The Gamma Ray Spectra Measurement in Reactor Pressure Vessel Simulator in WWER-1000 Engineering Benchmark

The space - energy distribution of the mixed neutron - photon radiation field has been measured over the Reactor Pressure Vessel (RPV) simulator thickness in the WWER-1000 engineering benchmark assembly in the LR-0 experimental reactor (in Nuclear Research Institute Řež plc) with a scintillation spectrometer. The spectra have been measured before the RPV in one quarter, one half, and three quarters of its thickness and behind the RPV in the energy range 0.5 - 10 MeV. The evaluated integral fluxes above 1 MeV and their ratio are compared with the MCNP and DORT calculation, the measured spectra are presented graphically. The measurements are being performed in the frame of the project REDOS [1], 5^th Framwork Programme of the European Community 1998 - 2002.