Japanese Hadron Project and shielding calculation

In the Japanese Hadron Project (JHP), a 1 GeV 200 μA proton beam will be handled, and the radiation shield of the facility will be very massive concrete and iron lump. Since the constructing cost is strongly affected by the shielding design, the design must be severely performed. Neutron yields in thin targets and a beam dump were calculated by the HETC-KFA-2 Monte Carlo code. Comparing the calculational results with experimental data, the calculated angular distribution of high energy neutrons was found to have stronger forwardness than the measurement. High energy neutron transport in thick iron and ordinary concrete slabs were calculated with the HETC code and also with the ANISN code. The difference of the shielding lengths calculated by these two codes was smaller than 6% for both cases. Induced radioactivity produced in cooling water was simply estimated, and it was found that the amount of 3H prevent from draining of the primary circuit water. The duct streaming of high energy neutrons was estimated for the case of a thermal neutron beam course shield at SINQ spallation neutron source facility of PSI, Switzerland. The intensity of streaming neutrons is strongly affected by the design of beam duct. (author)