Document: NUREG-0800
Document ID: b6428ab0-2037-4bac-9b93-b46af9f2fdfb
Document Type: srp
Title: DATA COMMUNICATION SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070650036.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.9
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Content:
er that does not become opaque or brittle under irradiation should be specified, or there should be a defined replacement schedule. NUREG/CR-6082 compares the qualities of optical and conductive media and provides guidance regarding environmental and performance criteria. • Diversity and Defense-in-depth (D3) analysis - If one or more DCSs are parts of systems (e.g., RTS, ESFAS, anticipated transient without scram [ATWS], diverse I&C) for which a D3 analysis is required, the analysis should be performed by the applicant, and the vulnerabilities to common-cause failure of all similar DCSs should be evaluated. Based on the credibility of postulated failures, potential consequences, availability of diverse preventive or mitigatory responses, and the NRC’s diversity requirements (see the Staff Requirements Memorandum on SECY-93-087, “Policy, Technical, and Licensing Issues Pertaining to Evolutionary and Advanced Light-Water Reactor (ALWR) Designs”), the reviewer should determine that the design, including DCSs, has sufficient D3. See SRP BTP 7-19 for guidance on reviewing D3 analyses. • DCSs exposed to seismic hazard - The reviewer should determine whether the subject DCS equipment is located in seismic Category I structures. In certain designs, some connected data communication or multiplexer equipment may be located in non-seismic Category I structures. For these cases, the reviewer must assure that simultaneous seismic destruction or perturbation of the exposed equipment does not simultaneously render redundant DCSs ineffective. For review of a DC application, the reviewer should follow the above procedures to verify that the design, including requirements and restrictions (e.g., interface requirements and site parameters), set forth in the final safety analysis report (FSAR) meets the acceptance criteria. DCs have referred to the FSAR as the design control document (DCD). The reviewer should also consider the appropriateness of identified COL action items.