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:
gh each injection flow path using all pump combinations are within the design specifications. Proper system activation time and sequencing should also be verified. Those plants that use this scheme to handle the loss-of-coolant accident (LOCA) should demonstrate the capability of the HPSI pumps to take suction from the low- pressure safety injection (LPSI) pumps. (c) Testing should verify that pump motors will not trip out under maximum possible flow conditions and that adequate design margin exists between trip points and maximum operating conditions for all pump motor trips. (d) Testing should verify that the electric power supply meets design acceptance criteria under all applicable design basis loading conditions. (2) Flow Test—Hot Conditions. The intent of this test is to demonstrate, by injecting water into the primary system at operating pressure and temperature conditions, that emergency core cooling water can be delivered into the reactor under conditions as close as possible to postulated accident conditions. Any planned or unplanned actuation of the HPSI that 1 Because borated water is not made up until the hot functional testing program is completed, the use of unborated water is acceptable for this test. DG-1253, Page 4 results in the injection of cold fluid into the hot RCS should be documented in the preoperational test records discussed in Regulatory Position C.3 of this RG. (a) The reactor vessel should be closed and the RCS filled and maintained at the acceptable operating pressure and temperature level. The water level in the pressurizer should be as low as practical. Actuation of the safety injection signal should initiate system operation. The temperature of the RCS will be much higher than that of the injection water, and there will be a thermal shock to the piping and reactor vessel as a result of the hot injection test of the HPSI. (b) This test should verify the capability of all HPSI pumps to deliver water as required under postulated