Safety analysis method in case of black-out accident on pool type research reactor

• Safety assessment method of black-out accident on pool type reactor is presented.
• All of the processes are described mathematically by engineering-applied formulas.
• The method is adapted and applied to a particular research reactor.
• The calculation results are validated by comparison with experimental results.

The presented method is intended to be used for the evaluation of the operating parameters influenced by processes in a pool type research reactor in case of black-out accident. For this initial event a systematic deterministic analysis under the assumption of a single independent failure in one of the safety systems has been prepared. The ongoing processes are defined in the scenarios examined. Each of the processes – the heat carrier movement in the primary coolant circuit by its own momentum, the residual heat generation in the nuclear fuel at cyclic operational mode of the facility after several periods of operation and idle time, the natural circulation thrust caused by the residual heat generation after the reactor scram system extinction of the fission reaction and the temperature fields distribution are described mathematically by engineering-applied formulas.The method is applied to the safety analysis of such failure development on a concrete facility, and the results of the assessment are validated by comparison with experimental data from performed tests on a similar facility.From the presented calculations results and analyses in case of black-out accident and subsequent reactor core cooling systems shutdown of the research reactor IRT – 2000 at operation power of 1000 kW, a general conclusion can be made, that the failure which terminates the forced circulation of coolant through the core with subsequent scram does not lead to the destruction of structures, systems and components of the facility.The developed method for accident analyses presented in this paper is applicable to nuclear facilities based on water–water reactor technology after proper adjustment according to their specific design.