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:
eview the staff finds the applicant's analysis acceptable, conclusions of the following type should be included in the staff's safety evaluation report: 1. The possibilities for single failures of the reactor control system which could result in 33 uncontrolled withdrawal of control rods beyond normal limits under power operation conditions have been reviewed. 15.4.2-7 DRAFT Rev. 3 - April 1996 2. The scope of the review has included investigations of possible initial conditions and the range of reactivity insertions, the course of the resulting transientAOO, and the instrumentation response to the transientAOO. 3. The methods used to determine the peak fuel rod response, and the input into that analysis, such as power distributions, rod reactivities, and reactivity feedback effects of moderator and fuel temperature changes, have been examined. (If audit calculations have been done, they should be summarized.) The staff concludes that the requirements of General Design Criteria 10, 17, 20, 34 and 25 have been met. This conclusion is based on the following: The applicant has met the following requirements of: a. GDC 10 and GDC 17, ensuring that the specified acceptable fuel design limits are not exceeded; b. GDC 20, ensuring that the reactivity control systems are automatically initiated so that specified acceptable fuel design limits are not exceeded; and c. GDC 25, ensuring that single malfunctions in the reactivity control 35 system will not cause the specified acceptable fuel design limits to be exceeded. These requirements have been met by comparing the resulting extreme operating conditions and response for the fuel (i.e., fuel duty) with the acceptance criteria for fuel damage (e.g., critical heat flux, fuel temperatures, and clad strain limits should not be exceeded), to assureensure that fuel rod failure will be precluded 36 for this event. The basis for acceptance in the staff review is that the applicant's analysis of maximum transientsAOOs for single