Document: NUREG-0800
Document ID: ac43f632-9db1-4857-9f56-bfba45965456
Document Type: srp
Title: * These are modifications to a plant’s design, operations, or other activities that require NRC approval. These modifica
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0232/ML023250195.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19
CFR Part: 
CFR Title: 

Content:
ment of uncertainties. • Increases in estimated CDF and LERF resulting from proposed LB changes are limited to small increments, and the cumulative effects of such changes are tracked and considered in the decision process. • The acceptability of the proposed changes has been evaluated by the licensee in an integrated fashion that ensures that all principles are met. • Data, methods, and assessment criteria used to support regulatory decisionmaking are clearly documented and available for public review. IV.2 Definition of the Proposed Change • Adequate traditional engineering and probabilistic evaluations are available to support the proposed LB change. Plant-specific and relevant industry data and operational experience also support the proposed change. • Cause-effect relationships have been identified to adequately link the application with the evaluation models, and the proposed models can effectively evaluate or realistically bound the effects of the proposed change. • Information from engineering analyses, operational experience, and plant-specific performance history have been factored into the decisionmaking process. IV.3 Evaluations of Defense-In-Depth Attributes and Safety Margins • Defense in depth is preserved (for example, system redundancy, diversity, and independence are maintained commensurate with the expected frequency and consequence of challenges to the system; defenses against potential common cause failures are maintained and the introduction of new common cause failure mechanisms is assessed; and defenses against human errors are maintained). • Sufficient safety margins are maintained (for example, NRC-approved codes and standards are met or deviations justified; and safety analysis acceptance criteria in the LB are met, or proposed revisions provide sufficient margin to account for analysis and data uncertainty). • Current regulations have been met, or the proposed exemption is acceptable. SRP 19-36 IV.4 Scope of Risk