Document: NRC Regulatory Guide
Document ID: c94378e6-d5f2-4911-8d1d-2a16783d9866
Document Type: regulatory_guide
Title: Installation of Overpressure Protection Devices
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1306/ML13064A109.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.67
CFR Part: 
CFR Title: 

Content:
l Code. ' American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section III, "'Nuclear Power Plant Components," hereinafter referred to as the Code. For those pressure relief valve stations within its scope, ASME Code Case 1569, "Design of Piping for Pressure Relief Valve Station," provides guidance that may be used in the design and analysis of piping for a pressure relief/safety valve station. However, because of the limited scope of the code case, the following additional guidelines should be employed: 1. Appendix B, "Owner's Design Specifications," of Section III of the Code indicates in paragraph B-1 223.2 that the' Design Specification should stipulate the loads, the effect of which must be combined with the design pressure effects for comparison with the several primary stress-intensity limits at the design temperature. Code Case 1569 requires inclusion of the reaction force (including dynamic effects) among those loads to be compared to the primary stress-intensity limit.;. Therefore, the magnitude 'of the reaction forces should be stipulated in the Owner's Design Specification, including the anticipated transient behavior of the forces. 2. Subarticles NB-7300, "Overpressure Protection Report," and NC-7300, "Overpressure Protection Analysis," of the Code require submission of a documented analysis of the transient conditions and operating conditions that give rise to the maximum relieving requirements. Therefore, for those systems where an overpressure report or analysis is required, the individuals preparing these documents should also evaluate, stipulate, and, where certification is required. certify the magnitude of the reaction force anticipated from discharge of the valves. They should also stipulate the anticipated transient behavior of this force. 3. Experience seems to indicate that the discharge of one valve in a multiple-valve installation on a single run pipe could 'lead to premature discharge of the other valves due to