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:
oblems have been satisfactorily resolved. The report should demonstrate that acceptance testing was executed according to the acceptance test procedure. One of the accepted methods of checking the V&V effort is to perform a “thread audit.” This consists of picking a sample of plant parameters and tracing the software implementation of these parameters from the purchase specification and development of the functional requirements to the writing and testing of the code. The sample size should be sufficiently large to ensure a representative sample of the requirements and of the software code. This may be as many as 5% of the requirements. The minimum sample size should be determined by statistical significance criteria. This review includes: (1) Reviewing actual sections of the code on a sample basis. Since the reviewer is seldom an expert in a particular language, this may necessitate that the responsible software design engineer walk the reviewer through the code. If the reviewer is unable to follow this explanation, this portion of the thread audit should be delegated to a more experienced staff person or an independent contractor. (2) Examining the various levels of software development documents and comparing them to the code. (3) Examining problem reports and test plans for the selected requirements, and verifying the corrections. It would be unusual if there were no problem reports, and if this is the case, the testing and review procedures should be carefully examined to ensure that a thorough test and review was done. Each of the completed problem reports should show what was done to resolve the problem, and how that resolution was tested. This would also be a good time to check the configuration management procedures to see how the revised code was put under configuration management. (4) Examining the engineering cross-discipline interfaces to ensure that nuclear specific needs were correctly incorporated into the code. (5) Examining the applicant or