Document: NUREG-0800
Document ID: 7b7303eb-a3a7-433b-8301-fcaba03194ea
Document Type: srp
Title: - 15.1.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070676.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.1.1
CFR Part: 
CFR Title: 

Content:
DECREASE IN FEEDWATER TEMPERATURE, INCREASE IN FEEDWATER FLOW, INCREASE IN STEAM FLOW, AND INADVERTENT OPENING OF A STEAM GENERATOR RELIEF OR SAFETY VALVE REVIEW RESPONSIBILITIES Primary - Reactor Systems Branch (RSBSRXB ) 1 Secondary - NoneEmergency Preparedness and Radiation Protection Branch (PERB)2 I. AREAS OF REVIEW A number of transients events which are expected to occur with moderate frequency, and which 3 involve an unplanned increase in heat removal by the secondary system, are covered by this Standard Review Plan (SRP) section. Excessive heat removal, i.e., a heat removal rate in 4 excess of the heat generation rate in the core, causes a decrease in moderator temperature which increases core reactivity and can lead to a power level increase and a decrease in shutdown margin. The power level increase will lead to a reactor trip. Any unplanned power level increase may result in fuel damage or excessive reactor system pressure. Each of the transients initiating events covered by this SRP section should be discussed in individual sections of the safety analysis report (SAR), as required by the Standard Format (Ref. 1). The transients initiating events to be evaluated include: 1. Pressurized Water Reactors (PWRs) and Boiling Water Reactors (BWRs) a. Feedwater system malfunctions that result in a decrease in feedwater temperature. DRAFT Rev. 2 - April 1996 15.1.1-2 b. Feedwater system malfunctions that result in an increase in feedwater flow. c. Steam pressure regulator malfunctions or failures that result in increased steam flow. 2. PWRs Only a. Inadvertent opening of a steam generator relief or safety valve. The topics covered in the primary review include: postulated initial core and reactor conditions which are pertinent to feedwater system malfunctions, pressure regulator or pressure relief valve malfunctions, methods of thermal and hydraulic analysis, postulated sequence of events including time delays prior to and after protective system actuation,