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:
lowing should be verified: (a) Verify design acceptance criteria are met for operation of the ADS Stage 1, 2, and 3 components, including the spargers, by blowing down the RCS to the IRWST. (b) Verify design acceptance criteria are met for operation of the CMTs during transition from the recirculation mode to the draindown mode of operation. g. Passive Core Cooling System—Emergency Makeup and Boration (AP1000) (1) Flow Test—Cold Conditions. System actuation and flow rates are verified to meet design acceptance criteria by the following test of the CMTs. Determine the resistance of the CMT cold-leg balance lines by filling the CMTs with flow from the cold legs. (2) Flow Tests—Hot Conditions. The PCCS emergency makeup and boration function is verified by the following test of the CMTs. During hot functional testing of the RCS, the CMT cold-leg balance line piping water temperature at various locations should be recorded to verify that the water in this line is sufficiently heated to initiate recirculation flow through the CMTs. h. Passive Core Cooling System—Emergency Core Decay Heat Removal (AP1000) (1) Flow Test—Cold Conditions. The resistance of the CMT cold-leg balance lines is determined by filling the CMTs with flow from the cold legs. This test is normally performed by filling the cold, depressurized RCS using a constant, measured discharge flow from the normal RHR pumps. The RCS is maintained at a constant level above the top of the cold-leg balance line(s). (2) Flow Test—Hot Conditions. Testing should verify the PCCS emergency core decay heat removal function by testing of the passive RHR (PRHR) heat exchanger. (a) During hot functional testing of the RCS, record the piping water temperature for the heat exchanger supply and return lines and verify 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