SHIELDING-RESEARCH AREA AT BATTELLE

The design and constructlon of the shielding facility at Battelle are described. This facility consists of an open pool with a fission plate, an instrument bridge and tower, a control room, and radiation-detection instruments. The shielding pool is located at the end of the thermal column of the Battelle Research Reactor (BRR). The fission plate is 28 in. in diameter and contains approximately 3.5 kg of U/sup 235/. The plate was fabricated from three pieces of highly enriched U and clad with about 25 mils of 2S Al. It generates about 24 w during steady-state reactor operation. The fission spectra of neutrons and gamma rays produced by the fission plate are free from appreclible background radiations. The ratio of thermal to epithermal neutrons impinging upon the fission plate is approximately 67, indicating a low fast-neutron background. Assuming an average energy of 2 Mev for backgrounnd gamma rays results in a ratio of thermal-neutron flux to gamma flux of 16. (auth