Implications of SiC irradiation creep and annealing to UN-SiC fuel rod behavior

[摘要] The adoption of Accident Tolerant Fuels in the US will only likely be realized through improving economics of existing commercial reactors. For this reason, the Nuclear Energy Institute refers to such concepts as Advanced Technology Fuel. This work provides an insight into the performance of the fuel rod with high-density uranium-nitride (UN) pellet in silicon-carbide (SiC) composite cladding for a pressurized water reactor. The UN higher uranium density is one way to overcome the higher cost of SiC relative to current Zirconium based claddings. The material properties and irradiation behavior models of UN and SiC have been incorporated into the BISON fuel performance code. The modeling capability of BISON for SiC cladding is extended with irradiation creep and post-irradiation thermal annealing models. The fuel rod performance during normal operation is evaluated across three fuel cycles with each cycle 24-month long. Selected accident scenarios include a large-break loss-of-coolant accident and a station blackout accident where the potential effects of SiC irradiation creep and annealing rate are emphasized. This work motivates further experimental investigation on irradiation properties of dense UN, SiC irradiation creep and nonisothermal annealing. (C) 2020 Elsevier B.V. All rights reserved.

[发布日期] 2020-12-15

[关键词] Uranium nitride;SiC;Accident conditions;Irradiation creep;Annealing;Wigner energy release