Document: NUREG-0800
Document ID: ddaa3c7d-ce79-4a3f-aaae-4e4436ab7bc1
Document Type: srp
Title: NUCLEAR DESIGN
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070740003.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.3
CFR Part: 
CFR Title: 

Content:
ave been developed for use in reactor analyses such as those for control requirements, stability, and transients and accidents. The reviewer examines: A. The applicability and accuracy of methods used for calculations including the use of more accurate check calculations. B. The models involved in the calculations, such as the model used for effective fuel temperature in Doppler coefficient analyses. C. The reactor state conditions assumed in determining values of the coefficients. For example, the PWR MTC to be used in the steamline break analysis is usually based on the reactor condition at end of cycle, with all control rods inserted except the most reactive rod, and the moderator temperature in the hot standby range. D. The applicability and accuracy of experimental data from critical experiments and operating reactors used to determine or justify uncertainty allowances. Measurements during startup and during the cycle of MTCs and full power Doppler coefficients in the case of PWRs, and results of measurements of transients during startup in the case of BWRs should be examined. As part of the review, comparisons are made between the values and uncertainty 4.3-14 Revision 3 - March 2007 allowances for reactivity coefficients for the reactor under review and those for similar reactors previously reviewed and approved. Generally, many essential areas will have been covered during earlier reviews of similar reactors. The reviewer notes any differences in results for essentially identical reactors and any lack of differences for reactors with changed core characteristics, and judges the significance and validity of any differences or lack of differences. E. The range of MTC values. The MTC should be non-positive over the entire fuel cycle when the reactor is at a significant power level. F. The appropriateness of reactivity coefficients used in evaluating reactivity accidents reviewed under SRP Sections 15.4.8 and 15.4.9. 4. The review procedures in the area of