Document: NUREG-0800
Document ID: 68c52f40-6536-4c97-a8ab-72ea2a8c1c8c
Document Type: srp
Title: TURBINE BYPASS SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070595.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.4.4
CFR Part: 
CFR Title: 

Content:
design of the turbine bypass system, as described in the applicant's safety analysis report (SAR), is based on the specific General Design Criteria, industry standards, and other criteria listed below and on the similarity of the design to that of plants previously reviewed and found acceptable. The design of the turbine bypass system is acceptable if the integrated design of the system is in accordance with the following criteria: 1. General Design Criterion 4 (GDC 4), "Environmental and Dynamic Effects Design Basis," in that failure of the TBS due to a pipe break or malfunction of the TBS should 22 not adversely affect essential systems or components (i.e., those necessary for safe shutdown or accident prevention or mitigation). 2. General Design Criterion 34 (GDC 34), "Residual Heat Removal," as related to the 23 ability to use the system for shutting down the plant during normal operations. The operation of the TBS eliminates the need to rely solely on safety systems, which are required to meet the redundancy and power source requirements of this criterion. DRAFT Rev. 3 - April 1996 10.4.4-4 For BWR plants that do not incorporate an MSIVLCS and for which TBS holdup and plateout of fission products is credited in the analysis of design basis accident radiological consequences, guidance from SECY 93-087 (Reference 6) is applicable as follows: A. The turbine bypass lines from the first valve up to the condenser inlet need not be classified as seismic category I if the following criteria are met: 1. They have been analyzed using a dynamic seismic analysis method to demonstrate their structural integrity under SSE loading conditions. 2. All pertinent QA requirements of Appendix B to 10 CFR Part 50 are applied. 3. For lines utilized as an MSIV leakage path to the condenser, reliable power sources must be available for control and isolation valves so that a control operator can establish the flow path assuming a single active failure. B. TBS lines and other components