A5022244558- Nuclear reactor physics and engineering
- Nuclear Materials and Properties
- Graphite, nuclear technology, radiation studies
- Nuclear Physics and Applications
- Nuclear and radioactivity studies
- Radiation Shielding Materials Analysis
- Radiation Detection and Scintillator Technologies
- Thermal and Kinetic Analysis
- Chemical Synthesis and Characterization
- Radioactive contamination and transfer
- Radioactive element chemistry and processing
Japan Atomic Energy Agency
2018-2025
Futaba (Japan)
2022
We investigated the possibility of estimating effective neutron multiplication factor (keff) fuel debris inside canister and primary containment vessel (PCV) Unit 2 Fukushima Daiichi Nuclear Power Station (1F) using remote gas-radioactivity measurement via Monte Carlo simulation-based calculations. Our results demonstrate an almost linear correlation between keff 88Kr-to-135Xe activity ratio with respect to various compositions. This is maintained regardless geometries such as PCV.
In order to evaluate three-dimensional distributions of radionuclides with high precision from gamma-scanning profiles adsorption vessels used for decontamination radioactive water performed at severe accidents, gamma scanning the submerged demineralizer system vessel Three Mile Island Unit 2 (TMI-2) accident was simulated in axial and radial directions real cylindrical-shaped using a Monte Carlo calculation code [Particle Heavy Ion Transport Code System (PHITS)].In simulation, true...
Prediction of the fuel debris location and distribution inside primary containment vessel (PCV) Fukushima Daiichi Nuclear Power Station is important to decide further decommissioning step strategy. The radiation measurements in past internal investigations have not yet provided enough information predict its PCV. To support measurement efforts, we simulate detector response PCV finding possible gamma unique debris. calculation result could provide useful for future developments.
Modification of the Monte Carlo depletion calculation code OpenMC was performed to enable subcritical neutron multiplying system. With modified code, it became possible evaluate quantity short half-life fission products from spontaneous and induced fissions in As a preliminary study, applied fuel debris storage canister filled with nuclear materials nuclides. It confirmed that could successfully provide (FPs) over time relationship between activity ratio 88Kr 135Xe effective multiplication...