’s 

review of NIOSH’s response indicates that while the definition and implementation of an incident reporting system evolved over time at Pantex (as it did across DOE), 

recorded event-driven bioassays became progressively more complete (with fewer exceptions noted for lack of worker identification, inconsistent dates) until a clearly 

comprehensive program was implemented by the late 1980s. Recognizing that the SEC period encompasses this earlier era and accepting that SC&A’s sampling of 

incidents suggests exceptional cases to more complete event-driven bioassay results, SC&A recommends that this issue be closed. However, this matrix item remains 

open pending Work Group consideration.

SC&A Status Update (9/4/14)

Based on SC&A’s recommendation, the work group determined this issue is closed.

10 Adequate 

Consideration has not 

been given to the 

Potential Exposures 

at the Firing Sites

The summary of the dose assessment methodology for the firing 

sites is outlined in the ER. A bounding intake can be determined 

using air-sampling results and additional assumptions. Because the 

employees at the firing sites were likely different than the 

assembly/disassembly workers, a separate bounding dose 

appropriate is provided for these workers (pg. 42).

Hydroshots were conducted at Firing Site 5 using DU as a 

surrogate material, resulting in uranium contamination at the 

firing sites. Significant quantities of DU were used in test fire 

shots during the late 1960s and early 1970s. Approximately 83% 

of the uranium was recovered, and approximately 95% could be 

accounted for at the firing site. The remaining 5% was vaporized 

and dispersed in the test fire cloud. Microscopic uranium was 

dusted beyond the perimeter under certain meteorological 

conditions, and sizeable pieces of uranium were propelled 

considerable distances.

Consideration of dose assignment from hydroshot and burning 

operations should be conducted to adequately reflect potential 

internal and external exposures, particularly from cleanup 

activities and incidental entries into these areas. Based on a 

limited amount of air-sampling data, NIOSH developed 

inhalation dose models for site operators and drivers that are 

based on 95th percentile values and appear to be claimant 

favorable. SC&A reviewed available air-sampling data from 

Firing Station 4 starting October 27, 1959, and ending December 

22, 1961, and compared these data with information presented in 
Draft Pantex Issues Matrix – Rev. 4 20 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

Figures 5-1 and 5-2 of the TBD (Hickey et al. 2007). The raw 

data SC&A reviewed does not support use of the 95th percentile 

of the 1960s’ outside air concentration of 24 pCi/m3 as 

appropriate or claimant favorable. SC&A questions the use of 1 

DAC-hour in this case, and finds it inconsistent with other 

calculated intakes for unmonitored workers, particularly 

considering the nature of the fired materials that were being 

remediated. 

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

Both the ER and ORAUT-TKBS-0013-5 (Pantex Occupational Internal Dose TBD) deal effectively with dose assignment from potential intakes from hydroshots and 

burning uranium contaminated HE. 

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

This area remains the subject of further data capture and will be addressed following SC&A’s remaining site visit.

SC&A Status Update (10/8/13)

No additional information was identified from SC&A’s site visit that would raise a question regarding the adequacy and completeness of information upon which 

NIOSH’s dose estimation approach for firing sites is based. The only remaining question is one of the conservatism of the proposed use of the 95th percentile of the 

1960s’ outside air concentration of 24 pCi/m3, based on SC&A’s review of available air sampling data from Firing Station 4 starting October 27, 1959, and ending 

December 22, 1961. Pending a Work Group discussion of this question, this item remains open.

SC&A Status Update (9/4/14)

NIOSH noted that with the SEC covering all uranium sources for 1958–1991, this issue is moot. The work group agreed that this issue is closed.

11 Validation that the 

Most Highly Exposed 

Workers were 

Badged [Petitioner 

Issue]1

Overall, personal monitoring was focused on those workers most 

likely to be exposed to radiation—radiography technicians, 

production technicians, material handlers, transportation workers, 

quality control technicians/inspectors, and warehouse production 

workers. Other workers at Pantex had little occasion to enter 

radiological areas, and their potential for radiation exposure or 

intakes of radioactive materials was considerably less.

The criteria or guidance that were used to determine who was 

badged (and how well that policy and wearing of the badges 

were enforced) and for what type of exposure (i.e., photon, beta, 

and neutrons), and how the badging policy varied as a function 

of job type (including transient-location workers), facility, and 

time, needs to be determined to assess if workers were 

appropriately badged to allow adequate dose reconstruction, and 

if that data can be used to create a coworker database for 

unmonitored workers. The external TBD does an analysis of the 

 

1

 Issue correlates to the following petition concern: The assumption that available records reflect worst-case scenarios or highest-exposed work groups 

does not appear to be borne out by worker histories. 
Draft Pantex Issues Matrix – Rev. 4 21 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

collective exposure received by fifteen job categories, which 

indicated that assembly/production workers, warehouse 

operators, and quality control/inspectors received the highest 

collective dose. The petition and the external TBD provided 

information on monitoring by year indicating little monitoring 

prior to 1957, with the number of monitored workers peaking in 

1996. Assuming that workers who were badged were the most 

highly exposed does not validate this assumption, nor justify 

using the distribution of coworker doses for unmonitored 

workers. Verification of monitoring policies and evaluation of 

changing badging practices over time should be completed.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

The documented policy of who was monitored at Pantex was based on the AEC/ERDA/DOE Manual Chapter 0524 (and later the Radiological Control Manual) 

requirement to monitor all workers who had the potential to exceed 10% of the applicable radiation dose limit. This requirement was carried down into applicable 

Pantex operating requirements and SOPs. NIOSH cites evidence that the coworker study (Strom 2004) included all of the highest exposed workers during the 1994–

2000 disassembly period. NIOSH concludes that there is a “solid” technical basis for defining the 95th percentile doses from 1994–2000 from Strom’s study as 

bounding doses for use in estimating the radiation doses for unmonitored workers for the entire 1952–1991 period.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

The information presented by NIOSH addresses practices in the later disassembly years (1980-2000), but not in the earlier era. While no documentation is available 

regarding the implementation of monitoring against these requirements, the issue of back-extrapolating exposure experience and monitoring effectiveness has been 

challenged by SC&A for internal dose estimation (addressed in Issue 1). For external dose estimation, SC&A indicated at the 5/2/11 WG meeting that it believes the 

use of latter day dose distributions for co-worker dose assignment (per Strom) is sufficiently accurate for the weapon systems involved.

SC&A Status Update (10/8/13)

Based on discussions and agreement by the Work Group at its June 18, 2013, meeting, this issue was closed. Closure reflects that the remaining questions surrounding 

external dose monitoring were resolved at the May 2, 2011, Work Group meeting (with internal dose monitoring issues subsumed in Matrix Issue #1.)

12 Accuracy of 

Available Radiation 

Exposure Data 

[Petitioner Issue]2

 The measured photon dose data, with appropriate corrections 

for lead apron use and dosimeter response uncertainty, provide 

reliable bounding photon doses. The available beta-dose data 

can also be used to calculate/establish bounding beta doses. 

(1) The ER implies that early film dosimeter data for Pantex are 

reliable. The ER and external TBD do not recognize the 

inaccuracies in calibration methods and uncertainties 

introduced into the dosimetry program by poor or improper 

 

2

 Issue correlates to the following petition concerns: In addition to the paucity of radiologic monitoring data, the accuracy of the available radiation 

exposure data is called into question by the lack of quality assurance data, ... As is the case for most facilities, records for exposures and releases were 

apparently not always well documented or maintained. 
Draft Pantex Issues Matrix – Rev. 4 22 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

 Neutron doses measured at Pantex with a new system since 

1994 are reliable, and these measurements are suitable for use 

in bounding the doses received by Pantex workers. Photon 

doses (with appropriate corrections for lead apron use and 

dosimeter response uncertainty) were reliably measured and 

can be used with a neutron-to-photon ratio to calculate 

conservatively bounding neutron doses for the years prior to 

1994 (Fix et al. 2007) (ER, pg. 52).

practices. In an assessment of the external dosimetry 

program, the Investigative Board cited key findings that 

concluded the following (DOE 1980, p. 51):

• Gamma calibration response curves for TLDs 

... did not have sufficient range.

• The scientist and laboratory technicians 

assigned to the Pantex dosimeter program were 

inadequately trained.

• There were no formal operating procedures for 

the Pantex dosimetry program.

• The quality of the Pantex dosimetry program 

was less than adequate.

SC&A considers the deficiencies identified by the DOE 

Investigative Board to be highly relevant to the credibility of 

dosimetry data for Pantex. The ER needs to consider these 

deficiencies for their implications on the accuracy of 

external dose reconstruction.

(2) Further complicating matters are issues with individuals not 

wearing their dosimeters all the time. During a survey of 

film badge utilization in June 1969, Poynor found several 

instances where personnel were not wearing their badges 

(Poynor 1969). The extent of issues that involved 

inappropriate wearing of dosimetry is unknown; however, 

radiological control staff subsequently established a program 

to spot check badge racks to determine whether individuals 

were wearing their badges.

(3) Refer to Item #8 for a discussion on neutron dose.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

The deficiencies noted in DOE (1980) only apply to the 1972–1980 period that the TLD program was operated “in-house.” Prior to 1972, film badge service was 

supplied by a reliable commercial service (uncertainty: +/- 30%). From 1980–1993, the TLD dosimetry program was based on reliable Panasonic TLDs and readers, 

with an estimated uncertainty in measured photon doses of +/- 20%. After 1993, the DOELAP-accredited Panasonic TLD program had an uncertainty of +/- 10%.
Draft Pantex Issues Matrix – Rev. 4 23 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A notes this additional information in response to petitioner’s issues and recommends that the WG consider this issue closed.

SC&A Status Update (10/8/13)

The Work Group at its June 18, 2013, meeting, confirmed that this matrix issue is now closed.

13 Too Few Workers 

Monitored for Valid 

Dose Reconstruction 

[Petitioner Issue]3

 The bounding doses for monitored workers can be used with 

coworker study statistics to assign bounding doses to 

unmonitored workers, because the monitored workers are 

considered the maximally exposed work group within the 

proposed class (based on historical Pantex radiological 

program documentation). The combination of these dose 

calculation methods makes it feasible to bound the external 

dose (reconstruct the dose with sufficient accuracy) for the 

Pantex proposed worker class evaluated in this report (pg. 50).

 NIOSH has obtained credible information stating that prior to 

1988, Pantex issued dosimeters only to workers likely to 

receive 10% or more of the radiation protection guidance. 

There is also strong evidence that a majority of the workforce 

was not exposed to radiological sources during that time 

period. From 1952 through 1957, the number of badged 

workers was particularly low, as industrial radiography and 

medical x-rays were the only significant sources of radiation 

exposure onsite during that time. Variations in the number of 

badged radiation workers from 1958 through 1988 reflect 

changes in weapons productions rates and the quantity of 

radioactive materials present onsite. Reviews conducted of the 

Pantex Plant health protection and monitoring programs have 

repeatedly found that monitoring levels are consistent with 

exposure potentials. Interviews with Pantex safety officers 

and health physicists working within the class timeframe also 

(1) Statistics provided for external monitoring by year are based 

on limited data prior to 1958. 

(2) The ER does not provide the population of radiological and 

non-radiological workers by year for comparison to the 

number monitored.

(3) Early monitoring was concentrated on radiographers, 

whereas later years included multiple job categories.

(4) The ER has not demonstrated that variations in badged 

radiation workers are the result of changes in weapons 

production rates and the quantity of the radioactive material 

present.

 

3

 Issue correlates to the following petition concern: One argument we make is that too few workers were monitored for statistical purposes for 

generalizations to the rest of the workforce to be valid. Until 1979, the majority of the Pantex workforce went completely unmonitored. The assumptions that 

the most exposed workers were monitored was not found to be valid at IAAP, as above, and is likely not valid at Pantex. 
Draft Pantex Issues Matrix – Rev. 4 24 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

supported a proper correlation between exposure potentials 

and monitoring levels (pg. 51).

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

NIOSH cites ORAUT-TKBS-0013-6 and Carr (1992, SRDB Ref ID: 14338) to provide statistical responses to SC&A questions regarding this concern raised by the 

petitioners.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A addresses this issue in more detail in its recent Data Completeness and Adequacy for the Pantex Plant (April 2011) and will defer further conclusions until a 

response is forthcoming from NIOSH on it.

SC&A Status Update (10/8/13)

NIOSH provided its response to SC&A’s Data Completeness and Adequacy for the Pantex Plant (April 2011) in Faust and Ruhter’s NIOSH Responses to SC&A’s 

Draft Data Completeness and Adequacy for the Pantex Plant (August 5, 2011). SC&A’s review of NIOSH’s response finds agreement that limited monitoring existed 

prior to the arrival of sealed plutonium pits in 1958, and that relatively small variations in historic badging can be linked to weapons production and dismantlement 

rates, and changing DOE policies. NIOSH also cites its statistical treatments in ORAUT-0013-6 and Carr (1992, SRDB ID #14338) regarding use of Pantex external 

monitoring data. At its June 18, 2013, meeting, the Work Group asked NIOSH and SC&A to revisit this material prior to further Work Group review. Based on its 

review, as noted, SC&A recommends that this issue be closed. However, this matrix item remains open pending Work Group consideration.

SC&A Status Update (9/4/14)

The work group accepted SC&A’s recommendation and considers the issue closed.

14 Records Incomplete 

for Subcontractor, 

Temporary, or ShortTerm Employees 

[Petition Issue]4

Response not specifically provided in the ER. SC&A response is pending additional records review.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

All short-term or temporary workers were treated as visitors and monitored as such. These records were preserved by name and other identifying information.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A will be reviewing additional data capture information in its upcoming site visit to Pantex; however, unless additional information is found that would be 

inconsistent with NIOSH’s characterization of past practice in this regard, SC&A would recommend WG closure of this issue.

 

4

 Reference was made to subcontractor, temporary, probationary, and short-term employees who, when exposed to high levels of radiation, were in the 

words of participants, “flushed.” To this day, they are not fully represented in the records. 
Draft Pantex Issues Matrix – Rev. 4 25 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

SC&A Status Update (10/8/13)

SC&A reported to the Work Group at its June 18, 2013, meeting, that its subsequent onsite review did not find any new information that is inconsistent with NIOSH’s 

assessment of past practices at Pantex for visitors and temporary workers. The Work Group subsequently closed this issue.

15 Exposure from 

Tritium Leaks 

[Petition Issue]5

From available procedures, program reviews, and interviews 

conducted, it is evident that Pantex tritium monitoring has been 

appropriately focused on workers with the highest likelihood of 

exposure. As such, the data obtained can be used to bound tritium 

doses for all workers (pg. 39).

(1) Reservoirs began arriving at Pantex in late 1956 or early 

1957; however, there is no mention of how tritium doses 

prior to 1960 will be assessed.

(2) The ER indicates that Pantex tritium monitoring focused on 

workers with the highest likely exposure. Furthermore, they 

indicate this data can be used to bound tritium dose. Prior to 

1972, the ER suggests that 10 individuals were randomly 

selected per month for tritium bioassay from 1960–1971. 

The ER does not explain how the “highest likely exposed” 

individuals were selected and how they have verified this 

assumption. 

(3) Evaluation of Table 5-3 of the internal dose TBD indicates 

that the number of workers monitored for tritium uptakes 

was not constant, and only 0–4 workers were monitored per 

year from 1972–1975 (Hickey et al. 2007, pg. 15). In the 

absence of bioassay data prior to 1972, NIOSH has proposed 

to assign twice the highest uptake from the 1970s for the 

years 1957–1971. For the period 1972 to the present, 

unmonitored tritium exposures are assigned to production 

technicians, radiation safety technicians, and quality 

assurance technicians. The TBD uses a triangular 

distribution with a minimum of zero and a mode and 

maximum as defined in Table 5-6 to assign the missed dose 

(Hickey et al. 2007).

(4) The TBD does not clearly define either the data used to 

 

5

 In addition, we heard about several situations in which tritium leaks occurred, and believe there is uncertainty in the accuracy and completeness of 

radiation exposure data regarding such events. The impression from reading the available NIOSH documents is that one such exposure occurred, whereas 

workers indicated that such events were not uncommon and reported a practice of the medical office sending workers home with prescriptions for a “case of

beer.”
Draft Pantex Issues Matrix – Rev. 4 26 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

derive values in Table 5-6 or the number of data points used 

for determining the mode. Many of the values are assumed 

without adequate basis for the assumption. It is supposed 

that tritium bioassay occurred, yet few monitoring data were 

discovered in the dosimetry files. Unmonitored tritium 

exposures are also limited to three job classifications, which 

is not inclusive of all individuals handling reservoirs or 

tritium-contaminated components or those in the immediate 

vicinity when these activities are performed. For example, 

this would include those disposing of retired reservoirs and 

other tritium-contaminated equipment and materials and 

those receiving or preparing components for shipment, to 

name a few.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

NIOSH cites ORAUT-TKBS-0013-5 as explaining the approach and methodology to obtain a claimant-favorable dose estimation for tritium. 

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A addresses this issue in more detail in its recent Data Completeness and Adequacy for the Pantex Plant (April 2011), and will defer further conclusions until a 

response is forthcoming from NIOSH on it.

SC&A Status Update (10/8/13)

NIOSH provided its response to SC&A’s Data Completeness and Adequacy for the Pantex Plant (April 2011) in Faust and Ruhter’s NIOSH Responses to SC&A’s 

Draft Data Completeness and Adequacy for the Pantex Plant (August 5, 2011). At the June 18, 2013, Work Group meeting, NIOSH and SC&A committed to 

disposition remaining issues addressed in both respective papers and to bring them to the next Work Group meeting for discussion. SC&A’s review of NIOSH’s 

response indicates that its original issues regarding the bases of determining the “highest likely exposed” to tritium and how it was corroborated (e.g., using additional 

bioassay data for 1962–1971), and the inclusion of only three job classifications for unmonitored dose estimation, remain unaddressed (other than referring back to the 

site profile). However, given that the time period of concern for tritium is the same as that of the existing SEC period, SC&A defers to the Work Group for direction 

regarding the value of a full analysis of these and any remaining site profile-related issues surrounding tritium. This matrix item remains open pending further review.

SC&A Status Update (9/4/14)

SC&A provided additional clarification in advance of the work group meeting regarding its concerns over the current approach to tritium dose reconstruction in the 

TBD, particularly the use of MDA in Table 5-3 based on an appraisal of the Pantex HP program, not actual instrumentation or methods at Pantex. NIOSH agreed to 

revise Tables 5-1, 5-2, and 5-3, and corresponding guidance in the TBD to reflect the actual Pantex MDA. These proposed changes will be provided in a note or memo 

to the work group, followed by a subsequent revision of the TBD. Pending this resolution, the work group considers this issue to be held in abeyance.
Draft Pantex Issues Matrix – Rev. 4 27 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

16 Badge Placement 

[Petition Issue]6

Response not specifically provided in the ER. Worker geometry and proximity to radioactive material is 

pertinent to organ dose reconstruction, particularly for those 

workers required to work in close proximity to the pits or those 

who held units in their laps during work processes. In its 

analysis of workplace radiation fields, the ER has not provided 

an adequate basis for assigning partial body exposures during 

weapons component handling. Dosimeters were worn at the 

collar, as instructed by health physics staff. The highest 

exposures may have been at the waist or lower, resulting in an 

underestimate of dose to organs at waist level. Dosimetry on the 

collar or even chest would not adequately reflect the exposure to 

lower organs. The correction factors applied for glovebox 

workers proposed in the TBD may not be appropriate for 

situations encountered by Pantex workers, where radioactive 

material is often handled directly against the body. The ER 

should evaluate potential organ exposures exceeding the 

measured whole-body dose. 

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

Petitioners have stated that some workers held bare pits on their laps during some work practices, such as cleaning the pit surface. It was determined that the surface of 

a new pit could be cleaned in only a few minutes prior to assembly. It was also determined that throughout the history of Pantex operations, pits and other components 

have been handled in fixtures of various kinds. NIOSH acknowledges that while some workers could have held pits in their laps, it would be possible to estimate 

conservative doses requiring some adjustment to calculated organ doses for work in the early years (1959–1970), when use of fixtures for handling pits was not 

rigorously required. For pit operations that took place at waist level, the guidance in OCAS-TIB-0010 (OCAS 2005) should apply and would be an adequate basis for 

any corrections to organ doses.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

SC&A still questions how NIOSH will apply guidance in OCAS-TIB-0010 (OCAS 2005) for a glovebox geometry to a much more variable (from a geometry 

standpoint) work procedure involving direct handling by the worker.

SC&A Status Update (10/8/13)

This issue remains unresolved on the question of how OCAS-TIB-0010 will be applied at Pantex. The Work Group kept the issue open pending a NIOSH response.

 

6

 Most dosimeters have routinely been worn on the lapel of coveralls and shirts at a greater distance from the source then target organs. 
Draft Pantex Issues Matrix – Rev. 4 28 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

DRAFT PANTEX PLANT SEC ISSUES MATRIX

No. Issue SC&A’s Understanding of the NIOSH ER Position SC&A Initial Review

SC&A Status Update (9/4/14)

NIOSH indicates that it is revising OTIB-010 to apply a 95th percentile distribution for badge placement geometry to ensure such variabilities in badge location are 

addressed. This equates to a factor of 3.5 adjustment to such estimates which is conservative. The work group and SC&A will have the opportunity to validate this 

approach via the PER review process. On this basis, the work group decided to close this issue.

17 Efficacy of the HP 

and IH Programs 

[Petitioner 

Issue/Raised in ER]7

Excerpts from a 1990 Tiger Team report at the Pantex Plant 

relayed information related to (and critical of) the following: 

health physics support staffing levels and training; questions 

regarding quality assurance for radiation monitoring data; health 

and safety program inadequacies; the control of radioactive 

sources; maintenance of employee exposure records; 

contamination reports; and discussion of pre-employment or new 

employee baseline monitoring.

Although the report contains information which indicated that the 

Pantex Plant radiological program was deficient in implementing 

DOE Order 5480.11 requirements, the report did not find that 

radiation exposures and radiation doses were not monitored, either 

through personal or area monitoring. With the exception of 

neutron monitoring, the Tiger Team review did not indicate that 

occupational exposure monitoring data obtained were deficient, 

inaccurate, or unsuitable for use in bounding doses to Pantex 

workers.

(1) SC&A has addressed adequacy of employee exposure 

records under Items #2 and #7 for internal and external 

exposure data, respectively.

(2) The characterization of the workplace exposure conditions is 

addressed under Item #1.

(3) Health physics support staffing levels and training, general 

health and safety program inadequacies, and the control of 

radioactive sources provide valuable background 

information on the effective control of the source term, but 

are not directly pertinent to dose reconstruction for an 

individual.

(4) Maintenance of survey records, contamination records, and 

field air-sampling records are important to the dose 

reconstruction effort in the absence of personnel monitoring 

data, at least as a method to verify the reasonableness of the 

bounding doses for unmonitored or inappropriately 

monitored workers.

SC&A Reading of highlights of NIOSH Response (2/25/10 and 3/10/11 Responses)

[Issues are addressed elsewhere, as noted] – Recommend WG close this issue as separate item.

SC&A Response (4/2010 issues update response; supplemented by 5/4/10 and 5/3/11 WG responses)

[Issues are addressed elsewhere, as noted] – Recommend WG close this issue as separate item.

SC&A Status Update (10/8/13)

Based on SC&A’s previous recommendation, the Work Group closed this issue at its June 18, 2013, meeting.

 

7

 Real questions regarding the efficacy of the HP and IH programs at the site as reflected by workers’ histories and the Tiger Team report. 
Draft Pantex Issues Matrix – Rev. 4 29 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Addendum: Note regarding Burn Area Exposures 

Weapons components were in some cases recovered. To sanitize weapons components to render 

them unclassified, parts were removed and subjected to granulation, smelting, crushing, 

shredding, burning, incineration, and other processes. The average amount of hazardous material 

generated averaged about 75 pounds per weapon. This included DU as well as other metals and 

components (DOE 1995). In the early years, this material was handled with bare hands. In 

addition, burn pits were used to dispose of chemical wastes. The basis for determining exposure 

to uranium from burning activities was air-sampling activity for the period of 1960–1967. The 

default intake rate of DU for the burning ground was 130 pCi/day for 1952 to present. No airsampling data were available for 1952–1959 and 1963 (Hickey et al. 2007). 

Furthermore, dose assignment from hydroshot and burning operations should adequately reflect 

potential internal and external exposures, particularly from cleanup activities and incidental 

entries into these areas. Based on a limited amount of air-sampling data, NIOSH developed 

inhalation dose models for site operators and drivers that are based on 95th percentile values 

and appear claimant favorable. SC&A reviewed available air-sampling data at Firing Station 4 

starting October 27, 1959, and ending December 22, 1961, and compared these data with 

information presented in Figures 5-1 and 5-2 of the TBD (Hickey et al. 2007). The raw data 

SC&A reviewed does not support the determination that using the 95th percentile of 1960s’

outside air concentration of 24 pCi/m3is appropriate or claimant favorable. SC&A questions the 

use of 1 DAC-hour in this case and finds it inconsistent with other calculated intakes for 

unmonitored workers, particularly considering the nature of the fired materials that were being 

remediated. The 19 pCi/d intake factor at Pantex is inconsistent with that used for IAAP. 
Draft Pantex Issues Matrix – Rev. 4 30 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

References 

Carr, B.H. 1992. Pantex History: 1942-1992, US Army, AEC, ERDA, DOE, Pantex Plant, 

Amarillo, Texas. [SRDB Ref ID: 14338] 

DOE (U.S. Department of Energy) 1980. Report of the Investigation of a Radiation Exposure 

Incident at the Pantex Plant During September 1979, Albuquerque Operations Office, 

Albuquerque, New Mexico, January 10,1980. (Classified) 

DOE (U.S. Department of Energy) 1990. 1990 Tiger Team Assessment of the Pantex Plant, 

Amarillo, Texas, DOE/EH-0130, Department of Energy, Washington, DC, February 1, 1990. 

DOE (U.S. Department of Energy) 1995. Final Enivronmental Impact Statement for the 

Continued Operation of the Pantex Plant and Associated Storage of Nuclear Weapon 

Components, U.S. Department of Energy; DOE/EIS-0225; October 1995; 

http://www.globalsecurity.org/wmd/library/report/enviro/eis-0225/index.html. 

DOE (U.S. Department of Energy) 2001. [2000-2001 Investigation of the Rocky Flats Building 

771 Worker Exposure Report, Summary Report, 2001.] 

Faust, Leo G. and Ruhter, Paul J., 2011. NIOSH Responses to SC&A Draft Data Completeness 

and Adequacy Review for the Pantex Plant, M.H. Chew & Associates, August 5, 2011. 

Fix, J.J., Martin, J.B., Strom, D.J., Traub, R.J., and Stansbury, P.S., 2007. Pantex Plant National 

Security Complex – Occupational External Dose, ORAUT-TKBS-0013-6, Revision 01, Oak 

Ridge Associated Universities Team, Oak Ridge, Tennessee, June 22, 2007. 

Helgeson, 1989. Report of In Vivo Counting for Mason & Hanger Silas Mason Co., Inc. Pantex 

Plant-Work Performed on September 22 through October 6, 1989, Helgeson Scientific Services, 

November 3, 1989, SRDB Ref ID: 14337. 

Hickey, E.E., Bihl, D.E., and Strom, D.J., 2007. Pantex Plant – Occupational Internal Dose, 

ORAUT-TKBS-0013-5, Revision 01, Oak Ridge Associated Universities Team, Oak Ridge, 

Tennessee, June 22, 2007. 

Jones, R. and D. Levell, 2004. Metal Tritides Technical Basis Document, RSD-TBD-0036, Issue 

A, BWXT Pantex Plant, Amarillo, Texas. March 1, 2004. 

National Bureau of Standards, 1955, Intercomparison of Film Badge Interpretations, from 

“Isotopics;” National Bureau of Standards; April 1955; SRDP Ref ID: 3640.

NIOSH (National Institute for Occupational Safety and Health) 2008. NIOSH SEC Petition 

Evaluation Report Petition SEC-00068, Revision 0, August 5, 2008, Office of Compensation 

Analysis and Support, Cincinnati, Ohio. 
Draft Pantex Issues Matrix – Rev. 4 31 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

OCAS 2005. Special External Dose Reconstruction Considerations for Glovebox Workers, 

OCAS-TIB-0010, Revision 1. National Institute for Occupational Safety and Health, Office of 

Compensation Analysis and Support, Cincinnati, Ohio. May 18, 2005. 

Personal Communication, October 1, 2003, Personal Communication with [Name Eight 

Redacted], communication with a member of the Pantex Radiation Safety Department, October 

1, 2003, SRDB Ref ID: 11077 

Personal Communication, April 8, 2008, Personal Communication with [Name Five Redacted]; 

communication with site expert; April 8, 2008, SRDB Ref ID: 46110. 

Poynor, E.D., 1969. Memorandum from E.M. Poynor (Pantex Plant) to D.W. Hardwick, Survey 

of Utilization of Film Badges June 17, 1969 — June 23, 1969, Mason and Hanger-Silas Mason 

Co., Inc., Amarillo, Texas. July 7, 1969. 

Rawlston, J.E., 1991, Final HERS Phase III Status Report, memorandum to W.E. Ivie; J.E. 

Rawlston; September 12, 1991; SRDB Ref ID: 14258. 

SC&A 2011. Data Completeness and Adequacy for the Pantex Plant. Draft white paper. 

SC&A, Inc., Vienna, Virginia, and Saliant, Inc., Jefferson, Maryland. April 28, 2011. 

Special Exposure Cohort Petition SEC-00068, Pantex Plant, All employees who worked in all 

facilities at the Pantex Plant in Amarillo, Texas, from January 1, 1951 through December 31, 

1991, Petition qualified by NIOSH on November 20, 2007.

Strom, D.J. 2004. Log Probability Analysis of Grouped Pantex Photon and Neutron Dosimeter 

Data, Pacific Northwest National Laboratory, Richland, Washington. [SRDB Ref ID: 21850]

Strom, unknown date. Log Probability Analysis of Grouped Pantex Photon and Neutron 

Dosimeter Data; Dan Strom; SRDB Ref ID: 14348.
Draft Pantex Issues Matrix – Rev. 4 32 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ATTACHMENT 1: EXAMPLES OF NEUTRON-TO-PHOTON RATIO (n/p) VALUES 

GREATER THAN THE RECOMMENDED 1.7 VALUE AT PANTEX 

(a) 1960 and 1979 n/p Values for Some Inspector and Warehouse Workers Exceeded 1.7 

See pages 41 and 42 of TKBS-0013-6 for details; Section 6.6.3 recommends using the higher 

n/p value measured instead of the n/p value of 1.7 for these cases. However, this measured 

n/p value would be derived from unreliable NTA film results because they are not sensitive 

to lower energy neutrons; hence, this is not technically sound or favorable to claimant. 

(b) 1979 Measurements on Pits in Shipping Containers and in High Explosives (HE) 

Measurements by instruments in 1979 suggest that the n/p value for pits in shipping 

containers and pits in HE exceed the n/p value of 1.7 for some workers; in such areas as 

radiography, inspection, storage, and transportation of weapons. 

(DOE, Report of the Investigation of a Radiation Exposure Incident at the Pantex Plant 

During September 1979, January 10, 1980, as cited in pages 16 and 109 of SC&A's 

7/17/2008 review of Pantex Site Profile) 

(c) Data from Documents listed on Pages 65 and 66 of NIOSH's SEC ER of July 10, 2008 

Ref ID# Document

pdf.page Date Area Neutron

(mrem/hr)

Gamma

(mR/hr)

n/p

14319 5 9/12/1975 12-42 North vault 11.159 5.5 2.03

25440 18 10/12/1983 12-2 Source Rm 1.8 0.6 3.00

25440 18 10/12/1983 12-2 Source Rm 2 0.5 4.00

25440 18 10/12/1983 12-2 Source Rm 3 0.4 7.50

25440 18 10/12/1983 12-2 Source Rm 0.4 0.1 4.00

14148 8 4/14/1983 12-2 Source Rm 3.9 0.95 4.11

14158 3 5/21/1986 12-42 Test Bay* 0.5 0.175 2.86

14158 3 5/21/1986 12-42 Test Bay* 0.6 0.188 3.19

25471 4 2/18/1987 12-10 Source Rm** 1.8 0.4 4.50

25471 4 2/18/1987 12-10 Source Rm** 1.8 0.6 3.00

25471 4 2/18/1987 12-10 Source Rm** 1.9 0.4 4.75

25471 4 2/18/1987 12-10 Source Rm** 7.8 1.0 7.80

25471 4 2/18/1987 12-10 Source Rm** 5.3 1.7 3.12

25471 4 2/18/1987 12-10 Source Rm** 7.1 1.0 7.10

25471 4 2/18/1987 12-10 Source Rm** 3.8 0.8 4.75

25471 4 2/18/1987 12-10 Source Rm** 27.1 2.0 13.55

25471 4 2/18/1987 12-10 Source Rm** 26.8 2.0 13.40

25471 4 2/18/1987 12-10 Source Rm** 28.3 3.0 9.43

25471 4 2/18/1987 12-10 Source Rm** 38 7.2 5.28
Draft Pantex Issues Matrix – Rev. 4 33 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

Ref ID# Document

pdf.page Date Area Neutron

(mrem/hr)

Gamma

(mR/hr)

n/p

25471 4 2/18/1987 12-10 Source Rm** 23.1 3.5 6.60

25508 5 8/9/1990 12-21 Neutron Radio. 2.0 0.3 6.67

25508 5 8/9/1990 12-21 Neutron Radio. 1.0 0.3 3.33

* Non-radiation worker area where a value of n/p = 0.8 would be used in DR. Average = 5.6

**With Cf-252 source extended. GM = 5.0

Range = 2.0-13.6

(d) 1992–1995 Radiation Surveys of Different Weapon Types

Weapons program Neutron-to-proton ratio greater than 1.7

48 Yes, in certain configurations

57 No

61 Yes, in certain configurations

62 No

68 Yes, in certain configurations

71 No

76 No

78 No

79 Yes, approximately 10:1 ratio*

80 Yes, in certain configurations

83 No

87 Yes, in certain configurations

*Survey data was limited for this unit.

Source: Pantex 1992, Pantex 1993, Pantex 1994, Pantex 1995a, Pantex 1995b.

(From page 65 of SC&A's 7/17/2008 review of Pantex Site Profile.

Surveys taken with Victoreen 440 and Rem Ball instruments.)
Draft Pantex Issues Matrix – Rev. 4 34 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

ATTACHMENT 2: SC&A’S RESPONSE TO NIOSH’S EVALUATION REPORT 

CONCERNING EXTERNAL DOSE FOR PANTEX SEC-00068

NIOSH’s ER Position concerning External Dose for Pantex SEC-00068 

Page 26 of the ER states the following: 

The TBD neutron-to-photon ratios are based on worker dosimeter measurements 

that were recorded using the Panasonic UD-809/UD-812 system and correspond 

to doses in which both the photon and neutron doses of the individual exceeded 

50 mrem per year. From these data, a median neutron-to-photon ratio of 0.8 

and a 95th percentile value of 1.7 were calculated. For dose reconstruction of 

monitored workers, NIOSH recommends the 95th percentile neutron-to-photon 

ratio of 1.7. [Emphasis added.] 

NIOSH claims that the neutron doses at the Pantex facility can be bound by this method. 

Page 47 states the following: 

Neutron doses measured at Pantex since this time [1993] with this new system are 

considered reliable for use in this radiological dose reconstruction program, and 

these measurements provide a basis for using neutron-to-photon dose ratios to 

permit estimating worker neutron doses for the periods prior to the accreditation. 

Based on NIOSH’s review and evaluation of the weapons systems handled at 

Pantex, and the assembly of the list that permits comparison across all times 

associated with this evaluation, NIOSH is able to establish that the neutron-tophoton dose ratios, applied to bounding photon doses, result in calculated 

neutron doses that are considered bounding across all time periods. The 

method used to bound neutron doses is addressed in Section 7.3.4. [Emphasis 

added.] 

Section 7.3.4, page 50, states the following: 

Photon doses (with appropriate corrections for lead apron use and dosimeter 

response uncertainty) were reliably measured from 1994 forward and can be 

used with a neutron-to-photon dose ratio of 1.7 to calculate neutron doses for the 

years prior to 1994 (ORAUT-TKBS-0013-6; Strom, unknown date). The average 

neutron-to-photon dose ratio determined from reliable collective neutron and 

photon doses measured since 1994 is only 0.25 (see Table 6.1 in ORAUT-TKBS0013-6). Thus, this method for calculating neutron doses prior to 1994 will result 

in average neutron doses to workers that are approximately 6.8 times the 

expected doses, which will be bounding (ORAUT-TKBS-0013-6) for the class 

evaluated in this report. [Emphasis added.] 

Note that there is apparently an error in the first sentence in the statement above, because it 

currently reads as though the photon doses measured from 1994 forward can be used along with 
Draft Pantex Issues Matrix – Rev. 4 35 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

the n/p value of 1.7 to calculate neutron doses for years prior to 1994; what it most likely means 

is that the photon doses measured from 1994 forward can be used to determine the n/p values of 

0.8 and 1.7 so that the photon doses measured prior to 1994 can be used to calculate neutron 

doses prior to 1994. 

SC&A’s Response to NIOSH’s ER Position concerning External Dose at Pantex 

While the recommended n/p method may bound some of the Pantex worker’s neutron dose, it 

cannot be assured that it will bound all workers’ neutron doses for 1951–1992 because of the 

following issues: 

(a) Back-extrapolating to previous 42 years not supported – The n/p value of 0.8 and 1.7 

was obtained from 43 data points taken during the period of 1993–2003 (no data for 

1997); the data are reasonably distributed during this period with 4 to 5 points per each 

year. However, there is no supporting evidence that the operating conditions and 

radiation fields were sufficiently similar during this period to the previous 42-year period, 

1951–1992. The only mention of this issue in NIOSH’s ER was on page 47 where it is 

stated, “Based on NIOSH’s review and evaluation of the weapons systems handled at 

Pantex, and the assembly of the list that permits comparison across all times associated 

with this evaluation...” There is no further supporting evidence or references provided. 

Bench-mark measurements would have to have been made to establish a relationship 

between the n/p values during the early period compared to the latter period when the n/p 

value was derived. NTA film results cannot be used for this purpose because they have 

been deemed unreliable. Documentation of dose measurements (such as by survey 

instruments) at various locations and time periods compared to the 1993-2003 neutron 

and photon dose measurements would be required to determine whether radiation fields 

were compatible or not to justify use of NIOSH’s recommended method and n/p values.

(b) Examples where n/p of 1.7 is not bounding – There are numerous examples, over a 

significant time period (1960–1995) that indicate that using an n/p value of 1.7 would not 

bound the neutron dose. See Attachment 1 for some examples where the n/p values 

ranged from 2.0 to 13.6, with a GM = 5.0, when measured during surveys. Additionally, 

if a worker’s recorded NTA film results show a dose greater than that calculated using an 

n/p value of 1.7, it cannot be used (as recommended in ORAUT-TKBS-0013-6, page 42) 

because the correct neutron dose is not known from the NTA film results, which have 

been deemed unreliable. SC&A performed a preliminary review of 14 Pantex claims and 

found that of the eight DR cases where neutron doses were assigned, that the dose 

reconstructions did not always use an n/p value of 0.8 for unmonitored and 1.7 for 

monitored workers, but instead used n/p values ranging from 0.25 to 2.5; only 50% of the 

time were the recommended n/p values of 0.8 or 1.7 used. SC&A found that n/p values 

of 0.25, 0.80, 1.0, 1.7, 2.0, and 2.5 were used in the cases examined to date. 

(c) Comparison to collective dose n/p value not valid – The statement on page 50 of the 

ER that the recommended n/p value of 1.7 is 6.8 times the n/p value of 0.25 derived from 

collective doses is not a valid comparison because much of the collective photon dose 
Draft Pantex Issues Matrix – Rev. 4 36 SC&A – Updated September 29, 2014 

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

was from workers who had only photon doses; hence, the results were diluted by photon 

doses. This was discussed by NIOSH in ORAUT-TKBS-0013-6, page 33, where it is 

stated that “However, these ratios are not directly applicable to claimants because they 

are derived from collective doses. They do not take into account the “diluting” effect of 

numerous workers who had photon doses only (Martin, 2006b).” The annotations in 

brackets are further discussed on page 56. Therefore, the ER statement concerning the 

factor of 6.8 times is somewhat misleading. 

(d) Reliability of recorded photon dose not established – While SC&A agrees that the 

systems used to create and store external dose records at Pantex appears to be adequate, it 

is not as apparent that the measured photon doses are as reliability as are required for use 

to assign both photon dose and to derived the neutron doses, while relying on only one 

measured parameter, the photon dose. An error in photon dose assignment is magnified 

by a factor of 2.7 (for example, if a 100 mrem photon reading is in error by 10%, this 

leads to: 10 mrem photon + 1.7 n/p × 10 mrem = 27 mrem total error; this is a total error 

of 27%). 

In the ER, NIOSH states the following on page 46: 

Since first used, the film badges and TLDs assigned at Pantex have been capable 

of measuring photon exposures in the workplace with sufficient accuracy to 

permit the calculation of bounding photon exposures. There is strong evidence 

that workers who had the highest potential for radiation exposure were monitored 

with state-of-the-art dosimeters (National Bureau of Standards, 1955) and the 

measured photon doses were reasonably accurate and complete (ORAUT-TKBS0013-6). Dosimetry records maintained by the Radiation Safety Department have 

been independently reviewed by the HERS project to verify accuracy and to 

ensure complete documentation (Rawlston, 1991). 

In TKBS-0013-6, page 28, NIOSH states, “Photon radiation in the workplace would have been 

readily measured at Pantex, with available dosimeter technology, during all years of operation.”

However, SC&A has identified the following areas of concern: 

 Calibration using medium to high energy photons (Co-60 and Cs-137), when major 

photon fields were 60 keV.

 Early photon dosimetry under response as well as over response must be considered. 

 Wide range of photon energies present in work areas. 

 Three different dosimetry vendors used without access to classified photon energy 

spectra.

 Pantex TBD and SEC ER state photon dosimetry was correct, while IAAP TBD, for 

similar operations, states that only 37% of 60 keV dose was measured. 
Draft Pantex Issues Matrix – Rev. 4 37 SC&A – Updated September 29, 2014

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82.

 DOE Investigative Board findings are relevant to the credibility of photon; and hence, 

neutron dose reconstruction at Pantex.

The support for these concerns includes the following:

Calibration vs. Work Area Photon Energies

Dosimeters were calibrated using medium to high energy photons (Co-60 and Cs-137, page 23 of 

ORAUT-TKBS-0013-6), but according to pages 25 and 54 of ORAUT-TKBS-0013-6, the 

predominant source of radiation dose at Pantex is photons from Am-241, with the 60 keV photon 

being the most significant energy. This would lead to the film over responding in the open 

window (OW) of the badge (shallow dose), but could lead to the film under-responding under 

the shielded portion of the badge (deep dose) for some earlier dosimeters with thick filters, such 

as 1 mm Pb. This is discussed in detail in SC&A’s evaluation of the Pantex Site Profile on pages 

51–56 [SCA 2008].

Additionally, there was a wide range of photon energies present in the various work areas at 

Pantex as stated on page 24 of ORAUT-TKBS-0013-6. This would require different calibration 

factors for different work areas if the dosimeters were calibrated using only one photon energy 

spectrum.

Three different dosimetry vendors performed the dosimetry services for Pantex, yet the details of 

the photon energy fields were not available to them for use in calibration because this 

information was classified. This would not provide for a situation where the dosimeter results 

could be demonstrated to be technically reliable by matching the calibration photon energy 

spectra to the work place photon energy spectra.

As illustrated above, NIOSH’s SEC ER and the Pantex TBD state that photon dosimetry results 

were correct without any correction factors, except for lead aprons; while IAAP, a facility with

similar operations, TKBS-0018 [ORAUT 2005] states that only 37% of 60keV photon dose was 

measured and recommends a correction factor of 1/0.30 = 3.33 based on Hanford studies. 

Comparing the TBDs for IAAP and Pantex leads to the conclusion that the two plants were very 

similar in operations and functions; however, the recommendations for low-energy photon dose 

corrections are inconsistent with each other; one using a correction factor of 3 and the other a 

correction factor of 1.0.

Problems Identified during Investigation are Relevant

DOE Investigative Board findings are relevant to the credibility of photon, and hence, neutron 

dose reconstruction at Pantex. As late as 1979, when TLD dosimeters were being used, the 

procedures for, and characteristics of, photon exposures at the Pantex plant were not completely 

documented or understood. The dosimetry section at that time appears to have been under 

staffed and not sufficiently equipped to support NIOSH’s statement that the photon doses of 

record are accurate and do not require any adjustment factors. Some of the deficiencies are 

discussed in SC&A’s review of the Pantex TBD (SC&A 2008) and provided in detail in a 

classified report issued in 1980 by DOE, titled, Report of the Investigation of a Radiation 
Draft Pantex Issues Matrix – Rev. 4 38 SC&A – Updated September 29, 2014

NOTICE: This September 29, 2014, update has been reviewed for Privacy Act information and has been cleared for 

distribution. However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation 

and Worker Health for factual accuracy or applicability within the requirements of 42 CFR 82.

Exposure Incident at the Pantex Plant During September 1979 (DOE 1980). These deficiencies 

in the dosimetry program as late as 1979 raise ever more concerns about the reliability of prior 

photon dose of record; especially in the early years when dosimetry was less advanced.

References:

Martin, Jerome. Personal Communication. ORAU Team. Senior Health Physicist. August 

2006.

ORAUT (Oak Ridge Associated Universities Team) 2005. Technical Basis Document for

Atomic Energy Operations at the Iowa Ammunition Plant (IAAP), ORAUT-TKBS-0018,

Revision 01, Oak Ridge Associated Universities Team, Cincinnati, Ohio. March 14, 2005.

SC&A 2008. Pantex Plant Site Profile Review, Revision 1-Draft. S. Cohen and Associates, 

Vienna, Virginia. July, 17, 2008.