Document: NUREG-0800
Document ID: 7ed8e5d3-fcfd-49cc-84ad-3b25caba06af
Document Type: srp
Title: STEAM SYSTEM PIPING FAILURES INSIDE AND OUTSIDE OF CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550006.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.1.5
CFR Part: 
CFR Title: 

Content:
ons (maximum fuel center–line temperature, maximum clad temperature, or maximum fuel enthalpy); – steam generator pressure; – containment pressure; – relief and/or safety valve flow rates; – discharge flow rate; – steam line and feedwater flow rates; and pressurizer and steam generator water levels. The values of the more important of these parameters for the steam line break accident (as listed in subsection I) are compared with those predicted for other similar plants to see that they are within the range expected. 1. To the extent deemed necessary, the reviewer evaluates the effect of single active failures of systems and components that may affect the course of the accident. For new applications, loss of offsite power should not be treated as a single active failure, as discussed under subsection II, assumptions b and d. This phase of the review is done using the system review procedures described in the SRP sections for Chapters 5, 6, 7, 8, and 10 of the SAR. The reviewer also considers single failures that may cause more than one steam generator to blow down or failure of main feedwater to isolate, thus increasing the reactivity addition to the core. 2. The reviewer confirms that a commitment has been made in the SAR to conduct preoperational tests for verifying that valve discharge rates and response times (including, for example, opening and closing times for main feedwater, auxiliary feedwater, turbine and main steam isolation valves, and steam generator and pressurizer relief and safety valves) have been conservatively modeled in the accident analyses. In addition, preoperational testing should include verification of reactor trip delay times, startup delay times for auxiliary feedwater system actuation, safety injection signal delay time, and delay times for delivery of any high concentration boron solution required to bring the plant to a safe shutdown condition. The reviewer should note that for AP1000 the safety related means of decay heat