Document: NUREG-0800
Document ID: e0eea886-ec25-403e-a3e9-8aee7722a4bf
Document Type: srp
Title: 5
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350392.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.4
CFR Part: 
CFR Title: 

Content:
Rev. 1 - July 1981 A number of plant transients can result in a core flow increase. Those that might be expected to occur with moderate frequency are the startup of an idle recirculation pump (BWR); flow controller malfunction causing increasing core flow (BWR); startup of a pump in an inactive reactor coolant loop (PWR); and startup of a pump in an initially isolated Inactive reactor coolant pump.* All these postu- lated transients have been reviewed. It was found that.the most limiting with regard to core thermal margins and pressure within the reactor coolant and main steam systems was the transient. This transient was evaluated by the applicant using a mathematical model that has been previously reviewed and found acceptable by the staff. The parameters used as input to this model were reviewed and found to be suitably conservative. The staff concludes that the plant design with regard to transients that result in an increase in coolant flow through the reactor core is acceptable and meets the relevant requirements of General Design Criteria 10, 15, 20, 26, and 28. This conclusion is based on the following: 1. The applicant has met the requirements of General Design Criteria 10, 20, and 26 with respect to demonstrating that the specified acceptable fuel design limits are not exceeded for this event. 2. The applicant has met the requirements of General Design Criteria 15 and 28 with respect to assuring that the design con- ditions of the reactor coolant pressure boundary are not exceeded because the protection system operates to maintain the maximum pressure within the reactor coolant and main steam system pressures below 110%.of the design values. 3. The applicant has met the positions of Regulatory Guide 1.53 as related to the single-failure criterion and Regulatory Guide 1.105 as related to instrument actuations of systems and components important to safety. V. IMPLEMENTATION The following is intended to provide guidance to applicants and licensees regarding