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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: Josie Beach, Chair, Subcommittee for Procedure Reviews, ABRWH; 

R. William Field, Ph.D., M.S., Chair, Grand Junction Facility ABRWH Work Group 

From: Alek P. Kranbuhl, NIOSH Health Physicist

Subject: Responses to SCA-TR-2021-PR001, Revision 0: SC&A’s Review of ORAUT-TKBS0060, Revision 00, “Site Profile for Grand Junction Facilities” (August 17, 2021) 

Date: January 27, 2022

The following responses are provided based on SC&A observations contained in their review of the 

following document: 

NIOSH. (2018). Site profile for Grand Junction Facilities (ORAUT-TKBS-0060, rev. 00). Cincinnati, 

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

National Institute for Occupational Safety and Health. 

Response to SCA-TR-2021-PR001, Revision 0, Observation 1

In this document, Observation 1, Unclear Language use in the Occupational Medical Dose Section, 

States:

The recommendations for 1943-1946 contains the term “each year”. This could be misleading, 

because all the x-ray exams would not be assigned for each and every year. 

The NIOSH response is:

NIOSH concurs that the language used in this section could be unclear. The recommendation to assign

preemployment and postemployment posterior anterior (PA) chest and anterior-posterior (AP) pelvis xray exams only once, and annual PA and AP x-ray exams assigned for each year of employment will be 

updated in the Site Profile Technical Basis Document, which is currently being revised. 

Response to SCA-TR-2021-PR001, Revision 0, Observation 2 

In this document, Observation 2, Inconsistent DAC Usage, States:

In section 5.3.4 of the TBD (p. 19), NIOSH used a Th-230 DAC value of 3.00×10-12 μCi/ml to 

derive intake values for table 5-6 for co-exposure intakes after 1990. However, NIOSH’s (2017) 

memorandum (p. 5) indicated that a DAC value of 7 × 10-12 μCi/ml was being used at the site 

(NIOSH, 2017). There appears to be an inconsistency in the DAC values used that needs 

clarification.
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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.

The NIOSH response is:

The DAC of 3.00E-12 μCi/ml for Class W 230Th was incorrectly used to calculate the daily intake values

in Table 5-6 of the TBD because it is common for sites to control areas using the most limiting DAC. The 

Grand Junction Site, however, was using the DAC of 7.00E-12 μCi/ml for Class Y 230Th from DOE Order 

5840.11 (1988) Attachment 1 as the control level for airborne 230Th and basis for the 10% DAC trigger 

for bioassay monitoring. Because the control level at the site was higher than the DAC used for Table 5-6 

of the TBD it is possible that potential intakes are not bound by the values used and they need to be 

reassessed for the higher DAC value. Table 5-6 will be updated with daily intake values based on the 

DAC of 7.00E-12 μCi/ml used at the site. The Site Profile Technical Basis Document is currently being

revised primarily due to this issue. 

Response to SCA-TR-2021-PR001, Revision 0, Observation 3 

In this document, Observation 3, Potential radon calibration chamber exposure, states:

The TBD states (p. 20): 

Any exposure from radon while working around the radon calibration chamber were calculated 

as WLM and should be provided in a workers exposure file.

 Did NIOSH examine the claimant files and find that workers who entered the chamber had such 

working level month (WLM) dose records in some claim files? The radon calibration chamber 

could be a source term that may not be appropriately bounded by the 5.7 pCi/L found in Building 

30B. 

The NIOSH response is:

Based on interviews with a former Grand Junction Facility employee, the only routine Airborne 

Radioactivity Area at the site was the radon calibration chamber. The chamber was an environmentally 

controlled cylindrical vessel through which air containing radon was circulated for the calibration of 

radon and radon-daughter measuring equipment. The chamber was posted as an ARA “when in use”, and 

the employee stated that “when in use,” there would not be anyone in the chamber itself. Access to the 

chamber was controlled with double entry locking doors. Post-use, the air in the chamber would have 

been vented and the air sampled before the chamber was de-posted as an ARA through requirements of 

the radiation control program, prior to personnel entry. All available claim data were reviewed and none 

of the claimants had radon chamber working level month values in their data entry files. 
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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.

Response to SCA-TR-2021-PR001, Revision 0, Observation 4 

In this document, Observation 4, Assigning 95th percentile neutron doses to geologists only, states: 

Workers besides those with the job title of geologist may have handled sources of neutrons in 

performing work and could have been in the 95th percentile exposure category. Geologists 

themselves may not have handled the tools as much as laborers and other workers. 

The NIOSH Response is:

After a review of site documents, NIOSH concurs that there is a possibility of workers outside the job title 

of geologist that may have elevated neutron exposures. This matter is being investigated further, and an 

update will be provided at the next Procedures Subcommittee Meeting.

Response to SCA-TR-2021-PR001, Revision 0, Observation 5 

In this document, Observation 5, Need substantiation for not assigning co-exposure neutron dose after 

1985, states:

The TBD states (p. 28): 

After 1985, based on a review of GJF records, neutron dosimetry records are assumed to be 

complete. Therefore, no unmonitored dose should be assigned after 1985. 

SC&A could not locate information in the TBD that supports this assumption. A summary of 

NIOSH’s review of the GJF records and the resulting assumption that monitoring for neutron 

exposure was complete would be appropriate to include in the TBD. 

The NIOSH response is:

NIOSH concurs that there is insufficient information in the Technical Basis Document to justify the 

assumption that unmonitored neutron dose should not be assigned after 1985. NIOSH reviewed all 

available Dosimetry Records from GJF (SRDB ID 100312, 090509, 100319, 100346, 100300) and INL 

Dosimetry Records for GJF (SRDB ID 107374), which consisted of over 16,000 dosimetry results from 

the site for the years 1986-2007 and compared the results to those available in REMS. There are 66 

neutron doses available in REMS for GJF beginning in 1986 and the last neutron dose entry in 2005. 

NIOSH found that all non-zero neutron doses from site records were included in the REMS database. 

Additionally, there is evidence that the site was conducting investigations of unexpected dosimetry 

results, including abnormally high neutron doses and recorded zero doses when neutron exposure was 

expected (SRDB ID 098172, 098175, 098164, 098160, 097873). For instances where neutron dosimetry 

was lost or absent, there are entries in REMS to show that missed neutron doses were assigned to these 

individuals based on coworker exposure. This summary of NIOSH’s evaluation of the REMS data to 

substantiate the assumption that the REMS data is complete will be included in the revision of the Site 

Profile Technical Basis Document.