Document: NRC Regulatory Guide
Document ID: 0d99822b-1af0-41be-a088-75b961301b4f
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:
f r*1 ≤ rLIMIT(1) and r*2 ≤ rLIMIT(2) then the dataset satisfies the outlier test; otherwise it does not. In either case proceed to Step 2(d). DG-1299, Page 11 Table 4. α = 1% Threshold Value for the Outlier Test. n rLIMIT(2) rLIMIT(1) 3 1.55 2.71 4 1.73 2.81 5 1.84 2.88 6 1.93 2.93 7 2.00 2.98 8 2.05 3.02 9 2.11 3.06 10 2.16 3.09 11 2.19 3.12 12 2.23 3.14 13 2.26 3.17 14 2.29 3.19 15 2.32 3.21 17 2.37 3.24 26 2.53 3.36 64 2.83 3.62 (d) Outcome of Step 2 i. Assessment: If all surveillance materials meeting the data quantity requirements of Step (1)(b)(ii) satisfy all three statistical surveillance tests of Steps (2)(a), (2)(b), and (2)(c), then the RTMAX-X screening criteria in Table 1 of 10 CFR 50.61a can be used without modification. The values of ΔT30 used in estimating the RTMAX-X values should be based on the ETC defined by Equation (5) using best-estimate input values for the plant and plant materials being assessed, and should not be modified based on surveillance data. In the event that any of the statistical tests in Steps (2)(a), (2)(b), and (2)(c) are not satisfied, 10 CFR 50.61a stipulates that: … the licensee shall review the data base for that heat in detail, including all parameters used in [the ETC] and the data used to determine the baseline Charpy V-notch curve for the material in an unirradiated condition. The licensee shall submit an evaluation of the surveillance data to the NRC and shall propose ΔT30 and RTMAX-X values, considering their plant-specific surveillance data, to be used for evaluation relative to the acceptance criteria of this rule. These evaluations must be submitted for review and approval by the Director in the form of a license amendment… The following guidance provides information for these additional evaluations. ii. Factors to Consider When the Step 2 Statistical Test are not Satisfied: When any of the statistical tests are not satisfied, values of ΔT30 predicted using Equation (5) may under-estimate the