Hanford Special Exposure Cohort

Petition Evaluation Report (SEC-00155)

Samuel Glover, PhD

Research Health Scientist

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

December 2012

Knoxville, TN
Talking Points

 Quick petition review

 Discuss Hanford’s bioassay program during this time 

period

• Focus on Super S and fecal sampling

 Discuss OTIB-0049 

 Discuss application of OTIB-0049 at Hanford for 

cases involving fecal sampling
Petition Overview

 Petition received on November 10, 2009

 Petitioner proposed class definition:

• All personnel who were internally monitored (urine or 

fecal), who worked at the Plutonium Finishing Plant in 

the 200 Area at the Hanford Site, from January 1, 

1987 through December 31, 1989

 May 3, 2010: Petition qualified for evaluation

• Accepted petition basis: Radiation monitoring records 

for members of the proposed class have been lost, 

falsified, or destroyed 
Petition Overview—cont. 

 Four SEC classes previously added at Hanford:

1. October 1, 1943 through August 31, 1946, for selected 

areas of Hanford (SEC-00057-1)

2. September 1, 1946 through December 31, 1968, for 

selected areas of Hanford (SEC-00057-2)

3. October 1, 1943 through June 30, 1972, for all areas of 

Hanford (this class subsumed previous two classes; SEC00152)

4. July 1, 1972 through December 31, 1983, for all areas of 

Hanford (SEC-00201)
Petition Overview—cont. 

 SEC-00057 petition requested the SEC class be 

continued through 1990

• Advisory Board and NIOSH continue to review post 

1983

 The timeframe associated with SEC-00155 was 

encompassed by SEC-00057

 SEC-00155 was specific and focused on data 

falsification and was deemed appropriate for 

separate review
Petition Overview—cont. 

 The petitioner’s specific evidence of accusations 

by the U.S. EPA of purposeful wrong doing by US 

Testing (UST) resulted in NIOSH determining that 

issues regarding quality of bioassay data 

required further investigation as a separate issue 

from the continuing Board evaluation of 

SEC-00057 

 The intent of NIOSH’s separate evaluation of 

SEC-00155 was to ensure that issues identified 

with UST’s non-bioassay analytical programs did 

not also adversely affect the company’s bioassay 

analysis operations in Richland, WA
Periods of NIOSH Evaluation

 NIOSH evaluated the time period requested by 

the petitioner January 1, 1987 through 

December 31, 1989

 While the location was specified as employees 

who worked at the Plutonium Finishing Plant, 

the evaluation was primarily focused on the 

overall program which applies to all of Hanford
Some Sources of Exposure: 1987-1989

 Plutonium Finishing Plant (1987-9)

• Weapons grade metal production, Remote Mechanical C Line*

• Plutonium Reclamation Facility

• Miscellaneous treatment system glovebox operations

• Analytical laboratory operation

• Development laboratory operations

• Polycube processing (a polycube is a solid mixture of polystyrene and 

plutonium oxide)

 PUREX

• Oxide production line was run during the early part of this time 

frame*

*Identified at Hanford as being a potential source of insoluble 

plutonium with low 241Am content (fresh plutonium)
Personal Monitoring Data

 Internal monitoring data

• US Testing processed many thousands of bioassay 

samples during the period in question

– Urinalysis was the principal plutonium bioassay method

– Workers deemed to have a higher risk or those involved in 

potential incident may also have fecal samples

– Americium typically monitored with in-vivo counting 

methods, usually as an indicator of plutonium intake

• Hanford maintained an extensive area monitoring 

program (was not the focus of this review)
Background

 Pacific Northwest National Laboratories (PNNL) 

was responsible for overseeing the quality of the 

data produced by US Testing for Hanford from 

1979 thru the 1991

• Quality assurance program included blind bioassay 

samples (~250 blanks and quality control during 1987 

thru 1989)

• Annual reports during the time period of interest 

were reviewed by NIOSH as part of this evaluation
 Hanford modernized its 

bioassay methods from 

total alpha to recovery 

corrected alpha 

spectrometric methods 

(use of an isotopic tracer) 

in about 1983

 UST developed methods to 

respond to expedited 

samples (such as to 

determine if chelation was 

needed) which may have 

different Minimum 

Detectable Activities 

(MDA’s).

Americium

keV

3500 4000 4500 5000 5500 6000

0

50

100

150

200

250

300

Counts

Plutonium

keV

3500 4000 4500 5000 5500 6000

Counts

0

100

200

300

400

500 243

241

242

239

238

Uranium

keV

3500 4000 4500 5000 5500 6000

Counts

0

50

100

150

200

250

300

235

234 238 232

Alpha Spectra of Typical Radionuclides

Thorium

keV

3500 4000 4500 5000 5500 6000

Counts

0

200

400

600

800

1000

230

232 229 228

225Ac

Background—cont.
Background—cont.

0

20

40

60

80

100

120

140

160

180

200

1987 1988 1989 1990 1991 1992 1993

# of bioassay samples within 1 yr

Year of Fecal Bioassay

Number of urinalysis or in-vivo results within one year of a Pu fecal 

bioassay for an individual

1 2 3 4 5 6 7 8 9 10+
Number of Plutonium Urine (U) and 

Fecal (F) Bioassay Samples Per Period

U F U F

V5

0

1500

3000

0

1500

3000

0

1500

3000

Count

V3: 1/1/1987 to 12/31/1987 V3: 12/31/1987 to 12/30/1988

V3: 12/30/1988 to 12/30/1989 V3: 12/30/1989 to 12/30/1990

V3: 12/30/1990 to 12/30/1991 V3: 12/30/1991 to 12/29/1992

V3: 12/29/1992 to 12/29/1993
Bioassay at Hanford related to 

Potentially Super S 

Plutonium Compounds

 Hanford presented overview of technology shortfalls for 

Super Class Y (aka Super S) in a 1988 document, “Methods to 

Improve Pu Monitoring”

 Document uses ICRP 30 biokinetic models and data from 

modified retention in the ICPR 26 lung model and found that 

both urine and lung counting would be insufficient to meet 

DOE orders to determine intakes of 100 mrem Annual 

Effective Dose Equivalent

• The amount of Pu going to the urine was too low to be observed 

using the alpha spectrometric methods

• Hanford had several processes that produced freshly separated 

plutonium during this time period which reduced the capabilities of 

the lung counting program since it relies on 241Am measurements
Target Intake Amounts from 

1988 Document
Bioassay Challenges

(from 1988 document) 

 For both graphs, curve 

A is the excretion in 

urine from acute intake 

measurable at one year

 Curve B shows what 

the expected urine 

excretion would be for 

the ‘target’ intake
Pilot Program Notes

 1986-87: Pilot fecal program conducted to evaluate 

the feasibility of a routine program. Approximately 

50 workers participated, quarterly sampling. Issues 

regarding providing samples and sample amount 

reported. 

• Only 58 of 84 scheduled samples received. 

• 1719 Pu urinalysis samples for 1987

• Not well received by the workers
Pilot Program Notes—cont.

 1988: Pilot program was continued for 100 workers 

at the Plutonium Finishing Plant. Fecal samples 

showed 40-50% of the workers statistically greater 

than controls (details in 1993 Health Physics 

publication), and the results confirmed by special 

air sampling. 

• Pu urinalysis: 2008 routine, 130 special

• Pu fecal analysis: 37 routine and 34 special
Pilot Program Notes—cont.

 1989: In April, after 12 months as a pilot program, 

sampling frequency was changed to annual with 

provision of obtaining approximately equal number 

of samples each quarter

• 1989 Pu urinalyses: 2156 routine + 70 specials

• 1989 Pu fecal analyses: 259 routine + 16 specials
Pilot Program Notes—cont.

 Implemented using the experiences learned during 

the pilot program

 Mandated by the employers

 While external spike fecal samples were not 

provided, they did still use standard radiochemistry 

required practices

• Reagent blank with each batch

• Spiked quality control sample with each batch
Pilot Program Notes—cont.

 1990: Routine fecal program operated normally until 

contract default with UST on June 1, 1990 

• May samples never analyzed

 In September, before an interim contract could be put in 

place for routine analysis of fecal samples, Hanford 

terminated the program. This was done because 

Hanford facilities were no longer processing material 

that could be classified as freshly separated super class 

Y plutonium. 
Pilot Program Notes—cont.

 Dose determinations made for workers in the 

program at the start of the year, assumed chronic 

exposure January through September, based on 

fecal results obtained December 1989 through April 

1990 

• 1990 Pu urinalyses: 759 routine + 56 specials

• 1990 Pu fecal analyses: 35 routine + 44 specials
Pilot Program Notes—cont.

 1993 published paper on the experiences of a routine 

fecal sampling program

 Approximately 100 workers

 Quality control samples using artificial and known blank 

natural samples included to compare the results of the 

workers

• 391 samples from workers provided

• 47 control samples (blanks), consisting of 31 artificial and 16 

samples from unexposed individuals
OTIB-0049: Estimation of Doses for

Plutonium Strongly Retained in the Lung

 Sampling and radiochemical methods used 

described

 Estimation of doses for plutonium strongly retained 

in the lung

 While the newer International Commission on 

Radiological Protection (ICRP) insoluble plutonium 

increased the retention time compared to ICRP 30, 

various accident cases show longer retention
OTIB-0049: Estimation of Doses for

Plutonium Strongly Retained in the Lung—cont.

 OTIB-0049 developed based on nine cases from 

Rocky Flats and one case from Hanford that had 

well-defined intakes and exhibited long retention 

times

 Upper bound cases used to establish bounding dose 

for Super S materials

 Data compared to US Transuranium and Uranium 

Registries (USTUR) autopsy cases
OTIB-0049 Adjustment Factors

 TIB-0049 developed dose 

adjustment factors based 

on intakes from bioassay 

data using the type S 

ICRP model

 Dose adjustment 

depends on the type of 

data being used to 

determine intake (air, 

urine, lung, feces)
Adjustment Factors—cont.
Adjustment Factors—cont.
Fecal Adjustment Factor

 OTIB-0049 specifically addresses adjustment of fecal data

 Fecal samples collected less than 2 months after an acute 

inhalation intake or less than 2 months after the end of a 

chronic intake should be evaluated with the standard type S 

model

 Once intake is determined, dose is adjusted using direct 

measurement factors (e.g. air monitoring)

 Fecal samples collected after this 2 month time should be 

modeled as if they were urine samples and the dose 

adjusted upward by a factor of 3
Correction Factors for Super S Dose 

Based on Fecal Data
Urine/Fecal Activity Ratios from 

System Plutonium
Application at Hanford

 During this period, standard DCAS procedures are 

applied to Hanford bioassay data

 Assumptions include the age of plutonium, the 

plutonium isotopic makeup (fuel grade or weapons 

grade), solubility class (including Super S if 

appropriate), and evaluation of the information 

available for a case
Dosimetry Assumptions

 NIOSH TBD currently uses the contractual MDA’s

 Methods during this time period for SEC-00155 in the 

current TBD indicates 10 year old plutonium should be used

 Weapons grade and fuel grade may be evaluated

 Rarely is fecal data available, but OTIB-0049 should be used 

to evaluate and compare it with other intake indicators

 Sometimes intakes are not favorable assumptions if they 

would result in detection by other methods used 

 Case specific data must be reviewed since in vivo data may 

make some assumptions not claimant favorable