Document: NRC Regulatory Guide
Document ID: 5f4d6577-6c2a-473a-9a76-4033a95dba4c
Document Type: regulatory_guide
Title: Radiation Embrittlement of Reactor Vessel Materials (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740284.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.99
CFR Part: 
CFR Title: 

Content:
57 290 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 0.40 175 189 207 231 257 288 320 fluence that fits the plant surveillance data in such a way as to to obtain mean values of shift, ARTNDT· In calculating the margin, minimize the sum of the squares of the errors. the value of a A may be reduced from the values given in the last paragraph of Regulatory Position 1.1 by an amount to be decided To calculate the margin in this case, use Equation 4; the values on a case-by-case basis, depending on where the measured values given there for a}. may be cut in half. fall relative to the mean calculated for the surveillance materials. If this procedure gives a higher value of adjusted reference temperature than that given by using the procedures of Regulatory 2.2 Charpy Upper-Shelf Energy Position 1.1, the surveillance data should be used. If this procedure gives a lower value, either may be used. The decrease in upper-shelf energy may be obtained by plot- ting the reduced plant surveillance data on Figure 2 of this guide For plants having surveillance data that are credible in all respects and fitting the data with a line drawn parallel to the existing lines except that the material does not represent the critical material in as the upper bound of all the data. This line should be used in the vessel, the calculative procedures in this guide should be used preference to the existing graph. 1.99-4 TABLE 2 CHEMISTRY FACTOR FOR BASE METAL, °F Copper, Wt-% 0 0.20 0.40 0 20 20 20 0.01 20 20 20 0.02 20 20 20 0.03 20 20 20 0.04 22 26 26 0.05 25 31 31 0.06 28 37 37 0.07 31 43 44 0.08 34 48 51 0.09 37 53 58 0.10 41 58 65 0.11 45 62 72 0.12 49 67 79 0.13 53 71 85 0.14 57 75 91 0.15 61 80 99 0.16 65 84 104 0.17 69 88 110 0.18 73 92 115