Progress is reported in the fabrication and inspection of metals.

The purpose of this project proposal revision is to request authorization of total project funds for back-up radioiodine removal and additional nitric acid recovery facilities for the Purex Plant. It is proposed to provide new facilities at the Purex Plant for the further removal of radioiodine from the dissolver off gases and for further recovery of nitric acid. The facility design will be based on meeting iodine emission requirements under 1961 goal conditions. It is expected that the facilities will include equipment such as an acid absorber, a caustic scrubber, heat exchangers, process vessels, process piping, jets, jumpers, remote control instrumentation, a continuous iodine monitor, new utility supply and discharge piping, waste disposal facilities, utilities, and other auxiliaries. The new equipment will be housed in a reinforced concrete building and vault which will provide necessary shielding and contamination control. A new vessel will also be installed in the 202-A aqueous-make-up facility. The equipment will be contact maintained. Some work will also be performed for tie-ins and alternations to existing facilities. The new iodine removal facilities are desired as early as practical since the effect of iodine emission on the environs surrounding HAPO is more serious during the winter months.

Neutron spectra were obtained for a series of subcritical fuel assemblies with light water as moderator. It is concluded from the experimental results that the observed spectra are in reasonable agreement with the Wigner-Wilkins thermal neutron spectra calculations. (L.T.W.)