RADIONUCLIDE INVENTORY MANAGEMENT AT THE NEW 100 MeV ISOTOPE PRODUCTION FACILITY AT LANL

The Isotope Production Facility (IPF) at Los Alamos is operated on the authorization basis of a radiological facility with an inventory limit of a Category 3 Nuclear Facility. For the commissioning of IPF, a ''dummy'' target stack containing Zn, Nb and Al disks, and a ''prototype'' stack were irradiated with a proton beam. The ''prototype'' stack contained two pressed RbCl disks, encapsulated in stainless steel, and a Ga metal target. Typical ''prototype'' stack beam parameters were 88.9 {micro}A, 101.3 h. Operation procedures require the projection of all generated radionuclide activities. This is mandatory in order to determine both maximum beam current and maximum beam exposure time. The Monte Carlo code MCNPX and the burn-up code CINDER90 were used to determine maximum beam parameters prior to irradiation. After irradiation, activity estimates were calculated assuming actual average beam parameters. They were entered into an online inventory database, and were later, after chemical separation and radioactive assays, replaced by experimental values. A comparison of ''prototype'' stack experimental yield data to Monte Carlo calculation results showed that the computer codes provide realistic, conservative estimates