Savannah River Site SEC Update

Co-Worker Models (ORAUT-OTIB-0081)

SEC00103 

Timothy D. Taulbee, PhD, CHP

Research Health Scientist

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support
Co-worker Models (ORAUT-OTIB-0081)

 Multi-Radionuclide Co-Worker Models

1. Tritium (H3)

2. Plutonium (Pu)

3. Uranium (U)

4. Mixed Fission Products (MFP)/Strontium-90

5. Exotic Radionuclides (Am, Cm, Cf, Th)

6. Neptunium (Np) 

7. Cesium-137

8. Cobalt-60

 Demonstration nuclides for ABRWH evaluation are bolded

Division of Compensation Analysis and Support
Co-Worker Strata

 Co-worker Implementation Guide indicates that 

known differences in monitoring or work types 

should be stratified.

 As a result, Construction Trades Workers (CTW) 

need to be stratified from operations workers. 

 CTW’s were identified via one method for Exotic 

Radionuclide (Am, Cm, Cf, Th) (ORAUT-RPRT-0055)

 Different criteria was used for the Tritium co-worker 

models. ORAUT-RPRT-0049, ORAUT-RPRT-0050.

 We had to go back and use the same criteria for 

both co-worker models and all future models. 

Division of Compensation Analysis and Support
Co-worker Models (ORAUT-OTIB-0081)

 Co-worker Implementation Guideline requires 

evaluation of dataset used in model. 

 DCAS established acceptable transcription error 

rates

 Less than 1% error on critical fields (analytical results)

 Less than 5% error on all critical and non-critical fields 

combined (analytical results, name, payroll ID, sample 

date, sample type, etc...)

 ORAU developed a sampling plan to evaluate 

error rates within these parameters. 

Division of Compensation Analysis and Support
Exotic Radionuclide Evaluation

 37,461 analytical results (critical fields)

 Sampled 2866 critical fields and compared to hard 

copy records for transcription errors

 38 critical field errors or 1.33% - failed

 95th% Confidence Interval (0.96%, 1.79%)

 229,342 non-critical fields

 Sampled 16,354 fields compared to hard copy records 

for transcription errors

 152 non-critical field errors or 0.93% - passed

 95th% Confidence Interval (0.79%, 1.08%)

Division of Compensation Analysis and Support
Exotic Radionuclide Evaluation

 100% line by line validation comparison conducted 

for analytical results (critical fields) and corrections 

made when discrepancies were identified. 

 Resample

 38,054 analytical results

 Sampled 2864 critical fields and compared to hard 

copy records for transcription errors

 7 critical field errors or 0.24% - passed

 95th% Confidence Interval (0.11%, 0.49%)

Division of Compensation Analysis and Support
Tritium (H3

) Evaluation

 260,278 analytical results (critical fields)

 Sampled 3131 critical fields and compared to hard

copy records for transcription errors

 9 critical field errors or 0.29% - passed

 95th% Confidence Interval (0.13%, 0.54%)

 780,834 non-critical fields

 Sampled 624 fields compared to hard copy records for

transcription errors

 3 non-critical field errors or 0.48% - passed

 95th% Confidence Interval (0.10%, 1.40%)

Division of Compensation Analysis and Support
Status

 Exotic Radionuclide (Am, Cm, Cf, Th) dataset has 

passed QA check, the model using TWOPOS is 

being developed.

 Tritium dataset is trailing as one of the underlying 

datasets (Mixed Fission Products MFP) used for 

strata identification only recently failed QA check.

 Subsequent QA check of strata identification of 

compiled tritium dataset is necessary. 

 Anticipate delivering these two completed models 

to the SEC Issues workgroup in July before the 

ABRWH meeting in August. 

Division of Compensation Analysis and Support