Information Notice 2007-26, Combustibility of Epoxy Floor Coatings at Commercial Nuclear Power Plants: Difference between revisions

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{{Adams
#REDIRECT [[Information Notice 2007-26, 12/17/2007 E-mail from Alex Klein to Alex Marion Regarding NRC Information Notice 2007-26]]
| number = ML071920090
| issue date = 08/13/2007
| title = Combustibility of Epoxy Floor Coatings at Commercial Nuclear Power Plants
| author name = Case M J, Pierson R C
| author affiliation = NRC/NMSS/FCSS, NRC/NRR/ADRA/DPR
| addressee name =
| addressee affiliation =
| docket =
| license number =
| contact person =
| document report number = IN-07-026
| document type = NRC Information Notice
| page count = 7
| revision = 0
}}
{{#Wiki_filter:
[[Issue date::August 13, 2007]]
 
NRC INFORMATION NOTICE 2007-26:COMBUSTIBILITY OF EPOXY FLOORCOATINGS AT COMMERCIAL NUCLEAR POWER PLANTS
 
==ADDRESSEES==
All holders of operating licenses for nuclear power reactors and fuel cycle facilities exceptlicensees for reactors that have permanently ceased operations and who have certified that fuel has been permanently removed from the reactor vessel.
 
==PURPOSE==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to informaddressees of a fire protection issue raised by NRC inspectors at two nuclear power plants that involves the combustibility of epoxy floor coatings over the concrete floors in various plant area The issue discussed in this IN could similarly apply to fuel cycle facilitie The NRC expects that recipients of this IN will review the information for applicability to their facilities and consider taking actions, as appropriate, to avoid similar problem However, suggestions contained in this IN are not NRC requirements; therefore, no specific action or written response is required.
 
==DESCRIPTION OF CIRCUMSTANCES==
IntroductionOne of the principal goals of NRC fire protection regulation for commercial nuclear power plantsis to ensure that, in the event of fire in any area of the plant, one train of equipment needed to achieve and maintain safe-shutdown conditions in the reactor will remain free of fire damag The regulations in Title 10 of the Code of Federal Regulations (10 CFR) Part 50, "DomesticLicensing of Production and Utilization Facilities," require each operating nuclear power plant to have a fire protection pla This plan must satisfy Appendix A to Part 50, "General Design Criteria for Nuclear Power Plants," specifically General Design Criterion 3 (GDC 3), "Fire protection," as required by 10 CFR 50.48(a). GDC 3 states, in part, "Noncombustible and heat-resistant materials shall be used whereverpractical throughout the unit, particularly in locations such as the containment and control room." However, GDC 3 does not preclude the use of combustible material Examples of combustible materials found in nuclear power plants are electrical cable insulation and jackets,lubricants, hydraulic and control fluids, diesel generator fuel oils, charcoal and other filters, and  flammable gase In general, when such materials are properly managed, are accounted for inthe plant design and operation, and are incorporated as integral components of the plant fire protection program, including the fire hazard analysis, they may be acceptabl NRC inspectors at two facilities raised an issue involving the fact that epoxy floor coating may or may not be considered combustible in the NRC-approved fire protection program depending on (1)
the thickness with which the coating is applied, and (2) an independent laboratory testing of the flame spread rating for the specific epoxy floor coatin The inspectors found that although these licensees considered the epoxy floor coatings non-combustible, they had not evaluated and controlled the thickness with which the epoxy coating was applied on floor When subsequent evaluation and testing by these licensees showed that the epoxy coating must be considered combustible, these licensees performed a fire hazards analysis that incorporated the combustible epoxy coating in accordance with their NRC-approved fire protection progra The criteria for determining material combustibility are contained in NRC Generic Letter 86-10,"Implementation of Fire Protection Requirements," dated April 24, 1986, which provided guidance for satisfying NRC regulatory requirements for fire protectio Enclosure 1 to NRC Generic Letter 86-10 included interpretations related to compliance with Appendix R, "Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979," to 10 CFR Part 5 Enclosure 2 to NRC Generic Letter 86-10 provided the NRC staff's responses to a list of industry question NRC staff's response to Question 3.6.2, "In-Situ Exposed Combustibles," states that a non-combustible material is defined as: "a. A material which in the form in which it is used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat; and b. Material having a structural base of noncombustible material, as defined in a., above, with a surfacing not over 1/8-inch thick that has a flame spread rating not higher than 50 when measured using the test protocol of American Society for Testing and Materials (ASTM) E 84, "Standard Test Method for Surface Burning Characteristics of Building Materials.""There is an exception to the Generic Letter 86-10 definition of non-combustible material. Appendix A to Branch Technical Position Auxiliary and Power Conversion Systems Branch 9.5-1, ?Guidelines for Fire Protection for Nuclear Power Plants, Docketed Prior to July1, 1976," dated February 24, 1977, Position D.1.(d) allows the use of combustible interior finishes when listed by a nationally recognized testing laboratory, such as Factory Mutual Research Corporation or Underwriters Laboratory, Inc., for a flame spread of 25 or less in its end use configuration using the test protocol of ASTM E 84.Regulatory Guide 1.189 "Fire Protection for Nuclear Power Plants," states that floor coveringcritical radiant flux be determined by testing in accordance with National Fire Protection Association (NFPA) 253, "Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source." ASTM E 84 is the standard test method required by NRC regulations and should be in the licensing basis, unless the licensee has changed their test requirement for floor covering flame spread or adopted NFPA 25 Interior finish materials, such as epoxy floor coating, should meet the NRC regulation, testing, and qualification for surface flame spread rating when tested under approved test methods. NRC Inspection Procedures 71111.05T, "Fire Protection (Triennial)," and 71111.05AQ, "FireProtection (Annual/Quarterly)," provide guidance to the inspector on verification of combustible material controls in plant areas containing components, equipment, or cabling relied on for post-fire safe-shutdow This guidance addresses unusual configurations of combustiblematerials as well as other combustible material controls.Donald C. Cook Nuclear Power Plant, Units 1 and 2An NRC inspection report for Donald C. Cook Nuclear Power Plant (D.C. Cook) documented anunresolved item (URI) regarding the fire spread rating and the thickness of the epoxy floor coating used at the plan (NRC Inspection Report 05000315/2003005; 05000316/2003005, dated July 16, 2003, Agencywide Documents Access and Management System (ADAMS)
Accession No. ML032100754.) Specifically, the inspectors were concerned that the epoxy floor coating that was applied over the concrete flooring in various plant areas may have a combustible loading that was not accounted for in the approved fire protection progra The URI was opened pending NRC review of the licensee's evaluation and testing of the epoxy flooring's flame spread characteristics. In response to the URI, the licensee performed additional evaluation and testin The testreport results indicated that the epoxy floor covering of the type installed at D.C. Cook had a flame spread rating of 140 at 0.115 inches thickness and 150 at 0.230 inches thicknes The test results for smoke development were 516 and 545, respectivel The licensee's overall evaluation concluded that:*the additional combustible loads attributed to epoxy are within the amount allowed or areinsignificant additions,*the epoxy flooring did not affect the Appendix R separation criteria, and
*the epoxy flooring would not cause fires to propagate between contiguous fire zones.
 
However, the licensee also concluded that the characteristics of the combustion process of thecoating make it undesirable as a floor coatin Considering the low ignition temperature and the test results for flame spread rate and smoke development, the licensee concluded that the use of epoxy as a coating on floors should be immediately discontinued from future us In addition, the licensee concluded that it should develop a multi-year plan to replace the current floor coating with one that conforms to the flame spread criteri The NRC closed the URI based on the results of the licensee's fire hazards evaluation whichindicated that the additional combustible loading due to the epoxy floor coating produced no impact on the fire load classification in the plant fire hazards analysi There was a negligible increase in fire hazard due to the epoxy floor coating and sufficient margin existed for maintaining combustible loading/fire severity within the established allowable limit Additionally, the fire zones that contained the epoxy floor coating did not rely on a 20-foot horizontal separation distance in order to meet Appendix R complianc The NRC inspection report that closed the URI stated that no licensee performance deficiency or violation was identifie (NRC Inspection Report 05000315/2006002; 05000316/2006002, dated March 22, 2006, ADAMS Accession No. ML060830130.)Duane Arnold Energy Center An NRC inspection report for Duane Arnold Energy Center (DAEC) documented a URI that theepoxy floor covering applied over concrete floor-such as in the reactor building, high-pressure coolant injection pump room, and other plant areas-may be a combustible not accounted for in the approved fire protection progra The URI was opened pending NRC review of the licensee's evaluation and testing of the epoxy flooring's flame spread characteristic (NRC Inspection Report 05000331/2003002, dated May 22, 2003, ADAMS Accession No.
 
ML031430217)In response to the URI, the licensee performed additional evaluation and testin The epoxytesting report results indicated that the epoxy floor covering of the type installed at DAEC had a flame spread rating of 110, which is greater than the criteria of 50 specified in NRC Generic Letter 86-10, and therefore, was considered a combustible materia The licensee performed an evaluation that determined the epoxy floor coating was acceptable.The NRC closed the URI based on the licensee's determination that there were no adjacent fireareas having the relatively high reported flame spread rating epox The inspectors concluded that the coatings would not contribute towards the spread of a fire from one area to anothe In addition, the combustible fire loads due to epoxy floor coatings did not present a challenge to the DAEC fire barrier Also, those fire areas taking credit for 20-foot separation had epoxy floor coatings with a relatively low flame spread rating and were less than 1/8-inch thic No violation was identifie (NRC Inspection Report 05000331/2005009, dated July 12, 2005, ADAMS Accession No. ML051940049.)
 
==BACKGROUND==
The basic fire protection regulation for U.S. commercial nuclear power plants is Section 50.48,"Fire protection," of 10 CFR Part 5 It requires, in part, that each operating nuclear power plant have a fire protection plan that satisfies GDC 3 in Appendix A to 10 CFR Part 5 This fire protection plan, using guidance provided in NRC Generic Letter 88-12, "Removal of Fire Protection Requirements from Technical Specifications," dated August 2, 1988, is incorporated into the operating license for the plant as a fire protection license conditio Each operating nuclear power plant has an approved fire protection program that is anchored in the long-established defense-in-depth safety principle of providing multiple protective barriers to prevent and mitigate accident The concept of defense-in-depth as applied to fire protection in fire areas important to safety, is described in Section II, "General Requirements," of Appendix Rto 10 CFR Part 5 It describes the following objectives: to prevent fires from starting; to detect rapidly, control, and extinguish promptly those fires that do occur; and to provide protection for structures, systems, and components important to safety so that a fire that is not promptly extinguished by the fire suppression activities will not prevent safe-shutdown of the plan The multiple levels of protection that are embodied in the defense-in-depth philosophy ensure fire safety throughout the life of the plant by minimizing both the probability and the consequence of fire While the NRC recognizes that no one level can be perfect or complete by itself, and strengthening any one level can compensate in some measure for known or unknown weaknesses in the others, each level of protection must meet certain minimum requirements.All licensees are required to meet commitments in their fire protection program, as well as their fire protection license conditio Fire prevention is the first line of defense-in-depth for fireprotectio The fire prevention attributes of the program are directly related to the fire protection plan objectives that are to minimize the potential for fire to occur, involve design and administrative measures that provide a reasonable level of assurance of adequate protection and management against fire hazards, and limit fire consequences for those fires that do occur.
 
==DISCUSSION==
Epoxy floor coatings have been applied to various building concrete floors at U.S. commercialnuclear power plants as a protective coating that provides a smooth surface that is easy to clean and helps to reduce the spread of radioactive contaminatio Because the epoxy floor coatings may be combustible depending on their thickness and flame spread rating, these coatings must be evaluated and controlled in accordance with the NRC-approved fire protection progra There have been instances where the installed or repaired epoxy floor coatings have been (1) purchased from numerous vendors, (2) installed to various thicknesses, (3) installed over a previous epoxy floor coating, or (4) purchased with various flame spreading ratings, that were not accounted for in the NRC-approved fire protection progra Licensee evaluations of the epoxy floor coating serve to identify instances where the licenseemay need to include the fire loading of epoxy floor coating into plant fire hazards analysis in an area where the rated fire barriers are provide The purpose of the fire hazards analysis is to evaluate the increase in hazard due to the epoxy floor coating and to verify that the increased combustible loading due to the epoxy floor coating does not present a challenge to the plant's fire barrier In addition, a licensee could have a fire protection exemption (i.e., a commitment to have no combustibles in the areas housing safety-related systems, equipment, and components for safe-shutdown) that would not be met with an epoxy floor coating that was combustibl The epoxy floor coating could also cause a licensee to no longer meet the 20-foot horizontal separation distance in order to meet Appendix R, Section III.G.2 of 10 CFR Part 50requirements, i.e., no intervening combustible or fire hazards between opposite redundant trains of post-fire safe-shutdown equipment. CONCLUSIONThe problem of epoxy floor coatings that are considered combustible can be avoided by using aproduct with a low flame spread rating, applying it in accordance with the manufacturer's/
vendor's recommendations, and providing plant procedural controls for applying the coating to ensure it does not exceed recommended thicknes Coatings that are applied thicker than a manufacturer's recommendations may exceed the listed flame spread ratin
 
==CONTACT==
This information notice does not require any specific action or written respons Please directany questions about this matter to the technical contacts listed below or to the appropriate Office of Nuclear Reactor Regulation (NRR) project manager./RA//RA by TQuay for/Robert C. Pierson, Director Michael J. Case, DirectorDivision of Fuel Cycle Safety Division of Policy and Rulemaking and Safeguards Office of Nuclear Reactor Regulation Office of Nuclear Material Safety and Safeguards Technical Contacts: Naeem Iqbal, NRR Darrell L. Schrum, Region III301-415-3346 630-829-9741 E-mail: nxi@nrc.gov E-mail: dls3@nrc.govNote: NRC generic communications may be found on the NRC public Web site,http://www.nrc.gov, under Electronic Reading Room/Document Collection IN 2007-26 }}
 
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