Document: NRC Regulatory Guide
Document ID: 2704425a-c58a-45c4-93ab-8761721c3e7a
Document Type: regulatory_guide
Title: Evaluation of Reactor Pressure Vessels with Charpy Upper-Shelf Energy Less Than 50 Ft-Lb
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740038.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.161
CFR Part: 
CFR Title: 

Content:
lues for both orientations may not be known. ff the CVN value for the T-L (weak) orientation is not available, the L-T (strong) orientation CVN value may be multiplied by a factor of 0.65 (Ref. 18) to obtain the CVN value for the T-L (weak) orientation. However, if the CVN value for the T-L (weak) orientation is known and the L-T (sdrug) orientation is to be estimated, the CVN value for the L-T (strong) orientation is assumed to be the same as that of the T-L (weak) orientation. 3.3.1 High-Toughness Model (S < 0.018 Wt-%) For plate material with sulphur content greater than 0.018 wt-%, the use of this model should be justified as discussed above. For analyses addressing Service Levels A, B, and C, a conservative representation of the J-R curve is obtained by setting the margh fctor, MW = 0.749. For analyses addressing Service Level D, set MF - 1.0. CI = exp[-2.44+1.13 ln(C/WA)-0.0027771 C2 = 0.077 + 0.116 InCl C0 = -0.0812 - 0.0092 InCl C4 = -0.409 (26) (27) (28) (29) 1.161-9 DEFINITION OF ASME AND ASTM ORIENTATIONS "WEAK" DIRECTION ASME TRANSVERSE ASTM T-L RPV CIRC. FLAW "STRONG" DIRECTION ASME LONGITUDINAL ASTM L-T RPV AXIAL FLAW K Figure 2. DefInition of the ASNM and ASIh Flaw Oricntations in an RPV. 1.161-10 3.3.2 Low-Toughness Plate (S k 0.018 Wt-%) For analyses addressing materials with a sulphur content greatcr than 0.018 wt-%, the J-R curve data are scarce. Very > limited J-R data for a 6-inch-thick specimen (ASTM 6T CT at 180I' temperature) from an A-302B plate in the T-L (weak) orientation, avaiable in NUREOGCR-5265 (Ref 15), may be used with adjustments for the specimen temperature and CVN value (Ref. 19), or a material-specificjustification should be provided to support the use of other data. For analyses addressing Service Levels A, B, and C, a lower bound reptwentation (mean - 2 standard deviations) of the J-R curve should be used. For analyses addressing Service Level D, the mean value of the J-R curve should be usecd Additional J-R curve test data