Document: NRC Regulatory Guide
Document ID: ff075502-711b-4416-bfc8-a2a645bfe130
Document Type: regulatory_guide
Title: Nonmetallic Thermal Insulation for Austenitic Stainless Steel + HISTORY - HISTORY DG-1312 , Proposed Revision 1, published 09/2014 (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1407/ML14079A671.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.36
CFR Part: 
CFR Title: 

Content:
ngs required for the issuance or continuance of a permit or license by the Commission. Paperwork Reduction Act This regulatory guide contains information collection requirements covered by 10 CFR Part 50 that the Office of Management and Budget (OMB) approved under OMB control number 3150-0011. The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number. B. DISCUSSION Reason for Revision RG 1.36, Revision 1, updates NRC guidance to approve for use current voluntary consensus standards (specifications) related to thermal insulation in contact with austenitic stainless steel. The standards have been revised and improved in the recent years; thus they represent current best practices available for the purpose. Significantly, the current standards offer more than one test method to satisfy the objective of the standard. Additionally, several test methods identified in the previous RG 1.36 are no longer in use and the references to them have been removed. Background Whether sensitized or not, austenitic stainless steel is subject to stress corrosion and should be protected from certain contaminants that can promote cracking. Chloride and fluoride ions are the most serious contaminants, so it is necessary to minimize the levels of these ions (and others that have the potential to cause stress-corrosion cracking) in all material that may come in contact with austenitic stainless steel. Thermal insulation is often employed adjacent to, or in direct contact with, stainless steel piping and components. Accidental spillages and leakages of fluids through pipe fittings, valves, and equipment cannot be entirely prevented, and contaminants present in the thermal insulation may be leached by these liquids and deposited on the stainless steel surfaces. Extensive test programs by Dana (Ref. 2) demonstrated that stress-corrosion