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:
Vessel for Service Lcve C. A-S 0 V Un C4 0 0 .0 CdA T -o i'5 * PWR Vessel, Level C, High Toughness Plate R1=90 In, t=9 In, Axial Crack, ao0.9 In T=550-250[exp(-.1 tm)]°F, tm=20 minutes : J (Appliled Load, pi = 6.75 ksl) "1--43 :J-R Curve (CVNP= 108 ft-lb, T=4000F) -- : J (Applied Load, ph = 7.56 ksl) K K 0 a a v 0 0.2 0.3 0.4 Crack Extension (in) Figure A-5: Safety Margin Evaluation in a BWR Vessel for Sevice Level C. A-9 I • I.- I8 . 'C 8.93 Ii. td€. a 5/16 a.. (-60F0r. F-50 M. +.4 r C I-V). X Cý <-00 FlIV. <-0 Fltw. 0 . . . , , ,, , , , , , ,, , , , , Tftnllfly -Ise F 0 0.2 0.3 0.4 0.5 I Normalized Crack Depth (a/f) Figure A-6: Peak Thermal Stress Intensity Factors in a PWR Vessel for Transients with Several Different, but Constant. Cooldown Rates. K A-1O "APPENDIX B COMPUTATION OF STRESS INTENSITY FACTORS Information about computing transient temperature gradient across the vessel wall thickness, themal stresses, pressure, and thermal stress intensity factors (K.,, Kt) are provided in this Appendix as FORTRAN subroutines fiom the VISA-1 code. Additional details on the computational method, theory used, limitations, and names of the major variables used are available in NUREG/CR-4486' and NUREG/CR-3384.' The computer code provided in this Appendix is for general illustration only, to show how the cladding effects could be incorporated for thermal stresses and thermal sres intensity factors caused by differential fthemal expansion between the cladding and the base metal. i.censees should ensure that the computer codes they use include an idepth evaluation of ts effiects. A description of cladding-iduced thermal stress intensity factors is presented in Appendix A to NUREOICR-4486. Limitations of the stress intensity factor correction factors for finite length semi-elliptical surface flaws are indicated in Appendix C to NUREG/CR-4486. In developing these correction factors, only uniform membrane and linear bending stresses were considered. In addition, the