Westinghouse has developed EnCore® Fuel, an Advanced Technology Fuel that has the potential to significantly increase the tolerance for nuclear reactor severe accident scenarios. This technology could be “game changing” for the nuclear industry, with the capability of improving nuclear plant safety and reliability, and with the potential to provide financial savings to the utilities that operate the plants. Westinghouse and Exelon are jointly pursuing a Lead Test Rod (LTR) program to begin irradiation in Byron Unit 2 Cycle 22. The LTR program will include up to twenty (20) lead test rods (LTRs) of the 17x17 Optimized Fuel Assembly (OFA) design with coated Optimized ZIRLOTM fuel rod cladding along with the fuel reload for Byron Unit 2 Region 24. Four (4) LTRs will contain uranium silicide pellets. Up to 16 rods will have coated cladding. Four (4) rods will contain ADOPTTM pellets. Oxidation resistant chromium coatings have been applied to ZIRLO® and Optimized ZIRLOTM cladding tubes using a cold spray process. Application parameters for cold spray have been optimized to achieve dense and adherent coatings, while polishing processes have been developed to achieve the thickness and surface finish required for in-reactor performance and seamless integration into current fuel designs, without a need for fuel assembly structure modifications. Optimized coatings have been subjected to extensive testing simulating normal operation and accident conditions, including corrosion in pressurized water, high temperature corrosion in steam, crud deposition, and mechanical testing. The effect of surface imperfections and scratches is being evaluated. Cold spray deposits particles and produces coatings in solid state, eliminating the need for controlled atmospheres, which has enabled the scalability of the process for full length tubes. The proposed Westinghouse accident-tolerant fuel pellet design is also expected to deliver improved fuel cycle economics as a result of the higher density and thermal conductivity of the uranium silicide (U3Si2) fuel pellets. Significantly more U can be packed into the same volume as uranium dioxide (UO2), enabling longer fuel cycles while staying below the five percent enrichment limit that is the design basis for many operating plants. In addition, third feature of the LTR program, ADOPTTM pellets are high density UO2 pellets that enable higher U assembly loading, have lower fission gas release during transients and less washout from secondary failures. At high temperatures observed during ramp tests they are also softer than UO2 which increases the PCI failure threshold [1]. Westinghouse-Exelon EnCore LTR program will thus demonstrate integrated performance of three ATF features. The EnCore LTR Accident Tolerant Fuel program, hence, paves the way to make safer fuel and with improved economics. Westinghouse Non‐Proprietary Class 3 WAAP‐10756
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