Fuel element performance
Description:
For some time, it has been considered that cycling natural uranium fuel elements through the {alpha}-{beta} transformation point (approx. 662 C) is a contributing factor in split type ruptures. This hypothesis is based upon the fact that the transition temperature, a one percent increase in volume occurs. It is reasoned that as the uranium hardens under irradiation, it becomes progressively less able to adjust to the severe stresses imposed by the volume change as the material cycles through the {alpha}-{beta} transformation point. Failure finally occurs by a splitting of the core. The IPD is now interested in evaluating some of the effects of reactor operation upon fuel performance. It appears that the life of solid fuel elements may be prolonged if sudden changes in reactor operation can be minimized. It is the purpose of this report to bring to the attention of FPD management the new ideas being developed in the IPD on split type failures and to point out the effect such thinking may have on future fuel element development activities. Based on a discussion with personnel in PID, there is reasonable hope that the performance of solid fuel elements will not be limited by the {alpha}-{beta} transformation, and that the solid geometry can be used to advantage in all HAPO production reactors.
Date:
December 31, 1957
Creator:
Hagie, L. T.
Item Type:
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Partner:
UNT Libraries Government Documents Department