Document: NRC Regulatory Guide
Document ID: 3df13dae-14ee-4f25-95b4-1cedf617ae15
Document Type: regulatory_guide
Title: Regulatory Guidance on the Alternate Pressurized Thermal Shock Rule + HISTORY - HISTORY 03/2015 – DG-1299 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1405/ML14056A011.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.230
CFR Part: 
CFR Title: 

Content:
mates (i.e., mean plus one standard deviation) based on generic data should be used. Step 2: Perform Statistical Assessments of the Surveillance Data For each material remaining after Step (1)(b)(ii), determine if each of the following three statistical tests are met: (a) Mean Test Paragraph (f)(6)(ii) of 10 CFR 50.61a requires that the licensee perform a statistical mean test. Licensees utilizing this guidance should perform the statistical mean test as follows: i. Determine the mean deviation from the data from the ETC using the following equation for each surveillance datum identified in Step 1: DG-1299, Page 8 ) ( 30 ) ( 30 predicted Measured T T r Δ − Δ = (8) where the measured ΔT30 represents the shift in CVN transition temperature at the 30 ft-lb energy level produced by irradiation for each datum identified in Step 1, and the predicted ΔT30 is estimated using Equation (5) and the best-estimate composition and exposure values for the plant from which the companion measured ΔT30 value was obtained. ii. Estimate the mean residual (rmean): { }  = = n i i mean r n r 1 1 (9) where n is the number of data points in the specific data set, iii. Estimate the maximum credible heat-average residual (rmax): 5.0 max 33 .2 n r σ = (10) where σ is from Table 2. iv. If rmean exceeds rmax, then the mean test is not satisfied; in this case proceed to Step 2(d). If rmean is less than or equal to rmax then the mean test is satisfied; in this case proceed to Step 2(b). Table 2. Standard Deviation of Residuals about Eq. (5). Product Form Standard Deviation (°F) Cu ≤ 0.072 wt % Cu > 0.072 wt % Weld 18.6 26.4 Plate 21.2 (a) Forging 19.6 a. Includes the standard reference materials. (b) Slope Test Paragraph (f)(6)(iii) of 10 CFR 50.61a requires that the licensee perform a statistical slope test. Licensees who utilize this guidance should perform the statistical slope test as follows: i. Using the method of least squares, estimate the slope of the ETC model residuals