Pinellas Site Profile Review

Final Status Report

John Stiver

SC&A, Inc.

Contractor to:

Advisory Board on Radiation and Worker Health

Centers for Disease Control and Prevention

August 9, 2016
Background

• Original Pinellas technical basis documents (TBDs) prepared in the 

2005–2006 timeframe.

• SC&A Site Profile review completed September 2006 – 11 primary 

issues and 8 secondary issues were identified.

• Subsequently, 6 Work Group (WG) meetings and 1 set of worker 

interviews:

– June 11, 2008, WG meeting

– June 11, 2009, WG meeting

– October 13, 2011, WG meeting

– January 24–25, 2012, Classified worker interviews – FBI building, Tampa Florida

– November 19, 2012, WG teleconference meeting

– February 11, 2016, WG teleconference meeting (stable metal tritide [SMT] model 

reviewed)

– March 1, 2016, WG teleconference meeting (remaining issues closed out)

• 2011–2012, NIOSH made extensive revisions to their TBDs – most 

complete rewrites. 2
Status as of March 2016 Board 

Meeting

• SC&A and the Pinellas Work Group agree that 

all of the primary and secondary issues raised in 

SC&A’s site profile review have been adequately 

addressed and resolved.

• Primary Issue 2 in abeyance until NIOSH 

delivers a revision of the internal dose TBD.

• The Work Group recommends closure on 

remaining issues.

3
Primary Issue 2

Issue Description: Potential doses from insoluble metal 

tritides (stable metal tritides [SMTs]) not sufficiently 

addressed

– December 2015: Updated SMT model delivered by 

NIOSH (see file “dc-pinellastrit-r0.pdf” on the DCAS 

website).

– There were 5 key aspects of the SMT model.

– SC&A White Paper Response (February 2016)

• Review contained 7 observations and 1 finding. 

(Note: Sole finding was withdrawn after NIOSH clarified 

that worker exposures are assigned for 2,600 hours/year.)

4
Primary Issue 2, continued

Five Key Aspects of December 2015 SMT model:

1. Resuspension factor: Increased from 1E-6 to 5E-5 per meter (same as 

Mound).

2. The use of the highest tritium contamination measurement (1957–1973): 

Airborne contamination estimated based on highest observed value in monthly 

health physics reports from 1957 to 1973. (Note: Assumed level of SMT 

contamination level is 1 to 2 orders of magnitude higher than the assumed 

values at the Mound Site.)

3. Technical adequacy of the method to detect tritium that is bound to 

particulate metal: Contamination swipes utilize a cotton ball that was rinsed 

with DI water (counting liquid) and then filtered prior to measurement by liquid 

scintillation counting. Particulate tritium could potentially be trapped in the cotton 

ball and not transfer to the counting liquid. 

4. The magnitude and the extent of potential for tritide contamination at 

Pinellas: SMTs only handled in areas where tritium was handled, and all tritium 

workers were monitored via urinalysis. Model only applied to those with tritium 

bioassay (i.e., coworker intakes not applied to unmonitored workers).

5. Choice of solubility type for the metal tritides present: Assumes all SMT 

intakes are Type M or Type S depending on which is favorable to the individual 

claimant. 5
Primary Issue 2, continued

• February 2016 WG Meeting

– Discussions focused mainly on the applicability of the sample 

method (NIOSH Item 3), and the documentation supporting 

prompt cleanup of spills and contamination that evidenced a 

strong health physics program (SC&A Observations 4–6).

– SC&A and the WG concurred that the NIOSH model is 

sufficiently accurate and claimant favorable. The WG accepted 

the SMT model and motioned to put Issue 2 into abeyance 

until the TBD was revised.

– A remaining SC&A concern pertained to the treatment of 

organically bound tritium (OBT). NIOSH responded that OBT 

behaves more like an insoluble particulate than tritiated water 

(HTO) and is subsumed in the SMT dose. The next TBD revision 

will include a discussion of how intakes of tritides, OBT, and 

HTO are addressed individually. 6
NIOSH Occupational Internal Dose 

TBD Revision 3, 7/18/2016

• Sections 5.7.1.1 and 5.7.1.2 were modified to incorporate 

changes agreed upon by the Pinellas Plant Working Group. 

• Section 5.3.1 was modified to provide more details about the 

tritium contamination smear collection and analysis 

procedures. 

• Sections 5.2.1 and 5.3.1 were modified to provide additional 

details, which included changes to the References section. 

• Section 5.2.1 was modified to provide additional details 

regarding organically bound tritium. 

• Section 5.4.2 was modified to provide additional details 

regarding the analysis of the tritium bioassay samples. 

Incorporates formal internal and NIOSH review comments. 

7
SC&A Position on TBD-5 Rev. 3

• Exposures to tritium gas (HT), HTO, and OBT 

– Exposures to HT, HTO, and OBT should be assessed 

using the worker’s urine sample data. 

– Both 100% HT and HTO doses and 100% OBT doses 

are assessed, and the most favorable to the claimant 

is assigned. 

– Potential exposures to HT and HTO should be 

assessed assuming that 100% of the tritium intake 

was attributable to HTO because HTO is the most 

dosimetrically significant form of tritium

– SC&A agrees that this is a claimant-favorable 

approach. 8
SC&A Position on TBD-5 Rev. 3, 

continued

• Exposures to HT and HTO

– Calculations of HTO doses use worker’s urine bioassay 

data according to ORAUT-OTIB-011.

– SC&A initially concerned about potential for using this 

methodology for composite samples.

– TBD 5 Rev. 3 explains that records of bioassay results 

from workers do not indicate the use of composite 

samples.

– SC&A has reviewed the bioassay records indicated by 

NIOSH and confirmed that only individual samples from 

individual workers were analyzed.

– SC&A has no objections to the use of OTIB-011 to 

calculate tritium doses. 9
SC&A Position on TBD-5 Rev. 3, 

continued

• Exposures to OBT

– Potential exposures to OBT assessed using IMBA 

assuming 100% of the tritium intake is attributable to 

OBT; calculated in accordance with ORAUT-OTIB0060, Internal Dose Reconstruction.

– Detailed guidance provided for OBT intakes and 

doses using IMBA to ensure claimant favorability.

– SC&A agrees with the method proposed by 

NIOSH.

10
SC&A Position on TBD-5 Rev. 3, 

continued

• Exposures to SMT

– All 5 key aspects of the SMT model have been 

incorporated into TBD-5 Rev. 3.

– SC&A agrees with the method proposed by 

NIOSH and believes that TBD-5 Rev. 3 has 

faithfully incorporated the needed changes.

11
Board Member Concern Regarding 

Urine Bioassay Sampling Frequency

• At the March 2016 Board meeting in Tampa, Florida, a 

Board member questioned whether a monthly sampling 

frequency was adequate to detect tritium in urine, given 

its rapid biological clearance.

– For acute exposures, ICRP Publication 78 (1997) provides a 

simple rule that limits the possible error in the estimate of intake 

arising from the unknown time of exposure. ICRP 130 (2015) 

maintains this rule.

• For each radionuclide, the monitoring periods are selected so that 

any underestimation introduced by an unknown time of intake is no 

more than a factor of 3 when an acute intake in the middle of the 

monitoring interval is assumed.

• For tritium, the ICRP recommends monitoring intervals up to 

30 days.

12
Questions?