Aspects regarding the fuel management for PHWR nuclear reactor

Fuel management for the PHWR nuclear reactor (natural uranium -D2O) is completely different from the PWR reactor fuel management. PHWR reactor fuel loading procedures are repeated after an interval of time, as defined and specified in the project documentation, using a fuel machine that can be attached to the terminal fittings of horizontal pressure tubes while the reactor is at full power. Another aspect of fuel management policy is related to the possibility of bi-directional loading of the reactor, with the primary advantage of uniform and symmetrical characteristics. The fuel manipulation process of a PHWR reactor can be optimized using the dynamic simulation program. To know and minimize the Xenon concentration consequences when the reactor is shut down, a calculation code was built. The results were used to determine the optimal enrichment of the fuel, the techniques of poison control and the core minimum volume in order to get maximum power. (authors)