Document: NUREG-0800
Document ID: c766e34e-6ea5-45e7-9123-75964d118447
Document Type: srp
Title: REACTOR CORE ISOLATION COOLING SYSTEM (BWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070540102.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.6
CFR Part: 
CFR Title: 

Content:
ssion pool cooling mode of the RHR system - provides the cooling water necessary for decay heat removal, but the dynamic effects of water hammer could degrade system effectiveness. Compliance with GDC 4 ensures that the RCIC system will remain functional. 2. GDC 5 prohibits the sharing of structures, systems, and components among nuclear power units unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions, including, in the event of an accident in one unit, an orderly shutdown and cooldown of the remaining units. The RCIC system - in conjunction with the HPCS (or HPCI) system, the SRVs, and the suppression pool cooling mode of the RHR system - provides the essential cooling water necessary for decay heat removal. The RCIC system should be designed so that the ability to accomplish these safety-related functions is not compromised for each unit, regardless of equipment failures or other events that may occur in another unit. Meeting the requirements of GDC 5 provides reasonable assurance that the unacceptable effects of equipment failures or other events in one unit of a multiunit site will not propagate to the unaffected unit(s). 3. GDC 29 requires that the protection and reactivity control systems be designed to ensure an extremely high probability of accomplishing their safety functions in the event of anticipated operational occurrences. The RCIC system provides a standby source of cooling water and limited decay heat removal capability whenever the main feedwater system is isolated from the reactor vessel. This system can mitigate the consequences of anticipated operational occurrences such as loss of feedwater, inadvertent isolation of main steam, or loss of offsite power; therefore, it must have an extremely high probability of accomplishing its function. The reactor protection or ESF system activates initiation of the RCIC system during appropriate anticipated operational occurrences. The design of