Document: NUREG-0800
Document ID: 7ed30441-8f7a-44a4-b42a-6bbe8c5bbff4
Document Type: srp
Title: UNCONTROLLED CONTROL ROD ASSEMBLY WITHDRAWAL AT POWER
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070712.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.2
CFR Part: 
CFR Title: 

Content:
nitoring system. 3. A PWR analysis, on the other hand, generally involves larger power changes and requires transientAOO calculations. Because power distributions in the course of the transientAOO can frequently be predicted conservatively using design-limit peaking factors, point kinetics may be used for the nuclear transientAOO. The nuclear transientAOO is coupled, however, to core and system thermal-hydraulic response to the power changes (fuel and moderator thermal feedback and system instrumentation response). For a PWR, the reviewer ascertains that a full range of transientAOO conditions are explored; that the transientAOO calculation models are adequate; and that scram response of the flux, temperature, or pressure instrumentation is correctly calculated. The range of parameters to be considered includes: a. Initial power levels from low to full power. b. Reactivity insertion rates from very low to maximum possible for the control system, including allowance for uncertainties. c. Fuel and moderator feedback reactivity coefficients covering the range expected throughout the cycle, including allowance for uncertainties. d. Power peaking factors at design limits for the initial power level conditions. 4. For both types of reactors, the reviewer determines whether the applicant's analytical methods and models are acceptable, including steady-state, transientAOO, system DRAFT Rev. 3 - April 1996 15.4.2-6 response, and fuel response models. This may be done by using one or more of the following procedures: a. Determine whether the method has been reviewed and approved previously by considering past safety evaluation reports (SERs) and reports prepared in response to technical assistance requests. b. Perform a de novo review of the method (usually described in a separate licensing topical report and frequently handled outside the scope of the review for a particular facility). c. Perform auditing-type calculations with methods available to the staff. d. Require