Mark-18A Target Materials Recovery Study

The Department of Energy (DOE) manages an inventory of materials that contains a range of long- lived radioactive isotopes that were produced from the 1960s through the 1980s by irradiating targets in production reactors at the Savannah River Site (SRS) to produce special heavy isotopes for DOE programmatic use, scientific research, and industrial and medical applications. During the late 1960s, one of the production reactors was configured to operate in a very high flux mode, and >8 kg of 242Pu contained in Mark-18A targets were irradiated to produce 252Cf for use in neutron source applications. Several targets were processed at Oak Ridge National Laboratory (ORNL) to recover the 252Cf, heavy curium, and 244Pu. Sixty-five of the Mark 18A targets were not processed and are currently in wet storage at SRS. In 2012 DOE’s Office of Nuclear Materials Integration (ONMI) tasked ORNL and Savannah River National Laboratory (SRNL) to evaluate options for recovery of valuable isotopes and/or disposal of the targets presently in storage. Based on the results of that study, ONMI established the Mark-18A Target Material Recovery Program (MTMRP) to recover the 244Pu and heavy curium in the Mark-18A targets. Recent efforts at ORNL to support the development of implementation plans for the Mark-18A TMRP are summarized in this report.