Purification of 242Pu by irradiation with thermal neutrons

The feasibility of purifying a radioisotopically impure sample of 242Pu using neutron irradiation to “burn up” the plutonium isotopic contaminants 238,239,240,241Pu is investigated. A starting point of 95% 242Pu is assumed, and different neutron energy spectra, fluxes, and irradiation periods representative of the conditions found at available reactors in North America were assessed with Monte Carlo simulation methods to predict the maximum obtainable enrichment of 242Pu. Calculations indicate that radioisotopic purities of 242Pu in excess of 99.5% are achievable with neutron fluxes at Oak Ridge National Laboratory’s High Flux Isotope Reactor, pointing encouragingly to experimental verification of these estimates.

► 242Pu can be purified from Pu isotopic impurities by reactor irradiation.
► MCNP/CINDER90/ORIGEN computations indicate 99.8% purity is achievable.
► Simulations indicate best results are achieved in High Flux thermal environments (e.g., HFIR).