Document: NUREG-0800
Document ID: 3263aa5f-b2bf-46fe-b625-e0ffd142404d
Document Type: srp
Title: TURBINE AREA VENTILATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070557.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.4.4
CFR Part: 
CFR Title: 

Content:
ity to suitably control release of gaseous radioactive effluents to the environment. Acceptance is based on meeting the guidance of Regulatory Guides 1.52 and 1.140, as related to design, testing, and maintenance criteria for normal ventilation, exhaust system air filtration and adsorption units of light-water-cooled nuclear power plants, Position C.2, and Positions C.1 and C.2, respectively.45 Technical Rationale46 The technical rationale for application of these acceptance criteria to reviewing the TAVS is discussed in the following paragraphs:47 1. Compliance with GDC 2, as related to the system being capable of withstanding the effects of earthquakes, requires that structures, systems, and components important to safety be designed to withstand the effects of a design basis earthquake without loss of capability to perform their safety functions. The function of the TAVS is to maintain ventilation in the turbine area, to permit personnel access, and to control airborne radioactivity in the area during normal operation, during anticipated operational occurrences, and during and after postulated accidents, including loss of offsite power. This requirement is imposed to ensure that, during and after a design basis earthquake, essential portions of the TAVS will remain functional and that the failure of nonessential portions of the system or of other systems not designed to seismic Category I standards will not result in offsite doses in excess of 5 mSv (0.5 rem) to the whole body or its equivalent to any part of the body. 48 9.4.4-5 DRAFT Rev. 3 - April 1996 Meeting the requirement of GDC 2 provides added assurance that the TAVS will operate as designed, thus providing protection against release of radioactivity exceeding regulatory limits.49 2. Compliance with GDC 5 requires that structures, systems, and components important to safety shall not be shared among nuclear power units unless it can be shown that such sharing will not significantly impair their ability