New long-cycle small modular PWR cores using particle type burnable poisons for low boron operation

Autor: Hoseong Yoo, Dae Hee Hwang, Ho Choel Shin, Ser Gi Hong
Rok vydání: 2017
Předmět:
Zdroj: Nuclear Engineering and Design. 314:173-181
ISSN: 0029-5493
DOI: 10.1016/j.nucengdes.2017.01.020
Popis: In this paper, new small long-cycle PWR (Pressurized Water Reactor) cores for low boron concentration operation are designed by employing advanced burnable poison rods (BPRs) in which the BISO (Bi-Isotropic) particles of burnable poison are distributed in a SiC matrix. The BPRs are designed by adjusting the kernel diameter, the kernel material and the packing fraction to effectively reduce the excess reactivity in order to reduce the boron concentration in the coolant and achieve a flat change in excess reactivity over a long operational cycle. In addition, axial zoning of the BPRs was suggested to improve the core performances, and it was shown that the suggested axial zoning of BPRs considerably extends the cycle length compared to a core with no BPR axial zoning. The results of the core physics analyses showed that the cores using BPRs with a B 4 C kernel have long cycle lengths of ∼4.5 EFPYs (Effective Full Power Years), small maximum CBCs (Critical Boron Concentration) lower than 370 ppm, low power peaking factors, and large shutdown margins of control element assemblies.
Databáze: OpenAIRE