Document: NUREG-0800
Document ID: a2598df1-7ec6-43a6-9d2a-d8210d1f944f
Document Type: srp
Title: through 7.9. Additional information relevant to the review process can be found in the references in
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500461.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.1
CFR Part: 
CFR Title: 

Content:
f 10 CFR 50.62, as discussed in Section 7.8. The level of review depends upon the importance to safety of the system under review. Control systems receive a limited review as necessary to confirm that control system failures cannot have an adverse effect on safety system functions and will not pose frequent challenges to the safety systems. An area of special emphasis for control systems will be to ensure that the control system design is consistent with the commitments for control system/safety system independence. Isolation of safety systems from control system failures should be addressed. Data communication systems are treated as support systems (see Section 7.9), although they are often composed of specialized hardware, embedded software, and communication protocol software that runs on the computers linked together by the data communication system. They may support protection systems, other safety systems, diverse I&C systems, control systems, or any combination thereof. A design may provide separate safety and non-safety data communication systems. The review topics applicable to any data communication system are the combination of topics applicable to the I&C systems supported by that data communication system. Rev. 4 — June 1997 SRP 7.0-A-10 Computer internal data communication is at present accomplished by high-speed databuses that are usually designed by the makers of the computer system package itself. There are a number of standardized computer internal buses, and, unlike data communication systems, no software is involved (other than operating system software). Operation of computer internal buses is usually under the control of hardware. Unless this situation changes, computer internal data communication should be reviewed by confirming critical hardware characteristics. If software is involved in computer internal data communication, the review should proceed as described above under data communication systems. C.3.3. Review of Defense-in-Depth and