MIR reactor tests of VVER fuel elements in cyclic power variation regimes

Tests of prefabricated VVER fuel elements burnup 50–60 MW·days/kg in regimes with cyclic power variation have been performed in a circuit setup of the MIR research reactor. The testing procedures are described, and the designs of the irradiation setups are presented. Some fuel elements are equipped with sensors for performing in-reactor measurements, which yielded the experimental data on the variation of the fuel element parameters during the tests (gas pressure, fuel temperature, length). Some results of post-reactor materials-engineering investigations are presented. All fuel elements remained airtight. __________ Translated from Atomnaya énergiya, Vol. 104, No. 2, pp. 80–84, February, 2008.