Determination of BWR minimum steam cooling reactor water level and associated steam flow using MAAP4 code

作者：Chen Jyh Jun; Wang Shih Jen^*; Chien Chun Sheng; Chiang Kuan Shen; Teng Jyh Tong

来源：Nuclear Engineering and Design, 2010, 240(11): 3791-3796.

DOI：10.1016/j.nucengdes.2010.08.019

The minimum steam cooling reactor pressure vessel (RPV) water level (MSCRWL) is defined to be the lowest RPV water level at which the covered portion of the core is capable of generating sufficient steam to preclude peak cladding temperature (PCT) in the uncovered portion of the core from exceeding 1500 F. The associated steam flow rate is called Wg-1500. Both MSCRWL and Wg-1500 are important parameters for safe operation of nuclear power plant. In the past, the calculations of MSCRWL and Wg-1500 were calculated by indirect way via simple model and provided by the vendor. It has to be revised quite often during the operation period of nuclear power plant. The process is time-consuming. To improve the situation, a direct and easy method of generating MSCRWL using MAAP4 code by the utilities in conjunction with the proportional and integral (PI) controller is developed in this study. The developed control loop with a PI controller is capable of generating the MSCRWL in a fast and precise manner. The MSCRWL and Wg-1500 are calculated simultaneously by controlling the PCT equal to 1500 degrees F. Furthermore, the adjusting process is done automatically and readily with this methodology. The effect of feedwater inlet temperature is taken into account via thermal kits of the balance of plant system. The calculated MSCRWL is consistent with the calculated Wg-1500. The sensitivity study of power level and power shape are performed. For a given power shape, the MSCRWL is less sensitive to the power level. However, Wg-1500 is almost proportional to the power level. This information is helpful for the associated EOP application. This technique can be applied for other system codes.

• 出版日期2010-11