Document: NUREG-0800
Document ID: e6b7e6d3-a99d-424d-bfa0-491bc48f46cf
Document Type: srp
Title: ISOLATION CONDENSER SYSTEM (BWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0708/ML070810517.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.13
CFR Part: 
CFR Title: 

Content:
REVIEW RESPONSIBILITIES Primary - Organization responsible for boiling-water reactor systems Secondary - None I. AREAS OF REVIEW The isolation condenser system (ICS) in a boiling-water reactor (BWR) is a safety system that removes decay heat after reactor isolation during power operations. By removing decay heat, the system also limits reactor pressure increase to below the safety relief valve (SRV) setpoint and prevents SRV actuation following a scram. Upon actuation, the ICS provides water inventory that was held in the system piping to the reactor vessel. The ICS also provides decay heat removal (DHR) from the reactor core via the reactor coolant system (RCS) by natural circulation for an extended period without needing operator action. Abnormal events include an inadvertent isolation of all main steamlines, loss of condenser vacuum, pressure regulator failure, loss of feedwater, loss of offsite power (LOOP) or station blackout (SBO), anticipated transient without scram (ATWS), or a loss-of-coolant accident (LOCA). For each of these events, the high pressure part of the emergency core cooling system (ECCS) provides a backup function to the ICS. This review of the ICS is performed to assure conformance with the requirements of General Design Criteria (GDC) 2, 4, 5, 17, 33, 34, 35, 36, 37, and 54. In some plant designs, the ICS, in conjunction with the gravity-driven cooling system (GDCS) or the automatic depressurization system (ADS), may be part of the ECCS. In such cases, the ECCS function of the ICS is reviewed under Standard Review Plan (SRP) Section 6.3. The 5.4.13-2 March 2007 ability of the ICS to perform these ECCS functions is reviewed to assure conformance to the requirements of 10 CFR 50.46. In addition, the ICS may provide necessary DHR to cope with a SBO. The capability of the ICS to perform this DHR function is reviewed to assure conformance with the requirements of 10 CFR 50.63. The ICS consists of high-pressure, independent loops operating by