Abstract
The concrete biological shield (CBS) of light water reactors is exposed to high neutron radiation dose in the long term, which may lead to the degradation of the concrete's mechanical properties. Given the important shielding role of the CBS, it is necessary to investigate the irradiation effects at the structural scale and provide estimates of the damage extent from the wall's inner surface to study potential license renewals. For this purpose, we developed a mechanical model accounting for radiation-induced expansion, creep, and damage in concrete using the Grizzly finite element code, informed by ex-core neutron flux calculations using the VERA tool. The model was applied to a 3D CBS structure represented by the CBS wall, a steel liner, reinforcement bars, and a concrete base mat and evaluated damage at 40, 60, and 80 years of operation. The VERA model predicted a maximum fluence of approximately 2×1019 n cm−2 at 80 years of operation. The results showed that damage is highest at the inner surface of the CBS wall and gradually decreases with depth. It extends beyond the rebar after 60 years and reaches a depth of approximately 12 cm at 80 years.
Original language | English |
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Article number | 112217 |
Journal | Nuclear Engineering and Design |
Volume | 405 |
DOIs | |
State | Published - Apr 15 2023 |
Funding
This work is supported by the US Department of Energy, Office of Nuclear Energy, Nuclear Energy Advanced Modeling and Simulation (NEAMS) under contract number DE-AC05-00OR22725 and the Effects of Irradiation on Bond Strength in Concrete Structures project ( 31310018S0021 ) of the US Nuclear Regulatory Commission. This research made use of Idaho National Laboratory (INL) computing resources which are supported by the Office of Nuclear Energy of the US Department of Energy and the Nuclear Science User Facilities under Contract No. DE-AC07-05ID14517. The authors would especially like to thank the INL High-Performance Computing Team for their efforts in supporting these calculations on Lemhi and Sawtooth. The authors also thank Dave J. Kropaczek (ORNL) and Nathan A. Capps (ORNL) for supporting this work. Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Funders | Funder number |
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Nathan A. Capps | |
Oak Ridge National Laboratory | |
U.S. Department of Energy | |
Idaho National Laboratory | |
Office of Nuclear Energy | |
Not added | 900012 |
Nuclear Energy Advanced Modeling and Simulation | 31310018S0021, DE-AC05-00OR22725 |
U.S. Nuclear Regulatory Commission | DE-AC07-05ID14517 |
Keywords
- Biological shield
- Concrete degradation
- Radiation transport
- Structural model