Document: 10 CFR Part 50
Document ID: 1c9db254-4b16-4016-8411-63ac96dc3718
Document Type: cfr
Title: Environmental qualification of electric equipment important to safety for nuclear power plants.
Source: 10 CFR Part 50
Source URL: https://www.ecfr.gov/current/title-10/part-50/section-50.49
Revision Date: 
Chapter: 
Section ID: 50.49
CFR Part: 50
CFR Title: 10

Content:
ls, and submergence at the location where the equipment must perform as specified in accordance with paragraphs (d) (1) and (2) of this section. ( e ) The electric equipment qualification program must include and be based on the following: ( 1 ) Temperature and pressure. The time-dependent temperature and pressure at the location of the electric equipment important to safety must be established for the most severe design basis accident during or following which this equipment is required to remain functional. ( 2 ) Humidity. Humidity during design basis accidents must be considered. ( 3 ) Chemical effects. The composition of chemicals used must be at least as severe as that resulting from the most limiting mode of plant operation (e.g., containment spray, emergency core cooling, or recirculation from containment sump). If the composition of the chemical spray can be affected by equipment malfunctions, the most severe chemical spray environment that results from a single failure in the spray system must be assumed. ( 4 ) Radiation. The radiation environment must be based on the type of radiation, the total dose expected during normal operation over the installed life of the equipment, and the radiation environment associated with the most severe design basis accident during or following which the equipment is required to remain functional, including the radiation resulting from recirculating fluids for equipment located near the recirculating lines and including dose-rate effects. ( 5 ) Aging. Equipment qualified by test must be preconditioned by natural or artificial (accelerated) aging to its end-of-installed life condition. Consideration must be given to all significant types of degradation which can have an effect on the functional capability of the equipment. If preconditioning to an end-of-installed life condition is not practicable, the equipment may be preconditioned to a shorter designated life. The equipment must be replaced or refurbished at the end of