Radiation Shielding Analyses for the GUINEVERE Project

The VENUS-F facility of the GUINEVERE project must satisfy the nuclear safety criteria required by the licensing regulations of the Belgian authority. For this reason, radiation shielding analyses were performed at Forschungszentrum Karlsruhe (FZK) in the course of nuclear safety assessments in support of the GUINEVERE project. The Monte Carlo (MC) MCNP5 model was developed in accordance with the current design of the VENUS-F fast lead reactor. The reactor was assumed to operate on 500-W fission power, which is called zero power, with accelerator-driven system (ADS)-related experimental aims. The MC variance reduction techniques, such as particle splitting, Russian roulette, weight windows, and point detectors, were applied. To speed up the MCNP calculations, the advantages of message-passing interface parallel computations on FZK's CampusGrid Linux Cluster were employed. The MCNP track-length estimations, point detectors, and the mesh tally superimposed over the GUINVERE geometry were used in dose rate calculations. The neutron and photon maps of dose equivalent rate were produced in places of possible personnel access inside the reactor control room and on the accelerator room's floor. To obtain the dose equivalent, the neutron and photon fluences were converted by means of ICRP-77 and ANSI/ANS-6.1.1-1977 conversion factors, respectively. The contributions of the D-D and D-T fusion neutron sources to the dose rate fields were estimated. Activation analyses of the lead core and building materials were performed by the FISPACT-2005 inventory code with the EAF-2005 library to manage the radioactive materials after the series of ADS experiments in the GUINEVERE project. The activity density and shutdown contact dose rate have been calculated. The effect of the impurities in lead on its radioactivity after the VENUS-F campaign was examined.