Modelling of the Compton neutron detector Hf emitter burn-up in the core of WWER-1000

The Compton emission detectors with a Hf metal emitters were examined in this study. MCNPX software was used to simulate the behavior of emitter material during 4 fuel cycles in the core of the WWER-1000 reactor. The study considered 7 detectors located along the height of the core at the positions of the standard Rh detectors currently in use. Through the simulation for 7 SPDs, it was obtained the following sets of data: detailed nuclide composition; rates of (n, γ)-reaction for main nuclides; specific neutron losses; n- and γ-fluxes distribution; the emissive current from the Hf emitter.