SC&A’s Review of NIOSH’s SEC-00253 

Petition Evaluation Report for the 

Reduction Pilot Plant, Huntington, WV

Ron Buchanan, PhD, CHP 

Advisory Board on Radiation and Worker Health

April 27–28, 2022
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Reduction Pilot Plant overview

 The Reduction Pilot Plant (RPP) was also known as the Huntington 

Pilot Plant (HPP)

 Occupied a 3.67-acre fenced-in parcel adjacent to a larger nickel 

plant operated by the International Nickel Company

 RPP built by the Atomic Energy Commission in 1951 to supply 

nickel powder

 Nickel powder was used to make gaseous diffusion barriers for the 

gaseous diffusion plants in Paducah, KY, and Portsmouth, OH

 20–25 employees during operations at RPP

 1956: Facility began using contaminated feed material (nickel with 

low-enriched uranium and fuel reprocessing contaminants)
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Reduction Pilot 

Plant photograph 

(April 1963)

Photo credit: NIOSH. (2020). SEC 

Petition Evaluation Report Petition 

SEC-00253, p. 14.
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Reduction Pilot Plant history and evaluated 

SEC period

 Operational period: 1951–April 30, 1963

 Standby period: May 1, 1963–November 26, 1978

 The decontamination and demolition of classified and contaminated 

equipment at the facility took place between November 27, 1978, 

and May 18, 1979

 Special Exposure Cohort (SEC)-00253 period: June 7, 1976–

November 26, 1978

– SEC-00253 during the latter part of the standby period

– Standby period not initially considered a covered period (added by the 

U.S. Department of Labor in November 2019)

– No other SECs have been evaluated for RPP
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Reduction Pilot Plant conditions during standby 

period (~1976–1978)

 Operational activities had ceased by 1962

 Buildings placed in standby condition:

– Entrance by security guards once per shift (3 times daily) to check the 

process and compressor rooms

– Maintenance checks to maintain operational capability ceased in 1975 

when Oak Ridge Operations determined that nickel production would 

not continue in the future

– Inspections may still have occurred on a biannual basis 
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RPP document history

 ORAUT-TKBS-0004, revision 00, October 31, 2003

 ORAUT-TKBS-0004, revision 01, January 16, 2004

 OCAS-PER-025, revision 0, September 28, 2007

 OCAS-TKBS-0004, revision 00, August 13, 2008

 DCAS-PER-033, revision 0, December 9, 2011

 SCA-TR-SP2013-0043, June 4, 2013, review of the revised HPP site 

profile

 DCAS-TKBS-0004, revision 01, December 12, 2013

 OCAS-PER-066, revision 0, November 30, 2015

 DCAS-TKBS-0004, revision 02, November 5, 2018

 RPP SEC-0253 petition qualified, December 13, 2019
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Evaluation report for petition SEC-00253

 NIOSH issued the SEC petition evaluation report (ER) for 

petition SEC-00253 for RPP on April 24, 2020

 The class evaluated was all International Nickel Company 

security personnel who worked at any location within RPP 

during the period from June 7, 1976, through November 26, 

1978

 NIOSH’s ER concluded that all external and internal doses for 

security personnel could be adequately reconstructed during 

the SEC period
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SEC-00253 internal exposure monitoring and 

sources of potential exposure

 No individual internal monitoring data during SEC period

 Process building surveyed in January 1975:

– Very little removable contamination

– Highest amounts of fixed contamination were found in the residue system

 Low-enriched uranium residual contamination (generally 1–4% 

enrichment)

 Reprocessed uranium fuel contaminants:

– Pu-239, Pu-240, Pu-241, U-236, Th-232, Np-237, U-237

– All measured alpha contamination assumed to be uranium

– Contaminant ratios assumed for K-25 barrier materials used in RPP dose 

assessment
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SEC-00253 external exposure monitoring and 

sources of potential exposure

 No individual external monitoring data during SEC period

 1975 survey determined majority of dose rates were within 

normal background with a maximum of 250 μR/hr contact 

readings on equipment (assumed for beta dose reconstruction)

 1980 survey taken post-demolition found a maximum of 

35 μR/hr (at 3 feet, assumed for gamma dose reconstruction) 

and 45 μR/hr (contact reading)

 Site-specific medical x-ray information not identified, generic 

annual medical exams to be assumed
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SC&A’s review of the evaluation report

 On September 2, 2020, SC&A was tasked with a review of 

NIOSH’s ER for SEC-00253 for this focused group of workers 

and time period

 SC&A issued its review as SCA-TR-2021-SEC003, rev. 0, on 

April 2, 2021

 NIOSH issued a memorandum on April 29, 2021, “Reduction 

Pilot Plant SEC Evaluation Report Review,” responding to 

SC&A’s review of the NIOSH ER for the RPP SEC
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SC&A’s review approach

 Verification of survey information (1975 and 1979–1980 Oak 

Ridge Operations surveys)

 Claim file review:

– SC&A reviewed the 77 claimant records in the NIOSH DCAS Claims 

Tracking System (NOCTS) files associated with RPP to identify any 

information relevant to dose reconstruction (DR) feasibility for security 

personnel during the period from June 7, 1976, to November 26, 1978

– SC&A found that a total of 44 claimants worked a portion or all of 1976 

through 1978 at RPP
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SC&A’s review results

 SC&A did not identify any information that would impact the 

feasibility of DR during the SEC-00253 period for security 

guards

 Key facet of the proposed DR process includes the exposure 

time

– “Exposure time” = time spent inside the facility where residual 

contamination was present

– Estimates of time spent during relevant activities are properly 

characterized and bounded for affected workers
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Observation 1: Suggest further refinement of 

exposure time

 Computer-assisted telephone interview information indicated that 

exposure time may be longer:

– Original estimate was 15 minutes per day

– Claimant A had to check all 7 floors and the perimeter

– Claimant B estimated it took 30 minutes per day

 SC&A recommended NIOSH attempt to contact and interview 

security guards or other workers with specific knowledge of the 

surveillance activities to assure an accurate or bounding estimate of 

the time required to walk through the facility

 Assumptions about exposure time should not preclude DR feasibility 

and can be considered site profile issues
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NIOSH’s 2021response to observation 1: 

Exposure time

 NIOSH’s April 2021 revised estimate of time spent in the facility 

was 52 minutes per day, 6 days per week, for 250 days per 

year (260 hours per year)

– Estimated 5 minutes per floor (based on original ER assumptions of 

time spent walking the building floor footprint with stops) multiplied by 

7 floors

– Accounted for the physical dimensions of the lot at a walking rate of 

4.4 feet per second for the perimeter check

 Increases the exposure time by a factor of approximately 3
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NIOSH’s response to observation 1: Assumed 

dose rate modification

 NIOSH used a maximum dose rate of 0.035 mrem/hour to 

complete the ER in a timely manner.

 NIOSH will reevaluate all dose rate data to obtain a more 

realistic estimate

 DCAS-TKBS-0004, rev. 02 (2018), to be revised:

– Consider various dose rates

– Add the standby period: May 1, 1963, through November 26, 1978
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NIOSH’s response to observation 1: Overall 

annual dose

 The overall annual doses may be lower even when using the 

increased exposure time because of the lower dose rates 

obtained by considering all the available dose data
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SC&A’s evaluation of NIOSH’s response to 

observation 1

 SC&A concurs with NIOSH’s reevaluation of the potential 

exposure time and finds it reasonable

 SC&A concurs with NIOSH’s original use of the maximum dose 

rate to facilitate completion of the ER

 SC&A finds it is appropriate to consider all applicable dose rate 

data in the revised site profile

 SC&A recommends observation 1 be designated in abeyance 

pending review of the revised site profile
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Observation 2: Ingestion intake not addressed 

for SEC period

 Tables 3 and 4 of the site profile give ingestion intake values 

for production workers and administrative personnel during the 

operational period and decontamination and decommissioning 

period

 However, the ER does not address potential ingestion intakes 

for the SEC period (resulting doses likely to be small)
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NIOSH’s response to observation 2

 Ingestion dose for the security guards can be estimated based 

on contamination levels

 The ER used the bounding alpha contamination value of 

19 dpm/100 cm2 to estimate inhalation intakes

 That value is applied to a 10E-4 m2/hour ingestion coefficient 

from NUREG/CR-5512 (1992) to derive a 0.19-disintegrationsper-hour alpha ingestion rate for the security guards

 Details for assigning ingestion intakes will be included in the 

revised site profile
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SC&A’s evaluation of NIOSH’s response to 

observation 2

 SC&A concurs with NIOSH’s recommendations to address 

ingestion intakes

 SC&A recommends observation 2 be designated in abeyance 

pending review of the revised site profile
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Summary of SEC ER review issues (likely site 

profile issues)

Observation 1: Exposure time

 SC&A concurs with NIOSH’s 

reevaluation of the potential 

exposure time and all 

applicable dose rate data.

 SC&A recommends this 

observation remain in 

abeyance pending review of 

the revised site profile.

Observation 2: Ingestion intake

 SC&A concurs with NIOSH’s 

recommendations to address 

ingestion intakes. 

 SC&A recommends this 

observation be designated 

in abeyance pending review 

of the revised site profile.
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Conclusions

 SC&A concurs with NIOSH that upper bounds can be 

established for internal intakes and external exposures.

 SC&A concurs that DR is feasible for security personnel during 

the SEC-00253 period. 

 The URAWE work group discussed the issues on February 17, 

2022, and concurred that DR is feasible for security personnel 

during the SEC-00253 period. 
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Questions?