A large-scale irradiation facility for the HSSI program

A new facility for the irradiation of large (up to 3-cm width [times] 60-cm height [times] 25-cm depth, and 25kg mass) specimen capsules has been built and installed at the University of Michigan Ford Nuclear Reactor (FNR). The facility was constructed for the irradiation of reactor pressure vessel steel specimens in support of the U.S. Nuclear Regulatory Commission's Heavy Section Steel Irradiation (HSSI) Program. The program is administered by Martin Marietta Energy Systems out of Oak Ridge National Laboratory. The facility is centered on four materials test reactor-type fuel elements when positioned for irradiation. These elements span the full width of the specimen cage. The bottom of the speciment cage is [approximately]1 cm above the beginning of active fuel in the axial direction, and the active fuel height extends upward 6-cm.