Document: NRC Regulatory Guide
Document ID: e16da529-b6b4-4fdf-bc3f-7490180363f3
Document Type: regulatory_guide
Title: Environmental Qualification of Certain Electric Equipment Important to Safety for Nuclear Power Plants (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2018/ML20183A423.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.89
CFR Part: 
CFR Title: 

Content:
eded to be applied at least twice. Appendix A to IEEE Std. 323-1974 also included a figure that showed a representative test chamber profile for a combined PWR and BWR test. IEEE Std. 323-1974 stated, in part, that if it is desired to qualify equipment for in-containment service for both PWRs and BWRs, the test conditions may be chosen to encompass both test profiles, including the chemical spray specified for PWRs and the temperature/pressure profile specified for BWRs. If the actual conditions are different from these curves, the parameters may be adjusted accordingly. Section 7.4.1.10 should be supplemented to clarify the following: (1) A double-transient should be used with equipment that may be vulnerable to thermal binding from different expansion rates of materials during the initial heatup. DG-1361, Page 15 (2) The use of double transients could help offset tests where the ramp rate (initial temperature rise) of the test is slower than the required profile. This is commonly the result of test chamber and steam supply limitations. o. Section 8.3 of IEC/IEEE Std. 60780-323, Edition 1, 2016-02, discusses specific documentation requirements for equipment located in a mild environment. These documentation requirements are considered outside the scope of 10 CFR 50.49. 2. Staff Position 2 represents additional clarifications that were not addressed in IEC/IEEE Std. 60780- 323, Edition 1, 2016-02: a. In accordance with 10 CFR 50.49(l), replacement electric equipment installed after the issuance of 10 CFR 50.49 (February 22, 1983) must be qualified according to the provisions of 10 CFR 50.49 unless there are sound reasons to the contrary. The NRC staff considers the following to be sound reasons for the use of replacement equipment previously qualified in accordance with DOR Guidelines or NUREG-0588 in lieu of upgrading the qualification of electric equipment to the provisions of 10 CFR 50.49: (1) The item of equipment to be replaced is a component of equipment that