Evaluation of Fuel Rod Cladding Failure
16th Symposium of AER on VVER Reactor Physics and Reactor Safety (2006, Bratislava, Slovakia)
Reactor Dynamics, Thermal Hydraulics and Safety Analysis
The paper describes methodology for quantification of fuel cladding failure as a result of Loss of Coolant Accident (LOCA) for VVER-440 reactor type. The methodology is based on external coupling of the thermo-hydraulic code RELAP5 and thermo-mechanical code TRANSURANUS. The thermo-hydraulic response of the unit to the accident is simulated by RELAP5 code, providing initial and boundary conditions for the thermo-mechanical simulation by the TRANSURANUS code. Cladding failure criterion of the TRANSURANUS code, derived and implemented into the code in the framework of EXTRA EURATOM 5th Framework Programme is used. Cladding failure probability is evaluated by the Monte Carlo algorithm varying the outer cladding temperature. In the second part of the paper, an example of application of the methodology for typical maximum design accident of the VVER-440 is given, presenting every step of methodology and typical failure rate for this type of accident.