Document: 10 CFR Part 50
Document ID: a6c1b81f-bcf5-4ef9-9e8b-2a055aaed0aa
Document Type: cfr
Title: Fracture toughness requirements for protection against pressurized thermal shock events.
Source: 10 CFR Part 50
Source URL: https://www.ecfr.gov/current/title-10/part-50/section-50.61
Revision Date: 
Chapter: 
Section ID: 50.61
CFR Part: 50
CFR Title: 10

Content:
�F for welds and 8.5 °F for base metal; the value of σΔ need not exceed one-half of ΔRT NDT . ( iv ) The use of results from the plant-specific surveillance program may result in an RT NDT that is higher or lower than those determined in paragraph (c)(1). ( 3 ) Any information that is believed to improve the accuracy of the RT PTS value significantly must be reported to the Director, Office of Nuclear Reactor Regulation. Any value of RT PTS that has been modified using the procedures of paragraph (c)(2) of this section is subject to the approval of the Director, Office of Nuclear Reactor Regulation, when used as provided in this section. Table 1—Chemistry Factor for Weld Metals, °F Copper, wt-% Nickel, wt-% 0 0.20 0.40 0.60 0.80 1.00 1.20 0 20 20 20 20 20 20 20 0.01 20 20 20 20 20 20 20 0.02 21 26 27 27 27 27 27 0.03 22 35 41 41 41 41 41 0.04 24 43 54 54 54 54 54 0.05 26 49 67 68 68 68 68 0.06 29 52 77 82 82 82 82 0.07 32 55 85 95 95 95 95 0.08 36 58 90 106 108 108 108 0.09 40 61 94 115 122 122 122 0.10 44 65 97 122 133 135 135 0.11 49 68 101 130 144 148 148 0.12 52 72 103 135 153 161 161 0.13 58 76 106 139 162 172 176 0.14 61 79 109 142 168 182 188 0.15 66 84 112 146 175 191 200 0.16 70 88 115 149 178 199 211 0.17 75 92 119 151 184 207 221 0.18 79 95 122 154 187 214 230 0.19 83 100 126 157 191 220 238 0.20 88 104 129 160 194 223 245 0.21 92 108 133 164 197 229 252 0.22 97 112 137 167 200 232 257 0.23 101 117 140 169 203 236 263 0.24 105 121 144 173 206 239 268 0.25 110 126 148 176 209 243 272 0.26 113 130 151 180 212 246 276 0.27 119 134 155 184 216 249 280 0.28 122 138 160 187 218 251 284 0.29 128 142 164 191 222 254 287 0.30 131 146 167 194 225 257 290 0.31 136 151 172 198 228 260 293 0.32 140 155 175 202 231 263 296 0.33 144 160 180 205 234 266 299 0.34 149 164 184 209 238 269 302 0.35 153 168 187 212 241 272 305 0.36 158 172 191 216 245 275 308 0.37 162 177 196 220 248 278 311 0.38 166 182 200 223 250 281 314 0.39 171 185 203 227 254 285 317 0.40 175 189