Document: NUREG-0800
Document ID: d0e1f2cb-f296-449d-9f9a-85a571917a44
Document Type: srp
Title: EMERGENCY CORE COOLING SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340709.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.3
CFR Part: 
CFR Title: 

Content:
ter (steam) hammer due to such mechanisms as voided discharge lines, water entrainment in steam lines and steam bubble collapse. For systems with a water supply above the discharge lines, voided lines are prevented by proper vent location and filling and venting procedures. However, for the core spray and low pressure coolant injection systems of BWRs, the low elevation of the suppression pool will result in line voidage because of back leakage through pump discharge check valves and leaking valves in the full flow test line. Proper vent location and filling and venting procedure are still needed. In addition, a special keep-full system with appropriate alarms is needed to supply water to the discharge lines for any system which has a water source below the level of the highest pump discharge lines and at sufficiently high pressure to prevent voiding. For the High Pressure Coolant Injection (HPCI) system of BWRs which uses a steam-driven turbine, typical design features for the steam supply line include (a) drain pots with testable drain pot level switches, (b) sloped lines, and (c) limitations on opening and closing sequences and seal-ins for manual operation of the isolation valves to prevent introducing water slugs into the line. The turbine exhaust line features include sloped lines and vacuum breakers. 16. The reviewer confirms that no component or feature of the ECCS in one reactor facility on a multiple plant site is shared with the ECCS in another facility, or that shared features clearly meet the requirements of GDC 5 (Ref. 3). 17. The reviewer confirms that within an individual reactor facility, any com- ponents shared between the ECCS and other systems (e.g., coolant makeup systems, residual heat removal systems, containment cooling systems) satisfy engineered safeguard feature design requirements and that the ECCS function of the shared component is not diminished by the sharing. 18. The reviewer confirms that ECCS components located exterior to the