Radiation-Induced Volumetric Expansion and Temperature Effects on the Structural Integrity of Concrete Biological Shield Wall
Year: 2024
Type: article
Abstract: This study assesses the structural integrity of concrete biological shield (CBS) walls in nuclear power plants, considering the effects of radiation-induced volumetric expansion (RIVE).The research focuses on the impact of neutron irradiation on concrete material properties, particularly in the context of extending nuclear power plant lifespans beyond their original operating license period.This study outlines a method to estimate neutron fluence levels in CBS walls using data from reactor pressure vessel surveillance programs.It describes the process of calculating fluence attenuation starting from the inside surface of the reactor pressure vessel (RPV) to the CBS wall outside and presents a model for radiation-induced volumetric expansion (RIVE) in concrete.The effect of temperature rise of the CBS wall during the operation is considered in addition to the RIVE effects because the stress state of the CBS wall can be affected by elevated temperature.A finite element analysis was conducted to evaluate the effects of RIVE and temperature on the CBS wall structure.The results indicate that compressive stresses in the inner region of the CBS wall can exceed the compressive strength limit of the concrete, while tensile stresses in the outer region may lead to cracking.The stress distribution shows an increasing trend with accumulated neutron fluence over time.The temperature also affects the stress state of the CBS wall but its influence is not that significant compared to the effect of RIVE because the level of thermal strain and its gradient through CBS wall is less than those of RIVE.Further research considering more practical geometries, fluence distributions, and the inclusion of reinforcing rebar elements in CBS wall models will be performed and the assessment of radiation effects on reactor pressure vessel support structures and anchor systems will also be considered in the future.
Authors: Jinbok Choi, Daegi Hahm
Language: English
Subfield: Safety, Risk, Reliability and Quality
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4405982407