Document: NUREG-0800
Document ID: fea61ff0-f344-4101-adfb-590e3d9dfafe
Document Type: srp
Title: Draft Revision 6 – August 2015
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A946.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
ore any robustness characteristics can be accepted. The tests used should be specifically analyzed to determine if the tests do indeed test for the robustness characteristic, such as invalid inputs or environmental stressors, are actually being validated. Safety - The safety of the digital system should be explicitly considered in the design process, and documented in the design outputs. Security - The establishment of a SDOE for digital safety systems per RG 1.152. Timing - The system timing should be analyzed for indication of deterministic behavior. Process Characteristics Completeness - This characteristic is difficult to define and check, and depends to a large degree on the thoroughness of the review and the experience of the reviewer. A requirements compliance matrix, showing all system requirements and where in hardware and software, software code, test and the V&V process each of these individual requirements was address is valuable. The method the applicant or licensee used to reach the determination of completeness should be reviewed. Consistency - Determination of consistency requires careful examination of the individual hardware and software components and a thorough understanding of the inputs and outputs of each. For purchased items which undergo commercial grade dedication, insight into the design process used for these purchased items may be required. Each plan should be internally consistent, and the complete set of plans should be mutually consistent. Correctness - One of the often overlooked aspects of correctness is simplicity. The system and specifically the software should be no more complex than required to perform the needed functions. Unused or unneeded functions and code should not be in the safety-related software, even if the software developer wishes to include them for ease of use, future development, or other reasons. The system and software requirements and the final code should be examined to insure that only those features need to