Nuclear Metals Inc.

Special Exposure Cohort

Petition Evaluation Report

Samuel Glover, PhD

Research Health Scientist

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

September 2012

Denver, CO
Brief Site Overview

 Nuclear Metals, Inc. (NMI) grew out of the

special metallurgical operations conducted 

Massachusetts Institute of Technology (MIthe Manhattan Engineer District which welater consolidated into the Hood Building a

perimeter of the MIT campus

 NMI took over the MIT operations at the H

Building as a private company and in 1958

transferred the operations to Concord, MA
Brief Site Overview—cont.

 NMI provided the AEC fabrication capabilit

and metallurgical consulting services for

uranium, thorium, and many alloys of thes

elements

 In the mid 1970s, NMI began large scale

fabrication of depleted uranium munitions the US military

 The covered period for NMI as an AWE fac

October 29, 1958 through 1990, Residual

Radiation 1991 through March 1, 2011
Petition Overview

 October 20, 2011: petition received Petitioner proposed class definition:

• All employees who worked in Buildings A, B, C

the Butler Building, external storage container

outside areas immediate to plant grounds at t

Nuclear Metals, Inc. facility in West Concord,

Massachusetts, during the period from Januar

1970 through December 31, 1983.

 January 17, 2012: petition qualified for

evaluation based on the potential for

unmonitored internal radiation exposures
Petition Overview—cont.

 NIOSH expanded the time period and scope

evaluated versus that requested by the pet

 NIOSH evaluated class:

• All employees who worked at the Nuclear Meta

facility in West Concord, Massachusetts, during 

period from January 1, 1958* through Decembe

1983.

*It was later determined by the Department o

that the earliest covered period at NMI is Octo

1958
Sources of Available Informat

 ORAU Team Site Profiles and Technical Informa

Bulletins (TIBs) and Procedures

 NIOSH Site Research Database Existing claimant files Information from petitioner which included 9

affidavits with 23 supporting documents

 Worker interviews (9) as well as information fr

claimant telephone interview files (CATIs)

 ATL/ORAUT/NIOSH conducted three outreach

meetings in Concord attended by approximate60 former workers and company management

(some of whom were present from day 1)
Data Capture Efforts

 DOE Opennet (OSTI data base)

 Standard data base search (DDRS, NNSA, CEDR 

 Internet search

 Various DOE locations (OSTI, Hanford, DOE

Germantown, Legacy Management, Grand Jun

Morgantown, Sandia, Savannah river)

 HASL‐EML Hagley Museum & Library NRC June 13 ORAU received 16,000 documents from 

Department of Environmental Protection
Status of Claims

(as of August 7, 2012)

 Total number of claims submitted: 

 Total number of claims who worked

during proposed (SEC): 

 Total number with a DR (at DOL):  Total number claims with internal dosimetry record

 Total number claims with external dosimetry record
Background

 NMI operated at the Hood Building (a DOE facility) 

the MIT campus until October 28, 1958

 NMI at Concord (the subject of the evaluation) was 

at 2229 Main St, Concord MA on originally 30 acres which was later expanded to 46.4 acres (in 1990)

 NMI began transferring operations to Concord after 

1958 and fully transitioned as of October 29, 1958 a

point DOL has determined it became an Atomic We

Employer (AWE) facility

 Workforce varied from 60 to over 650 workers durin

time period under review (peaking in the early 198
Background—cont.

 Original facility consisted of three buildings

• Building A containing office space and research

laboratories (analytical, x‐ray equipment, vacuu

furnaces)

• Building B contained services (e.g., cafeteria, el

switch room, lockers, etc) and sometimes used 

needed to hold radioactive materials.

• Building C was the main production facility and

included equipment for melting metals, extrusi

metal working, pickling and etching, and electr
Background—cont.

 Additional buildings added over time

• Building D (1978) built to expand the production • Building E (1983) production area for wet proce

(pickling, coolant recovery, waste treatment)

• Butler Buildings (BB) were added over time and 

for storage and sometimes pressed into service 

needed

o BB 1 (1958): Primarily non‐DU related but over time 

and storage of DU components occurred here

o BB 2 (1960) unrestricted access, non‐DU purposeso BB 3 (1976) used for storing DU components

o BB 4 (1977) unrestricted access, non‐DU purposes
Background—cont.

Diagram of NMI in 1994
Background—cont.

 Partial listing of operations conducted pre‐1972

• Principally fundamental metallurgy, physical metallu

chemical metallurgy, engineering and product develo

fuel element development and manufacture, and maof high temperature materials.

 Operations 1972‐1979

• Shifted towards large scale production including the

manufacture of depleted uranium (DU) shields, counweights, armor penetrators, metal powders, berylliuberyllium alloys, and specialty titanium parts

 Post 1979

• Operations continued, but this period has been rese

further review
Health Physics Program

 NMI had no trained Health Physics staff until 1981

 The program transferred from the Hood Building in 

 The programs were research in nature and thus the 

often unaware of new hazards which may be encou

 Program evolved over many years, and may have p

lapses into poor practices

• Mid‐1960s reports describe significant uranium spills 

contamination which were left unreported

• Inspection reports from the mid‐1970s emphasize th

contamination controls and monitoring
Health Physics Program—cont

 Improvements in the radiation protection program 

with the growth of the company in the late 1970s a

and emphasis to becoming a production program

 While the period after 1979 will be described in a fu

report improvements included

• Access controls enforced• Increased air monitoring program

• Air and swipe sample analysis brought in‐house to re

delays

• Employee radiation safety training provided by full t

training specialists as part of orientation

• Increased health physics coverage for all three work 

• Large increase in the amount of bioassay samples co
Sources of Internal Exposur

 NMI’s research and production activities inv

numerous sources of exposure

 Amounts changed over time (up and down) Some NMI activities and materials remain c

 Sources of internal dose included

• Uranium (depleted, natural, enriched) in many p

forms and as the result of fires and explosions

• Thorium (oxides, powders and metal)

• Uranium and thorium progeny

• Recycled uranium components
Thorium

 Thorium was transferred from the Hood building at 

of operations (approximately 1 ton)

 In the 1960s NMI extruded thorium rods for British 

French companies

 Converted thorium rods to powder

 Extruded thorium powder

 NMI cast thorium to billet size followed by machini

jacketing, extrusion, pickling and machining

 Given the limitations on records, NIOSH has identif

persistent and radiologically significant thorium sou

over the operating history of NMI for which no mon

exists for the period 1958 through 1979
Sources of External Exposur

 Processing of depleted/natural/enriched ura

and thorium metal

 Submersion in contaminated air and exposu

contaminated surfaces

 Concentration of progeny during metal work

separation processes enhanced radiation

 X‐ray sources

• Two industrial X‐ray units (by the mid 1960’s the

five units)

• 40 mCi unencapsulated Ir‐192 source and 45 Ci o

• 100 kV medical X‐ray machine
External Monitoring Programs 

Data Availability

 Personnel monitoring program in place prio

relocation of operations to Concord

 In the late 1950s, film badges were issued to 

uranium processing employees

 In the 1960s, all personnel wore film badges

(according to documents)

• Processed every 6 1⁄2 weeks

• Clerical personnel badges processed annually
External Dose Monitoring Prog

and Data Availability—cont.

Nuclear Metals, Inc. Dosimeter Results Summary 

YEAR 

Number of Badges 

SRDB Reference 

YEAR Number of 

Badges 

SRDB Refe

1958 98a 25034 1971 604 25046 

1959 341b 25034; 28468 1972 364 25046; 25

1960 1424 28468 1973 433 25054 

1961 1196 25038 1974 451 25054 

1962 1071 25037 1975 368 25054 

1963 828 25037 1976 462e 25054 

1964 

979c 

25037 1977 811 25054; 25072

11327

1965 1284 25037; 29184 1978 942 25054; 25

1966 902 25045 1979 2615 25054; 25

1967 617 25045 1980 4230 25054; 29132

1968 312d 25045; 28465 1981 5422 28481; 28

1969 622 25040 1982 1970 28582; 28

1970 688 25046 1983 7739 29151; 29
External Monitoring Programs 

Data Availability

 Weekly smear sampling program began in 1

• Only limited results available to this point

 AEC inspectors remarked (9/18/1969) on

contamination smears not being taken as re

 Other inspection reports (5/16/1973) indica

measurement surveys were not recorded on 

sheets as required
Internal Dose Monitoring Progr

and Data Availability

 The bioassay program consisted of urinalysis sampl

lung counts

 Bioassay program evolved over time due to the AEC 

inspection reports

• In 1977, bioassay sampling started increasing

• In 1983, program reportedly consistent with Regulat

8.11

• NIOSH currently has identified 2,600 urine bioassay s

for uranium between 1958 and 1979 and 12,500 samthe period 1980 through 1983

• No urine samples located to date for 1968, 1972, and 
Internal Dose Monitoring Progr

and Data Availability—cont.

 Lung counts for uranium annually on representative 

of employee population (approximately 100 per yea

• Approximately 500 lung counts are available for the 

1982 through 1986
Internal Dose Monitoring Progr

and Data Availability—cont.
Internal Dose Monitoring Progr

and Data Availability—cont.
Internal Dose Monitoring Progr

and Data Availability—cont.
Internal Dose Monitoring Progr

and Data Availability—cont.

 NMI maintained an air monitoring program from th

years

 NIOSH obtained some of the monthly reports for th

1980 years (31 of 255) with summary data which pr

average, minimum and maximum concentration da

• Described as having 12 fixed air samplers located through

plant (increased later)

• 1959 report says that operations involving enriched urani

special jobs of uranium were to have air sampling (results 

available if implemented)

• 1974 inspection report specifically observed that the fixed 

sampling did not approximate worker’s breathing zones

• New data available to NIOSH consists of approximately 28

breathing zone and work area samples (1980‐1983)
Summary of Monitoring Gap

 External

• No neutron monitoring (although limited exposure

potential) but methods exist which may be suitable 

estimating dose

 Internal

• The early bioassay program (pre 1980) results are of

sparse and NIOSH can not verify they represent the 

case exposures

• Early air sample data limited and not equivalent to

breathing zone sampling

• Prior to late 1970s’ difficult to determine if bioassay 

included incidents

• No results for thorium operations (urine or air)

• No results for radon/thoron sources
NMI SEC Petition 195

 Why the class?

• Workers were potentially exposed to enriched urani

thorium, uranium progeny, and thorium progeny wh

not monitored nor does a suitable dose reconstructi

exist.

• Decision was based on lack of adequate biological m

data, sufficient air monitoring information, and/or su

process and radiological source‐term data to reconst

with sufficient accuracy.
NMI SEC Petition 195—cont.

 Why everyone?

• Based on reports by the AEC and facility layout, 

process areas were not isolated from the non‐prareas and no barriers to access were in place.
NMI SEC Petition 195—cont.

 What about employees not included in the SEC?

• NIOSH intends to use any internal and external mon

data that may become available for an individual clathat can be interpreted using existing dose reconstru

processes or procedures). Therefore, dose reconstruindividuals employed at Nuclear Metals, Inc. during t

from October 29, 1958 through December 31, 1979, do not qualify for inclusion in the SEC, may be perforthese data as appropriate.

• Furthermore, NIOSH intends to estimate doses from 

rays using information from employee medical recor

claimant favorable medical dose reconstruction assu

and methods.
NMI SEC Petition 195—cont.

 Why stop in 1979?

• Because the continuing analysis affects only pos

NIOSH has determined that it is appropriate to pwith the pre‐1980 feasibility evaluation while coto analyze the impact that newly obtained data 

post‐1979 dose reconstruction. NIOSH is therefo

reserving its full assessment of the available pos

data and will continue to evaluate the feasibility 

sufficiently accurate dose reconstruction for the 

from January 1, 1980 through December 31, 198
Health Endangerment

 The evidence reviewed in this evaluation indicate

some workers in the class may have accumulated 

radiation exposures through intakes of radionucli

direct exposure to radioactive materials.

 Consequently, NIOSH is specifying that health ma

been endangered for those workers covered by th

evaluation who were employed for a number of w

days aggregating at least 250 work days within th

parameters established for this class or in combinwith work days within the parameters established 

one or more other classes of employees in the SE
Proposed Class

All Atomic Weapons Employees who work

the facility owned by Nuclear Metals Inc. (

subsequent owner) in West Concord,

Massachusetts during the period from Oct

29, 1958 through December 31, 1979, for a

number of work days aggregating at least 2

work days, occurring either solely under themployment or in combination with work 

within the parameters established for one 

more other classes of employees included Special Exposure Cohort.
Recommendation

 For the period October 29, 1958 through

December 31, 1979, NIOSH finds that radia

dose estimates cannot be reconstructed focompensation purposes

Class Feasibility Health Enda

October 29, 1958

–

December 31, 1979 No Yes