The Theoretical And Computational Analysis For The Drop Events Of HTR-PM Spent Fuel Storage Canister

The key technology research and engineering validation of spent fuel storage are important sub-topics of HTR-PM(High Temperature Reactor-Pebblebed Modules),. One significant part of the topic is the safety validation of the drop events of HTR-PM spent fuel storage canister. That is, to assess the damages to the spent fuel storage canister, one of the key equipments of the spent fuel storage system, after dropping from top to bottom in the extreme case, thus validating the accuracy and reliability of the structure of the spent fuel storage canister.The dropping experiments of the spent fuel storage canister of HTR-PM are faced with more difficulties, compared to those of present spent fuel storage casks. That is because it has high dropping height, lack of independent buffer and the storage canister is thin-walled. These make it necessary to do in-depth analysis and calculations, which is the focus of this research subject.Scaled module will be used before the full-size experiments. First, we analyzed the scaling laws, showing its feasibility. Then, the analysis of the safety criteria was carried out to determine the judgement methods of the safety when doing the simulations.On the basis of the theoretic analysis, simulation calculations of dropping events of both full-size and scaled storage canisters under two conditions, including dropping to bearing and to placed storage canister, were carried out with the help of LS-DYNA procedures. In addition, we studied several possible conditions, such as inclination. And the safeties of the dropping events were determined based on the safety criteria.The results are as following: 1.Thesafety of the drop events is validated.2.Compared to that of the full-size module, the results of the scaled one conformed with the scaling laws, verifying the feasibilities of the experiments.3.There were differences among the results of dropping experiments in different cases. Nevertheless, these did not affect the judgement of the safety.4.Theoretical basis were provided for the selections and arrangements of the strain gauges and acceleration sensors.5.The calculations support for subsequent experimental design.