236U Compensation in Recycled Uranium Fuel for the VVER Reactors
Compensation problem of 236U initial content in recycled uranium fuel for VVERs is considered. The calculation method for fuel compensative additional 235U enrichment is proposed. It is proved that a compensative enrichment can be well approximated by a linear function of 236U content in fuel. Approximation coefficients linearly depend on the effective fuel enrichment. After the compensation performed by the proposed method, the multiplication properties of fuel assembly with both natural and recycled uranium fuel show little difference in the course of a fuel cycle. Therefore, for the purpose of recycled fuel safety it is possible to utilize the same safety margin as in case of the natural uranium fuel.