Document: NUREG-0800
Document ID: a7fafe76-5570-446b-96dd-3e53ec9bccb3
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340663.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4
CFR Part: 
CFR Title: 

Content:
ran- sients, other possible xenon reactivity transients, and non-xenon- induced reactivity transients, are discussed in sufficient detail so that the reviewer can confirm for each item that the method of calcula- tion (e.g., nodal analysis, diffusion theory, transport theory, synthesis) and the number of spatial dimensions used (1, 2, or 3) are acceptable. f. Verification of the data base, computer codes, and analysis procedures has been made by comparing calculated results with measurements obtained from critical experiments and operating reactors. The reviewer ascertains that the comparisons cover an adequate range for each item and that the conclusions of the applicant are acceptable. 8. The analysis of neutron irradiation of the reactor vessel may be used in two ways. It may provide the design basis for establishing the vessel .material nil-ductility transition temperature as a function of the fluence, nvt. Or, it may provide the relative flux spectra at various positions between the pressure vessel and the reactor core so that the flux spectra for various test specimens may be estimated. This information is used in determining the reactor vessel material surveillance program requirements and pressure-temperature limits for operation under SRP Sections 5.3.2 and 5.3.3. CPB reviews the calculational method, the geometric modeling, and the uncertainties in the calculations under this SRP section. The review procedures for pressure vessel irradiation include determinations that: a. The calculations were performed by higher order theory than diffusion theory. b. The geometric modeling is detailed enough to properly estimate the relative flux spectra at various positions from the reactor core boundary to the pressure vessel wall. c. The peak vessel wall fluence for the design life of the plant is less than 1020 n/cm2 for neutrons of energy greater than 1 MeV. If the peak fluence is found to be greater than this value, the reviewers of SRP Sections 5.3.2 and 5.3.3 are