Document: NUREG-0800
Document ID: 9c59dff8-9325-43e2-8e81-843a0f6b4b2f
Document Type: srp
Title: and Regulatory Guide 1.189.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0327/ML032740044.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.5.1
CFR Part: 
CFR Title: 

Content:
cations for Hot Standby [Pressurized Water Reactors (PWRs)], Hot Shutdown [Boiling Water Reactors (BWRs)], and Cold Shutdown. Regulatory Guide 1.139 and Branch Technical Position (BTP) RSB 5-1 specify Cold Shutdown as 93.3 C (200 F) for PWRs and 100 C (212 F) for BWRs. Passive reactor designs are limited by the inherent ability of the passive heat removal processes and cannot reduce the temperature of the reactor coolant system below the boiling point of water for heat transfer to occur between the reactor coolant and the heat sink. The plant designs include cooling systems to bring the reactor to cold shutdown or refueling condition; however, these systems are not safety grade. These non-safety grade systems (i.e., makeup water to the heat sink and cool-down capability) are necessary to maintain long-term cooling (i.e., beyond 72 hours) and must demonstrated by design and analysis to be capable of accomplishing their respective functions without damage to the fuel. Based on the discussion and recommendations of SECY-94-084, the passive decay heat removal systems must be capable of achieving and maintaining 215.6 C (420 F) or below for non-loss-of-coolant-accidents (non-LOCA) events. This safe shutdown condition is predicated on demonstration of acceptable passive safety system performance and the acceptable resolution of regulatory treatment of non-safety systems that are necessary for long term shutdown. 3. Passive Plant Safe Shutdown Spurious Operations The safe shutdown analysis for passive reactor designs should be evaluated for adverse impacts caused by spurious operations of non-safety interfacing systems. These spurious operations may be caused by associated circuits (see BTP Section C.2.3) located within the fire area of concern, which may cause an adverse effect on the ability of the passive systems to perform the safe shutdown function. 4. Applicable Industry Codes and Standards Revision 4 - October 2003 52 The fire protection program for advanced