Spent nuclear fuel project surface area estimates for N-Reactor fuel in the K East basin

Spent N-reactor fuel will be moved from wet to dry storage at Hanford Washington. The majority ofthis fuel exists as intact fuel assemblies, however, small amounts ofscrap will be included. Varying amounts of uranium metal are exposed in these fuel assemblies, depending upon the amount of mechanical damage sustained by the zircaloy cladding. The total exposed uranium surface area in each storage pool is estimated through the release of radioisotopes to the storage pools. The exposed uranium surface area of individual fuel assemblies in the K-East basin were estimated through the results of a camera survey. The exposed uranium surface area of scrap is estimated from the known particle side range and an estimated log normal particle size distribution. This document uses the radioisotope release calculations, the estimated scrap surface area, and the carnera survey results to estimate the ``worst case`` amount of surface area that could exist in a given ``MCO`` container containing 4 levels of fuel assemblies and one scrap basket. The total exposed uranium metal surface area for this ``worst case`` was 120,000 cm{sup 2}.