Document: NUREG-0800
Document ID: d2857477-655b-4e97-aa7c-3321de2d556e
Document Type: srp
Title: CONTROL ROD DRIVE SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190004.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.4
CFR Part: 
CFR Title: 

Content:
ty of the CRDS to withstand the effects of an earthquake. The CRDS must satisfy Seismic Category I requirements and be capable of controlling reactivity when subjected to a seismic disturbance thereby ensuring that the fission process can be rapidly terminated. Consequently, plant protection and safety is augmented by the capability of the CRDS to perform its safety function under earthquake conditions. 3. GDC 14 establishes requirements regarding the RCPB portion of the CRDS. The CRDM is relied on, in part, to provide a barrier to the release of fission products to the containment through proper design of the control rod drive housing and components that are part of the RCPB. Application of the GDC 14 criteria to the CRDM components functioning as a RCPB enhances safety by ensuring that the RCPB will have an extremely low probability of failure. 4. GDC 26 establishes requirements regarding the reactivity control systems’ redundancy and capability. The CRDS is one of the reactivity control systems relied on during normal operating and anticipated operational occurrences to control reactivity changes and ensure that the fuel design limits are not exceeded. Application of GDC 26 criteria to the CRDS improves safety by providing protection for the fuel rods and cladding, which is the primary barrier to the release of fission products. 5. GDC 27 establishes requirements regarding the combined reactivity control system capability. The CRDS is one of the reactivity control systems relied on to control reactivity changes and ensure that the capability to cool the core is maintained during postulated accident conditions. Requiring compliance with GDC 27 for the CRDS augments the protection provided for the primary fission product barrier by providing one means to ensure that the core will be maintained in a coolable geometry under postulated accident conditions. 6. GDC 29 establishes requirements regarding the capability of the CRDS to accomplish its safety functions in