Grand Junction Facilities

Special Exposure Cohort 

James W. Neton, Ph.D., CHP

Associate Director for Science

NIOSH

Division of Compensation Analysis and Support

March 2015

Richland, WA
Facility

 Department of Energy (DOE) facility in Grand 

Junction, Colorado 

 Covered period 1943-present

 Processed thousands of samples, including 

ores and tailings

 Numerous projects used large quantities of 

ores and tailings to for materials and 

calibration pads
Site History

 March 23, 1943 US Army established the Colorado 

Area Engineer Office 

 Site later became the Grand Junction Operations 

Office (GJOO)

 Refinery plant construction and operation to make 

uranium concentrates for the Manhattan Engineer 

District (MED) 

 Post 1945 GJOO was the center of uranium ore 

exploration, procurement, processing, and sampling 

activities
Site History

 347 million pounds of uranium concentrates 

received, sampled, assayed in the Analytical 

Laboratory, last drums of materials shipped sent off 

site January 1975

 Operated two pilot plants in the 1950s to develop 

methods of extracting uranium from ores, with the 

ore tailings buried on site

 Managed National Uranium Resource Evaluation 

(NURE) program 1974-84 (exploration and sampling 

nation’s uranium reserves) 
Major Projects 

and Operations Timeline
Petition History

 Special Exposure Cohort (SEC) petition received 

June 30, 2010 then qualified for evaluation 

September 7, 2010 based on lack of monitoring 

records

 Covered all on-site personnel who worked at the 

Grand Junction Operations Office from January 1, 

1943 through July 31, 2010

 The Board voted to recommend adding worker class 

from March 23, 1945 – January 31, 1975 to the SEC
Petition History

 NIOSH let the Board know work will continue on 

the January 1975 through July 2010 time period

 NIOSH drafted the Evaluation Report (ER) 

Addendum with a proposed class for post 1975

 NIOSH lacks sufficient information to fully 

reconstruct internal doses from processing of those 

materials prior to January 1, 1986
NIOSH Post-1975 Findings

 Legacy Contamination of soil and buildings 

from prior work

 Buried uranium ore tailings from 1950s Pilot 

Plants

 Continuing operations

 Many activities occurred offsite

 Sample processing greatest potential for 

exposure
Continuing Operations

 Crushing and grinding samples, ores, and tailings

 Analytical Laboratory operated through 2003 to 

support the various site projects

 NURE program from 1974 - 1984

 Uranium Mill Tailings Remedial Action (UMTRA) 

program, offsite remediation in 1980s and 1990s

 Grand Junction Remedial Action Project 

(GJRAP), offsite remediation in 1970s and 1980s

 Grand Junction Projects Office Remedial Action 

Project (GJPORAP) from 1988
Crushing and Grinding

 Sample Preparation Laboratory in Building 7A 

 Considered greatest source of internal dose from 

on-site operations after January 1975

 Dust from work area was ventilated to a baghouse

 Processed thousands of samples for Analytical 

Laboratory

 Numerous projects through 1988 to grind uranium 

ores, tailings, and thorium ores to specified mesh 

size prior to downblending into reference materials 

and for use in calibration pads
Analytical Laboratory

 Building 20

 Assayed uranium ores, concentrates, and 

other samples in support of site projects

 Had upper concentration limits on incoming 

samples

 Samples prepared in Building 7A

 Permanently closed in 2003
Sources of Available Information

 ORAU Team Technical Information Bulletins 

(TIBs) and Procedures

 Interviews with 9 former employees

 Claimant files

 Documentation from petitioner

 NIOSH Site Research Database (SRDB) 1,116 

additional documents added 

 Additional data capture efforts
Additional Data Capture Efforts

 Atomic Energy Commission (AEC)

 DOE Opennet (OSTI database)

 Internet search

 DOE Comprehensive Epidemiological Data 

Resource (CEDR)

 NARA Atlanta

 DOE sites
Claims

 75 Grand Junction claims submitted to NIOSH

 48 Claims with employment in the evaluated 

class

 47 DRs completed for claims with 

employment in the evaluated class 

 10 Claims with a PoC > 50% 

 37 Claims with a PoC < 50% 

 6 Claims containing internal dosimetry

 22 Claims containing external dosimetry
External Exposure Sources

 Direct radiation from handling and processing 

the ore and tailings

 Submersion in contaminated air

 Contaminated buildings, grounds, and buried 

tailings

 Sealed sources for data loggers
External Sources of Exposure—cont. 

 Photons

• Uranium and progeny

• Largest source was radium 

 Beta

• Uranium progeny (protactinium)

 Neutrons

• Californium-252

• Zetatrons
External Dose Reconstruction

 Photons

• Some dosimetry records in claim files

• REMS database results modified for missed dose 

used to supplement records

 Beta

• Beta:gamma ratio used to supplement individual 

records

 Neutrons

• REMS data available starting in 1985

• Prior years assumed to be similar
External DR Feasibility

 Enough information exists to estimate 

external doses from on-site operations with 

sufficient accuracy from February 1, 1975 

through July 31, 2010

 Can estimate with sufficient accuracy medical 

x-ray dose using existing program technical 

documents
Internal Sources of Exposure

 Uranium (main source of exposure) 

 Uranium progeny (Th-230 and Ra-226)

 Thorium in limited quantities

 Thorium progeny
Internal Sources of Exposure

 Inhalation and ingestion from sample 

preparation and preparation of ores used in 

calibration models: crushing, grinding, drying in 

Building 7A

 Downblending of ores and tailings used in 

reference materials and calibration models in 

Building 7

 Residual contamination from previous 

operations and airborne radioactivity from site 

remediation
Available Bioassay Data

 None from 1975 through 1983

 Very few sample samples for on-site workers 

in 1984 (mostly baseline samples)

 Fecal samples for Samples Prep Lab workers 

in 1986

 Some bioassay samples available starting in 

1991 when more rigorous requirements were 

implemented
Available Air Sampling Data

 No available data from 1975 through 1979

 Maximum air sample result reported for 

Sample Prep Lab from samples taken in July 

1980

 MPC-Hr tracking for Sample Prep Lab in 1st

quarter of 1986: maximum 307 MPC-Hr

 Air sample results reported for Sample Prep 

Lab in 1990
Available Air Sampling Data

 Three on-site environmental air sampling 

stations initiated in July 1985

 Environmental air monitoring discontinued in 

1994 after open land was remediated 

 During site remediation there are records of 

air monitoring, surface contamination 

measurements, and worker bioassay
Radon Data

 Radon (in pCi/l)

• 1967 – 7 results (outdoors)

• 1968 – 9 results (outdoors)

• 1990 – 27 results (indoors/multiple buildings)

 Radon Daughters (in WL)

• 1985 – 300 results (3 buildings)

• Characterization data in building closeout 

reports
Internal Dose Feasibility

Sample preparation and processing of ores/tailings 

used in reference materials and calibration 

models:

 There are insufficient data and information to 

reconstruct maximum internal dose for 

intakes from February 1, 1975 through 

December 31, 1985

 There are sufficient data and information to 

reconstruct maximum dose from January 1, 

1986 through July 10, 2010
Internal Dose Feasibility

Intakes of uranium, thorium and their associated 

long lived progeny cannot be reconstructed from 

February 1, 1975 through December 1, 1985 due 

to: 

 Lack of air monitoring

 Lack of bioassay data

 Insufficient information to model intakes 

based on source term
Internal Dose Feasibility

Methods have been developed to estimate dose 

from radon and radon progeny from February 1, 

1975 through July 31, 2010:

 Buildings and areas from previous ore and 

tailings processing activities are presumed to 

be the greatest source of radon exposure

 Radon levels measured in the 1980s prior to 

remediation are presumed to be sufficient to 

estimate exposures starting February 1, 1975
Internal Dose Feasibility

Uranium, thorium and their long-lived progeny 

internal dose reconstruction methodology January 

1, 1986

Most significant sources of internal dose:

 Sample Prep Lab activities

 Site remediation and building demolition
Internal Dose Feasibility

Sample Prep Lab uranium, thorium and their longlived progeny internal dose reconstruction January 

1, 1986, through December 31, 1991:

 Maximum intakes can be based on the quarterly 

limit (520 MPC-Hr)

• Supported by MPC-Hr tracking and bioassay 

in 1986, and air monitoring from 1990

• Assumes no significant changes in Building 7A 

after 1986
Internal Dose Feasibility

Intakes from site remediation and building 

demolition January 1, 1988, through December 31, 

1991

 Air sampling data are available and have been 

analyzed

 “Operator” dose assigned based on the 95th

percentile of the air sample results

 Other personnel assigned intakes using a graded 

approach similar to TBD-6000
Internal Dose Feasibility

Intakes of uranium, thorium and their long-lived 

progeny internal dose reconstruction starting 

January 1, 1992

 Maximum intake for an unmonitored radiation 

worker based on 200 DAC-Hr per year airborne 

trigger levels for bioassay

 Intakes for non-radiation workers can be 

bounded based on 40 DAC-Hr per year trigger 

levels for air sampling
Summary of Feasibility Findings

Sources of 

Exposure

2/1/1975 through 12/31/1985 1/1/1986 through 7/31/2010

DR Feasible DR Not 

Feasible

DR Feasible DR Not 

Feasible

Internal X X

Radon X X

Thorium,

Uranium

X X

External X X

Gamma X X

Beta X X

Neutron X X

X-ray X X
Health Endangerment

 The evidence reviewed in this evaluation indicates that some 

workers in the class may have accumulated chronic radiation 

exposures through intakes of radionuclides and direct 

exposure to radioactive materials

 Consequently, NIOSH is specifying that health may have 

been endangered for those workers covered by this 

evaluation who were employed for a number of work days 

aggregating at least 250 work days within the parameters 

established for this class or in combination with work days 

within the parameters established for one or more other 

classes of employees in the SEC 
Recommendation

 For the period March 23, 1943 – January 31, 1975, 

NIOSH finds that radiation dose estimates cannot 

be reconstructed for compensation purposes

Class Feasibility Health 

Endangerment

February 1, 1975 –

December 31, 1985 No Yes
Proposed Class

“All employees of the Department of Energy, its 

predecessor agencies, and its contractors and 

subcontractors who worked at the Grand Junction 

Facilities Site from February 1, 1975 through 

December 31, 1985, for a number of work days 

aggregating at least 250 work days, occurring either 

solely under this employment or in combination 

with work days within the parameters established 

for one or more other classes of employees in the 

Special Exposure Cohort.”