Document: NUREG-0800
Document ID: eb0ea00d-43e4-45d1-8a5e-4daa4263d2cf
Document Type: srp
Title: EMERGENCY CORE COOLING SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550068.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.3
CFR Part: 
CFR Title: 

Content:
to such mechanisms as voided discharge lines and water entrainment in steam lines shall be provided, in order to meet the requirements of GDC 4. 7. The design of those portions of the system which are not safety related, whose failures could have an adverse effect on the ECCS system, must be in accordance with GDC 2, and acceptance is based on meeting Position C2 of Regulatory Guide 1.29. Also see SECY-94-084 for policy and technical issues associated with the regulatory treatment of non-safety systems in passive plant designs. 8. Interfaces between the ECCS and component or service water systems must be such that operation of one does not interfere with, and provides proper support (where required) for, the other. In relation to these and other shared systems, e.g., residual heat removal (RHR) and containment heat removal systems, the ECCS must conform to GDC 5. 9. The requirements of Task Action Plan Item II.K.3(15) of NUREG-0737 and NUREG-0718, which involves isolation of HPCI and RCIC for BWR plants, should also be satisfied. 10. The requirements and guidance regarding ECCS outage times and reports on ECCS unavailability, contained in Task Action Plan Item II.K.3.17, and Generic issue B-61, must also be satisfied. In addition to the above criteria, the acceptability of the ECCS may be based on the degree of design similarity with previously approved plants. Technical Rationale The technical rationale for application of these acceptance criteria to the areas of review addressed by this SRP section is discussed in the following paragraphs: 1. Compliance with GDC 2 requires that SSCs important to safety be designed to withstand the effects of natural phenomena without the loss of capability to perform their safety functions. 6.3-8 Revision 3 - March 2007 GDC 2 is applicable because the ECCS is relied upon to provide sufficient emergency core cooling flow to protect the integrity of the reactor core during postulated accidents, including the loss-of-coolant