Document: NRC Regulatory Guide
Document ID: c361be32-682d-4496-bb9f-6e52a80b0bd9
Document Type: regulatory_guide
Title: Instrument Sensing Lines + HISTORY –HISTORY 01/2019 – DG-1352 , Proposed Revision 2 09/2016 – Periodic Review of Revision 1 – Revise 12/2008 – DG-1178 , Proposed Revision 1 Draft IC 126-5, Proposed Revision 0, published 03/1982 (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1815/ML18158A303.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.151
CFR Part: 
CFR Title: 

Content:
, ANSI/IEEE Std. 622-1987 (reaffirmed in 1994), “IEEE Recommended Practice for the Design and Installation of Electric Heat Tracing Systems for Nuclear Power Generating Systems” (Ref. 13) provides recommended practices for designing and installing electric heat tracing on systems in nuclear power generating stations. These electric heat tracing systems are applied to both critical process temperature control and process temperature control, in mechanical piping systems that carry borated water, caustic soda, and other solutions. Electric heat tracing systems are also applied to water piping systems to prevent them from freezing in cold weather and to prevent certain concentrations of chemicals, such as boric acid solutions, from crystallizing or solidifying within an instrument piping system. The recommendations include identification of requirements, heater design considerations, power systems design considerations, temperature control considerations, alarm considerations, finished drawings and documents, installation of materials, startup testing, temperature tests, and maintenance of electric pipe heating systems. The NRC staff found that ANSI/IEEE Std. 622-1987 (reaffirmed in 1994) contains additional technical information and criteria useful for designs and installations that require heat tracing. This revision (Revision 2) of RG 1.151 considers ANSI/IEEE Std. 622-1987 as a technical reference; therefore, it removes Regulatory Position C.3 that was found in Revision 1. Harmonization with International Standards The NRC staff reviewed guidance from the International Atomic Energy Agency and did not identify any standards that provided guidance to NRC staff, applicants, or licensees, as it relates to the content of this RG. In addition, the NRC staff reviewed guidance from ISO and found that ISO 2186- 2007 includes guidance on pipe diameters for long impulse sensing lines and provides useful information for sensing line designs, as discussed above. Therefore,