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

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

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

Subcommittees. Documents produced by SC&A, such as memorandum, white paper, draft or working documents are not 

final NIOSH or ABRWH products or positions, unless specifically marked as such. This document prepared by SC&A 

represents its preliminary evaluation on technical issues.

NOTICE: This 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.

MEMORANDUM

TO: Nevada Test Site Work Group 

FROM: Arjun Makhijani, SC&A, Inc.

DATE: December 29, 2016 

SUBJECT: NTS Site Profile Matrix Comments and December 2016 Update by SC&A

This update to the Nevada Test Site (NTS) issues matrix is to be read in conjunction with the 

January 30, 2014, version of the matrix (NIOSH 2014) that contains National Institute for Occupational 

Safety and Health (NIOSH) responses to the December 14, 2012, SC&A issues matrix (SC&A 2012). 

Comment # Issue Description Status

1 Some radionuclide lists are not complete. This

is especially important for atmospheric testing

and for early re-entry workers.

SC&A comment, December 2016: 

Resolved except as it relates to

Issue 5.

2 The technical basis document (TBD) does

not provide adequate guidance for dose 

estimation to gonads, skin, and gastrointestinal (GI) tract for early reactor test

re-entry personnel. Large hot-particle doses 

to skin and GI tract have not been evaluated.

Naval Radiological Defense Laboratory 

(NRDL) documents and models have not

been evaluated, though one document is

referenced.

SC&A comment, December 2016: 

The issue can be considered 

resolved so far as NRDL is 

concerned if NIOSH will paste the 

response to Issue 3 applying to the 

Nuclear Rocket Development 

Station and add it to the response to 

Issue 2 (as per the December 2014 

Work Group (WG) transcript 

(pp. 19–26).

3 Doses from large (non-respirable) particles to

GI tract and skin for workers in the early

atmospheric test period have not been

evaluated. These doses could be high. Hotparticle doses also need to be evaluated for

early drillback and other early re-entry 

workers during underground testing periods. 

SC&A comment, December 2016: 

This issue can be considered 

resolved based on the discussion 

during the December 2014 WG 

meeting along with the text on 

page 58 of the NTS site profile, 

Vol. 6, Rev. 3 (November 2012). 

The generic oro-nasal breathing 

issue is pending on a complex-wide 

basis.
Memo – NTS Issues Matrix Dec. 2016 Update 2 SC&A – December 29, 2016

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

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

Comment # Issue Description Status

4 Ingestion of non-respirable hot particles by 

reactor testing and nuclear weapons testing

workers due to oro-nasal breathing needs to

be evaluated.

SC&A Comment, December 

2016: This issue can be 

considered resolved based on 

the comments added for 

Issues 2 and 3 above.

5 Resuspension model and resuspension factor

are not scientifically defensible or claimant

favorable, due to a variety of factors. Doses

may be underestimated by an order of

magnitude or more. Mass-loading approach 

would be preferable for internal dose.

SC&A comment, December 2016:

Review is continuing.

6 The use of the site average air concentration

values when worker location is not known is

not claimant favorable. Largest value

consistent with job-type data should be used in

such cases.

SC&A comment, December 2016: 

Review is continuing.

7 Resuspension doses to monitored workers,

especially early re-entry workers, may be 

underestimated, due to the presence of shortlived radionuclides and higher resuspension 

expected in the days and months after a test

(including safety tests). TBD does not specify

procedures for estimating environmental

internal doses in such cases.

SC&A comment, December 2016: 

Review is continuing.

8 Use of 1967 external dose data for 1963–1966 

is not claimant favorable. There was no test in

1967 with measurable offsite fallout.

Relatively short-lived radionuclides, which

were likely present in 1963–1966, would have

substantially decayed away by 1967. 

SC&A comment, December 2016: 

Resolved as per the December 2014 

WG meeting transcript.

9 Lack of environmental external dose data for

1968–1976 is puzzling. TBD has not specified

an approach to estimating external

environmental dose for this period. Venting in

the 1968–1970 period likely made external

dose in that period (and possibly beyond)

higher than 1967. 

SC&A comment, December 2016: 

Resolved as per the December 2014 

WG meeting transcript.
Memo – NTS Issues Matrix Dec. 2016 Update 3 SC&A – December 29, 2016

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

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

Comment # Issue Description Status

10 The TBD does not provide any guidance for

pre-1963 external environmental dose. Issues

relating to unmonitored workers, as well as

time of entry into contaminated areas, could

be important.

SC&A comment, December 2016: 

This issue is resolved, conditional 

on NIOSH revision of Table 6-11 as 

per the NIOSH comment in the 

January 30, 2014, issues matrix. See 

the December 2014 WG meeting 

transcript.

11 Correction factors for external environmental

dose due to geometry of organ relative to

badge, and angular dependence of the dose

conversion factor need to be developed. 

SC&A comment, December 2016: 

NIOSH to provide data showing 

basis for the value of 1.04 for the 

beta/gamma ratio and the reason 

for the differences with the Hicks 

tables. Also, NIOSH to verify the 

photon energy spectra being used 

and attenuation factors in that 

context. See the December 2014 

WG transcript.

12 Radon doses in G-Tunnel are not claimant

favorable. Gravel Gertie radon doses are not

discussed, and could be substantial. (Site

status of Gravel Gertie workers needs

clarification.)

SC&A comment, December 2016: 

Resolved conditional upon NIOSH 

modifying the TBD to reflect that 

doses will be assigned when 

workers entered Gravel Gerties. 

See the December 2014 WG 

transcript.

13 Environmental doses due to I-131 venting 

need to be taken into account for nonmonitored workers

SC&A comment, December 2016: 

Review is continuing.

14 There are no internal monitoring data until late

1955 or 1956; some Pu from then on; some

tritium from 1958; Pu, T, and mixed fission

products from 1961; and full radionuclide

coverage established in about 1967. The TBD

does not provide significant guidance for

estimating internal dose for the pre- 1967 

periods for many radionuclides

SC&A Comment, December 2016: 

Closed due to grant of the Special 

Exposure Cohort (SEC); December 

2014 WG transcript.

15 Resuspension of radionuclides by the blast

wave, fractionation of relatively non-volatile

radionuclides, and the variability of Cs-137 to

Sr-90 ratios need to be taken into account in

internal dose estimation.

SC&A comment, December 2016: 

Review is continuing as part of 

Issue 5.
Memo – NTS Issues Matrix Dec. 2016 Update 4 SC&A – December 29, 2016

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

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

Comment # Issue Description Status

16 Use of photon dose, as done by Defense

Threat Reduction Agency (DTRA), as the

basis for estimating internal dose during 

periods when there are no data or scattered

internal monitoring data has significant

uncertainties. These uncertainties are

compounded by the data integrity issue

associated with NTS (see Comment 20 

below). 

SC&A Comment, December 2016: 

Closed as per the December 2014 

WG transcript.

17 Ingestion doses need to be better evaluated. SC&A Comment, December 2016: 

Closed except for the 

environmental dose part under 

Issue 5, as per the December 2014 

WG transcript.

18 Recommended use of ORAUT-OTIB-0002 for 

post-1971 tunnel re-entry workers is contrary

to guidance in that document, and its

scientific validity has not been established. Its

use may not be satisfactory even with

restrictions, for instance, for reactor testing

early re-entry workers.

SC&A Comment, December 2016: 

Closed as per the December 2014 

WG transcript.

19 There are no beta dose data until 1966; the

TBD does not specify a procedure for

estimating pre-1966 beta dose. When the

approach is developed, the large hot-particle

issue will need to be taken into account.

SC&A Comment, December 2016: 

Review continuing – see Issue 11 

above as per the December 2014 

WG transcript.

20 There appears to have been intentional nonuse of badges in some circumstances to avoid

approaching or exceeding operational dose 

limits. The practice may have occurred until

the mid-1960s or even extended into the

1970s. NIOSH has not investigated this

problem, which raises questions on the

integrity of the external dose record possibly

into the 1970s, which need to be explicitly

addressed. 

SC&A Comment, December 2016: 

Review continuing – see Issue 11 

above as per the December 2014 

WG transcript.

21 The TBD does not contain information about 

extremity dosimetry. Site status of bomb

assembly workers is unclear.

SC&A Comment, December 2016: 

NIOSH to query database 

regarding extremity cancers, per 

the December 2014 WG meeting 

transcript.
Memo – NTS Issues Matrix Dec. 2016 Update 5 SC&A – December 29, 2016

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

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

Comment # Issue Description Status

22 There are no neutron dose data until 1966, 

and partial data until 1979. 

TBD assertion that neutron doses during

atmospheric testing were negligible has not

been substantiated and may be in error for

some workers.

SC&A Comment, December 2016: 

Once the n/p ratio matter is 

resolved for Pantex, the same ratio 

would be used for NTS. Update 

from NIOSH pending.

23 Adequacy of soil data for estimating

resuspension doses needs to be evaluated, for

instance, in relation to hot spot detection and

Pu soil data.

SC&A Comment, December 2016: 

Review continuing as part of 

Issue 5.

24 The presence of high-fired oxides resulting

from atmospheric weapons testing and reactor

testing needs to be investigated

SC&A Comment, December 2016: 

Closed due to grant of SEC.

25 NOISH documentation of site expert 

interviews is inadequate, and crucial site

expert interviews have not been performed or 

performed in an incomplete manner, notably

Barton Hacker and

Potentially critical archives and documents 

have not been reviewed, including the NRDL

and Barton Hacker primary reference

materials.

SC&A Comment, December 2016: 

This issue has been transferred to 

the Worker Outreach WG. See the 

December 2014 transcript.

26 A number of issues in relation to waste

handling, decommissioning, and other post1992 site activities were reviewed by SC&A

in SC&A 2005 or during the SEC review.

SC&A Comment, December 2016: 

NIOSH to review the SC&A 2005 

NTS site profile review and provide 

responses to the waste handling 

issues raised there, as per the 

December 2014 WG transcript.

References

NIOSH 2014. NIOSH Responses to the SC&A NTS Issues Matrix, National Institute for Occupational 

Safety and Health, Cincinnati, Ohio. January 30, 2014. 

SC&A 2005. Review of the NIOSH Site Profile for the Nevada Test Site, SC&A, Inc., McLean, Virginia. 

December 13, 2005. 

SC&A 2012. Update of the Nevada Test Site (NTS) Issue Resolution Matrix Based on the SC&A Review 

of the NIOSH Site Profile for the Nevada Test Site, SCA-SP-IM2012-0042, Revision 1, SC&A, Inc., 

Vienna, Virginia. December 14, 2012.