Document: NUREG-0800
Document ID: 78c093cc-6cc4-4fac-aea2-087f774d42c3
Document Type: srp
Title: CONTROL ROD DRIVE STRUCTURAL MATERIALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070414.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.5.1
CFR Part: 
CFR Title: 

Content:
ng agents should not be used. Technical Rationale40 The technical rationale for application of the above acceptance criteria to the control rod drive structural materials is discussed in the following paragraphs: 1. GDC 1 and 10 CFR 50.55a require that structures, systems, and components (SSCs) be designed, fabricated, erected, constructed, tested, and inspected to quality standards commensurate with the importance of the safety function to be performed. 10 CFR 50.55a also incorporates by reference applicable editions and addenda of the ASME Boiler and Pressure Vessel Code. The control rod drive system provides a means for positioning control rods to effect reactivity control and comprises a part of the RCPB. Application of 10 CFR 50.55a and GDC 1 to the control rod drive structural materials provides assurance that established standard practices of proven or demonstrated effectiveness for selecting materials, fabrication, and testing/inspection of components are used to achieve a high likelihood that these safety functions will be performed. 2. GDC 14 requires that the RCPB be designed, fabricated, erected, and tested so as to have an extremely low probability of abnormal leakage, of rapidly propagating failure, and of gross rupture. The RCPB provides a fission product barrier and a confined volume for the inventory of reactor coolant. The RCPB includes portions of the control rod drive system. Application of GDC 14 assures that control rod drive materials are selected, fabricated, installed, and tested to provide a low probability of significant degradation and in the extreme, gross failure of the RCPB that could cause substantial reduction in capability to contain reactor coolant inventory and/or reduction in capability to confine fission products. DRAFT Rev. 3 - April 1996 4.5.1-6 3. GDC 26 establishes requirements regarding the reactivity control systems redundancy and capability. GDC 26 requires a control rod system, preferably including a positive means for