Page 1 of 20

Response to SC&A’s “Focused Review of 

ORAUT-RPRT-0092, Revision 00, and 

Remaining Petition SEC-00103 Evaluation 

Report Period: 1991–2007”

Response Paper

National Institute for Occupational 

Safety and Health

November 22, 2022 

Nancy Chalmers and Mike Mahathy

Oak Ridge Associated Universities Team

Reviewed by Tim Taulbee and John Cardarelli 

Division of Compensation Analysis and Support

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 2 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

INTRODUCTION

In June 2019, the Oak Ridge Associated Universities (ORAU) Team issued Evaluation of 

Bioassay Data for Subcontracted Construction Trade Workers at the Savannah River Site, 

ORAUT-RPRT-0092 [ORAUT 2019]. The purpose of that evaluation was to use a Radiation 

Work Permit (RWP) sampling plan to determine whether subcontracted construction trade 

workers (subCTWs) were sufficiently monitored by bioassay such that their radiation doses 

could be reconstructed with sufficient accuracy. By November 2019, SC&A issued their first set 

of comments titled Review of ORAUT-RPRT-0092, Revision 00, “Evaluation of Bioassay Data 

for Subcontracted Construction Trade Workers at the Savannah River Site” [SC&A 2019]. The 

National Institute for Occupational Safety and Health (NIOSH) responded in a response paper 

titled NIOSH Response to SC&A Comments on ORAUT-RPRT-0092 [NIOSH 2020], issued in 

August 2020. In November 2020, SC&A issued a follow-up response in Review of NIOSH 

response to SC&A on ORAUT-RPRT-0092, Revision 00, on Bioassay Data for Subcontracted 

Construction Trade Workers at the Savannah River Site [SC&A 2020]. In April 2022, SC&A 

issued Focused Review of ORAUT-RPRT-0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007 (hereafter referred to as SC&A Focused Review) [SC&A 

2022]. 

The timeline in Figure 1 shows the documents described above as well as other events that took 

place as part of the RWP sampling plan. 

Figure 1: Timeline of pertinent events and documents regarding ORAUT-RPRT-0092 [ORAUT 2019]. 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 3 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

In this response document, NIOSH addresses the five conclusions as outlined in Section 7 of the 

SC&A Focused Review [SC&A 2022]: 

1. Sampling premise is not sufficiently grounded in historical SRS practices. 

2. Results for direct and effective monitoring may be overstated.

3. Generalized matching is not sufficient.

4. RWP-specified, job-specific bioassay data are incomplete.

5. Feasibility of co-exposure model needs to balance RWP implementation with completeness 

of coworker data.

SC&A’s Conclusion 5 demonstrates that SC&A has shifted the focus of their ORAUT-RPRT0092 review from determining whether subCTW radiation doses can be reconstructed to 

determining whether a co-exposure model could be constructed for the subCTWs, in which case 

NIOSH can reconstruct dose. NIOSH agrees with SC&A’s current focus. 

SC&A CONCLUSIONS WITH NIOSH RESPONSES

In the sections below, NIOSH presents SC&A’s five conclusions with a detailed response 

following each SC&A conclusion.

SC&A Conclusion 1: Sampling premise is not sufficiently grounded in historical SRS 

practices

Measured against the review criteria used by SC&A’s review of RPRT-0092, the 

sampling premise is not sufficiently grounded in actual WSRC policies, procedures, and 

practices within the time period 1991–1998. While RWPs were implemented by 

procedure in 1992 (and were being rolled out by WSRC before then), along with more 

specific target radionuclides listed on RWPs, SC&A finds that demonstrable 

implementation of these requirements was not apparent in the workplace until 1994–

1995, as evidenced by figure 1 and table 2. Figure 1 shows that the percentage of 

required bioassays listed on the RWPs rose from very few (less than 5 percent) in 1991–

1993 to over 60 percent in 1994 and over 80 percent in 1995. Correspondingly, table 2 

shows that the percent of RWP-specified radionuclide bioassays compared to total 

bioassays listed in table C-1 of RPRT-0092 rose for plutonium from zero percent in 1991 

to 78 percent and 100 percent in 1994 and 1995, respectively. While these results could 

also imply that prescheduled bioassays were actually performed in place of job-specific 

bioassays but simply not cited on the RWPs, they also indicate that RWPs may have 

lacked adequate documentation and completeness. (Table 2 also notes that for other 

radionuclides of concern—americium, uranium, and neptunium—the percent of 

radionuclide-specific bioassays required by RWPs ranged from zero to 25 percent for 

1991–1993). While RPRT-0092 finds a relatively high level of direct and effective 

matches for sCTWs listed on RWPs, this may not be a valid comparison for the sake of 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 4 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

bioassay data representation, given the nascent state of RWP program implementation 

that may bias the percentage of sCTWs bioassayed higher for the already prescheduled 

radionuclides of concern (e.g., plutonium, americium, and fission products). [SC&A 

2022, PDF p. 42] 

NIOSH Response to SC&A Conclusion 1

Conclusion 1 mentions Figure 1 and Table 2 from the SC&A Focused Review [SC&A 2022, 

PDF pp. 28–29] multiple times and seems to be the basis for this conclusion. Figure 1 and Table 

2 are SC&A’s summaries of the information presented in ORAUT-RPRT-0092, Table C-1 

[ORAUT 2019, PDF p. 82–85]. Based on their Figure 1, SC&A commented on the very low 

percentages of listed bioassays on the RWPs from 1991–1993 and the increase in those 

percentages for 1994–1998. SC&A went on to describe the perceived rise in plutonium 

percentages from 1991 (0%) to 1994 (78%1

1 For clarity, the 78% means that 78% of the 32 RWPs (or 25 RWPs) sampled from 1994 have Pu marked as 

required on the RWP. The remaining 22% (or 7 RWPs) are assumed to require Pu bioassay based on the work 

and/or area.

) to 1995 (100%), as presented in their Table 2. It is 

not surprising to see the increase in percentages that SC&A identified because during the 

transition between prime contractors (from DuPont to Westinghouse) bioassay programs were 

prescribed by procedure, not RWP. The RWP forms from the early 1990s did not contain check 

boxes for RWP requirements, whereas the RWP forms from the middle and late 1990s did 

contain those check boxes. There was a proceduralized, pre-specified routine bioassay program 

in place in the early 1990s, so the fact that those RWPs do not specify the required bioassay is 

irrelevant for developing co-exposure models. As long as the workers were being monitored for 

the nuclides of concern, it does not matter whether the RWP specified those nuclides or the 

routine program did. Lack of RWP-specified bioassay requirements does not equate to an 

immature or inadequate bioassay program.

The preceding paragraph includes the phrase “perceived rise.” The information in ORAUTRPRT-0092, Table C-1 was from a sample of RWPs collected for a specific purpose: to be able 

to estimate the percentage of monitored subCTWs to within +/- 5% with 95% confidence. The 

summaries in Figure 1 and Table 2 of the SC&A Focused Review are not part of that specific 

purpose and were not characteristics captured in the March 2018 inventory (year was 

characterized but bioassay requirements were not), so the uncertainties in those summary 

statistics are unknowable. As such, all of the SC&A-provided percentages are not reliable 

because of their unknowable uncertainties and the point estimates should not be compared. If 

those uncertainties could be taken into account, the perceived “increase” and “rise” in 

percentages may not still be there. Therefore, the uncertainty in the point estimate of 78% (and 

all of the other percentages in that table) is unknowable and should cause one to question the 

reliability of that value because it was calculated from only 32 sampled RWPs2

2 Since bioassay requirements were not part of the March 2018 inventory, the number of RWPs in the population 

that require Pu is not known. For example, if there were only 32 RWPs in the population that require Pu and all were 

sampled, the point estimate of 78% would have no uncertainty. If there were 50 RWPs in the population that require 

(all other 

 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 5 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

percentages were from fewer than 32 sampled RWPs). In general, point estimates with unknown 

or unknowable uncertainties (or without confidence intervals) should not be compared to other 

point estimates or fixed threshold values [Taylor 1997, PDF pp. 24–25]. 

In summary, SC&A concludes that the Savannah River Site (SRS) RWP program was not 

adequately implemented until 1994–1995. That conclusion is based on the change in practice 

from bioassay specified by procedure to bioassay specified by RWP, not an inadequate RWP 

program. Additionally, SC&A is basing Conclusion 1 on Figure 1 and Table 2 that have 

unknowable uncertainties, making all conclusions drawn from Figure 1 and Table 2 within the 

SC&A Focused Review suspect. It is neither necessary to have RWPs nor to analyze them to 

justify the feasibility of making a co-exposure model. Co-exposure models can be created 

without having any RWPs, so the absence of bioassay requirements on some of the RWPs is 

irrelevant. 

SC&A Conclusion 2: Results for direct and effective monitoring may be overstated

SC&A continues to conclude that, as with the earlier SEC period of 1972–1990, NIOSH 

did not address all of the radionuclides listed in the RWPs when determining data 

completeness for job-specific bioassay monitoring, and, therefore, the percentage of 

matching results for direct and effective monitoring appear to be overstated in the RPRT0092 summary in section 6.3. This is most relevant for the 1991–1994 period, when (as 

noted in conclusion 1) many exposure-relevant radionuclides of concern were not yet 

included in RWPs and inaccurate facility source term assumptions may have been made, 

as noted by DOE in 1990 (DOE, 1990) and by WSRC in 1999 (WSRC, 1999a). While 

RPRT-0092 claims a relatively high percentage of both direct and effective matches 

between RWPs and listed sCTWs or their coworkers for at least one bioassay (averages 

of 96 and 98 percent, respectively), SC&A’s review found these values to be lower 

(averages of 77 percent directly and 89 percent effectively monitored) when matched 

against all mandated radionuclides for RWPs. These results tend to be dampened in a 

sitewide comparison, given the much larger numbers of prescheduled bioassays 

(plutonium, Sr/FPs, uranium), but become more apparent at the facility level, as shown 

in tables 5, 6, and 7. For the period 1991–1994, there are facility-specific instances of 

significantly lower percentages of directly bioassayed sCTWs (e.g., 50 percent for 

uranium at A-773 and at F-247 in 1991, as shown in table 7). RWPs themselves would 

not necessarily have included complete in vitro bioassay requirements until March 1999, 

when WSRC expanded its bioassay specifications to include facility-specific analytic 

characterization information (WSRC, 1999a). [SC&A 2022, PDF pp. 42–43]

 

Pu and 32 were part of the sample, the uncertainty in the 78% estimate would be fairly small. However, if there were 

500 RWPs in the population that require Pu and only 32 were sampled, the uncertainty in the 78% estimate would be 

much larger.
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 6 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

NIOSH Response to SC&A Conclusion 2

Regarding SC&A’s Conclusion 2 statement that “NIOSH did not address all of the radionuclides

listed in the RWPs...” [SC&A 2022, PDF p. 42], ORAUT-RPRT-0092, Section 2.1 defines what

it means for a subCTW to be monitored; it states “...for all radionuclides listed on the RWP

other than tritium (3H)” [ORAUT 2019, PDF p. 16]. This definition was also part of the final 

draft of the sampling plan [ORAUT 2018, PDF p. 3]. In section 4.2 of ORAUT-RPRT-0092, it is 

clear that the summaries for the report were created using a definition of monitoring that meant

the worker needed “...at least one required bioassay...” [ORAUT 2019, PDF p. 39]. SC&A is

correct that the intended definition of “monitoring” in the sampling plan is not what was tallied

for the results in ORAUT-RPRT-0092. 

As mentioned in the response to Conclusion 1, the sampling plan was designed to collect RWPs 

to be able to estimate the percentage of monitored subCTWs to within +/- 5% with 95% 

confidence, regardless of the definition of “monitored.” Recall that direct monitoring means the 

subCTW was monitored, while effective monitoring means that either the worker was monitored 

or their coworker was monitored. The confidence interval in ORAUT-RPRT-0092 is still valid

but applies to direct monitoring, where “monitored” means “at least one required nuclide.” Note 

that while the unweighted point estimate is more easily calculated (number monitored divided by 

number of subCTWs), the weighted point estimate is the more appropriate summary statistic,

since the sampling plan was a stratified multi-stage sample. If the sampling plan had been a 

simple random sample, all of the weights would be equal, and the weighted and unweighted 

point estimates would be the same [Biemer and Christ 2008]. Despite not being included in 

ORAUT-RPRT-0092, a confidence interval can also be calculated for effective monitoring 

where “monitored” still means “at least one required nuclide.” The summary statistics for “at

least one required nuclide” are in Table 1. 

Table 1: Summary statistics when “monitored” is defined as “at least one required nuclide” 

Monitoring 

type

Number of 

subCTWs

Number 

monitored

Unweighted 

point estimate

Weighted 

point estimate

95% confidence 

interval

Direct 662 633 95.62% 95.13% (87.18%, 98.84%)

Effective 662 652 98.49% 97.52%a (87.50%, 99.92%)a

a These summary statistics do not appear in ORAUT-RPRT-0092, but were calculated for this response using 

ORAUT-RPRT-0092 data.

The sampling plan was carefully designed to cover all areas and years of interest where there 

were RWPs inventoried. Any finer partitioning (by nuclide, craft, building, etc., or any 

combination thereof) of the RWP results was not part of the original design of the sampling plan, 

meaning those characteristics were not inventoried in March 2018. As mentioned in the response 

to Conclusion 1, the uncertainty in those results could be very large and cannot be calculated 

because the weights cannot be determined. Therefore, the remainder of this response to 

Conclusion 2 will deal with changing the definition of “monitored” to “all of the radionuclides 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 7 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

listed in the RWPs,” but will only present summaries by area and year along with updated 

confidence intervals. 

When changing the definition of “monitored” from “at least one required nuclide” to “all 

required nuclides,” SC&A calculated monitoring percentages of 77% directly monitored and 

89% effectively monitored. Note that these percentages are unweighted point estimates and their 

weighted counterparts would be more appropriate. Prior to the NIOSH recalculation for this 

response, the ORAU Team performed a very thorough Quality Assurance (QA) review of the 

information contained in Attachment C of ORAUT-RPRT-0092. After the QA and changing the 

definition of “monitored” from “at least one required nuclide” to “all required nuclides,” the 

updated summary statistics are in Table 2. 

Table 2: Summary statistics after QA when “monitored” is defined as “all required nuclides”

Monitoring 

type

Number of 

subCTWs

Number 

monitored

Unweighted 

point estimate

Weighted 

point estimate

95% confidence 

interval

Direct 663 448 67.57% 75.16% (68.15%, 81.32%)

Effective 663 525 79.19% 88.13% (80.14%, 93.74%)

Summaries by area and year are in Tables 3 and 4, respectively. Figures 2 and 3 provide a 

graphical representation of the tabled information. Although it is possible to calculate 

uncertainties in the results by area and year, the calculation would be very complicated. The only 

benefit to calculating those uncertainties for Tables 3 and 4 of this document would be for 

comparison to the point estimates in Tables 3 and 4 of the SC&A Focused Review [SC&A 2022, 

PDF pp. 30–31] or Table 4-1 of ORAUT-RPRT-0092 [ORAUT 2019, PDF p. 39], but since 

uncertainties were not calculated in those documents, there is no need to calculate them here. 

Two point estimates should not be compared without their accompanying uncertainties [Taylor 

1997, PDF pp. 24–25].

Table 3: Summary statistics by area when “monitored” is defined as “all required nuclides”

Area subCTWs Direct Direct % Effective Effective %

A 112 84 75.00% 95 84.82% 

E 23 16 69.57% 17 73.91% 

F 199 135 67.84% 156 78.39% 

H 232 149 64.22% 187 80.60% 

M 18 16 88.89% 17 94.44% 

Z 79 48 60.76% 53 67.09% 

All 663 448 67.57% 525 79.19% 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 8 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

Table 4: Summary statistics by year when “monitored” is defined as “all required nuclides”

Year subCTWs Direct Direct % Effective Effective % 

1990 1 0 0.00 % 0 0.00 %

1991 81 31 38.27 % 57 70.37 %

1992 106 83 78.30 % 94 88.68 %

1993 173 122 70.52 % 136 78.61 %

1994 140 91 65.00 % 100 71.43 %

1995 57 46 80.70 % 50 87.72 %

1996 24 17 70.83 % 19 79.17 %

1997 56 41 73.21 % 49 87.50 %

1998 25 17 68.00 % 20 80.00 %

All 663 448 67.57 % 525 79.19 %

Figure 2: Percent monitored (direct and effective) by area for ORAUT-RPRT-0092 and when “monitored” is 

defined as “all required nuclides.” The numbers above the bars are the number of subCTWs on RWPs in 

that area.
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 9 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

Figure 3: Percent monitored (direct and effective) by year for ORAUT-RPRT-0092 and when “monitored” is 

defined as “all required nuclides.” The numbers above the bars are the number of subCTWs on RWPs in 

that year.

For convenience in comparing the effect of changing the definition of “monitored,” Table 5 

contains the appropriate information from Tables 1 and 2 above. 

Table 5: Summary information for Conclusion 2

Monitoring type with definition Weighted point 

estimate

95% confidence 

interval

Direct (at least one required radionuclide) 95.13% (87.18%, 98.84%)

Direct (all required radionuclides) 75.16% (68.15%, 81.32%)

Effective (at least one required radionuclide) 97.52% (87.50%, 99.92%)

Effective (all required radionuclides) 88.13% (80.14%, 93.74%)

Changing the definition of “monitored” from “at least one required nuclide” to “all required 

nuclides” decreases the point estimates for direct monitoring in the sample from 95.13% to 

75.16% and the point estimates for effective monitoring from 97.52% to 88.13%, keeping in 

mind that these true monitoring percentages could plausibly be any value in their respective 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 10 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

confidence intervals. Because the two direct monitoring confidence intervals do not overlap (the 

second interval from Table 5 is completely below the first), one can conclude that the direct 

monitoring percentage decreases with the change in definition. Because the two effective 

monitoring confidence intervals overlap, the appropriate conclusion is that the change in 

definition does not have a significant effect on the effective monitoring percentage3.

3 Strictly speaking, overlapping confidence intervals do not always mean that there is not a significant difference, 

but with this much overlap, this is an appropriate conclusion.

In Section 5.4 of the SC&A Focused Review, SC&A suggests a monitoring threshold when they 

state “SC&A’s selection of the compliance value less of [sic] than 80 percent was arbitrary, but 

it was a reasonable value below which the rate of compliance certainly would be questionable” 

[SC&A 2022, PDF p. 33]. The choice of any such monitoring percentage threshold would be 

completely arbitrary. Despite the arbitrary nature of the SC&A threshold, every confidence 

interval in Table 5 is above or contains the SC&A value of 80%, so SC&A should not consider 

these monitoring percentages “questionable.” 

Section 5.4 of the SC&A Focused Review focuses on “compliance as a function of building” and 

is where the arbitrary value of 80% is discussed [SC&A 2022, PDF pp. 33–37]. Their analysis is 

not only a function of building because the sampling plan results have been partitioned three 

ways (by building, year, and nuclide) to make those tables. As mentioned above, this triplepartitioning affects the uncertainty in all of the numbers in that section. Because building and 

nuclide were not a part of the design of the sampling plan, the uncertainties in those numbers 

cannot be calculated. It is likely that every number in that section is not significantly different 

from the arbitrary 80% if the uncertainty could be taken into account. 

As mentioned above, any suggestion of a quantitative monitoring threshold based solely on 

subCTWs would be an arbitrary choice. If there is agreement between SC&A and NIOSH that 

monitoring for prime construction trade workers (CTWs) and/or nonCTWs was adequate enough 

to construct co-exposure models, then those monitoring percentages could be used as thresholds 

for the subCTWs. Given the monitoring percentages (and their uncertainties) for subCTWs, 

prime CTWs, and nonCTWs, statements could be made about how the monitoring percentages 

for these groups of workers compare to each other (i.e., Is the monitoring percentage for 

subCTWs significantly different from the percentage for nonCTWs?). 

While there is an expected drop in the monitoring percentages with the change in definition, the 

monitoring percentages, by either definition, must be combined with what is known about the 

exposure potential for the unmonitored workers. Consider a few scenarios: 

• The smallest weighted point estimate from Table 5 is approximately 75%. If the 25% of 

subCTWs from the sampling plan sample who were unmonitored constitute an insignificant 

fraction of the most highly-exposed workers in the entire population, a co-exposure model 

could still be constructed. 

 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

• To take the scenario above a step further, if only 10% of the subCTWs in the sampling plan 

sample were monitored, but a significant fraction of the most highly-exposed workers from 

the entire population are monitored, a bounding co-exposure model could be made. 

• At the extreme, if only the single most highly-exposed worker in the population was 

monitored (and his/her dose is known), this would result in a monitoring percentage estimate

from the sample of at most 1/663. Even with a percentage that low, a bounding co-exposure 

model could be made by assigning the known dose to all the other workers. 

In summary, as expected, changing the definition of monitored from “at least one required 

nuclide” to “all required nuclides” causes the monitoring percentage point estimates in Table 5 to 

decrease (confidence intervals show a decrease for direct but no difference for effective). 

Comparing monitoring percentage estimates to any subCTW threshold is inappropriate; a 

comparison (including uncertainties) with another group of workers would be more appropriate. 

While the definition of “monitored” affects the resulting summary statistics, those summary 

statistics from the sampling plan sample should be balanced with the consideration of the 

exposure potential of the population of unmonitored workers when considering whether it is 

feasible to create a co-exposure model. 

SC&A concludes that NIOSH did not address all of the radionuclides listed (or assumed) on the 

RWPs when summarizing results. NIOSH agrees that they did not address all radionuclides but 

has updated those tallies in this response. NIOSH contends that their conclusion has not changed: 

a co-exposure model can still be constructed. 

SC&A Conclusion 3: Generalized matching is not sufficient

Concerning co-exposure model datasets, SC&A found in a focused review of RPRT-0092 

plutonium coworker matches during the 1991– 1998 WSRC period that, while nearly 96 

percent of identified coworker matches involved the same RWP, inclusion of additional 

criteria (e.g., the same date, time, and craft) decreases this percentage significantly 

(down to 45 percent) (SC&A, 2019a, p. 66). Given the often nonroutine and intermittent 

nature of sCTW jobs under RWPs, sometimes involving unique radiological source terms, 

SC&A believes such matching needs to be more closely aligned with what is listed on the 

actual RWP. While the co-exposure implementation guide (NIOSH, 2020b) does not 

specify an objective measure for data completeness to support the representativeness of a 

co-exposure model, it does require a determination be made that “there are sufficient 

measurements to ensure that the data are either bounding or representative of the 

exposure potential for each job/exposure category at the facility” (NIOSH, 2015, p. 5). 

SC&A does not consider a generalized match of workers to RWP-specified, job-specific 

bioassays to satisfy the need to demonstrate that this data set is either bounding or 

representative of subcontractor exposure potential that should have been monitored by 

job-specific bioassay. [SC&A 2022, PDF p. 43] 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 12 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

NIOSH Response to SC&A Conclusion 3

SC&A concludes that the coworker matching criteria should be more restrictive than was used in 

ORAUT-RPRT-0092. For example, the SC&A Focused Review states for plutonium, “while 

nearly 96 percent of identified coworker matches involved the same RWP, inclusion of 

additional criteria (e.g., the same date, time, and craft) decreased the percentage significantly 

(down to 45 percent4).” 

4 Note that the SC&A Focused Review references (SC&A 2019a, p. 66) for the value of 45%. That value is actually 

found on page 60.

In the final draft of the SRS Work Permit Sampling Plan, the matching 

criterion was only “co-worker on the same RWP” [ORAUT 2018, PDF p. 16]. At that point, 

there was no documented objection to the matching criterion [SC&A 2018]. While not 

documented in ORAUT-RPRT-0092, the criteria used for a coworker match was a subCTW on 

the same RWP, same date, and same time (within no more than 15 minutes). Additionally, a 

laborer could not be used as a coworker for another craft, even if all the other matching criteria 

were met [ORAUT 2019]. There are only two differences between what SC&A is suggesting 

(same RWP, date, time, and craft) and what was done in ORAUT-RPRT-0092 (same RWP, date, 

time within 15 minutes, and laborer exception): (1) 15 minutes of time and (2) the exact craft 

versus the laborer exception. 

NIOSH believes that the criteria for coworker matching in ORAUT-RPRT-0092 were more 

restrictive than necessary and that the additional criteria suggested by SC&A are far too 

restrictive. SC&A is suggesting that a monitored coworker needed to be working right alongside 

the unmonitored worker for the match to count. This same misconception spawned a discussion 

during the December 5, 2019, SRS and SEC Issues Work Group Joint Meeting where it was 

suggested that coworker modeling be referred to as co-exposure modeling to clarify that these 

models are based on workers with similar exposure potential to the unmonitored worker, not 

necessarily their coworker who worked right alongside them [NIOSH 2019a, pp. 104–105]. This 

suggested change from coworker to co-exposure modeling was also discussed at the December 

11, 2019, Advisory Board meeting [NIOSH 2019b, pp. 136–138]. While there was no formal 

adoption of the term, NIOSH, SC&A, and the Advisory Board have all consistently used the 

term co-exposure when referring to these models since December 2019. 

As such, if a worker was unmonitored, the co-exposure model would be representative or 

bounding for that worker if the workers who were monitored had the same or higher exposure 

potential. There is no requirement that the monitored person work right alongside the 

unmonitored worker, or that the two workers be on the same RWP, same date, same time, and 

same craft (SC&A’s suggestion). In fact, the sampling plan for ORAUT-RPRT-0092 focused 

only on subCTWs. If there was any worker monitored (subCTW, prime CTW, or nonCTW) with 

the same or higher exposure potential, the co-exposure model would be representative or 

bounding for that unmonitored worker. 

In summary, coworkers used for effective monitoring matching need only have the same or 

higher exposure potential than the unmonitored worker. SC&A’s criteria of same RWP, same 

 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 13 of 20

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with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

date, same time, and same craft are far too restrictive and do not need to be considered when 

creating a co-exposure model. 

SC&A Conclusion 4: RWP-specified, job-specific bioassay data are incomplete 

RWP-required, job-specific bioassay data should be assumed to be substantially 

incomplete for purposes of demonstrating monitoring data completeness and 

representativeness for use in a co-exposure model until the end of 1996 (a 100-percent 

resampling of all workers on job-specific bioassays was performed for 1997; enhanced 

accountability and tracking of job-specific bioassays were implemented in 1998). This is 

based on independent program audits that found that lapses in bioassay submission 

existed during the 1991–1996 timeframe, spanning from the initial 1990 Tiger Team 

findings about bioassay program noncompliance to the 1997–1998 WSRC actions in 

response to DOE field audits, internal FEB findings, and DOE headquarters enforcement 

action. This is consistent with SC&A’s analysis in figures 4 and 5, where SC&A 

compared the noncompliance fraction (missed bioassay results) of directly bioassayed 

radionuclides (plutonium, uranium, americium, Sr/FPs neptunium), in terms of being 

greater or lower for the period 1991– 1994, as compared with 1995–1998, respectively. 

These comparisons are most evocative for uranium and americium, with bioassay 

noncompliance being significantly higher for the earlier period. The opposite is true for 

neptunium and Sr/FPs, but by only a small margin over fewer data points. As expected, 

plutonium is essentially the same for both periods, likely due to its outsized prevalence in 

SRS operations and by its prescribed, prescheduled monitoring[.] [SC&A 2022, PDF p. 

43] 

NIOSH Response to SC&A Conclusion 4

SC&A concludes that regulatory issues related to job-specific sampling and noncompliance 

fractions indicate that RWP-specified job-specific data are incomplete. Nearly half of the 

summary of Conclusion 4 is a discussion of Figures 4 and 5 of the SC&A Focused Review. 

SC&A compares what they call a “noncompliance fraction” for 1991–1994 to the fraction for 

1995–1998. As mentioned in the NIOSH responses to Conclusions 1 and 2, making any 

comparison for which the sampling plan was not designed should be done with great caution, if it 

is done at all. Uncertainties for what SC&A refers to as “noncompliance fraction” cannot be 

calculated. Nuclides were not considered in the sampling plan or its preceding inventory. 

Therefore, to use statements such as “significantly higher,” “statistically significant,” and 

“essentially the same” without confidence intervals or uncertainties is inappropriate. If the bars 

in Figures 4 and 5 of the SC&A Focused Review could have error bars, the “noncompliance 

fractions” in those sets of years may be indistinguishable. SC&A also mentions that there are 

“fewer data points” for neptunium and Sr/FPs. While that may be true, it would be helpful to 

include that information on the plots because the number of results by nuclide for the two time 

periods does not seem to be readily available in the SC&A Focused Review. When considering 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 14 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

percentages, proportions, or fractions, it is always good practice to also consider the total number 

of results from which those values come. 

The other half of the summary of Conclusion 4 deals with job-specific sampling, audits, a 1990 

Tiger Team finding, and the 1997–1998 Westinghouse Savannah River Company actions. 

ORAUT-RPRT-0102 is an assessment of plutonium bioassay at Los Alamos National 

Laboratory, but it also contains generic co-exposure concepts in Sections 2 and 4 [ORAUT 2021, 

PDF pp. 11–14]. Section 4 of ORAUT-RPRT-0102 discusses regulatory compliance and coexposure modeling. The conclusion from that section is that “compliance with the regulations in 

place at the time the radiological work was performed is not required in order to perform a dose 

reconstruction or develop a co-exposure model” [ORAUT 2021, PDF p. 14], which was echoed 

by Dr. Paul Ziemer at the April 15, 2021, meeting of the Advisory Board on Radiation and 

Worker Health [NIOSH 2021, PDF p. 91]. Therefore, the 1990 Tiger Team finding and the 

1997–1998 Westinghouse Savannah River Company actions do not necessarily prevent coexposure modeling for SRS. Section 2 of ORAUT-RPRT-0102 discusses the components of coexposure models and concludes that “...a representative or bounding co-exposure model can be 

constructed unless a significant portion of the most highly exposed workers were not monitored 

or do not appear in the study sample” [ORAUT 2021, PDF p. 13]. This means that if a 

significant portion of the most highly-exposed workers appear in the SRS datasets, co-exposure 

models could be constructed. 

The SRS 5Q1.1-506 manual seems to indicate that workers exposed to unknown conditions 

should be considered for job-specific sampling. This could lead one to incorrectly conclude that 

the most highly-exposed workers were monitored with job-specific sampling. SC&A quotes SRS 

5Q1.1-506: 

Caution: It is EXTREMELY IMPORTANT to note that the effectiveness of the 

bioassay program in general depends on combining both the routine program and 

the non-routine, job-specific program. Any time unusual events occur, or jobs are 

performed that may expose personnel to unusual hazards, a job-specific program 

should be considered per Section 5.1.2.1. [WSRC 1992, PDF p. 60]

Section 5.1.2.1 of 5Q1.1-506 states: 

Any time jobs are undertaken with the potential for unknown radiological 

conditions to occur or unusual radionuclides to be present, a non-routine, jobspecific bioassay program should be considered. In such cases, an in-vitro sample 

and/or in-vivo count may be required prior to commencing work and again at the 

conclusion of work. Such a sampling program is at the discretion of HPO 

supervision and is noted on the Radiological Work Permit for the task. Additional 

guidance on job-specific sampling programs is available from the Dosimetry 

Evaluation Group at x5-2931. [WSRC 1992, PDF p. 57] 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 15 of 20

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with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

These two statements from 5Q1.1-506 seemingly imply that job-specific samples are non-routine 

(or special) samples. This implication contradicts a 2017 interview response given by Dr. Tom 

LaBone, a former site internal dosimetrist at SRS, stating that “Job‐specific bioassay is a 

program prescribed in response to a specific event (the job) but is not a special bioassay” 

[ORAUT 2017, PDF pp. 10–11]. NIOSH conducted a follow-up interview in August 2022 to ask 

Dr. LaBone about this apparent contradiction [ORAUT 2022a]. In the August 2022 interview, 

Dr. LaBone acknowledges the confusion that may arise from the 5Q1.1-506 quotes above, but he 

maintains that job-specific samples were part of the routine program and were not special 

samples according to site practices, despite what the procedures say. In fact, regarding the 1997 

Notice of Violation (NOV), he says: 

Examining the correspondence associated with the 1997 NOV, it is clear that 

DOE initially considered job-specific samples to be special samples required by 

10CFR835 – a reasonable conclusion based on written site procedures as we 

have already discussed. At the enforcement meeting we had an opportunity to 

present our case for job-specific samples not being special samples and hence not 

being required by 10CFR835. DOE agreed with our position as evidenced by the 

change of the violation from 10CFR835 (Health and Safety) to 10CFR820 

(Procedures). In other words, in the final analysis DOE agreed that job-specific 

samples were not special samples. [ORAUT 2022a, PDF p. 6] 

Dr. LaBone also describes the program for special samples, samples that were collected when 

there were suspected intakes of radioactive material. At some point in 1991, field procedures 

were changed to require RadCon to call the internal dosimetrist for a suspected intake. This 

change in field procedures was corroborated by Dennis Hadlock, a current Radiation Protection 

Department Regulatory and Technical Advisor and former field health physicist [ORAUT 

2022b]. According to Section 2 of ORAUT-RPRT-0102, a bounding co-exposure model could 

be constructed if a significant portion of the most highly-exposed workers are part of the dataset

[ORAUT 2021, PDF p. 13]. Therefore, if samples collected when there were suspected intakes of 

radioactive material are part of the dataset, a bounding co-exposure model could be constructed, 

regardless of job-specific sampling and RWP work. 

In April 2022, during an Advisory Board discussion on Sandia National Lab [NIOSH 2022, PDF 

pp. 67–70], SC&A presented an analysis where they looked at the DAC-hr logs and WebDose 

databases that “should contain all the most highly exposed workers” and compared those results 

to the data NIOSH had captured. Nearly 100 percent of the results from the most highly-exposed 

workers (in DAC-hr logs and WebDose) were in the NIOSH dataset, so the SC&A (and NIOSH) 

conclusion was that a bounding value could be justified, despite not having all of the monitoring 

data in the NIOSH dataset. Although this analysis and discussion pertains to an SEC evaluation 

where NIOSH was only trying to come up with a bounding value, this same concept can be 

applied when developing co-exposure models. 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 16 of 20

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with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

Because Dr. LaBone didn’t provide more details of his prescription of special programs at SRS, 

a follow-up question was asked to give him an opportunity to explain more about those 

programs. That October 2022 follow-up response [ORAUT 2022c] states that the requests for 

special samples triggered by events at SRS were tracked in a computer program called Track,

until that information began to be entered into ProRad. There is also a procedure that governed 

the incident response. 

In summary, if the samples prescribed by the site internal dosimetrist when a suspected intake 

occurred (samples in the Track database) are part of NIOSH’s co-exposure database, this is 

evidence that a bounding co-exposure model could be constructed, despite the SC&A conclusion 

that “RWP-specified, job-specific bioassay data are incomplete.” 

SC&A Conclusion 5: Feasibility of co-exposure model needs to balance RWP 

implementation with completeness of coworker data

Given conclusion 4, it is also clear that sCTWs who were on RWPs and may not have 

been monitored likely worked alongside coworkers who were monitored according to the 

RWP requirements. If RWPs can be considered complete and adequate (because the 

concerns identified in conclusions 1 and 2 have been addressed) and implemented in an 

accountable manner with the requisite bioassays substantially performed (per conclusion 

4), SC&A would consider NIOSH’s conclusion valid that the RPRT-0092 sampling 

review demonstrates sufficient matches (direct and effective) in the 1991–1998 period to 

support development of a co-exposure model for sCTWs on job-specific bioassays who 

lacked internal monitoring data. While job-specific bioassays and source terms may be 

incomplete, given the programmatic shortfalls, this is mitigated by two considerations: 

(1) job-specific bioassays made up only 5 percent of total bioassays by 1997 and (2) a

full resampling of job-specific bioassay results for the second quarter of 1997 found no

evidence of intakes. Accordingly, a conclusion about the feasibility of a co-exposure

model for workers lacking bioassay results for nonroutine work may be reached by

balancing the programmatic limitations of the RWPs and job- specific bioassays with the

availability of suitable coworker bioassay data (as given in RPRT-0092). [SC&A 2022,

PDF pp. 43–44]

NIOSH Response to SC&A Conclusion 5

NIOSH asked for clarification of SC&A Conclusion 5 in an e-mail exchange [NIOSH/SC&A 

2022]. The NIOSH e-mail states “It appears this conclusion is a general statement that if 

conclusions 1–4 are addressed, then SC&A ‘would consider NIOSH’s conclusion valid...to 

support development of a co-exposure model...’ ” [PDF p. 3]. The SC&A e-mail response says 

that the NIOSH interpretation is correct, so a detailed response to SC&A’s overall conclusion is 

not necessary.
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 17 of 20

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with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

CONCLUSION

NIOSH has addressed the five conclusions as outlined in Section 7 of the SC&A Focused 

Review and concludes:

1. The absence of bioassay requirements on RWPs in the early 1990s is irrelevant because 

bioassay programs were prescribed by procedure during that time. 

2. Changing the definition of “monitored” has the expected effect, but the new summary 

statistics do not inhibit creating a co-exposure model. 

3. SC&A’s coworker matching criteria are far too restrictive because, for co-exposure, the only 

necessary criterion is that the monitored worker has the same or higher exposure potential 

than the unmonitored worker. 

4. Regardless of the issues SC&A pointed out, if the samples from the most highly-exposed

workers (in the Track database) are part of NIOSH’s co-exposure database, this is evidence 

that a co-exposure model could be constructed. 

5. NIOSH has addressed the SC&A issues from the SC&A Focused Review and maintains that 

co-exposure models can be developed. 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 18 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

REFERENCES

Biemer PP, Christ SL [2008]. Constructing the survey weights. In: Levy PS, Lemeshow S, 

eds. Sampling of populations methods and applications. 4th ed. Hoboken, NJ: John Wiley & 

Sons. [SRDB Ref ID: 194362] 

NIOSH [2019a]. Centers for Disease Control National Institute for Occupational Safety and 

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

Issues work groups joint meeting Thursday, December 5, 2019. Transcript. Washington, DC: 

U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 

National Institute for Occupational Safety and Health, Advisory Board on Radiation and Worker 

Health. [SRDB Ref ID: 182846] 

NIOSH [2019b]. Centers for Disease Control National Institute for Occupational Safety and 

Health Advisory Board on Radiation and Worker Health 132nd meeting Wednesday, December 

11, 2019. Transcript. Washington, DC: U.S. Department of Health and Human Services, Centers 

for Disease Control and Prevention, National Institute for Occupational Safety and Health, 

Advisory Board on Radiation and Worker Health. [SRDB Ref ID: 184395] 

NIOSH [2020]. NIOSH/ORAU: NIOSH response to SC&A comments on ORAUT-RPRT-0092. 

Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control 

and Prevention, National Institute for Occupational Safety and Health. August 18. [SRDB Ref 

ID: 182968] 

NIOSH [2021]. U.S. Department of Health and Human Services Centers for Disease Control 

National Institute for Occupational Safety and Health Advisory Board on Radiation and Worker 

Health 139th Meeting Thursday, April 15, 2021. Transcript. Washington, DC: U.S. Department 

of Health and Human Services, Centers for Disease Control and Prevention, National Institute 

for Occupational Safety and Health, Advisory Board on Radiation and Worker Health. [SRDB 

Ref ID: 187719] 

NIOSH [2022]. U.S. Department of Health and Human Services Centers for Disease Control 

National Institute for Occupational Safety and Health Advisory Board on Radiation and Worker 

Health 145th Meeting Thursday, April 28, 2022. Transcript. Washington, DC: U.S. Department 

of Health and Human Services, Centers for Disease Control and Prevention, National Institute 

for Occupational Safety and Health, Advisory Board on Radiation and Worker Health. [SRDB 

Ref ID: 193031] 

NIOSH/SC&A [2022]. Seeking clarification on conclusion 5 from the SC&A focused review of 

ORAUT-0092 2022. E-mail chain including NIOSH and SC&A. Cincinnati, OH: U.S. 

Department of Health and Human Services, Centers for Disease Control and Prevention, 

National Institute for Occupational Safety and Health. Arlington, VA: S. Cohen and Associates, 

Inc. May, June, October. [SRDB Ref ID: 194363] 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 19 of 20

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

ORAUT [2017]. Documented communication with Tom LaBone on Savannah River Site. Oak 

Ridge, TN: Oak Ridge Associated Universities Team. October 6. [SRDB Ref ID: 168231] 

ORAUT [2018]. SRS work permit sampling plan. Oak Ridge, TN: Oak Ridge Associated 

Universities Team. May 16. [SRDB Ref ID: 194480] 

ORAUT [2019]. Evaluation of bioassay data for subcontracted construction trade workers at 

SRS. Oak Ridge, TN: Oak Ridge Associated Universities Team. ORAUT-RPRT-0092 Rev. 00, 

June 14. [SRDB Ref ID: 176739]

ORAUT [2021]. Assessment of Los Alamos National Laboratory plutonium bioassay programs 

1996 to 2001. Oak Ridge, TN: Oak Ridge Associated Universities Team. ORAUT-RPRT-0102 

Rev. 00, December 2. [SRDB Ref ID: 187245] 

ORAUT [2022a]. Documented communication – interview with Tom LaBone – follow-up 

question about SRS. Oak Ridge, TN: Oak Ridge Associated Universities Team. August 19. 

SRDB Ref ID: 193551 

ORAUT [2022b]. Documented communication with Dennis Hadlock on SRS procedure 

regarding who made the decision to put workers on special bioassay program. Oak Ridge, TN: 

Oak Ridge Associated Universities Team. August 15–16. [SRDB Ref ID: 193470] 

ORAUT [2022c]. Documented communication – follow-up interview question with Tom 

LaBone about SRS 2022. Oak Ridge, TN: Oak Ridge Associated Universities Team. October 18. 

[SRDB Ref ID: 194367] 

SC&A [2018]. SC&A comments on NIOSH draft permit sampling plan. Memo to Savannah 

River Site Work Group. Arlington, VA: SC&A, Inc. April 26. [SRDB Ref ID: 176648] 

SC&A [2019]. Review of ORAUT-RPRT-0092, revision 00, “evaluation of bioassay data for 

subcontracted construction trade workers at the Savannah River Site” draft. Arlington, VA: 

SC&A, Inc. SCA-TR-2019-SEC005 Rev. 0, November 12. [SRDB Ref ID: 179239] 

SC&A [2020]. Review of NIOSH response to SC&A on ORAUT-RPRT-0092, revision 00, on 

bioassay data for subcontracted construction trade workers at the Savannah River Site draft. 

Arlington, VA: SC&A, Inc. SCA-TR-2020-SEC006 Rev. 0, November 5. [SRDB Ref ID: 

184019] 

SC&A [2022]. Focused review of ORAUT-RPRT-0092, revision 00, and remaining petition 

SEC-00103 evaluation report period: 1991–2007 – draft. Arlington, VA: SC&A, Inc. SCA-TR2022-SEC001 Rev. 0, April 22. [SRDB Ref ID: 192680] 

Taylor JR [1997]. An introduction to error analysis: the study of uncertainties in physical 

measurements. 2nd ed. Sausalito, CA: University Science Books [SRDB Ref ID: 194364] 
Response Paper Response to SC&A’s “Focused Review of ORAUT-RPRT0092, Revision 00, and Remaining Petition SEC-00103 

Evaluation Report Period: 1991–2007” (Rev. 0)

November 22, 2022

Page 20 of 20

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with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

WSRC [1992]. Routine in vivo and in vitro bioassay scheduling and administration. Savannah 

River Site, Aiken, SC: Westinghouse Savannah River Company. WSRC-5Q1.1-506 Rev 3. 

[SRDB Ref ID: 152159]