SC&A Status Update: SEC-00219 

INL and SEC-00224 ANL-W

John Stiver

SC&A, Inc.

Contractor to:

Advisory Board on Radiation and Worker Health/ABRWH

Centers for Disease Control and Prevention

August 9, 2016

1
INL/ANL-W Work Group Board 

Members

Phillip Schofield, Chair

Josie Beach

James Melius 

David Richardson

Genevieve Roessler

2
SC&A INL/ANL-W Team 

Members

Bob Barton

Hans Behling

Ron Buchanan

Doug Farver

Joe Fitzgerald

John Mauro

Amy Meldrum

Steve Ostrow

3
INL SEC-00219 Class Definition

Last brought before the Board at the March 23, 2016, Board 

meeting in Tampa , Florida (previously at the July and 

November 2015 meetings)

All employees of the Department of Energy, its predecessor agencies, and 

their contractors and subcontractors who worked at the Idaho National 

Laboratory (INL) in Scoville, Idaho, and (a) who were monitored for 

external radiation at the Idaho Chemical Processing Plant (CPP) (e.g., at 

least one film badge or TLD dosimeter from CPP) between January 1, 1963 

and February 28, 1970; or (b) who were monitored for external radiation 

at INL (e.g., at least one film badge or TLD dosimeter) between March 1, 

1970 and December 31, 1974, 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.

4
INL SEC-00219 Class Definition (cont.)

Recent INL Work Group/Board discussions regarding class definition:

• November 10, 2015 – WG meeting

• January 15, 2016 – WG teleconference meeting

• Jan. 25–28, 2016 – Initial WG/SC&A onsite data capture/interviews – with 

follow-ups on Feb. 16, Feb. 23–24, & March 15–16

• March 1, 2016 – WG meeting

• March 24, 2016 – ABRWH Meeting 110 in Tampa, Florida

• August 2, 2016 – WG meeting 

• SC&A white paper on new claimant evaluation: 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-inldrrev-r0.pdf 

5
INL SEC-00219 – Class Definition (cont.)

Part b) accepted March 23, 2016; Part a) held in reserve 

based on Board concerns regarding:

1. The completeness and adequacy of INL visitor cards/temporary film 

badge reports (TBR) and monthly Dosimetry Branch Activity Reports 

(DBAR) from 1963 through 1970. Involved extensive research on 

NIOSH’s part.

August 2, 2016, WG update:

• In March 2016, NIOSH captured the monthly DBARs from 1965 through 

1974. These were the “missing reports” that enable NIOSH to evaluate the 

completeness of the visitor cards/TBRs. 

• INL began indexing/coding the visitor cards in June and they are projected to 

be complete by the end of September 2016. Due to funding issues, TBR 

coding indeterminate – likely sometime after fiscal year turnover.

• SC&A to explore additional V&V strategies for WG consideration as the 

indexed visitor cards and TBRs become available.

6
INL SEC-00219 – Class Definition (cont.)

• NIOSH indicates only 1 CPP badge (annual or visitor) and 

documented 250 days on site for SEC inclusion.

• Thus, missing 1 temporary badge (TB) (worn 1 month max.) not 

significant because would have 12 for 250 days.

• Conversely, if a claimant had only 1 TB and it was missed, he or she 

would be excluded.

2. Where definitive location records are lacking, reliance on 

professional judgment based on “weight of evidence” to reject 

inclusion in the SEC.

• The WG remains concerned over how such criteria, which to date 

have been used in just one SEC class definition (Mound), would be 

implemented by DOL.

• NIOSH indicates that 911 out of 913 claims evaluated can be clearly 

adjudicated by parts (a) and (b) of the proposed class definition.

• WG remains concerned about Emergency Responder (fire fighter) 

badging protocols and the ability to identify CPP entry. Will require 

worker interviews (Nov 2016).

7
Update – Evaluation of Areas and 

Times that NIOSH Has Determined 

Doses Are Reconstructable

SEC-00219 INL 

and SEC-00224 ANL-W

(since November 2015)

8
INL Background – Recap

Dose Reconstructability/Gap Analysis

• Approach: “Horizontal” and “Vertical” analysis

• Horizontal – examine the DR methodology applied by NIOSH for 

all INL personnel – cross-cutting

• Vertical – specific characteristics of the individual areas at the 

INL site

• 6 areas of investigation:

1. Reactor Modeling (horizontal)

2. Test Area North (TAN) (vertical)

3. Central Facilities Area (CFA) (vertical)

4. Fission and Activation Product (FAP) Bioassay Indicator 

Radionuclides (horizontal)

5. Burial Grounds (vertical) pended

6. Chemical Processing Plant (CPP) Pre-1963 (vertical) pended

9
INL Recap and Update

• November 10, 2015, WG meeting

• White papers and progress reports on the six areas of 

investigation were delivered in September and 

October 2015

• Those papers are available on the DCAS website at: 

http://www.cdc.gov/niosh/ocas/pubm2015.html

• Preliminary results presented at the November 18, 2015, 

Board session

• Since November 2015, at the WG’s direction, SC&A 

has followed up on several areas:

• Reactor Modeling

• Fission and Activation Product (FAP) Bioassay Indicator 

Radionuclides

• Burial Grounds

• Chemical Processing Plant (CPP) Pre-1963

10
INL Update (continued)

• Data capture and worker interviews were conducted 

in conjunction with DCAS in March 2016.

• SC&A efforts focused principally on the burial ground and 

CPP pre-1963.

• Documents should be cleared and available to SC&A and 

DCAS by late August 2016.

• SC&A follow-on white papers on reactor prioritization 

and indicator radionuclides were discussed at the 

August 2, 2016, meeting and are available on the 

DCAS website:

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-inlsec219rsp-r1.pdf

(Reactor Prioritization)

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-inlwasterep-r0.pdf 

(FAP Indicator Radionuclides)

11
ANL-W SEC-00224 

Petition Overview

• Petition received on December 4, 2014.

• Petition qualified on March 13, 2015.

• Notification to Petitioner and ABRWH in June 2015 that 

NIOSH would exceed 180-day deadline due to site 

complexity and need for multiple data capture efforts 

on site.

• Further delay in September 2015 due to dosimetry records 

issue between ANL-E and INL.

• Evaluation Report sent to ABRWH on February 24, 2016.

• Evaluation Report sent to Petitioner on March 8, 2016.

• Presented to the Board at the March meeting in Tampa, 

Florida.

• Board voted to accept the class as proposed.

12
ANL-W SEC-00224 

NIOSH Class Definition

All employees of the Department of Energy, its 

predecessor agencies, and their contractors and 

subcontractors who worked at the Argonne National 

Laboratory-West between April 10, 1951 and 

December 31, 1957 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.

13
ANL-W SEC-00224 

NIOSH Determination of Feasibility of Dose 

Reconstruction

• Up until 1958, the West site (EBR-I complex) was 

determined to be infeasible due to limited mixed 

fission product bioassay and potentially incomplete 

external dosimetry records.

• Dose reconstruction was determined to be feasible for 

the East site (EBR-II complex), as there were routine 

mixed fission product bioassay and air sample data 

indicating alpha exposures were controlled to less 

than 10% of the maximum permissible concentration 

(MPC).

14
ANL-W: SC&A Preliminary Investigations

Seven areas of inquiry – similar approach as used for INL. Several 

were discussed at the August 2, 2016, combined INL/ANL-W WG 

meeting and are the subject of this presentation.

1. Review OTIBs and TIBs referenced as basis for the SEC ER to identify open 

issues and assess their relative impact on the SEC class determination.

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-anlwtibstatus062816.pdf

2. Review the ANL-W site profile and cross-walk the combined SP matrix and 

SEC matrix with ANL-W to identify potential commonalities.

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-anlwinlspsec-r0.pdf

3. Review ANL-W reactors for OTIB-0054 applicability and significance in an SEC 

context (e.g., years operated, frequency and intensity of operation, incidents, 

number of workers potentially affected) – same as done for INL.

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-anlwrp-r0.pdf

15
ANL-W: SC&A Preliminary Investigations 

(continued)

4. Investigations into changes in the completeness and 

adequacy of dosimetry and air sampling data between 

1951 and 1956 and from 1957 going forward (SEC break 

point). 

• 4a – Dosimetry completeness and adequacy (internal and 

external), including vertical analysis of neutron dosimetry and 

treatment in TBD-6 

 http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-anlwmtrprac070816.pdf 

• 4b – Area monitoring data (air sampling, swipe survey reports, 

area monitoring reports) completeness and adequacy – split 

between EBR-I and EBR-II (to be discussed at the next meeting)

 http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-anlwamd071416.pdf 

16
ANL-W: SC&A Preliminary Investigations 

(continued)

5. Investigate general air sampling data that NIOSH proposes for 

dose reconstruction of actinide intakes in the absence of FAP.

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/scaanlwairsamp-r0.pdf 

6. Evaluate available data that would indicate the ratios of MFPs 

and actinides to Cs/Sr (OTIB-0054 ratio approach – same as 

done for INL). 

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/scaanlwintakes-071416.pdf 

7. Investigate the strategy of using the 10% Maximum Permissible 

Concentration rule in dose reconstruction (not discussed per se 

at the August WG meeting but related to Issue 5 above). 

• http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/scaanlwsec224-071416.pdf

17
ANL-W Item 1 – Review OTIBs and TIBs 

Referenced as Basis for the SEC ER

13 OTIBs and 2 Procedures Referenced

• 3 OTIBs with outstanding findings that may impact the SEC class determination:

1. ORAUT-OTIB-0018, Revision 01, Internal Dose Overestimates for Facilities with Air 

Sampling Programs, August 9, 2005; SRDB Ref. ID 19436 

1 finding “in progress” awaiting NIOSH response on (a) does list of radionuclides 

include all worst case radionuclides, (b) does 10% of MPC account for time 

dependence, and (c) what does it mean to have a “robust” air sampling program. 

2. ORAUT-OTIB-0049, Revision 01 PC-2, Estimating Doses for Plutonium Strongly 

Retained in the Lung, November 29, 2010; SRDB Ref. ID 90666 

The second finding questioned, in part, calculating doses from urinalysis data with 

only a single intake or chronic intakes with time gaps between them. In NIOSH’s 

response, the question associated with intakes from urinalysis data was not 

addressed.

3. ORAUT-OTIB-0054, Revision 02, Fission and Activation Product Assignment for 

Internal Dose-Related Gross Beta and Gross Gamma Analyses, March 6, 2014; SRDB 

Ref. ID 130852 

SC&A recommends a highly focused review to ensure that the revised Pm-147 intake 

fractions in Tables 7-3b and 7-3c were calculated and entered correctly.

• Open findings and unreviewed documents pertinent to the ANL-W SEC are under the 

Subcommittee on Procedure Reviews.

18
ANL-W Item 2 – Cross-Walk the Combined 

INL SP Matrix and SEC Matrix with ANL-W

Tables 4 (INL Site profile) and 5 (INL SEC) of SC&A’s report identify 

commonalities with ANL-W:

• 3 outstanding site profile issues that may have the potential to become SEC 

issues:

1. Issue 16 – Potential need for an external dose coworker model

2. Issue 31 – Neutron dosimetry completeness issues

3. Issue 34 – Adequacy of neutron exposure monitoring

• All 3 issues relate to our investigations of TAN but may have broader 

implications (November 2015 WG).

• NIOSH’s response to Issue 16 was that they do not intend to develop an 

external dose coworker model. In response to Issues 31 and 34, NIOSH 

indicated that the data reviewed by SC&A are just a sampling and that 

more data will be made available.

• SC&A remains concerned that if, in the future, a coworker model is 

needed, there may not be enough granularity to identify worker location.

• At the November 2015 WG meeting, this was determined to be 

secondary priority pending the outcome of SEC evaluations.

19
INL/ANL-W Item 3 – Reactor 

Prioritization, Background

• As part of its review of the INL SEC-00219 and the ANL-W SEC-00224 

evaluation reports, the Board tasked SC&A with investigating the 

issue of dose reconstructability.

• Inherent in the SEC framework is the assumption that doses can be 

reconstructed with sufficient accuracy for areas and time periods 

that lie outside the SEC class definitions.

• A primary tool that NIOSH uses for internal dose reconstruction is 

the guidance appearing in ORAUT-OTIB-0054, Fission and Activation 

Product Assignment for Internal Dose-Related Gross Beta and 

Gamma Analyses. 

• SC&A, in two reports, performed preliminary assessments of 

whether the OTIB envelopes, with sufficient accuracy, the important 

conditions of the INL and ANL-W reactors, and prioritized the 

reactors into High, Medium, and Low categories for further detailed 

investigation. 

20
Background (continued)

• Operations at the INL and ANL-W sites involving radioactive 

materials were very complex, and many unique nuclear reactors and 

experiments were built and tested. Different:

o Fuel types (e.g., fissile materials, chemical forms, cladding, 

and physical arrangements)

o Blankets (e.g., to breed more fuel) and reflectors

o Moderators (e.g., light water, heavy water, or none)

o Coolants (e.g., light water, heavy water, liquid metal, gas, 

organic)

o Operating scenarios (e.g., steady-state, intermittent, pulsed, 

within design limits, outside of design limits)

o Burnups – often low so that the long-lived decay products did 

not have the opportunity to build up in the fuel, resulting in 

different isotopic ratios than in the OTIB-0054 characteristic 

reactor cases

21
OTIB-0054

• NIOSH uses OTIB-0054 to determine internal doses to claimants 

using indicator radionuclides in cases where only gross beta or gross 

gamma measurements (from air sampling or urinalysis) are 

available.

• The OTIB assigns fission and activation product intakes for different 

radioisotopes that are directly tied to an indicator radionuclide 

(strontium-90 or cesium-137).

• Limitations: OTIB methodology does not:

o Address predominately alpha-emitting radionuclides

o Include radionuclides generated outside the fuel 

o Apply to operations involving decay times <10 days 

o Apply if radionuclides have been extracted and concentrated

22
OTIB-0054 (continued)

 The OTIB generated 9 different representative cases based 

on four reactors, which are intended to envelope the range of 

reactor and nuclear fuel types and operating scenarios. 

Representative Reactors

Reactor Category Reactor

High-flux reactors Advanced Test Reactor (ATR)

Na-cooled fast reactors Fast Flux Test Facility (FFTF)

Pu production reactors Hanford N-Reactor

Research reactors TRIGA with stainless steel cladding
INL Site Reactors

There were a total of 52 reactors on the overall INL site.

INL Site Reactors

Location Number

INL 34 (28) *

ANL-W 12

NRF (Naval Research Facility) 4

Never Operated 2

24

* SC&A had already evaluated 6 of the INL reactors in 2 separate reports:

• NIOSH SEC-00219: Test Reactor Area Modeling, SCA-SEC-2015-0074-C, Rev. 0, 9/28/2015. 

(MTR, ETR, ATR)

• Review of NIOSH Strategy for Reconstructing Internal Doses to Workers at Test Area North, 

SCA-TR-2015-SEC0074A, Rev. 0, 9/28/2015. (HTRE-1, -2, -3)
SC&A Priority Rankings

• Following screening of each of the 28 INL and 12 ANL-W 

reactors, SC&A assigned priority rankings to each for further, 

detailed analyses, taking into consideration factors where the 

radionuclide mixtures in OTIB-0054 might result in an under- or 

unrealistic estimate of internal doses. 

o Type of fuel

o Enrichment

o Cladding

o Moderator

o Coolant 

o Operational mode and whether operations were inside or outside of 

design limits

o Length of operation/overall burnup 

25
SC&A Priority Rankings

• In addition to OTIB-0054 applicability, SC&A also 

considered (at the request of the INL WG) four 

additional factors, to the extent that they are 

known, that reflect the scope of the population 

potentially “at risk” of uncontrolled/ 

unmonitored exposures.

o Duration reactor was in operation

o Frequency/intensity of operation

o The approximate number of workers potentially 

exposed during its operation (this proved infeasible 

during the screening investigation)

o Incidents or other factors with potential to contribute 

to the risk of unintended/unprotected exposures

26
INL Reactor Assessment

INL SEC-00219 Reactor Prioritization for Evaluation of ORAUT-OTIB-0054 Applicability, 

SCA-TR-2016-SEC002, Rev. 1, 6/10/16.

SC&A assigned priority classes to the 28 INL reactors:

Reactor Priority Classes

Priority Class No. Reactors

High 7 LOFT, OMRE, PBF, SPERT-I, -II, -III, -IV

Medium 6 CRCE, ML-1, SCRCE, SNAPTRAN-1, -2, -3

Low 15 ARMF-1, -2, ATRC, CFRMF, CET, ETRC, 710, GCRE, 630-A, 

HOTCE, FRAN, RMF, STPF, SL-1, THRITS

27
ANL-W Reactor Assessment

Argonne National Laboratory-West SEC-00224 Reactor Prioritization for Evaluation of 

ORAUT-OTIB-0054 Applicability, SCA-TR-2016-SEC010, Rev. 0, 7/13/16.

SC&A assigned priority classes to the 12 ANL-W reactors:

ANL-W Reactor Priority Classes 

Priority Class No. Reactors

High 7 BORAX-I, -II, -III, -IV, -V, EBR-I, -II

Medium 1 TREAT

Low 4 AFSR, NRAD, ZPPR, ZPR-III

28
NIOSH Response

NIOSH Proposal for INL and ANL-W Reactor Prioritization for OTIB-0054 Evaluation, 7/28/16.

NIOSH proposes:

• Merging the INL and ANL-W high-priority category reactors for 

detailed evaluation of OTIB-0054 applicability using the ORIGEN 

isotope generation and depletion code. 

• Eliminating several reactors from the high-priority category: LOFT, 

BORAX-I, -II, -III, and -V. Reasons are given in the report. 

• Modeling the most extreme experiment from all four of the SPERT 

reactor tests as a “bounding case.”

• Modeling the most bounding case of the last two EBR-I cores. 

29
NIOSH Response

Summary: Reactors that NIOSH Proposes to Evaluate

OMRE Organic Moderated Reactor Experiment

PBF Power Burst Facility

SPERT I–IV Special Power Excursion Reactor Tests

BORAX-IV Boiling Water Reactor Experiments

EBR-I (Core 4) Experimental Breeder Reactor-I

EBR-II Experimental Breeder Reactor-II

30
August 2016 Work Group Update

• SC&A and NIOSH response paper discussed.

• SC&A is in basic agreement with NIOSH’s proposed list of 

reactor groupings for further evaluation.

• SC&A tasked to evaluate in greater depth the approximate 

number of workers potentially exposed during its operation. 

– This was not feasible at the time that our report was being prepared.

– NIOSH indicated that monthly dosimeter reports are now available for all 

the facilities and are relatively easy to access.

– Can now look at numbers of badged workers during the years of 

operation for each facility.

– SC&A expects to have a revised report prepared in time for a late 

September/early October WG teleconference.

31
ANL-W Item 4a – Evaluation of ANL-W 

Monitoring Practices

• SC&A randomly selected 50 ANL-W claims for 

evaluation of internal and external monitoring 

records.

• 10 additional claims purposely selected with a focus 

on employment at the end date of the SEC 

(12/31/1957).

• Review resulted in 4 Findings and 6 Observations.

• Discussed at August 2, 2016, Work Group meeting.

32
Evaluation of ANL-W Monitoring Practices –

Review Findings

• Finding 1: 

o Claimant had no external monitoring for over a decade.

o Claimant was on a consistent internal monitoring schedule (in vivo) 

during this time.

o SC&A recommends further inquiry with DOE to gain sufficient 

information about the apparent gap.

• Finding 2:

o There appears to be a sharp decrease in internal monitoring from 

approximately 1973–1979.

o SC&A recommends further investigation to determine potential 

operational changes.

o SC&A also recommends NIOSH evaluate the completeness and 

adequacy of records for use in a coworker model.

33
Evaluation of ANL-W Monitoring Practices –

Review Findings (cont.)

• Finding 3: 

o Claimant has external monitoring records beginning in 1963; 

however, was employed several years prior to this.

o Evidence suggests the claimant had positive external dose prior to 

1963 based on career dose totals.

o SC&A suggests further inquiry with the site on this worker.

• Finding 4: 

o Examination of claims with employment both before and after the 

SEC date (12/31/1957) showed a significant shift in radiation 

monitoring protection at the end of March 1958.

o SC&A feels it appropriate to further examine this short period (first 

quarter of 1958) to assure dose reconstruction feasibility.

34
Evaluation of ANL-W Monitoring Practices –

Observations

• Observation 1: 

o Some claims only have annual or career summaries for 

external dose.

o Additional records are being obtained to assure a 

complete dose reconstruction for affected claims.

• Observations 2, 3, and 6: 

o Several claims have “gaps” in dosimetry records.

o Often considerable uncertainty exists as to actual work 

history (exposure potential at the site).

o Infeasible to reasonably determine if unmonitored 

exposure may have occurred in many cases.

35
Evaluation of ANL-W Monitoring Practices –

Observations

• Observation 4: 

o Extremity monitoring is known to be sparse but is available for some 

claims.

o SC&A recommends comparing available data to current dose

reconstruction methods for unmonitored extremity claims 

(OTIB-0013).

• Observation 5:

o Neutron monitoring was non-routine among the sampled claims.

o NIOSH noted special investigations were conducted by ANL-W for

unmonitored neutron exposures.

o SEC Evaluation Report would benefit from further discussion of 

neutron monitoring protocols and special investigations.

• Discussed briefly at the end of the August 2, 2016, WG 

meeting – topic of discussion for the next WG meeting.

36
ANL-W Item 5 – Use of Air Sampling 

Data for Dose Reconstruction of 

Actinide Intakes in the Absence of 

FAP Assessment 

The SC&A review is limited to the proposed 

internal assessment for U, Th, and Pu for 

exposure conditions in the absence of MFPs by 

means of air sampling data.

37
NIOSH’s Approach for Assigning Internal 

Exposures to U, Th, and Pu without MFPs 

by Means of Air Sampling

• NIOSH explains the role of air monitoring for the 

protection of workers in the SEC Petition ER in the 

following statements:

The conventional [fixed] air-sampling units used were 

continuously-operating devices sampling at relatively low flow 

rates. Typical units sampled room air at 2 cfm on 2-in.- diameter HV-70 or Millipore filters. Samples were removed 

daily, Monday through Friday, and counted for alpha and beta- gamma activities. [Emphasis added.]

...In the instances where the air samples were counted for 

alpha radioactivity more than once due to the presence of 

short-lived alpha-emitting radionuclides, the latest result for 

gross alpha radioactivity will be used... [Emphasis added.]

38
NIOSH’s Approach for Assigning Internal 

Exposures to U, Th, and Pu without MFPs (cont.)

NIOSH believes that air sampling data assessed for gross alpha 

activity are sufficient for bounding internal radiation doses to U, Th, 

and Pu by means of the following criteria: 

• Uranium. Without MFPs, U intakes will be bounded by using 10% MPCair

values from available air monitoring data.

• At the Fuel Cycle Facility (FCF), estimates of internal dose to U (without 

MFPs) for August 1967 to June 1983 assessed using gross alpha radioactivity 

of air samples. 

• Thorium. For 1963–1967, dispersible Th without MFPs may have exposed 

workers at the FCF in Room 25. NIOSH intends to bound potential intakes of 

thorium by assuming intakes at 10% of the ANL-W MPCair.

• Plutonium. The plutonium-bearing Mark-II loops that were handled at the 

FCF mostly contained enriched UO2 with lower quantities of PuO2. But due to 

the much shorter half-life of Pu, NIOSH will conservatively assume that 100% 

of gross alpha activity represents Pu. 

39
Limitations of Air Sampling Data for Assignment of 

Internal Dose to FCF Workers

U, Th, Pu without MFPs:

• Most recorded air sampling data for ANL-W facilities 

typically show results below 10% of the MPCair. – SC&A questions whether fixed area air sampling data 

accurately represent levels of air contamination breathed 

by workers.

• The assumption that measured air concentrations

from general air (GA) sampling represent air 

concentrations respired by workers during facility 

operations is questionable at two levels: – (1) long air sampling times

– (2) limitations and uncertainties with GA air sampling for 

assessing worker intakes

40
Summary Conclusions – Air Sampling

• On the basis of recorded/available GA air sample data, NIOSH

concluded that an air concentration of 10% MPCair defined for

a 40-hour work week provides a bounding value for potential

intakes of U, Th, and Pu at the FCF (and other work locations

at ANL-W).

• Support and commitment for the use of the 10% MPC value

rely on the unconfirmed assumption that GA air

concentrations closely correspond to operational air

concentrations to which workers were exposed.

• SC&A’s review of FCF air data, typical daily operations, and

assessment of NIOSH’s proposed use of GA air sampling data

identified two issues of concern.

41
Summary Conclusions – Air Sampling 

(cont.)

• First concern – Low air flow rates for GA samplers. 

– Sampling times of up to 4 days, often when normal facility 

operation/activities were not in progress. Likely that air concentrations 

during non-working hours differed significantly from air concentrations 

during normal facility operations (likely limited to an 8-hour shift 

Monday through Friday).

• A second and more serious concern is the lack of parity between 

GA and BZ air concentration measurements. Studies have 

consistently shown poor correlation between GA and BZ air sample 

data with BZ/GA ratios spanning several orders of magnitude. 

• Given the high degree of uncertainty surrounding GA sampling data 

at the FCF (and possibly other locations at ANL-W), SC&A concludes 

that NIOSH’s proposed value of 10% MPC(40) as a bounding value 

for internal dose assessment lacks credibility.

42
Path Forward

• SC&A’s report was discussed extensively at the August 2, 

2016, INL/ANL-W WG meeting. 

• The WG considers this to be a high-priority issue with 

potential SEC implications.

• NIOSH was tasked to provide a response paper for further WG 

discussion.

43
SC&A’s Evaluation of FAP Bioassay Indicator 

Radionuclides 

(in Conjunction with OTIB-0054 and TBD-5) 

for Assessment of FAP and Actinide Intakes at 

INL & ANL-W

44
45

Important Assumptions for Assigning FAP and 

Actinide Intakes

1) Sufficient fission-activation product (FAP) 

bioassay records are available to assign Sr-90 

and/or Cs-137 intakes.

2) Sr-90/Cs-137 ratios and their relationship to 

other FAPs and actinides are known with 

sufficient accuracy for INL and ANL-W to allow 

assigning consistent radionuclide intakes.
46

FAP and Actinide Intakes

• NIOSH’s ER recommends using Sr-90 and/or 

Cs-137 bioassay results in conjunction with 

ratios in OTIB-0054 to assign FAP intakes.

• NIOSH’s ER recommends using Sr-90 and/or 

Cs-137 bioassay results in conjunction with 

ratios in TBD-5 (TKBS-0007-5) to assign 

actinide intakes.
47

Evaluation of Ratios

• The NIOSH ratio values were derived mostly 

by computer simulation (ORIGEN).

• SC&A searched for documentation that would 

provide measured radionuclide ratios 

(e.g., benchmarks).

• SC&A searched the following:

NOCTS

SRDB

INL electronic bioassay database
48

Evaluation of Ratios (continued)

SC&A located measured quantitative 

radionuclide analyses of:

• Nasal swabs

• Urinalyses

• Fuel element scale

• Fuel storage contamination swipes

• Air filters

• Liquid, solid, soil, and air waste from INL and ANL-W 

waste records
49

Summary of INL Cs/Sr Results

The majority of the INL Cs-137/Sr-90 ratios 

were not centered on unity. Only 33% of 251 

data points analyzed for Cs-137/Sr-90 from 

the 1957–1993 INL waste reports fell within a 

range of 0.5–2.0. Some ratio values were 

orders of magnitude above and below unity.
Summary of ANL-W Sr/Cs Results

The ANL-W Sr-90/Cs-137 ratios were more 

centered around unity (69% of 16 pair) than 

those for INL (33% of 251 pair), but there 

were only a very small number of data points 

located that could be used in this analysis.

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Summary of Cs/Sr Results – Conclusions

The Cs-137/Sr-90 ratios are not always 1:1 

as assumed in OTIB-0054 and TBD-5; 

frequently, large variations in the ratio exist. 

This brings into question the validity of using 

an indicator radionuclide when deriving FAP 

and actinide intakes. This may be the most 

important result of this study because a 

Cs-137/Sr-90 value of 1:1 is one of the 

cornerstones for use of the ratio method at 

INL and ANL-W.
Summary of FAP/Cs or FAP/Sr Results

The FAP/Cs-137 or FAP/Sr-90 ratios (as 

required by OTIB-0054 for assigning FAP 

intakes) may not be sufficiently constant (or 

known) for assigning intakes, even in 

situations where it can be assumed that the 

FAP is tied to an indicating radionuclide.

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Summary of Actinide/FAP Results

Actinide intakes assigned using NIOSH’s 

recommendations in TBD-5, Table 5-22 based 

on Sr-90 intake values, or Table 5-23 based on 

Cs-137 intake values, are sometimes 

significantly less than those derived from 

actual measured values.
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Recommendation 1

It needs to be determined if records of 

analyses of INL dissolver contents (containing 

the fuel elements) are available; preferably, 

for a variety of INL reactor fuel elements, and 

also fuel elements from offsite reactors.
55

Recommendation 2

Further ANL-W document research is needed 

to evaluate NIOSH’s recommended ratio 

values, especially for actinides and 

Cs-137/Sr-90. Records with quantitative 

radionuclide analyses are especially 

important.
Recommendation 3

Considering the results of this preliminary 

study and the numerous source terms at INL 

and ANL-W, the validity of using the present 

radionuclide indicator method (OTIB-0054 

and TBD-5) for assigning FAP and actinide 

intakes needs to be addressed further.

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Path Forward

• SC&A’s report was discussed at the August 2, 2016, WG 

meeting.

• Based on a request by NIOSH, SC&A was tasked to break 

down the waste data ratios by month instead of year where 

those data are available.

• SC&A was also tasked to analyze the 60 new SRDB 

documents that NIOSH will provide.

• SC&A will revise its report in time for a WG meeting before 

the November Board meeting.

o Revision will also include an assessment of NIOSH’s 

regression analysis and some example dose 

calculations for FAP and actinides to show the fraction 

of internal dose they contributed.
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Comments and Questions?