Document: NRC Regulatory Guide
Document ID: a2b67b51-f5fe-4c86-a879-f0e439601f7f
Document Type: regulatory_guide
Title: Format and Content of Report for Thermal Annealing of Reactor Pressure Vessels
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740052.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.162
CFR Part: 
CFR Title: 

Content:
ertainties in the values of RTNDT(U), nickel and copper content, fluence and the calculational procedures, as determined from Equation 8. M - 2 Ja12 + a,2 (Equation 8) where al = standard deviation of RTNDT(U) in OF, =a = standard deviation of ARTNDT in OF. From Revision 2 of Regulatory Guide 1.99 (Ref. 21), VA is 17°F for base metals and aA is 28*F for weld metals. Further, ARTNDT is given by: ARTNDT = (CF) (f)(0.28 - 0.10 log f) (Equation 9) where CF chemistry factor (in OF) based on the nickel and copper content of the material, or based upon results from the surveillance program if the program is "credible" according to the criteria in the PTS rule (10 CFR 50.61), and f = the best-estimate neutron fluence (in units of 1019 n/cm 2, E > 1 MeV), at the clad-base metal interface on the inside surface of the vessel. For reembrittlement, the lateral shift is accom plished by determining the "transition recovery flu ence," ft, by solving for the fluence value that satisfies Equation 10: RTNDT(A) - RTNDT(U) = (CF) (fl) (0.28 - 0.10 log ft) (Equation 10) where RTNDT(A) is the reference temperature, RTNDT, of the material in the post-anneal condition. 1.162-14 K LATERAL SHIFT METHOD Fluence (n/cm2, E > 1 MeV) LATERAL SHIFT METHOD Ruence (nIcr2, E > I MoV) Figure 1 1.162-15 wI For reembrittlement, the reference temperature (RTNDT) is evaluated by RTNDT = RTNDT(U) + ARTNDT + M (Equation 11) where ARTNDT = the mean value of the shift in reference temperature caused by irradiation (as given below by Equation 12) in OF, and M = margin term in OF to account for uncertainties in the values of RTNDT(U), nickel and copper content, fluence, and the calculational procedures, as given by Equation 13. ARTNDT = (CF) (f + ft)[0.28 - 0.10 log (f + ft)] (Equation 12) where CF = the same chemistry factor (in OF) used for the pre-anneal operating period, based on the nickel and copper content of the material or the results of the "credible" surveillance program, f f the increment of