Document: NUREG-0800
Document ID: dc63e8aa-2a74-4078-9e19-9a26ed1b4d8c
Document Type: srp
Title: Revision 6 – July 2012
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1105/ML110550791.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
or coolant inventory, containment isolation, and containment integrity. These displays and controls provide plant operators with information and control capabilities that are not subject to CCF due to errors in the plant automatic DI&C safety systems because the displays and controls are independent and diverse from the safety system. Revision 6 – July 2012 BTP 7-19-20 The point at which the manual controls are connected to safety equipment should be downstream of equipment that can be adversely affected by a CCF. These connections should not compromise the integrity of interconnecting cables and interfaces between local electrical or electronic cabinets and the plant’s electromechanical equipment. To achieve system-level actuation at the lowest possible level in the safety system architecture, the controls may be connected either to discrete hardwired components or to simple (e.g., component function can be completely demonstrated by test), dedicated, and diverse, software-based digital equipment that performs the coordinated actuation logic. The displays may include digital components that are not adversely affected by a CCF of the safety functions credited in the accident analysis. Functional characteristics (e.g., range, accuracy, time response) should be sufficient to provide operators with the information needed to place and maintain a plant in a safe shutdown condition. HFE principles and criteria should be applied to the selection and design of the displays and controls. Human-performance requirements should be described and related to the plant safety criteria. Recognized human-factors standards and design techniques should be employed to support the described human-performance requirements. 4. Review Procedures In reviewing the applicant’s D3 analysis using the above acceptance criteria and the detailed guidance of NUREG/CR-6303, emphasis should be given to the following topics: 4.1 System Representation as Blocks The system being assessed is