ML24200A052
| ML24200A052 | |
| Person / Time | |
|---|---|
| Site: | 07109297 |
| Issue date: | 07/31/2024 |
| From: | Westinghouse, Westinghouse |
| To: | Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML24200A049 | List: |
| References | |
| LTR-LCPT-24-27 | |
| Download: ML24200A052 (1) | |
Text
Westinghouse Electlic Company Traveller Safety Analysis Repo11 Westinghouse Non-Proprietary Class 3 2.12.9 Zirconium Alloy Performance During Testing Docket No. 71-9297 Rev. 16, 7/2024 The choice of Standard Zirconium Alloy used dming Traveller drop testing was based upon the energy absorbing capabilities the fuel cladding material used during constrnction of the fuel assemblies. The name Alloy is a generic naming convention because of the proprietary nature of these materials. Cladding may include perfo1mance features of chromium coating and/or an Optimized ZIRLO Liner (OZL) to enhance in reactor fuel perfo1mance. These cladding features ar*e in addition to the base cladding mate1ial. All Alloys ar*e compared to the Standar*d Zirconium Alloy when conside1ing their strnctural perfo1mance, specifically the strain energy absorption capability up to failure dming a 9-meter drop test, which demonstrates Standard Zirconium Alloy bounds all other Alloys. Table 2-58 compares all the Alloys' strain energy absorption capability up to failure to the HAC tested Standard Zirconium Alloy, and includes Alloy 1 (Optimized ZIRLO),
Alloy 2, Alloy 3, Alloy 4, Alloy 5, chromium-coated Alloy 1 (Optimized ZIRLO), chromium-coated Alloy 2, and lined Alloy 1 (Optimized ZIRLO), known as OZL. Since base cladding ductility dete1mines expected fuel cladding mechanical response up to cladding failure, Alloys 1-5 without perfo1mance features, or those claddings that are chome-coated, lin ed, oxide-coated, or any combination of those features are bounded by the tested Standard Zirconium Alloy cladding, as the other alloys ha.ve higher energy abso1ption capability. Thus, any combination of the evaluated cladding perfo1mance features are pe1mitted contents. As the base cladding defines the required cladding content specification, chemical or galvanic reactions with the existing packaging mate1ials is evaluated and discussed in Section 2.2.2.
As Table 2-58 shows the tested Standard Zirconium Alloy is the least ductile of the nine zirconium alloys considered including the chrome coated cladding and cladding with the inner liner. The failure of Standar*d Zirconium Alloy occurs at a much lower total strain energy than the other alloys making it the most susceptible to mechanical failure. Although the specification minimum tensile yield and ultimate stresses, as well as resilience strain energy, ar*e greatest for the Standard Zirconium Alloy, its elongation at fracture is less than the other alloys. By viitue of ha ving less ductility at fracture compared to the other alloys, Standar*d Zirconium Alloy possesses less total energy abso1ption capability compared to the more ductile Alloys 1-5 as well as chrome coated and OZL claddings.
Table 2-58 Fuel Rod Strain Energy Absorption Using Minimum Tensile Mechanical Properties Alloy Minimum Strain Energy (psi - in/in)
Yield Strength Resilience Failm*e Standard Zirconium Alloy 201 208 263 Alloy I 177 162 683 Alloy 2 141 102 1266 Alloy 3 126 81 1159 Alloy 4 141 102 1282 Alloy 5 141 102 1224 Alloy I (Optimized ZIRLO) 177 162 720 with Chrome Coating Alloy I (Optimized ZIRLO) 161 133 29924 with Liner Alloy 2 with Chrome 141 102 601 Coating 2-248