Document: NUREG-0800
Document ID: ecf7a8d4-0097-4a93-8609-630545f03f70
Document Type: srp
Title: REGULATORY TREATMENT OF NONSAFETY SYSTEMS FOR PASSIVE
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1308/ML13081A756.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.3
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arrier by ensuring that containment stresses do not exceed American Society of Mechanical Engineers service level C limits for a minimum period of 24 hours following the onset of core damage, and that following this 24-hour period the containment should continue to provide a barrier against the uncontrolled release of fission products. b. The conditional containment failure probability determined from the Level II PRA is less than or equal to 0.1. 8. The staff reviews the applicant’s evaluation of the potential for adverse interaction between passive safety-related and active nonsafety-related systems and assures that any nonsafety-related design features or functional capabilities relied upon to prevent nonsafety-related systems from adversely impacting a safety function have been included in the scope of RTNSS (RTNSS “E”). Area of Review – Functional Design of RTNSS SSCs 1. The staff reviews the design of SSCs to assure that the acceptance criteria listed in Section II have been satisfied. Review is limited to those functions of the SSC needed to assure that specified reliability/availability missions can be achieved. Area of Review – Focused PRA Sensitivity Studies 1. The PRA and Severe Accident staff reviews the focused PRA using guidance in SRP 19.0 to assure that acceptance criteria in Section II of this SRP are satisfied. 2. The PRA and Severe Accident staff reviews the mission statements for RTNSS SSCs and verifies that R/A missions are consistent with the assumptions in the PRA or other pertinent assumptions related to the function of the SSC. The staff issues requests for additional information when necessary to gain a clear understanding of the stated mission or support a determination that the mission is reasonable given the function of the SSC. Area of Review – Augmented Design Standards 1. The staff reviews the applicant’s determination of safety functions that must be satisfied to maintain the plant in a safe stable shutdown condition in