High burnup fuel simulation during a reactivity initiated transient using the FRAPTRAN code

CIP01 test simulated a RIA (Reactivity Initiated Accident) transient at the experimental CABRI reactor under sodium cooling conditions on November 29th 2001. The father rod was fabricated by ENUSA and irradiated during five cycles in Vandellos 2 NPP and it reached a maximum burnup at EOL (End of Life) of 75 GWd/tU. The test rodlet was refabricated in Studsvik from the span 5 of the father rod. The cladding material was ZIRLO with a mean oxide layer of 75 μm. This note describes the modelling of the CIP01 test carried out in the CABRI reactor under RIA conditions by the use of the transient FRAPTRAN code (1.2 version). The CIP01 test consisted in a power pulse of 32.4 ms with a deposited energy of 98.2 cal/g at PPN (Peak Power Node). The code results will be presented and compared to the experimental data available. In addition, the FRAPTRAN and the SCANAIR code estimations will be also contrasted. This work is framed within the CSN-CIEMAT agreement on 'Thermo-Mechanical Behaviour of the Nuclear Fuel at High Burnup'. (Author)