STATUS OF THE CONVERSION WORKING PLAN IN THE HIGH FLUX REACTOR (PETTEN, THE NETHERLANDS)

摘要

The conversion from HEU to LEU has often many disadvantages: flux penalties, increase of fuel consumption, cost and delay to obtain a new license, etc. But to fulfill the non-proliferation programme, and to simplify the future fuel supply, the HFR renewed in 1998 studies on conversion possibilities. To minimise the conversion costs, these studies were made with a progressive conversion that avoids the need of one new core and permits to begin the conversion with a replacement of 5 elements at each cycle. Hence the conversion can be made in 7 cycles, without special elements and with a normal burn-up for each element. To avoid an increase of fuel consumption, an increase of the fuel cycle length from 24.7 to 28.3 days was also considered. This point allows to reduce the number of annual cycles from 11 to 10 and enables in one cycle to have the possibility of four successive irradiations for Molybdenum production (7 days) in one irradiation position. A working plan for fuel licensing has been sent to the safety authorities and is presented in the paper.