Applicability Examination of PCM3D Method for YGN3 and YGN1 Nuclear Power Plants

In this report, the PCM3D method that is developed for a 3-D power synthesis method of SCOMS (SMART COre Monitoring System) is applied to the domestic commercial nuclear power plants and then its applicability is examined. The initial core (CY1) and the reload core of fuel cycle 7 (CY7) for YongGwang Nuclear Unit 3 (YGN3) and Unit 1 (YGN1) are selected for the applicability examination. For a systematic application of the PCM3D method, a PREPCM3D program that is a preprocessor of the PCM3D module to generate the PCM3D coefficient library and the signal detector is developed. Also, the User's Manual for the PREPCM3D program and the PCM3D module are produced. The 3-D power synthesis method and its library are verified through a base point test and a variation point test. The base point test is to verify the applicability of the 3-D power synthesis method, and the variation point test is to examine if the coefficients are functionalized adequately. The results of these tests are as follow: a. Base point test: ≤ Rounding Numbers in MASTER output file b. Variation test for YGN3 - Core Power level greater than 30 %: ≤ 1.5 %, ≤ 4.0 % - Core Power level less than 30 %: ≤ 4.0 %, ≤ 4.0 % c. Variation test for YGN1 - All the Core Power level: ≤ 2.5 %, ≤ 5.0 % where = Maximum error for 3-D node power distribution = Maximum error for 3-D nodewise peak pin power distribution The application results of the PCM3D method for the YGN3 and YGN1 can be summarized as: a. PREPCM3D program and PCM3D module work soundly. b. PCM3D method can be well applied to the other commercial plants. c. If the PCM3D method replaces the already established power distribution monitoring methods of the YGN3 and YGN1, it can contribute to the increase of the thermal margin due to the high accuracy in the power distribution