Summary of Issues Related to 

SEC Petition 00175 at the 

Grand Junction Facilities

R. William Field, Ph.D., M.S. (Chair)

James E. Lockey, M.D., M.S.

Genevieve S. Roessler, Ph.D.

Loretta R. Valerio

Presented to: 

The Advisory Board on Radiation and Worker Health 

Santa Fe, NM, Meeting

August 23–24, 2017
Grand Junction Site Overview

• U.S. Department of Energy facility in Grand 

Junction, Colorado

• Between 1943 and 1946, the Manhattan 

Engineering District acquired the Grand 

Junction site in order to concentrate U3O8.

• From 1974 to 1984, the Grand Junction 

Facilities (GJ, also referenced in documents as 

Grand Junction Operations Office) supported 

the National Uranium Resource Evaluation 

Program in the preparation of samples prior to 

analytical analysis.

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SEC-00175 Chronology

• June 30, 2010. Special Exposure Cohort (SEC) Petition 

SEC-00175 received by NIOSH. 

• January 12, 2011. NIOSH drafted Evaluation Report (ER) 

covering all onsite personnel who worked at the Grand 

Junction Operations Office from January 1, 1943, 

through July 31, 2010 (NIOSH 2011).

• February 24, 2011. The Board voted to recommend 

adding worker class from March 23, 1943, to January 

31, 1975, to the SEC (ABRWH 2011).

• NIOSH informed the Board that additional work will 

continue for the time period January 1975 through July 

2010.

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SEC-00175 Chronology (cont.)

• March 12, 2015. NIOSH drafted an Addendum to the ER 

that addressed the time period from February 1, 1975, 

through July 31, 2010. The Addendum identified 

insufficient information to fully reconstruct internal 

doses prior to January 1, 1986 (NIOSH 2015).

• March 26, 2015. The Board voted to add a worker class 

from February 1, 1975, to December 31, 1985, to the 

SEC (ABRWH 2015).

• The Board tasked SC&A to conduct a focused review of 

the Addendum that assessed the appropriateness of the 

revised SEC time period and the adequacy of air 

monitoring and bioassay data.

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Work Group Activities

• On May 17, 2016, SC&A submitted SCA-TR2016-SEC006, A Focused Review of the NIOSH 

SEC Evaluation Report for Grand Junction 

Operations Office, Addendum to Petition SEC00175 (SC&A 2016).

• SC&A concluded the SEC time period beginning 

February 1, 1975, through December 31, 1985, 

is appropriate based on the lack of sufficient air 

monitoring data prior to 1986.

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Work Group Activities (cont.)

• SC&A’s review identified the following finding 

for the post-1990 time period:

– Finding 1: There are insufficient workplace air monitoring 

data to support the assumption that unmonitored 

radiation workers would not have exceeded 200 DAC- hours or that non-radiation workers would not have 

exceeded 40 DAC-hours in a given year.

• The finding questioned whether GJ had implemented 

a workplace monitoring and worker bioassay 

program in 1991 that could be used to provide an 

upper bound intake for radiation and non-radiation 

workers.

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Work Group Activities (cont.)

• Subsequent Work Group (WG) discussions did 

not resolve the issue. 

• WG tasked NIOSH with: 

1. Determining activities in the 1991 era with the 

potential for generating significant air 

concentration data 

2. Interviewing the GJ personnel and internal 

dosimetrist for potential information about the 

air sampling and/or bioassay program

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Work Group Activities (cont.)

• NIOSH conducted additional searches for air 

monitoring records for the period 1991 through 

1993. 

• NIOSH also interviewed a GJ employee who had 

direct knowledge of work activities and monitoring 

programs that were conducted during this time 

period.

• Based on the employee interview combined with 

the identification of RWPs, surveys, air monitoring 

records, etc. for specific projects requiring air 

sampling, it is evident that a monitoring program 

was in place at GJ during the time period in 

question.

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Work Group Summary

• The WG considers the additional information in NIOSH 

references and records sufficient to conclude that GJ 

implemented a monitoring and bioassay program in 

1991 sufficient to identify workers who were exposed to 

the site’s 10% DAC trigger level for bioassay.

• The WG believes the information available to NIOSH is 

sufficient to document or estimate the maximum 

internal and external potential exposures to all 

employees under plausible circumstances during the 

specified period from January 1, 1986, through July 31, 

2010.

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Recommendation

• Based on the information in the original ER, 

ER Addendum, and follow-up investigations:

– The GJ WG recommends that the Board find 

radiation doses can be estimated with 

sufficient accuracy for employees of GJ from 

January 1, 1986, through July 31, 2010.

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References

ABRWH 2011. Transcript: Advisory Board on Radiation and Worker 

Health, held in Augusta, Georgia, on February 24, 2011.

ABRWH 2015. Transcript: Advisory Board on Radiation and Worker 

Health, held in Richland, Washington, on March 26, 2015.

NIOSH 2011. SEC Petition Evaluation Report, Petition SEC-00175, 

Grand Junction Operations Office, Revision 0, National Institute for 

Occupational Safety and Health, Cincinnati, Ohio. January 11, 2011.

NIOSH 2015. SEC Petition Evaluation Report, Petition SEC-00175, 

Addendum, Grand Junction Operation Office, Revision 0, National 

Institute for Occupational Safety and Health, Cincinnati, Ohio. March 

12, 2015.

SC&A 2016. A Focused Review of the NIOSH SEC Evaluation Report for 

Grand Junction Operations Office, Addendum to Petition SEC-00175, 

SCA-TR-2016-SEC006, SC&A, Inc., Vienna, Virginia. May 17, 2016.

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