KER Loop I operating report -- A report on the irradiation of zircaloy-2 jacketed tube-and-tube elements in KER Loop I

摘要

The objective of this test was to determine the in-reactor performance of co-extruded Zr-2 jacketed tube-and-tube elements. The effect of power, surface temperature, and uranium alloying on dimensional stability and uranium swelling and cracking was to be measured. The charge consisted of two unalloyed tube-and-tube elements, which were Zr-2 jacketed and were 36 inches in length. The rest of the charge consisted of spacer material and coupon holders. The test started on 6-29-59 and ran for a period of 32 days. On 7-30-59, the delayed neutron monitor reading and loop activities increased to a point that required reactor shutdown scram. The reactor was shut down, and the fuel elements were discharged. Loop water samples were analyzed for fission products. Evidence was found of high activity of Iodine isotopes of very short half-life. There was also some indication of other fission products. Visual inspection of the fuel elements after discharge disclosed small wrinkles on the jacket surface of the two unalloyed elements.