Implementation of assembly shuffling for maximizing fuel utilization in the VVER-1200 reactor

IF 1.9 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Nuclear Engineering and Design Pub Date : 2025-02-07 DOI:10.1016/j.nucengdes.2025.113901

Afroza Shelley , H. Rainad Khan Rohan , Md. Abidur Rahman Ishraq

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引用次数: 0

Abstract

This study aims to maximize reactor fuel utilization by employing assembly shuffling instead of traditional refueling. A homogeneous VVER-1200 core containing 163 fuel assemblies (4.95 wt.% enriched) and excluding control rods/absorber banks is taken as the reference and burnt for 950 EFPDs. It is found that the discharge burnup of the central 54 fuel assemblies (Zone-1) is 41.2 MWD/kg, the middle 55 assemblies (Zone-2) is 36.9 MWD/kg, and the outermost 54 assemblies (Zone-3) is 27.5 MWD/kg. Burnup of Zone-3 increased by 27.4% after interchanging fuel assemblies with those of Zone-1 at 500 EFPD, which is considered as the first cycle. Simultaneously, the k_eff jumped from 1.093 to 1.151, maintaining criticality up to 900 EFPD. However, further interchange of assemblies among the zones did not improve k_eff significantly. The fuel and moderator temperature coefficients at BOL were −1.898 pcm/K and −58.106 pcm/K respectively, and these became more negative through shuffling, especially towards the end of core life. Despite an immediate rise in radial power peaking factor, the assembly-wise linear power distribution became more uniform as burnup progressed. The beta-effective peaked immediately after shuffling but declined gradually afterwards. Although 1.16% rise in fissile ²³⁹Pu was observed in the discharged fuel, the total quantity of minor actinides and long-lived fission products decreased by 1.63%.

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来源期刊

Nuclear Engineering and Design 工程技术-核科学技术

CiteScore

3.40

自引率

11.80%

发文量

377

审稿时长

5 months

期刊介绍： Nuclear Engineering and Design covers the wide range of disciplines involved in the engineering, design, safety and construction of nuclear fission reactors. The Editors welcome papers both on applied and innovative aspects and developments in nuclear science and technology. Fundamentals of Reactor Design include: • Thermal-Hydraulics and Core Physics • Safety Analysis, Risk Assessment (PSA) • Structural and Mechanical Engineering • Materials Science • Fuel Behavior and Design • Structural Plant Design • Engineering of Reactor Components • Experiments Aspects beyond fundamentals of Reactor Design covered: • Accident Mitigation Measures • Reactor Control Systems • Licensing Issues • Safeguard Engineering • Economy of Plants • Reprocessing / Waste Disposal • Applications of Nuclear Energy • Maintenance • Decommissioning Papers on new reactor ideas and developments (Generation IV reactors) such as inherently safe modular HTRs, High Performance LWRs/HWRs and LMFBs/GFR will be considered; Actinide Burners, Accelerator Driven Systems, Energy Amplifiers and other special designs of power and research reactors and their applications are also encouraged.