Document: NUREG-0800
Document ID: 889e380e-bdb0-4af7-8056-db56551e3a1b
Document Type: srp
Title: UNCONTROLLED CONTROL ROD ASSEMBLY WITHDRAWAL FROM A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070711.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.1
CFR Part: 
CFR Title: 

Content:
lytical methods and input data are reasonably conservative and that specified acceptable fuel design limits will not be exceeded. For BWR/6 Designs The possibilities for single failures of the reactor control system which could result in uncontrolled withdrawal of control rods under low power startup conditions have been reviewed. The staff concludes that the requirements of General Design Criteria 10, 17, 20, and 25 have 17 been met. This conclusion is based on the following: The applicant has met the requirements of GDC 10 that the specified acceptable fuel design limits are not exceeded, GDC 20 that the reactivity control systems are automatically initiated so that specified acceptable fuel design limits are not exceeded, and GDC 25 that single malfunctions in the reactivity control system will not cause the specified acceptable fuel design limits to be exceeded. These requirements have been met since the system design contains a Rod Pattern Control System. This system has been reviewed and found acceptable because single failures in the reactor control system which could result in uncontrolled withdrawal of control rods under low-power conditions have been precluded. The scope of the review has included the design features, which act to prevent such withdrawals. This review has shown that no single 18 failure will permit an uncontrolled rod withdrawal that could lead to reactivity insertions greater than those routinely encountered during operation. For design certification reviews, the findings will also summarize, to the extent that the review is not discussed in other safety evaluation report sections, the staff's evaluation of inspections, DRAFT Rev. 3 - April 1996 15.4.1-6 tests, analyses, and acceptance criteria (ITAAC), including design acceptance criteria (DAC), site interface requirements, and combined license action items that are relevant to this SRP Section.19 V. IMPLEMENTATION The following is intended to provide guidance to applicants and licensees