Document: NUREG-0800
Document ID: 042bc5c0-5de0-44b4-9599-6c131e20eb7a
Document Type: srp
Title: FUNCTIONAL DESIGN OF CONTROL ROD DRIVE SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070413.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.6
CFR Part: 
CFR Title: 

Content:
lity of the reactivity control system to regulate the rate of reactivity changes resulting from normal operations and anticipated operational 49 occurrences. 54. General Design Criterion 27, "Combined Reactivity Control Systems Capability," as related to the combined capability of reactivity control systems and emergency core cooling systems to reliably control reactivity changes to assure the capability to cool the 50 core under accident conditions. 65. General Design Criterion 28, "Reactivity Limits," as related to postulated reactivity accidents. 76. General Design Criterion 29, "Protection Against Anticipated Operational Occurrences," as related to functioning under anticipated operational occurrencesevents . 51 8. 10 CFR 50.62, "Requirements for Reduction of Risk from Anticipated Transients Without Scram (ATWS) Events for Light-Water-Cooled Nuclear Power Plants", 4.6-5 DRAFT Rev. 2 - April 1996 paragraph (c)(3), in regard to those requirements that impact the control rod drive system functional design. Specifically for BWRs the alternate rod injection system must be diverse, independent (from the reactor trip system) and must have redundant scram air header exhaust valves.52 Technical Rationale:53 1. General Design Criterion 4 requires that SSCs be designed to accommodate the effects of, and to be compatible with, the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, and shall be appropriately protected against dynamic effects, including the effects of missiles, pipe whipping, and discharging fluids, that may result from equipment failures and from external events. The CRDS provides a capability to safely shutdown the reactor during normal operations, anticipated operational occurrences, and either prevents or mitigates the consequences associated with postulated accident scenarios. The CRDS needs to be designed such that the ability to perform these safety-related functions are not compromised by adverse