Measurement and Calculation of Gamma radiation from HWZPR Reactor

摘要

HWZPR is a research reactor with natural uranium fuel, D_2O moderator and graphite reflector with maximum power of 100 W. It is a suitable means for theoretical research and heavy water reactor experiments. Neutrons from the core participate in different nuclear reactions by interactions with fuel, moderator, graphite and the concrete around the reactor. The results of these interactions are the production of prompt gammas in the environment. Useful information is gained by the reactor gamma spectrum measurement from point of view of relative quantity and energy distribution of direct and scattered radiations. Reactor gamma ray spectrum has been gathered in different places around the reactor by HPGe detector. In analysis of these spectra, ~1H(n,γ)~2H, ~(16)O(n,n'γ)~(16)O,rn~2H(n,γ)~3H and ~(238)U(n,γ)~(239)U reactions occurring in reactor moderator and fuel, are important. The measured spectrum has been primarily estimated by the MCNP code. There is agreement between the code and the experiments in some points. The scattered gamma rays from ~(27)A1 (n,γ) (28)A1 reaction in the reactor tank, are the most among the gammas scattered in the reactor environment. Also the dose calculationsrnby MCNP code show that 72 % of gamma dose belongs to the energy range 3-11 MeV from reactor gamma spectrum and the danger of exposure from the reactor high-energy photons is serious.