Document: NRC Regulatory Guide
Document ID: c256f223-ee35-43e0-82e7-aa7b14469259
Document Type: regulatory_guide
Title: Preoperational Testing of Emergency Core Cooling Systems for Pressurized Water Reactors + HISTORY - HISTORY DG-1253 , Proposed Revision 2 (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1101/ML110110480.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.79
CFR Part: 
CFR Title: 

Content:
y that natural circulation flow initiates. (b) Testing should verify the heat transfer capability of the PRHR heat exchanger while the RCS is being cooled from hot-shutdown conditions with the reactor coolant pumps not running. The heat transfer rate measured in the test should be adjusted to account for differences in the hot-leg and IRWST temperatures, as well as the number of tubes plugged. DG-1253, Page 8 (c) Testing should verify proper operation of the PRHR heat exchanger and its heat transfer capability with every reactor coolant pump running. The heat transfer rate measured in the test should be adjusted to account for differences in the hot leg and IRWST temperatures, as well as the number of tubes plugged. 2. Component Testing The components of the systems involved in the system tests described in Regulatory Position C.1 should be tested, either in conjunction with the system tests or by independent component tests. Components that are common to the ECCS and other systems should be tested to the more stringent criteria. Performance data should be recorded and the following items verified: a. Instrumentation (1) Verify design acceptance criteria are met for operation of initiating instrumentation in various combinations of logic and instrument channel trip. (2) Verify design acceptance criteria are met for are met for functioning of instrumentation and alarms used to monitor system availability. Instruments and alarms should be calibrated and tested before plant startup. b. Valves (1) Verify design acceptance criteria are met for operation of system valves including response times with the energy source (e.g., air/nitrogen supply or electric power source) at its limiting design condition. This should include visual verification of valve position, as well as proper control room indication. (2) Valve operation under maximum expected differential pressure conditions (consistent with system test limitations). (3) Operability at maximum expected pressure and