Analysis of influence of fast neutron fluence irradiated to Beryllium element of The RSG-GAS reactor

Analysis of influence fast neutron fluence irradiated to the RSG-GAS beryllium reflector have been done. Methods of analysis was carried out by measuring fluxes neutron in beryllium element and block position that function as reflector.The calculation done for determination it is there any influence of neutron as long as beryllium in the core. Besides that, visualization done to make sure it there is any deformation at beryllium as effect of irradiation. Fluxes and fluences of beryllium element measurement result in 200 kW reactor power are 2.30E+07 n/cm².sec and 4.19E+17 n/cm² in position E-2, 3.70E+07 n/cm²s and 6.74E+17 n/cm² in position J-8, 2.19E+12 n/cm²s and 3.99E+22 n/cm² in position. Measurement results in the position B-3 are 2.12E+12 n/cm²s and 3.86E+22 n/cm² in position G-10 respectively. Other result are fluxes and fluence in beryllium block, those are 5,02E+07 n/cm²s and 9,15E+17 n/cm² in position (5-6), and 2,32E+07 n/cm²s and 4,23E+17 n/cm² in position (C-D). Deformation (L/L) results for beryllium element are 1,12E-08 in position E-2, 1,84E-08 in position J-8, 1,60E-03 in position B-3, and 1,55E-03 in position G-10. In beryllium block deformation results are 2,52E-08 in position (5-6) and 1,13E-08 in position (C-D). Those results are shown unseen deformation in beryllium element and beryllium block and demonstrably by visual observation in reactor hot cell. (author)