Research on Industrial Validation of VVER-1000 Based on PWR Core Physics Analysis Code Bamboo-C

This study aims to achieve precise physical analysis of VVER-1000 nuclear reactors. Based on Bamboo-C, an advanced PWR core physical analysis software developed by Xi'an Jiaotong University, a thorough methodological study is carried out. The research encompasses: in the aspect of assembly calculation, methods based on Constructive Solid Geometry (CSG) for hexagonal transport calculations and detailed modeling techniques for heavy reflector layers were studied; in core calculation, a method combining conformal mapping and nonlinear iterative strategies for hexagonal fuel assembly neutron diffusion was investigated. Using Bamboo-C, modeling calculations were performed for three consecutive fuel cycles of start-up physical experiments and power operations of a specific VVER-1000 unit, followed by a comparative analysis with actual measured data. The results indicate: ①In the start-up physical tests, the average error of critical boron concentration is −5.0ppm (1ppm=10^–6); the average errors of the moderator temperature coefficient and the isothermal temperature coefficient are 0.3 pcm/K and 0.9 pcm/K(1pcm=10^–5), respectively; the average error of the boron worth is −5.0%; and the average error in control rod worth is −7.8%. ②During power operations, the average errors of critical boron concentration for three cycles were −2.3ppm, −18.9ppm, and −7.8ppm, respectively; the average errors in the core power distribution for the three cycles were −0.010 (for assembly relative power greater than 1) and 0.012 (for assembly power less than 1). Therefore, Bamboo-C software meets the industrial threshold requirements for calculation errors of key physical quantities in the VVER-1000 reactor core, demonstrating its capability for engineering application.