Document: NUREG-0800
Document ID: b694ca5b-4dcc-4098-be04-431e0137a936
Document Type: srp
Title: - 15.5.2
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0708/ML070820081.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.5.1
CFR Part: 
CFR Title: 

Content:
INADVERTENT OPERATION OF ECCS AND CHEMICAL AND VOLUME CONTROL SYSTEM MALFUNCTION THAT INCREASES REACTOR COOLANT INVENTORY REVIEW RESPONSIBILITIES Primary - Organization responsible for review of transient and accident analyses for PWRs/BWRs Secondary - None I. AREAS OF REVIEW Certain anticipated operational occurrences (AOOs) can cause an unplanned increase in reactor coolant system (RCS) inventory. Depending on the boron concentration and temperature of the injected water and the response of the automatic control systems, a power level increase may result and, without adequate controls, could lead to fuel damage or overpressurization of the RCS. Alternatively, a power level decrease and depressurization may result. The reactor will trip from high water level, high flux, high pressure, low pressure, or from a safety injection signal. If the AOO that causes an unplanned increase in RCS inventory is a spurious actuation of the emergency core cooling system (ECCS), then the reactor is automatically tripped by the ECCS actuation signal. The ECCS, once started, is not stopped by receipt of an automatic signal. Manual action, taken according to Emergency Operating Procedures, is required to stop the ECCS. 15.5.1-15.5.2-2 Revision 2 - March 2007 This section of the Standard Review Plan (SRP) addresses the class of AOOs that increase RCS inventory [2]; but have no effect on core boron concentration. AOOs that decrease core boron concentration are addressed in SRP Section 15.4.6. AOOs that can increase RCS inventory are: 1. Boiling water reactors (BWRs) — Inadvertent operation of the high pressure core spray, high pressure coolant injection, or reactor core isolation cooling system and standby liquid control system. Other BWR transients that can result in an increase in reactor coolant inventory include feedwater system malfunctions (increasing flow), steam pressure regulator malfunctions (decreasing flow), loss of electrical load, turbine trip, main steam isolation valve