Document: NUREG-0800
Document ID: d0e1f2cb-f296-449d-9f9a-85a571917a44
Document Type: srp
Title: EMERGENCY CORE COOLING SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340709.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.3
CFR Part: 
CFR Title: 

Content:
r BWST) and the contain- ment sumps(s) to the safety injection pumps must be arranged so as not to preclude automatic switchover from the injection mode of ECCS operation to recirculation cooling from the sump. These piping systems must be arranged so that the differential pressure between the sump and the RWST (or BWST), even if there is a single active failure, will not result in a loss of core cooling or a path that permits release of radioactive material from the containment to the environment. C. Implementation 1. CPs Under Review and Future CP Reviews The proposed position will be applied to all CP reviews for which an SER was not published prior to April 16, 1975. It is expected that all of the events of the proposed position will be applied for such reviews. Taking this position on CPs would eliminate the need for various schemes such as locking out power to valves located in the line between the various ECCS pumps and refueling water storage tank. 2. OLs Under Review For operating licenses that are presently under review and OLs to be reviewed in the future that are not covered by item 1, the pro- posed position will not be completely applied. Specifically, locking out power to valves will be permitted. For most plants it is expected that this will be sufficient to meet the single failure criteria. However, in other plants changes to the piping and valving arrange- ments may be required to satisfy the single failure criteria. 3. Plants Under Construction These plants will be handled as discussed in item C.2. It is expected, however, that we will discuss the proposed position with each of the applicable PWR vendors. It will be obvious to the vendors which plants now under construction may have a problem. Then a generic review may be conducted for those plants that have a severe problem. 4. Operating Plants All of the operating plants are being evaluated as an ongoing part of the current ECC review. The review should be conducted as dis- cussed in item C.2 to