NUCLEAR TECHNOLOGY BRANCHES QUARTERLY REPORT July 1 - September 30, 1966

摘要

Values for B/A obtained recently in the ATRC using reactor noise techniques are reported, and the procedures for data analysis currently in use are described. Effects of flux trap experiments and outer shim positions on the ATRC power distribution are described.nThe importance of motion of ATR fuel assemblies induced by the operating conditions was evaluated. Although significant motion was calculated, the geo¬metrical changes that result do not appear detrimental.nHydraulic testing of production ATR fuel elements was continued. Inadequate roll-swage-joint strength appears to be the cause of the premature failure of one fuel assembly.nFrom a study of the physical, chemical, and metallurgical changes which take place in various fuel systems during irradiation, some of the fuel stability variables which reduce uniform fission product swelling and lower the accel¬erated swelling threshold temperature have been identified. Large differences in uniform swelling rates and in accelerated swelling temperatures from one system to the next suggest that control of these variables could result in greater fuel stability. The incorporation of initial porosity to accommodate uniform swelling from fission improves the irradiation performance of aluminum plate-type elements.nType 2219 aluminum alloy clad fuel plates have been corrosion tested in-pile under ATR conditions. Type 2219 aluminum in both the annealed (-0) and precipitation-hardened (T-62) condition appears superior to Type 6061-0 aluminum for application in the ATR.nUA1 alloys and inter metallic s appear to be compatible with liquid lead for short periods (≈ 72 hours) at 600°C. For longer periods, varying reaction and lead penetration occur.