1、Designation: D7491 08 (Reapproved 2015)Standard Guide forManagement of Non-Conforming Coatings in CoatingService Level I Areas of Nuclear Power Plants1This standard is issued under the fixed designation D7491; the number immediately following the designation indicates the year oforiginal adoption or
2、, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide provides the user with guidance on develop-ing a program for managin
3、g non-conforming coatings inCoating Service Level I areas of a nuclear power plant.1.2 Non-conforming coatings include degraded previouslyDBA-qualified or acceptable coatings, unqualified coatings,unknown coatings, and unacceptable coatings.1.3 This standard does not purport to address all of thesaf
4、ety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D4538 Terminology Relating to P
5、rotective Coating andLining Work for Power Generation Facilities2.2 Other Documents:Regulatory Guide 1.54 Service Level I, II, and III protectiveCoatings Applied to Nuclear Power Plants3EPRI Report 1003102 Guideline on Nuclear Safety-RelatedCoatings, Revision 1 (formerly TR-109937)43. Terminology3.1
6、 DefinitionsDefinitions for use with this guide areshown in Terminology D4538 or other applicable standards.3.2 Definitions of Terms Specific to This Standard:3.2.1 non-conforming coatings, na coating or coatingsystem in a Coating Service Level I application that lacks orhas insufficient documentati
7、on to support or verify DBAqualification.3.2.1.1 DiscussionThis would include coatings referred toas unqualified, unacceptable, and degraded qualified coatings.3.2.2 unacceptable coating system, nAsafety related coat-ing system for which no suitability for application reviewwhich meets the plant lic
8、ensing requirements has been com-pleted.3.2.2.1 DiscussionTherefore, no reasonable assurance ex-ists that, when properly applied and maintained, the coating orlining will not detach under normal or accident conditions.This is applicable to “pre-ANSI” plants.4. Summary of Practice4.1 The process and
9、use of this guide is summarized inFig. 1.5. Significance and Use5.1 There are several methods for managing non-conforming coatings in an operating nuclear power plant. Thisguide outlines methods that have been determined to beacceptable to the nuclear industry.5.2 Managing the amount of non-conformi
10、ng coatings iskey to ensuring the amount assumed, in the licensing bases isnot exceeded.5.3 EPRI Report 1003102 Revision 1 (formerly TR-109937) provides additional information on the selection,application, inspection and maintenance of nuclear plantsafety-related protective coatings. This reference
11、offers adetailed discussion of important considerations related toprotective coatings and can be used to supplement this guide asdeemed necessary.6. Establishing the Design Limit of Non-ConformingCoatings6.1 Determine what coatings do not meet the licensing basisfor the plant. For plants that have c
12、ommitments to meetRegulatory Guide 1.54 (applicable revision) and/or related1This guide is under the jurisdiction of ASTM Committee D33 on ProtectiveCoating and Lining Work for Power Generation Facilities and is the directresponsibility of Subcommittee D33.10 on Protective Coatings Maintenance Workf
13、or Power Generation Facilities.Current edition approved Dec. 1, 2015. Published January 2016. Originallyapproved in 2008. Last previous edition approved in 2008 as D7491 08. DOI:10.1520/D7491-08R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
14、at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U. S. Nuclear Regulatory Commission, Distribution ServicesSection, Washington, DC 205550001, http:/www.nrc.gov.4Available from EPRI Customer Fulfil
15、lment, 1355 Willow Way, Suite 278,Concord, CA 94520.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1FIG. 1 Managing Non-Conforming CoatingsD7491 08 (2015)2ANSI/ASTM standards typically require DBA testing of coat-ings and extensive do
16、cumentation associated with the applica-tion of the qualified coatings. This may be a more significantrequirement to satisfy than for an older plant which has notmade commitments to these requirements.6.2 The key to ensuring plant safety is to manage theamount of non-conforming coatings so that it d
17、oes not exceedthe amount assumed in calculations that support plantoperation, such as sump suction strainer head loss.6.3 Managing non-conforming coatings, must consider thecapacity of the Emergency Core Cooling System (ECCS)suction strainer to accommodate debris expected to reach theECCS suction st
18、rainer (including coating debris) withoutreducing the overall ECCS pump net positive suction head(NPSH) margin below an acceptable value. Those plants withsignificant operational NPSH margin for accommodating ad-ditional debris may require less precision when determining theamount of non-conforming
19、coatings; simplified bounding tech-niques may be sufficient.6.4 The non-conforming condition may also affect otherplant design and licensing limits, such as coating thicknessaffects on the accident heat transfer and peak temperaturecalculations, and Fire Hazards Analysis.7. Determining the Amount of
20、 Non-Conforming Coatings7.1 Essentially every plant has some amount of non-conforming coatings inside of primary containment and thismay be an acceptable condition. There are two considerationswhen identifying non-conforming coatings.7.1.1 Does the coating meet the licensing basis commit-ments?7.1.2
21、 Is there reasonable assurance the coating will notdetach during normal operation or a Design Basis Accident(DBA)?7.2 The amount of coating that was applied inconsistentwith licensing commitments and design requirements needs tobe identified.7.3 It may also be appropriate to review procurementdocume
22、nts (including records of work performed ) for equip-ment installed in containment to determine if coating applica-tions performed off site conforms to licensing bases and designrequirements.7.4 If records cannot be found that identify the types andquantities of coatings (for example, weight or volu
23、me) in-stalled in containment, then some area, thickness, and densityestimations need to be performed.7.5 The results of the investigation should be tabulatedaccording to the various containment surfaces, indicating thetype, quantity, location, and qualification classification of thecoating applied.
24、 Photographic documentation is also helpfulfor reference to the findings.7.6 The tabulation should also consider identification of thecomplete coating system as applied.7.7 Periodic reassessment or establishing a new baselineshould be considered.8. Guidance on Managing Non-Conforming Coatings8.1 Onc
25、e an accounting of the amount of non-conformingcoatings is determined, a decision will need to be made as tohow to manage the results. It is important to know the reasona particular area of coating is non-conforming.8.1.1 Conditions that may cause a coating to be non-conforming:(1) Lack of or incomp
26、lete documentation for the applica-tion process.(2) Lack of or incomplete documentation regarding appli-cator qualification.(3) Lack of or incomplete documentation regarding inspec-tor qualification.(4) Lack of incomplete design change documentation forthe use of alternate coatings.(5) Improper or i
27、nadequate specification of technical andquality procurement requirements for services and materials.(6) Improper dedication of commercial grade coatings.(7) Incomplete documentation for the testing used to estab-lish conformance with the design bases.(8) Incomplete/inadequate specifications and proc
28、edures.(9) Undefined or vague personnel qualification criteria.(10) Degraded coatings, both qualified and unqualified.(11) Misapplication of a DBA qualified coating system.8.2 Remove, Repair, or Replace Non-Conforming Coatings:8.2.1 If a condition assessment reveals that the coating hasphysically de
29、graded in service, the degraded coating should beremoved or replaced in accordance with the coatings programas appropriate to restore that area to a qualified status.8.2.2 Another option may be the replacement of a non-conforming coating with a qualified or an acceptable coatingsystem.8.3 Mitigate t
30、he Consequences of Further Coating Degra-dation:8.3.1 To preclude the removal, repair, or replacement ofnon-conforming coatings, techniques may be used to mitigatethe consequences of further degradation and detachment ofcoatings.8.3.1.1 These measures may include construction of con-tainment devices
31、 around the equipment coated with the non-conforming coating to prevent debris formation or transport.8.3.1.2 The acceptable resolutions must be based on plant-specific conditions, and the impact such containment wouldhave on the operation and maintenance of the equipment.8.4 Evaluate the Safety Imp
32、act of Non-Confoming Coatings:8.4.1 An evaluation that determines the impact of thenon-conforming coating on the operation of the ECCS suctionstrainers following a Loss of Coolant Accident (LOCA) mayneed to be performed.8.4.1.1 Typically, this will be required only when the totalamount of non-confor
33、ming coating exceeds the amount con-sidered in the ECCS suction strainer head loss calculation.(a) Consideration of the failure characteristics of thecoating, the time of failure, and the transport and strainer headloss characteristics of the detached coatings can all be used inthe evaluation.D7491
34、08 (2015)38.4.1.2 Use of the plant corrective action program willtypically be required when the amount of non-conformingcoatings exceeds that considered in the current ECCS suctionstrainer head loss calculations.8.4.2 Non-conforming coating can also have a potentialimpact on other safety related SSC
35、 performance, such as theaffect on the pressure/temperature curves during a LOCA orMain Stream Line Break (MSLB), Fire Hazards Analysis, etc.,and should be evaluated accordingly.8.5 Managing the Addition of New Coatings:8.5.1 The coatings program should address the use ofappropriate controls, such a
36、s procedural requirements andspecifications, to ensure that the amount on non-conformingcoatings does not increase in an uncontrolled manner.8.5.2 The introduction of new equipment or structuralcomponents as a result of plant modifications or maintenanceon existing equipment and structures could lea
37、d to an unwantedincrease in the amount of non-conforming coatings. Therefore,the plant modification and maintenance programs should havea means to evaluate such potential impacts.8.5.3 The Nuclear Coatings Specialist should ensure thattechnical requirements specified for replacement or repaireditems
38、, adequately addresses coatings program requirements.8.5.4 Acceptance of their respective responsibilities, byother licensee organizations, for example, design engineeringand procurement, who do not own the overall coatingsprogram, is an important issue. The responsibilities of otherdisciplines shou
39、ld be clearly resolved early in the developmentof a safety-related coatings program.8.5.5 Controls should be provided to address the use ofpaints and inks for labeling and stenciling. Some are organicmaterials and may not be included in the coatings program.8.6 Upgrading Non-Conforming Coatings:8.6.
40、1 The upgrade of non-conforming coatings to an accept-able status can be accomplished by conducting those evalua-tions and/or tests that will compensate for the missing orincomplete documentation that supports the acceptability of thecoating. The activities performed should result in reasonableassur
41、ance that the coatings were acceptable when applied.8.6.2 It is important to recognize that the objective inmoving particular coating work from a non-conforming statusto an acceptable status is the achievement of reasonableassurance that is consistent with the licensing basis of the plant.8.6.3 The
42、requirements for the evaluation/test are not pre-defined because they should be tailored to address the specificweaknesses identified.8.6.4 In some cases, it may be appropriate to supplement thedocumentation evaluation with limited testing to bolster theconclusions or address areas where the results
43、 of the documen-tation evaluation are inconclusive.8.6.5 In lieu of performing extensive documentation re-views to upgrade the status of a coating, it may be morepracticable and cost-effective to perform the necessary teststhat would provide at least an equivalent level of assurancewith regard to co
44、ating acceptability as would be achieved viaa documentation review.8.6.6 An acceptable method is to perform DBAqualificationtesting on representative samples of the non-conforming coat-ings. Acceptance of the test results will also require supportingdocumentation of the application of the original c
45、oating toensure the samples are representative of the coating beingtested. Alternately, actual samples from the facility may beremoved and DBA tested, if practical.9. Documentation9.1 Design Basis Limits for Non-Conforming Coatings:9.1.1 Each plant should have a documented basis for theamount on non
46、-conforming coatings that currently exist withinthe containment structure and are part of the debris source termin the design of the ECCS suction strainer configuration.9.1.2 This documentation should provide the maximumacceptable quantity of non-conforming coatings allowed withinthe containment str
47、ucture.9.2 Documentation of Actual Total Non-Conforming Coat-ings:9.2.1 The Nuclear Coating Specialist should maintain a logor some other documentation that details the quantities of eachtype on non-conforming coating.9.2.2 This documentation should include the type of non-conforming coating, the qu
48、antity of each, the location, why itis non-conforming, and the plan if any, to resolve the non-conformance.9.2.3 This documentation should be updated or revised eachrefueling cycle with the removal, remediation, replacement, oraddition of non-conforming coatings.9.2.3.1 The effect on design margin o
49、f the ECCS systemshould also be assessed by this update.10. Keywords10.1 Design Basis Accident (DBA); Emergency Core Cool-ing System (ECCS) suction strainer; licensing basis; safetyrelatedD7491 08 (2015)4ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at
