THE INFLUENCE OF OPTIMUM POWER LEVEL CHANGE ON BORATION AND DILUTION OPERATIONS

Xenon and samarium concentrations changes occur in a nuclear reactor a s a consequence of power level variations. To compensate for the react ivity introduced by these isotopes, the boron concentration in the rea ctor coolant also needs to be changed. Boron concentration changes res ult from boration or dilution operations. Both boration and dilution o perations have economic effects due to the cost of boric acid and the treatment of the effluent. A method is presented that finds the nuclea r power level change that leads to an optimization of the boration and dilution operations. The use of the method for practical applications is demonstrated by comparing the absolute reactivity change for the o ptimum power ramp and a ramp of +/- 3%/h. The numerical calculations a re very fast. Thus, the method may be implemented in the process compu ter of any nuclear power plant.