radioactive materials at W. R. Grace began in
July 1955 when Rare Earths, Inc. (W.R. Grace's
predecessor) entered into a contract with the
Atomic Energy Commission to extract thorium and
rare earths from naturally-occurring monazite
sands. In 1956, the Atomic Energy Commission
contract and Rare Earths' license to possess,
transfer, and use radioactive thorium were
transferred to W.R. Grace & Company. The
facility where thorium processing took place
(Building 23) operated until late spring of
1957, when W.R. Grace and the Atomic Energy
Commission agreed to terminate the contract,
effective January 31, 1958.
During the period of residual contamination, as designated by the National Institute for Occupational Safety and Health and as noted in the dates above, employees of subsequent owners and operators of this facility are also covered under the Energy Employees Occupational Illness Compensation Program Act.