Validation of severe accident codes against Phebus FP for plant applications: status of the PHEBEN2 project

Abstract

The European Commission-funded shared-cost action project PHEBEN2 brings together 13 partner organisations to understand the source term aspects of the integral Phebus FP experiments, to validate integral LWR severe accident codes against the test data, to develop and apply criteria regarding the strengths and weaknesses of the codes for plant applications, and to propose guidelines for their optimum use for this purpose. At the half-way point of the project, contributions to the final interpretation report of the first Phebus test FPT0 have been completed and work on the interpretation of the following test is proceeding. A detailed investigation by CFD and particle tracking appears to have identified the cause of the systematic underprediction of deposition in the steam generator tube of the Phebus circuit. Containment calculations using lumped-parameter codes have been supplemented by extensive CFD analyses, revealing complex circulation patterns within the relatively simple containment geometry of Phebus. Iodine chemistry studies have been made of both FPT0 and FPT1. Concerning criteria and code assessment for plant applications, a short list of safety-important phenomena explored in Phebus has been prepared, and partners have drafted a report analysing for each phenomenon its safety importance, the experimental data available, the modelling approach adopted in PSA codes, and the expected uncertainties. Jones et al. / Nuclear Engineering and Design 221 (2003) 225-240

Stand-Alone Containment Analysis of the Phébus FPT Tests with the ASTEC and the MELCOR Codes: The FPT-0 Test

“…A much smoother deposition behavior is shown by both codes, with the experimental "peak" at 21,818 s being reached at about 17,000 s in the calculations. The suspended aerosol mass trends obtained with both codes are similar to those reported in [25], even if in [25] maximum suspended aerosol masses of 0.06 kg between 16,000 s and 19,000 s were reported. After 23,000 s, the experimental data points are sufficient to stress that both codes well match the experimental evolution of the suspended aerosol mass.…”

Research Methods of Severe Accident Source Term for Nuclear Power Plant

“…Through comparing the model simulation and experiment results, the accuracy of codes is evaluated and optimized. The severe accident phenomena are better understood [12] . Fig.…”

The EC MUSA Project on Management and Uncertainty of Severe Accidents: Main Pillars and Status

“…AUQMIE is, hence, a drill for other application WPs and an opportunity to provide some early feedback to RUQM. The experimental test PHEBUS FPT-1 [20] was selected for this purpose. By no means is this intended as a data vs. code benchmark, and the only reason why reliable and representative data have been proposed is to have full and credited details of the scenario and experimental data that might help to calibrate the final model to be used.…”