Document: NUREG-0800
Document ID: a2d035da-992b-42e8-894f-787a019b437d
Document Type: srp
Title: NUCLEAR DESIGN
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070410.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.3
CFR Part: 
CFR Title: 

Content:
which is described in Reference 1, entails (1) establishing an envelope of allowed power shapes and power densities, (2) devising an operating strategy for the cycle which maximizes plant flexibility (maneuvering) and minimizes axial power shape changes, (3) demonstrating that this strategy will not result in core conditions that violate the envelope of permissible core power characteristics, and (4) demonstrating that this power distribution control scheme can be effectively supervised with excore detectors. Westinghouse argues that point 3, above, is achieved by calculating all of the load-follow maneuvers planned for the proposed cycle and showing that the maximum power densities expected are within limits. These calculations are performed with a radial/axial synthesis method which has been shown to predict conservative power densities when compared to experiment. While we have accepted CAOC on the basis of these analyses, we have also required that power distributions be measured throughout a number of representative (frequently, limiting) maneuvers early in cycle life to confirm that peaking factors are no greater than predicted. DRAFT Rev. 3 - April 1996 4.3-20 Additionally, we are sponsoring a series of calculations at BNL to check aspects of the Westinghouse analysis. The power distribution measurement tests described above will, of course, automatically relate incore and excore detector responses, and thereby validate that power distribution control can be managed with excore detectors. B. BRANCH TECHNICAL POSITION An applicant or licensee proposing CAOC for other than F = 2.32 and WI = ±5% is expected to Q provide: 1. Analyses of F x power fraction showing the maximum F (z) at power levels up to 100% Q Q and DNB performance with allowed axial shapes relative to the design bases for overpower and loss of flow transients. The envelope of these analyses must be shown to be valid for all normal operating modes and anticipated reactor conditions. (See Table 1