Fast Neutron Flux Calculation of Welding Line in Pressure Vessel of High Flux Engineering Test Reactor

This paper calculated the fast neutron flux of some places in different HFETR cores,such as the 13^rd ion chamber and L12 fuel rod in the 1^st core,the 12^nd ion chamber and the 1QS ion chamber in the 68^th –II core.Comparison of the calculated and the experimental results was made.It showed that the result was accurate.And we also chose different cores to get the fast neutron fluence of welding line in the reactor pressure vessel of HFETR up to 2004.The result was 1.212×10¹⁷cm^-2（^E≥1MeV） and 2.514×10¹⁷cm^-2（^E≥0.1MeV）.It showed that the maximum fast neutron fluence was less than the design data so far.