SC&A Evaluation of INL CPP Class 

Definition Requiring Evidence of 

External Dosimetry (1963–1974) 

Bob Barton, Health Physicist 

S. Cohen and Associates 

Contractor to: 

Advisory Board on Radiation and Worker Health/ABRWH 

Centers for Disease Control and Prevention 

July 23, 2015 
SC&A Investigative Approach 

1. Assessment of available interviews with 

former workers 

2. Evaluate claimant records to assess the 

dosimetry program in the context of the 

current class definition 

2 
Summary of Interview Assessment 

• 50 Sets of worker interview summaries 

• Interviews conducted by the Board, NIOSH, and SC&A in 

June, September, and November of 2014 

• Not all of the worker interview summaries have been 

finalized 

• Available summaries affirm universal badging of CPP 

personnel entering radiological areas 

• Recommendations: 

• Continue line of inquiry with future interviews and a focus 

on badging policies 

• Evaluate interviews that are not yet available 

3 
Goals of SC&A Claimant Evaluation 

1. Characterize the external dosimetry program for the 

completeness/availability of records 

2. Determine the extent to which “gaps” exist and 

explore potential explanations: 

• Not monitored, but not likely exposed 

• Not monitored, but likely should have been 

• Moved to another location onsite or likely not 

employed at INL 

3. Evaluate if the class definition captures all relevant 

workers 

4 
SC&A Approach and Methods 

• Analyze a subset of claimants and relevant 

records/information 

• Available dosimetry records 

• Department of Labor (DOL) case files 

• Computer-Assisted Telephone Interview (CATI) 

• Iterative process used in selection of claimants for 

focused review 

• Sampling is NOT a representative cross-section of the 

claimant population! 

5 
SC&A Approach and Methods (cont.) 

• Initial group of claimants chosen to cover several 

different job types (security, engineers, operators, 

laborers, maintenance, construction, instrument techs, 

HP techs, firemen, etc.) 

• Based on initial assessment, review focused on 

subcontract trades workers with intermittent 

employment 

• 30 total claims characterized (initial group + 

focused group) 

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Available Work Location Information 

• Area Dosimetry “Cycle” Reports (routine monitoring)

• Temporary and/or Visitor Badges 

• Internal Monitoring (in vivo, urinalysis) 

• Incident Reports (generally medical, not radiological) 

• CATI and/or other Interview Statements 

• Location File Cards 

• Master Security File Card 

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Results of 30 Claim Reviews 

• SC&A developed five “categories” of claimants based on 

the available dosimetry: 

• Category 1: No gaps observed in dosimetry records 

• Category 2: Gaps appear to exist, but records are likely 

complete based on “PSN number”

• Category 3: Gaps exist in monitoring records, but no 

evidence of exposure during unmonitored periods identified 

• Category 4: Gaps exist in monitoring records, but there is 

some indication of potential exposure during unmonitored 

periods 

• Category 5: Only annual dosimetry summaries available 

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Example of Category 1 

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Example of Category 2 

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Example of Category 3 

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Notes on Category 3 Example 

• In 1964, there are area dosimetry cycle reports, but no 

dose is recorded and record indicates “not in area”

• External Dosimetry from June 1967–September 1969 is a 

combination of CPP and material test reactor (MTR) areas 

• July 1970 to January 1971, the Energy Employee (EE) 

worked for “H.S. Wright,” but no location information is 

available 

• No bioassay or in-vivo samples were submitted during the 

Special Exposure Cohort (SEC) period 

• CATI report with survivor: “specific [work] locations are 

unknown.”

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Example of Category 4 

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Notes on Category 4 Example

• Location file card only indicates employer, not location, during SEC

• From CATI Report

• Building/Location: “At CPP, LOFT project, SL-1”

• Frequency of Badge Worn: “Daily”

• Badge Exchange Frequency: “Several times a week”

• “Area of contamination were all over the site... CPP was the most 

contaminated area. There were a lot of 55 gallon waste drums stored 

there. They had a lot of spills and evacuations which required 

restriction from the area for 2–3 days a time.”

• “CPP a lot of years. This was a very contaminated area because of the 

stack emissions. Worked on the calciner project.”

• Location file card indicates a brief assignment (~2 months) to CPP 

in 1978 (no dosimetry badge found)

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Category 5 (cont.)

• Only annual summary record available

• Not possible to ascertain where the worker was 

badged.

• Prompted SC&A to investigate how many claims fit the 

Category 5 criteria:

• SC&A identified 144 Category 5 claims out of 796 claims who 

worked during the SEC period.

• Of those 144 Category 5 claims, 39 had DIRECT evidence of 

assignment to CPP during the SEC (i.e., location file card 

indicates CPP).

• 12 of the 39 were subcontract workers.

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Finding 1

The dosimetry records contained in NOCTS are not 

sufficient to accurately determine if a given 

claimant worked at the CPP (and thus qualifies for 

the SEC) for at least some workers, due to the 

absence of external dosimetry records designating 

the area worked. 

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Supplemental Records Captured

• April 22, 2015, Technical Call: 

• NIOSH informed SC&A and the Work Group that 

significant additional dosimetry records had been 

captured 

• Uploaded files include over 7,200 pages of CPPrelated dosimetry files, including Routine Area Cycle 

Reports and Visitor/Temporary Badge reports

• SC&A utilizes available supplemental records to 

attempt to identify “at least one” dosimetry record 

for the 39 Category 5 workers at CPP

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Supplemental Records Captured (cont.)

• SC&A matches “at least one” dosimetry badge in 

available supplemental records for 36 of the 39 

Category 5 claims identified with CPP

• Three Category 5 workers were not located

• All three were employed by subcontractors in 

construction and/or maintenance-type jobs

• Note: 12 of the 39 CPP Category 5 claims were 

employed by subcontractors

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Supplemental Records Captured (cont.)

• July 8, 2015: INL Work Group Teleconference

• NIOSH queried DOE for specific dosimetry records 

related to the three subcontractor claimants

• DOE supplies additional dosimetry records not 

currently available to NIOSH/SC&A demonstrating 

badging at CPP for the three claims

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Finding 2 (Updated: 7/8/2015)

Finding 2: Based on the evaluation of available claimant 

records, a portion of the supplementary dosimetry 

records, and claimant-specific dosimetry recently 

provided by DOE, SC&A was able to find “at least one” 

dosimetry badge for all claimants reviewed who had 

direct evidence of work at the Chemical Processing Plant. 

However, SC&A is not able to evaluate the completeness 

of the full set of supplemental records until such a time as 

all CPP-related external monitoring (1/1/1963–

2/28/1970) and INL external monitoring (3/1/1970–

12/31/1974) is provided to NIOSH and the Board.

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SC&A Summary Conclusions

• NOCTS external dosimetry records are currently insufficient 

to administer the proposed SEC. Supplemental records will 

be required.

• It is SC&A’s opinion that the probability of incorrect 

exclusion of AEC and/or prime contract employees from the 

SEC based on the absence of dosimetry records is low.

• “At least one” CPP dosimetry record was identified for each 

claim reviewed in this report for which there is direct 

evidence of work at CPP.

• All supplemental external dosimetry records are not yet 

available.

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SC&A Recommendations

• Evaluate additional supplemental records (as they become 

available) to fill in any apparent gaps in monitoring.

• Conduct focused interviews with intermittent or transient 

subcontractors and trades workers to assure that the 

badging of individuals entering relevant areas was universal.

• Ascertain what subcontractors supported radiological work 

activities at CPP, and potentially obtain rosters of workers 

who were involved in such activities.

• Validate DOE records search process through appropriate 

focused searches for CPP workers lacking primary and 

supplemental records.

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