Experience from the post-test analysis of MEGAPIE

Analysis of nuclide production in the MEGAPIE target

“…[4,39] using FLUKA 2006.3b [12] and INCL4/ABLA (MCNPX 2.5.0) [13] are shown. It is seen that the agreement between various calculations is rather good, with the exception of some discrepancy at about 5-10 yr of cooling.…”

“…Table 4 illustrates the absolute values of activities of radionuclides calculated using various codes and data libraries. The data are shown for 25 radionuclides with the highest activity after 1 yr of cooling, chosen from the list of most relevant nuclides for safety analysis [4,40]. The difference of results is caused mainly by the use of various data sets and model calculations in the activation analysis.…”

“…From a scientific point of view, postirradiation experiments can lead to information on the nuclide inventory allowing benchmarking the calculation tools. Monte Carlo codes are an essential tool for this kind of investigation, and were used extensively during the design phase of MEGAPIE, as well as during the experimental measurement program [4].…”

Study of steady-state heat transfer with various large beam intensities in ADS windowless spallation target

“…Cho [6] proposed a numerical design study to obtain the optimal design parameters for a 20 MW spallation target for a 1000 MWth ADS and the results show that a 30 cm wide proton beam with a uniform beam distribution should be adopted for a spallation target of a 20 MW power. Zanini [7] performed the research of the thermal hydraulics behavior from the neutronic and nuclear aspects during the irradiation in the MEGAPIE target at the SINQ facility of the Paul Scherer Institute. Vanderhaegen [8] simulated the three-dimensional flow inside the vessel using the renormalization group k-ε turbulence model by the computational fluid dynamics software FLUENT and the results show that even with a high temperature margin derived from the ASCHLIM benchmark simulations, corrosion or solidification temperature limits are not exceeded.…”

PIE preparation of the MEGAPIE target

“…The results are collected in a voluminous report [4]. The post irradiation examination (PIE) of the MEGAPIE target, still pending, is the completion of an integral part of the project.…”