Regulatory Guide 1.36: Difference between revisions

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{{Adams
{{Adams
| number = ML003740046
| number = ML15026A664
| issue date = 02/28/1973
| issue date = 05/15/2015
| title = Nonmetallic Thermal Insulation for Austenitic Stainless Steel
| title = Rev. 1, Nonmetallic Thermal Insulation for Austenitic Stainless Steel
| author name =  
| author name = Alley D
| author affiliation = NRC/RES
| author affiliation = NRC/NRR/DE/EPNB
| addressee name =  
| addressee name =  
| addressee affiliation =  
| addressee affiliation =  
| docket =  
| docket =  
| license number =  
| license number =  
| contact person =  
| contact person = Jervey R
| document report number = RG-1.36
| case reference number = DG-1312
| document report number = RG 1.36
| package number = ML15026A655
| document type = Regulatory Guide
| document type = Regulatory Guide
| page count = 3
| page count = 8
}}
}}
{{#Wiki_filter:2/23/73 U.S. ATOMIC ENERGY COMMISSION
{{#Wiki_filter:U.S. NUCLEAR REGULATORY COMMISSION  
                                REGULATORY
May 2015 OFFICE OF NUCLEAR REGULATORY RESEARCH
                                DIRECTORATE OF REGULATORY STANDARDS
Revision 1 REGULATORY GUIDE
                                                                                                                                GUIDE
 
                                                                  REGULATORY GUIDE 1.36 NONMETALLIC THERMAL INSULATION FOR
Technical Lead David W. Alley
                                                        AUSTENITIC STAINLESS STEEL
 
Written suggestions regarding this guide or development of new guides may be submitted through the NRCs public Web site under the Regulatory Guides document collection of the NRC Library at http://www.nrc.gov/reading-rm/doc-collections/reg-guides/contactus.html . 
 
Electronic copies of this regulatory guide, previous versions of this guide, and other recently issued guides are available through the NRCs public Web site under the Regulatory Guides document collection of the NRC Library at http://www.nrc.gov/reading-rm/doc-collections/ . The regulatory guide is also available through the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html, under ADAMS Accession No. ML15026A664. The regulatory analysis may be found in ADAMS
under Accession No. ML14079A669 and the staff responses to the public comments on DG-1312 may be found under ADAMS Accession No.
 
ML15026A678.
 
REGULATORY GUIDE 1.36 (Draft was issued as DG-1312, dated September 2014)
 
Nonmetallic Thermal Insulation for Austenitic Stainless Steel


==A. INTRODUCTION==
==A. INTRODUCTION==
General Design Criterion 1, "Quality Standards and                           through pipe fittings, valves, and equipment cannot be Records," of Appendix A to 10 CFR Part 50, "General                                  entirely prevented, and contaminants present in the Design Criteria for Nuclear Power Plants," requires that                            thermal insulation may be leached by these liquidg and structures, systems, and components important to safety                              leposited on the stainless steel surfaces. Extensive test be designed, fabricated, erected, and tested to quality                              programs by Dana' and Karnes 2 have demonstrated that standards commensurate with the importance of the                                    ;tress-corrosion cracking of both unsensitized and safety function to be performed. In addition, General                                ;ensitized austenitic stainless steel can be induced by Design Criteria 14 and 31 require assurance that the                                 zhloride or fluoride ions leached from many reactor coolant pressure boundary will have an                                      representative thermal lilh lation materials. Karnes has extremely low probability of gross rupture or rapidly                                further shown that leachable sodium and silicate ions at propagating fracture. Stress-corrosion cracking, which is                            least partially inhibit the adverse effects of the chloride promoted by certain contaminants, is one mechanism                                  and fluoride ions.
Purpose 
 
This regulatory guide describes methods and procedures that the staff of the U.S. Nuclear Regulatory Commission (NRC) considers acceptable when selecting and using nonmetallic thermal insulation to minimize any contamination that could promote stress-corrosion cracking in the stainless steel portions of the reactor coolant pressure boundary and other systems important to safety. This guide applies to light-water-cooled reactors.


whereby such failures may be postulated. This guide describes an acceptable method for implementing these                                      Controls should be exercised to assure that criteria with regard to the selection and use of                                    nonmetallic thermal insulations employed in nuclear nonmetallic thermal insulation to minimize any                                      power plants do not contribute significantly to stress contamination that could promote stress-corrosion                                    corrosion of stainless steel. A quality assurance program cracking in the stainless steel portions of the reactor                              should be implemented at all steps from manufacturing coolant pressure boundary and other systems important                              through installation to minimize pickup of contaminants to safety. This guide applies to light-water-cooled                                  from external sources.
Applicable Rules and Regulations


reactors. The Advisory Committee on Reactor Safeguards has been consulted concerning this guide and                                     Each type 3 of insulation should pass an appropriate has concurred in the regulatory position.                                            qualification test (such as those identified in C.2.a.
*
General Design Criterion (GDC) 1, Quality Standards and Records, of Appendix A General Design Criteria for Nuclear Power Plants, (Ref. 1), to Title 10, Part 50, Domestic Licensing of Production and Utilization Facilities, of the Code of Federal Regulations (10 CFR Part 50)
requires that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety function to be performed.


below) to demonstrate that under conditions
*
GDC 14, Reactor Coolant Pressure Boundary, and GDC 31, Fracture Prevention of Reactor Coolant Pressure Boundary, require assurance that the reactor coolant pressure boundary will have an extremely low probability of abnormal leakage, gross rupture, or rapidly propagating fracture. Stress-corrosion cracking, which is promoted by certain contaminants, is one mechanism whereby such failures may be postulated.
 
Purpose of Regulatory Guides
 
The NRC issues regulatory guides to describe to the public methods that the staff considers acceptable for use in implementing specific parts of the agencys regulations, to explain techniques that the staff uses in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations and compliance with them is not required.
 
Methods and solutions that differ from those set forth in regulatory guides will be deemed acceptable if they provide a basis for the findings required for the issuance or continuance of a permit or license by the Commission.
 
RG 1.36, Rev. 1, Page 2 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==
==B. DISCUSSION==
conservatively representing those encountered in reactor operation, the insulation does not induce excessive Whether sensitized or not, austenitic stainless steel is                       cracking in stressed stainless steel specimens. A further subject to stress corrosion and should be protected from                             qualification test should consist of a chemical analysis to certain contaminants that can promote cracking.                                       demonstrate that the leachable chloride and fluoride ion Chloride and fluoride ions are the most serious contaminants, so it is necessary to minimize the levels of                                 'A. W. Dana, Jr., "Stress Corrosion Cracking of Insulated these ions (and others that have the potential to cause                              Austenitic Stainless Steel," ASTM Bulletin, October 1957.
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 recent years; thus they represent current best practices available for that 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 cracking of both unsensitized and sensitized austenitic stainless steel can be induced by chloride or fluoride ions leached from many representative thermal insulation materials. Whorlow, et. al. (Ref. 3) has further shown that leachable sodium and silicate ions have differing qualities for inhibiting the adverse effects of the chloride and fluoride ions.
 
A quality assurance program is typically implemented at all steps from manufacturing through installation to minimize pickup of contaminants from external sources. These Controls are recommended to ensure that nonmetallic thermal insulations employed in nuclear power plants do not contribute significantly to stress corrosion of stainless steel.
 
To provide reasonable assurance that nonmetallic thermal insulation will not contribute to stress- corrosion cracking of stainless steels, each type1 of insulating material should be evaluated in conditions similar to those routinely found in reactor operations. The requirements of American Society for Testing and Materials (ASTM) C795, Standard Specification for Thermal Insulation for Use in Contact with Austenitic Stainless Steel, (Ref. 4) define testing conditions which more approximate the stresses of operational conditions at power plants. A Preproduction Corrosion Test in accordance with ASTM C692, Standard Test Method for Evaluating the Influence of Thermal Insulation on External Stress Corrosion Cracking Tendency of Austenitic Stainless Steel, (Ref. 5) and a chemical analysis acceptance test for the
 
1 Type means material of similar composition, form, and class of consistent quality, formulation, and manufacturing process.
 
RG 1.36, Rev. 1, Page 3 material in accordance with ASTM C871, Test Method for Chemical Analysis of Thermal Insulation Materials for Leachable Chloride, Fluoride, Silicate and Sodium Ions (Ref. 6) are required for those who voluntarily wish to meet ASTM C795 for qualification of the insulation material. During production, each lot2 of insulation material should be evaluated to demonstrate acceptability. The Staff Regulatory Guidance section provides specific reference to these standards.
 
Harmonization with International Standards
 
The International Atomic Energy Agency (IAEA) has established a series of safety guides and standards constituting a high level of safety for protecting people and the environment. IAEA Nuclear Energy Series Technical Reports provide information in the areas of nuclear power, nuclear fuel cycle, radioactive waste management and decommissioning, and on general issues that are relevant to all of the above-mentioned areas.
 
The NRC staff identified one IAEA document pertinent to this regulatory guide, IAEA Nuclear Energy Series NP-T-3.13, Stress Corrosion Cracking in Light Water Reactors: Good Practices and Lessons Learned (Ref. 7), issued September 2011.  The IAEA document addresses the importance of stress-corrosion cracking as one of the significant aging degradations for major components of both pressurized-water reactors and boiling-water reactors. This regulatory guide incorporates similar design and testing guidelines and is consistent with the basic principles provided in IAEA Nuclear Energy Series NP-T-3.13.
 
Documents Discussed in Staff Regulatory Guidance
 
This regulatory guide endorses the use of one or more codes or standards developed by external organizations and other third-party guidance documents. These codes, standards and third-party guidance documents may contain references to other codes, standards or third party guidance documents (secondary references). If a secondary reference has itself been incorporated by reference into NRC
regulations as a requirement, then licensees and applicants must comply with that standard as set forth in the regulation. If the secondary reference has been endorsed in a regulatory guide as an acceptable approach for meeting an NRC requirement, then the standard constitutes a method acceptable to the NRC
staff for meeting that regulatory requirement as described in the specific regulatory guide. If the secondary reference has been neither incorporated by reference into NRC regulations nor endorsed in a regulatory guide, then the secondary reference is neither a legally binding requirement nor a generic NRC-approved acceptable approach for meeting an NRC requirement. However, licensees and applicants may consider and use the information in the secondary reference, if appropriately justified, consistent with current regulatory practice, and consistent with applicable NRC requirements.
 
2 A lot (batch) is defined as a definite quantity of some product manufactured under conditions of production that are considered uniform for quality analysis. A batch is not to be confused with an inspection lot, which is the sample taken to test the production batch. ASTM C390-08 (Ref. 8)
 
RG 1.36, Rev. 1, Page 4 C.  STAFF REGULATORY GUIDANCE
 
The levels of leachable contaminants in nonmetallic insulation materials3 that come in contact with austenitic stainless steels of the American Iron & Steel Institute (AISI) Type 3XX series used in fluid systems important to safety should be carefully controlled so that stress-corrosion cracking is not promoted. Insulation for the above application should minimize the leachable chlorides and fluorides to the lowest practicable levels by meeting the following conditions:
 
1.
 
All insulating materials should be manufactured, processed, packaged, shipped, stored, and installed in a manner that will limit, to the maximum extent practical, chloride and fluoride contamination from external sources.
 
2.
 
Qualification Testing. The test methods of ASTM C692 and ASTM C871 should be used as directed by ASTM C795.
 
a) Preproduction qualification testing.
 
Each material should be tested for stress corrosion effects using the 28-day stress corrosion test as specified in ASTM C692 to determine acceptability using the criteria of ASTM C795.
 
Duplicate specimens of each type of thermal insulating material used should be chemically analyzed using the test method ASTM C871 to determine leachable chloride, fluoride, sodium, silicate, and pH, sufficient to meet the acceptance criteria of ASTM C795, Figure 1, and to establish baseline values for confirming production quality control.
 
b) Production testing 
 
Duplicate specimens from each lot (batch) of insulation should be chemically analyzed as specified in ASTM C795 to determine leachable chloride, fluoride, sodium, silicate, and pH.
 
The material should meet the acceptance criteria of ASTM C795, Figure 1 using the averaged results from the duplicate specimens for each lot.
 
For each lot chemical analysis, the chloride plus fluoride ion concentrations should not exceed 150 percent of the average values determined on the sample used for preproduction qualification testing.
 
For each lot chemical analysis, the sodium plus silicate ion concentrations should not fall below 50 percent of the average values determined on the sample used for preproduction qualification testing.
 
3.
 
Requalification. The manufacturers production quality program should address periodic requalification requirements. Additionally, the insulation material should be re-qualified by repeating the preproduction (2.a) qualification testing when a change is made in the type, nature, or quality of the ingredients, the formulation, or the manufacturing process.
 
3 Thermal insulating materials include block insulation, pipe insulation, board insulation, and blanket insulation, and the cements and adhesives employed in their application.
 
RG 1.36, Rev. 1, Page 5
 
==D. IMPLEMENTATION==
The purpose of this section is to provide information on how applicants and licensees4 may use this guide and information regarding the NRCs plans for using this regulatory guide. In addition, it describes how the NRC staff complies with 10 CFR 50.109, Backfitting and any applicable finality provisions in 10 CFR Part 52, Licenses, Certifications, and Approvals for Nuclear Power Plants.
 
Use by Applicants and Licensees Applicants and licensees may voluntarily5 use the guidance in this document to demonstrate compliance with the underlying NRC regulations. Methods or solutions that differ from those described in this regulatory guide may be deemed acceptable if they provide sufficient basis and information for the NRC staff to verify that the proposed alternative demonstrates compliance with the appropriate NRC
regulations. Current licensees may continue to use guidance the NRC found acceptable for complying with the identified regulations as long as their current licensing basis remains unchanged.
 
Licensees may use the information in this regulatory guide for actions that do not require NRC
review and approval such as changes to a facility design under 10 CFR 50.59, Changes, Tests, and Experiments. Licensees may use the information in this regulatory guide or applicable parts to resolve regulatory or inspection issues.
 
Use by NRC Staff The NRC staff does not intend or approve any imposition or backfitting of the guidance in this regulatory guide. The NRC staff does not expect any existing licensee to use or commit to using the guidance in this regulatory guide unless the licensee makes a change to its licensing basis. The NRC staff does not expect or plan to request licensees to adopt this regulatory guide voluntarily to resolve a generic regulatory issue. The NRC staff does not expect or plan to initiate NRC regulatory action that would require the use of this regulatory guide. Examples of such unplanned NRC regulatory actions include issuance of an order requiring the use of the regulatory guide, requests for information under
10 CFR 50.54(f) as to whether a licensee intends to commit to the use of this regulatory guide, and generic communication or promulgation of a rule requiring the use of this regulatory guide without further backfit consideration.
 
During regulatory discussions on plant-specific operational issues, the staff may discuss with licensees various actions consistent with staff positions in this regulatory guide as one acceptable means of meeting the underlying NRC regulatory requirement. Such discussions would not ordinarily be considered backfitting even if prior versions of this regulatory guide are part of the licensing basis of the facility. However, unless this regulatory guide is part of the licensing basis for a facility, the staff may not represent to the licensee that the licensees failure to comply with the positions in this regulatory guide constitutes a violation.
 
If an existing licensee voluntarily seeks a license amendment or change and (1) the NRC staffs consideration of the request involves a regulatory issue directly relevant to this new or revised regulatory guide and (2) the specific subject matter of this regulatory guide is an essential consideration in the staffs
 
4 In this section, licensees refers to licensees of nuclear power plants under 10 CFR Parts 50 and 52, and the term applicants refers to applicants for licenses and permits for (or relating to) nuclear power plants under 10 CFR
Parts 50 and 52 and applicants for standard design approvals and standard design certifications under 10 CFR Part 52.
 
5 In this section, voluntary and voluntarily mean that the licensee is seeking the action of its own accord without the force of a legally binding requirement or an NRC representation of further licensing or enforcement action.
 
RG 1.36, Rev. 1, Page 6 determination of the acceptability of the licensees request, then the staff may request that the licensee either follow the guidance in this regulatory guide or provide an equivalent alternative process that demonstrates compliance with the underlying NRC regulatory requirements. This is not considered backfitting as defined in 10 CFR 50.109(a)(1) or a violation of any of the issue finality provisions in
10 CFR Part 52.
 
In addition, an existing applicant may be required to comply with new rules, orders, or guidance if 10 CFR 50.109(a)(3) applies.
 
If a licensee believes that the NRC is either using this regulatory guide or requesting or requiring the licensee to implement the methods or processes in this regulatory guide in a manner inconsistent with the discussion in this Implementation section, then the licensee may file a backfit appeal with the NRC in accordance with the guidance in NUREG-1409, Backfitting Guidelines (Ref. 9) and the NRC
Management Directive 8.4, Management of Facility-Specific Backfitting and Information Collection (Ref. 10). 
 
RG 1.36, Rev. 1, Page 7 REFERENCES6
 
1.
 
U.S. Code of Federal Regulations (CFR), Domestic Licensing of Production and Utilization Facilities, Part 50, Chapter 1, Title 10, Energy.
 
2.


stress-corrosion cracking) in all material that may come                                  SH. F. Karnes, "The Corrosion Potential of Wetted Thermal in contact with austenitic stainless steel.                                          Insulation," presented at American Institute of Chemical Engineers 57th National Meeting, September 1965 (Conf
Dana, Jr., A.W., Stress Corrosion Cracking of Insulated Austenitic Stainless Steel, ASTM
      "Thermal insulation is often employed adjacent to,                           650905-2).
Bulletin, 1957. (Agencywide Documents and Management System (ADAMS) Accession Number ML14087A400)
                                                                                          "aType means material of similar composition, form, and or m direct contact with, stainless steel piping and                                class and of consistent quality, formulation, and manufacturing components. Accidental spillages and leakages of fluids                              process.


USAEC REGULATORY GUIDES                                      Copies of published guides may be obtained by request indicating the divisions desired to the US. Atomic Energy Commission, Washington, D.C. 20645, Regulatory Guides we lsued to describe end make available to the public            Attention: Director of Regulatory Standards. Comments and suggestions for methods acceptable to the AEC Regulatory staff of implementing specific parts of    Improvemants in thes guides ae encouraged and should be sent to the Secretary the Commission's regulations, to delineate techniques used by the staff in          of the Commission, US. Atomic Energy Commission, Washington, D.C. 20545, evaluating specific problems or postulated accidents, or to provide guidance to    Attention: Chief, Public Proceedings Staff.
3.


applicants. Regulatory Guides are not substitutes for regulations end compliance with them Is not required. Methods and solutions different from those set out in    The guides are Issued in the following ten broad divisions:
Whorlow, Kenneth M. et.al., Effects of Halogens and Inhibitors on the External Stress Corrosion Cracking of Type 304 Austenitic Stainless Steel, STP 1320, Insulation Materials: Testing and Applications, Vol. 3, American Society for Testing and Materials (ASTM)7, West Conshohocken, PA.
the guides will be acceptable if they provide a basis for the findings requisite to the issuance or continuance of apermit or license by the Commission.                  1. Power Reactors                         


===6. Products===
4.
                                                                                    2.  Research end Test Reactors           


===7. Transportation===
ASTM C795-08 (Reapproved 2013), Standard Specification for Thermal Insulation for Use in Contact with Austenitic Stainless Steel, West Conshohocken, PA.
                                                                                    3.  Fuels and Materials Facilities          5. Occupational Health Published guides will be revised periodically, asappropriate, to accommodate        4.  Environmental and Siting                9. Antitrust Review comments and to reflect new information or experience.                              S. Materials and Plant Protection        1


===0. General===
5.


concentrations are within acceptable levels and that                        1. All        insulating    materials      should sufficient quantities of the corrosion inhibiting ions                                                                              be manufactured, processed, packaged, shipped, stored, and (sodium and silicate) are present in the insulation.
ASTM C692-13, Standard Test Method for Evaluating the Influence of Thermal Insulation on External Stress Corrosion Cracking Tendency of Austenitic Stainless Steel, West Conshohocken, PA.


installed in a manner that will limit, to the maximum extent practical, chloride and fluoride contamination The following procedures may be used in the                      from external sources.
6.


chemical analyses 4 for chlorides and fluorides:                            2. Qualification Test: Each type3 of insulating
ASTM C871-11, Standard Test Methods for Chemical Analysis of Thermal Insulation Materials for Leachable Chloride, Fluoride, Silicate, and Sodium Ions, West Conshohocken, PA.
        1. American Society foe Testing and Materials                    material should be qualified by the manufacturer or (ASTM) D512 - "Tests for Chloride Ion in Industrial                    supplier for use by:
  Water and Industrial Waste Water;" and                                            a. An appropriate test to reasonably assure
        2. ASTM Dl 179 -Tests            for Fluoride Ion in            that the insulation formulation does not induce stress Industrial Water and Industrial Waste Water.p                          corrosion. Two acceptable tests are:
                                                                                          (1) ASTM C692-71, "Standard Method Silicates may be analyzed using ASTM E60,                        for Evaluating Stress Corrosion Effect of Wicking-Type
  "Photometric Methods for Chemical Analysis of                           Thermal Insulations on Stainless Steel" (Dana Test). The Metals," by either of the following methods:                            material should be rejected if more than one of five
        1. ASTM E62 Molybdisilicic acid method; or                        specimens crack; and
        2. ASTM E120 or E146 - Molybdenum blue                                            (2) RDT M12-1T, 7 "Test Requirements method.                                                                for Thermal Insulating Materials for Use on Austenitic Stainless Steel," Section 5, (Knolls Atomic Power Sodium ion concentrations may be obtained by                    Laboratory (KAPL) Test). The material should be either spectrographic or flame photometric methods.                    rejected if more than one of four specimens crack.


b. Chemical analysis to determine the ion Further, each lot5 of insulation should be analyzed concentrations of leachable chloride, fluoride, sodium, to demonstrate that chlorides and fluorides are being                  and silicate. Insulating material that is not demonstrated maintained at acceptable levels and that the composition by the analysis to be within the acceptable region of is representative of the material employed in the Figure 1 of this guide should be rejected. This analysis qualification test. The production lot is considered should also be used as a comparison basis for the representative if the levels of the principal leachable                production test specified in C.3. below.
7.


promotors (chloride and fluoride ions) and inhibitors
International Atomic Energy Agency (IAEA)8, No. NP-T-3.13, Stress Corrosion Cracking in Light Water Reactors: Good Practices and Lessons Learned, Nuclear Energy Series, September
                                                                              3. Production Test: A representative sample 8 (sodium and silicate ions) of stress-corrosion cracking are            from each production lots of insulation material to be within fifty percent of the corresponding values                        used adjacent to, or in contact with, austenitic stainless determined for the qualification sample.                                steels used in fluid systems important to safety should be chemically analyzed to determine leachable chloride, fluoride, sodium, and silicate ion concentrations as in
2011, Vienna, Austria.


==C. REGULATORY POSITION==
8.
C.2.a. above. The lot should be accepted only if:
                                                                                    a. The analysis shows the material to be The levels of leachable contaminants in nonmetallic              within the acceptable region of Figure 1; and insulation materials 6 that come in contact with                                  b. Neither the sum of chloride plus fluoride austenitic stainless steels of the American Iron & Steel              ion concentrations nor the sum of sodium plus silicate Institute (AISI) Type 3XX series used in fluid systems                ion concentrations determined by this analysis deviates important to safety should be carefully controlled so                  by more than 50 percent from the values determined on that stress-corrosion cracking is not promoted. In                    the sample used to qualify the insulation in C.2. above.


particular, the 1-table chlorides and fluorides should                      4. Requalification: When a change is made in the be held to the lo vest practicable levels. Insulation for            type, nature, or quality of the ingredients, the the above application should meet the following                      formulation, or the manufacturing process, the conditions:                                                          insulation material should be requalified by repeating the tests described in C.2. above.
ASTM C390-08, (Reapproved 2013), Standard Practice for Sampling and Acceptance of Thermal Insulation Lots, West Conshohocken, PA.


'Thermal insulating materials include block insulation, pipe
9.
      'Samples for chemical analysis may be prepared by the            insulation, board and blanket and the cements and adhesives procedure described in Reactor Development & Technology employed in their application.


(RDT) M1 2-iT, Para. 6.1-6.3. Copies may be obtained from RDT
U.S. Nuclear Regulatory Commission (NRC), Backfitting Guidelines, NUREG-1409, issued July 1990, Washington, DC.
Standards Office, Oak Ridge National Laboratory, Building
                                                                            "1Copies may be obtained from RDT Standards Office, Oak Ridge National Laboratory, Building 1000, P.O. Box X, Oak
1000, P.O. Box X,Oak Ridge, Tennessee 37830.                            Ridge, Tennessee 37830.


'A lot is defined as the thermal insulation material of the
10.
                                                                            $A representative sample should be fully representative of same composition, form, type, grade, and class produced at one the cross section of the material; that is, it should include plant under the same conditions over a limited time span and            proportionate amounts of all components including facing designated by the producer as a production lot.                        fabrics and finishing layers.


1.36-2
NRC, Management of Facility-Specific Backfitting and Information Collection, Management Directive 8.4, Washington, DC


10,000
6 Publicly available NRC published documents are available electronically through the NRC Library on the NRCs public Web site at http://www.nrc.gov/reading-rm/doc-collections/ and through the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html  The documents can also be viewed online or printed for a fee in the NRCs Public Document Room (PDR) at 11555 Rockville Pike, Rockville, MD. For problems with ADAMS, contact the PDR staff at 301-415-4737 or (800) 397-4209; fax (301) 415-3548; or e- mail pdr.resource@nrc.gov.
    1,000
E
0.


0.
7 Copies of American Society for Testing and Materials (ASTM) standards may be purchased from ASTM, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959; telephone (610) 832-9585. Purchase information is available through the ASTM Web site at http://www.astm.org.


100                          J~ACCEPTIABLE ANALYSIS
8 Copies of IAEA documents are available at: http://www.iaea.org/Publications/index.html.}}
                                          pp (aI SO3
        101                      I    I 1 11111 t11            IIfI  111
          100              1,000              10,000              100,000
                                          ppm (Na +  SiO 3 )
                                      FIGURE 1 ACCEPTABILITY OF INSULATION MATERIAL BASED ON THE
            LEACHABLE (CI + F) AND THE LEACHABLE (Na + Si0 3 ) ANALYSES
                                    1.36-3}}


{{RG-Nav}}
{{RG-Nav}}

Revision as of 14:50, 10 January 2025

Rev. 1, Nonmetallic Thermal Insulation for Austenitic Stainless Steel
ML15026A664
Person / Time
Issue date: 05/15/2015
From: David Alley
Piping and NDE Branch
To:
Jervey R
Shared Package
ML15026A655 List:
References
DG-1312 RG 1.36
Download: ML15026A664 (8)
v • d • e


U.S. NUCLEAR REGULATORY COMMISSION

May 2015 OFFICE OF NUCLEAR REGULATORY RESEARCH

Revision 1 REGULATORY GUIDE

Technical Lead David W. Alley

Written suggestions regarding this guide or development of new guides may be submitted through the NRCs public Web site under the Regulatory Guides document collection of the NRC Library at http://www.nrc.gov/reading-rm/doc-collections/reg-guides/contactus.html .

Electronic copies of this regulatory guide, previous versions of this guide, and other recently issued guides are available through the NRCs public Web site under the Regulatory Guides document collection of the NRC Library at http://www.nrc.gov/reading-rm/doc-collections/ . The regulatory guide is also available through the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html, under ADAMS Accession No. ML15026A664. The regulatory analysis may be found in ADAMS

under Accession No. ML14079A669 and the staff responses to the public comments on DG-1312 may be found under ADAMS Accession No.

ML15026A678.

REGULATORY GUIDE 1.36 (Draft was issued as DG-1312, dated September 2014)

Nonmetallic Thermal Insulation for Austenitic Stainless Steel

A. INTRODUCTION

Purpose

This regulatory guide describes methods and procedures that the staff of the U.S. Nuclear Regulatory Commission (NRC) considers acceptable when selecting and using nonmetallic thermal insulation to minimize any contamination that could promote stress-corrosion cracking in the stainless steel portions of the reactor coolant pressure boundary and other systems important to safety. This guide applies to light-water-cooled reactors.

Applicable Rules and Regulations

General Design Criterion (GDC) 1, Quality Standards and Records, of Appendix A General Design Criteria for Nuclear Power Plants, (Ref. 1), to Title 10, Part 50, Domestic Licensing of Production and Utilization Facilities, of the Code of Federal Regulations (10 CFR Part 50)

requires that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety function to be performed.

GDC 14, Reactor Coolant Pressure Boundary, and GDC 31, Fracture Prevention of Reactor Coolant Pressure Boundary, require assurance that the reactor coolant pressure boundary will have an extremely low probability of abnormal leakage, gross rupture, or rapidly propagating fracture. Stress-corrosion cracking, which is promoted by certain contaminants, is one mechanism whereby such failures may be postulated.

Purpose of Regulatory Guides

The NRC issues regulatory guides to describe to the public methods that the staff considers acceptable for use in implementing specific parts of the agencys regulations, to explain techniques that the staff uses in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations and compliance with them is not required.

Methods and solutions that differ from those set forth in regulatory guides will be deemed acceptable if they provide a basis for the findings required for the issuance or continuance of a permit or license by the Commission.

RG 1.36, Rev. 1, Page 2 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 recent years; thus they represent current best practices available for that 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 cracking of both unsensitized and sensitized austenitic stainless steel can be induced by chloride or fluoride ions leached from many representative thermal insulation materials. Whorlow, et. al. (Ref. 3) has further shown that leachable sodium and silicate ions have differing qualities for inhibiting the adverse effects of the chloride and fluoride ions.

A quality assurance program is typically implemented at all steps from manufacturing through installation to minimize pickup of contaminants from external sources. These Controls are recommended to ensure that nonmetallic thermal insulations employed in nuclear power plants do not contribute significantly to stress corrosion of stainless steel.

To provide reasonable assurance that nonmetallic thermal insulation will not contribute to stress- corrosion cracking of stainless steels, each type1 of insulating material should be evaluated in conditions similar to those routinely found in reactor operations. The requirements of American Society for Testing and Materials (ASTM) C795, Standard Specification for Thermal Insulation for Use in Contact with Austenitic Stainless Steel, (Ref. 4) define testing conditions which more approximate the stresses of operational conditions at power plants. A Preproduction Corrosion Test in accordance with ASTM C692, Standard Test Method for Evaluating the Influence of Thermal Insulation on External Stress Corrosion Cracking Tendency of Austenitic Stainless Steel, (Ref. 5) and a chemical analysis acceptance test for the

1 Type means material of similar composition, form, and class of consistent quality, formulation, and manufacturing process.

RG 1.36, Rev. 1, Page 3 material in accordance with ASTM C871, Test Method for Chemical Analysis of Thermal Insulation Materials for Leachable Chloride, Fluoride, Silicate and Sodium Ions (Ref. 6) are required for those who voluntarily wish to meet ASTM C795 for qualification of the insulation material. During production, each lot2 of insulation material should be evaluated to demonstrate acceptability. The Staff Regulatory Guidance section provides specific reference to these standards.

Harmonization with International Standards

The International Atomic Energy Agency (IAEA) has established a series of safety guides and standards constituting a high level of safety for protecting people and the environment. IAEA Nuclear Energy Series Technical Reports provide information in the areas of nuclear power, nuclear fuel cycle, radioactive waste management and decommissioning, and on general issues that are relevant to all of the above-mentioned areas.

The NRC staff identified one IAEA document pertinent to this regulatory guide, IAEA Nuclear Energy Series NP-T-3.13, Stress Corrosion Cracking in Light Water Reactors: Good Practices and Lessons Learned (Ref. 7), issued September 2011. The IAEA document addresses the importance of stress-corrosion cracking as one of the significant aging degradations for major components of both pressurized-water reactors and boiling-water reactors. This regulatory guide incorporates similar design and testing guidelines and is consistent with the basic principles provided in IAEA Nuclear Energy Series NP-T-3.13.

Documents Discussed in Staff Regulatory Guidance

This regulatory guide endorses the use of one or more codes or standards developed by external organizations and other third-party guidance documents. These codes, standards and third-party guidance documents may contain references to other codes, standards or third party guidance documents (secondary references). If a secondary reference has itself been incorporated by reference into NRC

regulations as a requirement, then licensees and applicants must comply with that standard as set forth in the regulation. If the secondary reference has been endorsed in a regulatory guide as an acceptable approach for meeting an NRC requirement, then the standard constitutes a method acceptable to the NRC

staff for meeting that regulatory requirement as described in the specific regulatory guide. If the secondary reference has been neither incorporated by reference into NRC regulations nor endorsed in a regulatory guide, then the secondary reference is neither a legally binding requirement nor a generic NRC-approved acceptable approach for meeting an NRC requirement. However, licensees and applicants may consider and use the information in the secondary reference, if appropriately justified, consistent with current regulatory practice, and consistent with applicable NRC requirements.

2 A lot (batch) is defined as a definite quantity of some product manufactured under conditions of production that are considered uniform for quality analysis. A batch is not to be confused with an inspection lot, which is the sample taken to test the production batch. ASTM C390-08 (Ref. 8)

RG 1.36, Rev. 1, Page 4 C. STAFF REGULATORY GUIDANCE

The levels of leachable contaminants in nonmetallic insulation materials3 that come in contact with austenitic stainless steels of the American Iron & Steel Institute (AISI) Type 3XX series used in fluid systems important to safety should be carefully controlled so that stress-corrosion cracking is not promoted. Insulation for the above application should minimize the leachable chlorides and fluorides to the lowest practicable levels by meeting the following conditions:

1.

All insulating materials should be manufactured, processed, packaged, shipped, stored, and installed in a manner that will limit, to the maximum extent practical, chloride and fluoride contamination from external sources.

2.

Qualification Testing. The test methods of ASTM C692 and ASTM C871 should be used as directed by ASTM C795.

a) Preproduction qualification testing.

Each material should be tested for stress corrosion effects using the 28-day stress corrosion test as specified in ASTM C692 to determine acceptability using the criteria of ASTM C795.

Duplicate specimens of each type of thermal insulating material used should be chemically analyzed using the test method ASTM C871 to determine leachable chloride, fluoride, sodium, silicate, and pH, sufficient to meet the acceptance criteria of ASTM C795, Figure 1, and to establish baseline values for confirming production quality control.

b) Production testing

Duplicate specimens from each lot (batch) of insulation should be chemically analyzed as specified in ASTM C795 to determine leachable chloride, fluoride, sodium, silicate, and pH.

The material should meet the acceptance criteria of ASTM C795, Figure 1 using the averaged results from the duplicate specimens for each lot.

For each lot chemical analysis, the chloride plus fluoride ion concentrations should not exceed 150 percent of the average values determined on the sample used for preproduction qualification testing.

For each lot chemical analysis, the sodium plus silicate ion concentrations should not fall below 50 percent of the average values determined on the sample used for preproduction qualification testing.

3.

Requalification. The manufacturers production quality program should address periodic requalification requirements. Additionally, the insulation material should be re-qualified by repeating the preproduction (2.a) qualification testing when a change is made in the type, nature, or quality of the ingredients, the formulation, or the manufacturing process.

3 Thermal insulating materials include block insulation, pipe insulation, board insulation, and blanket insulation, and the cements and adhesives employed in their application.

RG 1.36, Rev. 1, Page 5

D. IMPLEMENTATION

The purpose of this section is to provide information on how applicants and licensees4 may use this guide and information regarding the NRCs plans for using this regulatory guide. In addition, it describes how the NRC staff complies with 10 CFR 50.109, Backfitting and any applicable finality provisions in 10 CFR Part 52, Licenses, Certifications, and Approvals for Nuclear Power Plants.

Use by Applicants and Licensees Applicants and licensees may voluntarily5 use the guidance in this document to demonstrate compliance with the underlying NRC regulations. Methods or solutions that differ from those described in this regulatory guide may be deemed acceptable if they provide sufficient basis and information for the NRC staff to verify that the proposed alternative demonstrates compliance with the appropriate NRC

regulations. Current licensees may continue to use guidance the NRC found acceptable for complying with the identified regulations as long as their current licensing basis remains unchanged.

Licensees may use the information in this regulatory guide for actions that do not require NRC

review and approval such as changes to a facility design under 10 CFR 50.59, Changes, Tests, and Experiments. Licensees may use the information in this regulatory guide or applicable parts to resolve regulatory or inspection issues.

Use by NRC Staff The NRC staff does not intend or approve any imposition or backfitting of the guidance in this regulatory guide. The NRC staff does not expect any existing licensee to use or commit to using the guidance in this regulatory guide unless the licensee makes a change to its licensing basis. The NRC staff does not expect or plan to request licensees to adopt this regulatory guide voluntarily to resolve a generic regulatory issue. The NRC staff does not expect or plan to initiate NRC regulatory action that would require the use of this regulatory guide. Examples of such unplanned NRC regulatory actions include issuance of an order requiring the use of the regulatory guide, requests for information under

10 CFR 50.54(f) as to whether a licensee intends to commit to the use of this regulatory guide, and generic communication or promulgation of a rule requiring the use of this regulatory guide without further backfit consideration.

During regulatory discussions on plant-specific operational issues, the staff may discuss with licensees various actions consistent with staff positions in this regulatory guide as one acceptable means of meeting the underlying NRC regulatory requirement. Such discussions would not ordinarily be considered backfitting even if prior versions of this regulatory guide are part of the licensing basis of the facility. However, unless this regulatory guide is part of the licensing basis for a facility, the staff may not represent to the licensee that the licensees failure to comply with the positions in this regulatory guide constitutes a violation.

If an existing licensee voluntarily seeks a license amendment or change and (1) the NRC staffs consideration of the request involves a regulatory issue directly relevant to this new or revised regulatory guide and (2) the specific subject matter of this regulatory guide is an essential consideration in the staffs

4 In this section, licensees refers to licensees of nuclear power plants under 10 CFR Parts 50 and 52, and the term applicants refers to applicants for licenses and permits for (or relating to) nuclear power plants under 10 CFR

Parts 50 and 52 and applicants for standard design approvals and standard design certifications under 10 CFR Part 52.

5 In this section, voluntary and voluntarily mean that the licensee is seeking the action of its own accord without the force of a legally binding requirement or an NRC representation of further licensing or enforcement action.

RG 1.36, Rev. 1, Page 6 determination of the acceptability of the licensees request, then the staff may request that the licensee either follow the guidance in this regulatory guide or provide an equivalent alternative process that demonstrates compliance with the underlying NRC regulatory requirements. This is not considered backfitting as defined in 10 CFR 50.109(a)(1) or a violation of any of the issue finality provisions in

10 CFR Part 52.

In addition, an existing applicant may be required to comply with new rules, orders, or guidance if 10 CFR 50.109(a)(3) applies.

If a licensee believes that the NRC is either using this regulatory guide or requesting or requiring the licensee to implement the methods or processes in this regulatory guide in a manner inconsistent with the discussion in this Implementation section, then the licensee may file a backfit appeal with the NRC in accordance with the guidance in NUREG-1409, Backfitting Guidelines (Ref. 9) and the NRC

Management Directive 8.4, Management of Facility-Specific Backfitting and Information Collection (Ref. 10).

RG 1.36, Rev. 1, Page 7 REFERENCES6

1.

U.S. Code of Federal Regulations (CFR), Domestic Licensing of Production and Utilization Facilities, Part 50, Chapter 1, Title 10, Energy.

2.

Dana, Jr., A.W., Stress Corrosion Cracking of Insulated Austenitic Stainless Steel, ASTM

Bulletin, 1957. (Agencywide Documents and Management System (ADAMS) Accession Number ML14087A400)

3.

Whorlow, Kenneth M. et.al., Effects of Halogens and Inhibitors on the External Stress Corrosion Cracking of Type 304 Austenitic Stainless Steel, STP 1320, Insulation Materials: Testing and Applications, Vol. 3, American Society for Testing and Materials (ASTM)7, West Conshohocken, PA.

4.

ASTM C795-08 (Reapproved 2013), Standard Specification for Thermal Insulation for Use in Contact with Austenitic Stainless Steel, West Conshohocken, PA.

5.

ASTM C692-13, Standard Test Method for Evaluating the Influence of Thermal Insulation on External Stress Corrosion Cracking Tendency of Austenitic Stainless Steel, West Conshohocken, PA.

6.

ASTM C871-11, Standard Test Methods for Chemical Analysis of Thermal Insulation Materials for Leachable Chloride, Fluoride, Silicate, and Sodium Ions, West Conshohocken, PA.

7.

International Atomic Energy Agency (IAEA)8, No. NP-T-3.13, Stress Corrosion Cracking in Light Water Reactors: Good Practices and Lessons Learned, Nuclear Energy Series, September

2011, Vienna, Austria.

8.

ASTM C390-08, (Reapproved 2013), Standard Practice for Sampling and Acceptance of Thermal Insulation Lots, West Conshohocken, PA.

9.

U.S. Nuclear Regulatory Commission (NRC), Backfitting Guidelines, NUREG-1409, issued July 1990, Washington, DC.

10.

NRC, Management of Facility-Specific Backfitting and Information Collection, Management Directive 8.4, Washington, DC

6 Publicly available NRC published documents are available electronically through the NRC Library on the NRCs public Web site at http://www.nrc.gov/reading-rm/doc-collections/ and through the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html The documents can also be viewed online or printed for a fee in the NRCs Public Document Room (PDR) at 11555 Rockville Pike, Rockville, MD. For problems with ADAMS, contact the PDR staff at 301-415-4737 or (800) 397-4209; fax (301) 415-3548; or e- mail pdr.resource@nrc.gov.

7 Copies of American Society for Testing and Materials (ASTM) standards may be purchased from ASTM, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959; telephone (610) 832-9585. Purchase information is available through the ASTM Web site at http://www.astm.org.

8 Copies of IAEA documents are available at: http://www.iaea.org/Publications/index.html.


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