Analysis of the VENUS-1 Ex-Core neutron dosimetry using the LEPRICON code system

The VENUS-1 Mock-up ex-core neutron dosimetry is analysed by means of the LEPRICON code system using the ELXSIR 56-group cross section library. Two analyses are performed: the first one using the old iron cross-sections, the second using the new evaluation of the inelastic iron cross-sections present in the ELXSIR library. Results, when compared with those from earlier analysis show the clear improvement of the Calculation-to-Experiment (C-E) ratios. The decreasing radial trend in the C/E observed in the former analysis is drastically reduced due to the finer energy group structure of the ELXSIR library (56 instead of 17 groups). This trend is still improved by the use of the iron cross-section evaluation of FU. This leads to a flat radial C-E (around a value of 1.0) from the edge of the core until the neutron pad. The objectives of this new analysis are triple: i) to quantify the improvement of the calculated detector responses when using the ELXSIR library, ii) to display the consistency of the VENUS-1 ex-core dosimetry results with the intention of their integration in the LEPRICON Associated Benchmark Data Base, iii) to show the drastic reduction of the standard deviation on the adjusted results leading to demonstrate that the LEPRICON methodology is adequate for the neutron surveillance dosimetry analysis.