Document: NRC Regulatory Guide
Document ID: ae72d1f2-aba4-4afd-bf00-6a4263c3f3e9
Document Type: regulatory_guide
Title: Control of Heavy Loads at Nuclear Facilities
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2100/ML21006A335.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.244
CFR Part: 
CFR Title: 

Content:
fuel configuration with an effective neutron multiplication factor greater than 0.95. • Resulting leakage from the reactor vessel and spent fuel pool is within makeup capabilities. • At least one train of equipment performing essential safety functions would be undamaged. In addition, the guidelines of NUREG-0612 provide practices addressing the conduct of normal load handling operations, including maintenance and testing. These practices include (1) defined load paths, (2) load handling procedures, (3) trained crane operators, (4) special lifting devices designed and maintained to appropriate standards, (5) appropriately selected standard lifting devices, (6) inspection, testing, and maintenance of the overhead crane to appropriate standards, and (7) overhead cranes designed to appropriate minimum standards. In 2019, ASME issued Std. NML-1 to provide guidelines for conducting lifting and handling operations at nuclear facilities using overhead handling systems. Compared to NUREG-0612 guidelines, the standard covers a broader scope in terms of the types of overhead handling systems and the safety significance of the load handling activities. The NUREG-0612 guidelines applied only to inherently stable overhead cranes with top running trolleys and wire rope hoists used in areas around stored nuclear fuel or over SSCs essential to achieve and maintain safe shutdown. The guidelines of Std. NML-1 apply to a variety of additional overhead handling systems, including gantries with hydraulic jacking towers commonly used for handling of dry spent fuel storage cask system components, underhung hoists suspended from monorails or jib cranes commonly used for heavy-component movement inside nuclear facility buildings, and mobile cranes with extendable booms for movement of heavy components above and around smaller structures (e.g., service water pump replacement through the roof of a water intake structure). The guidelines of Std. NML-1 use a risk-informed approach by