Document: NUREG-0800
Document ID: 6f2ffbec-a876-42d7-a247-d27c02ea9b4a
Document Type: srp
Title: DIVERSE INSTRUMENTATION AND CONTROL SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1602/ML16020A096.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.8
CFR Part: 
CFR Title: 

Content:
se-in-depth (D3). 1. The following systems are covered by this section: • The ATWS mitigation systems that are required for compliance with 10 CFR 50.62. As defined in 10 CFR 50.62, an ATWS event is an anticipated operational occurrence followed by failure of the reactor trip portion of the protection system. Regulations in 10 CFR 50.62 identify design requirements for ATWS mitigation systems and equipment. • Diverse manual controls and displays that are provided to comply with the NRC position on D3 as described in the Staff Requirements Memorandum (SRM) regarding SECY-93-087, “Policy, Technical, and Licensing Issues Pertaining to Evolutionary and Advanced Light-Water Reactor (ALWR) Designs.” These systems are to be independent and diverse from the associated digital safety systems(s). The associated operator interfaces (controls and displays) must be located in the main control room. They are to provide manual, system-level actuation of critical safety functions and monitoring of parameters that support the safety functions. • Diverse actuation systems (DAS) that are provided solely for the purpose of meeting the NRC position on D3. DAS and ATWS mitigation system functions may be combined into a single system. The reactor trip system (RTS), engineered safety features actuation system (ESFAS), control system, or other I&C systems may perform diverse functions credited in meeting the NRC D3 position. The functions of these systems are outside the scope of this section. These functions should meet the criteria applicable to the systems as a whole and should be consistent with the assumption of the applicant’s or licensee‘s D3 analysis. The requirements for these systems and the staffs review are found in the SRP sections for the individual systems. 2. Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC). For design certification (DC) and combined license (COL) reviews, the NRC staff reviews the applicant’s proposed ITAAC associated with the