Radiological Safety Experience in the Fabrication of Alloy Plate Fuels Bearing ²³³U/Pu

The first incidence of ²³³U-bearing fuel fabrication in India was the production of aluminum-clad Al-²³³U alloy fuel for the Kamini research reactor. The reactor physics experiments for this fuel are now being carried out in the Purnima III critical assembly, where Al-Pu alloy plate fuels will also be used. Both types of fuels were fabricated in the radiometallurgy laboratories of Bhabha Atomic Research Centre. The hazard potential of each step, evaluated from the site-specific radiological field data, is summarized. The parameters analyzed for this purpose include external and internal radiation hazards, contamination hazards, age of fuel material (i.e., time after separation), and experimental thermoluminescent detector exposure data. Gamma spectrometric data of the finished fuel plates were also analyzed for their utility in checking the material inventory. The collective dose equivalent from the fabrication operations for 12 subassemblies (9 bearing ²³³U and 3 bearing plutonium) was 67 mSv, arising from external exposures only. The internal exposure was nil. Fabrication of fuel plates constituted >60% of the total exposure. Fabrication of fuel subassemblies and quality control inspection at all the stages accounted for the remaining radiation exposure. Handling of ²³³U/Pubearing fuels is likely to increase in the years ahead in India. In this context, analysis of radiological field data has yielded useful guidelines for future work.