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Information Notice No. 92-82: Results of Thermo-Lag 330-1 Combustibility Testing
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C. 20555 December 15, 1992 NRC INFORMATION NOTICE 92-82: RESULTS OF THERMO-LAG 330-1 COMBUSTIBILITY TESTING Addressees All holders of operating licenses or construction permits for nuclear power reactors. Purpose The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to alert addressees to the results of Thermo-Lag 330-1 combustibility tests conducted for the NRC by the National Institute of Standards and Technology (NIST). It is expected that recipients will review the information for applicability to their facilities and consider actions as appropriate. However, suggestions contained in this information notice are not new NRC requirements; therefore, no specific action or written response is required. Description of Circumstances As part of a small-scale testing program of Thermo-Lag 330-1 fire barrier material, NRC staff had NIST perform combustibility tests using the following standards: (1) American Society for Testing and Materials (ASTM) E-136, "Standard Test Method For Behavior of Material in a Vertical Tube Furnace at 750 �C;" and (2) ASTM E-1354, "Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products using an Oxygen Consumption Calorimeter." NIST documented the results of these tests in Attachment 1, "Report on Test FR 3989, Analysis Of Barrier Material For Noncombustibility," of August 31, 1992. Based on the ASTM E-136 testing standard, the NIST tests revealed that Thermo-Lag 330-1 fire barrier material is combustible. This testing standard prescribes the material as combustible if three out of four samples exceed any of the following criteria: (1) the recorded temperature of the specimen's surface and interior thermocouples rise 30 �C [54 �F] above the initial furnace temperature; (2) there is flaming from the specimen after the first 30 seconds of irradiance; or (3) the weight loss of the specimen during testing exceeds 50 percent and either (a) the recorded temperature of the surface and interior thermocouples at any time during the test rise above the furnace air temperature at the beginning of the test or (b) there is flaming of the specimen. Each of the four Thermo-Lag specimens tested exhibited a weight loss of greater than 50 percent and exhibited flaming beyond 30 seconds. 9212090211. IN 92-82 December 15, 1992 Page 2 of 3 NIST performed the ASTM E-1354 calorimeter test on four Thermo-Lag specimens, subjecting them to an irradiance of 75 kW/m2 [6.6 BTU/ft2-s]. The total amount of heat released from the Thermo-Lag exceeded that released from Gypsum board and was about equal to the heat released from fire-retardant plywood. Discussion Section 50.48(a) of Title 10 of the Code of Federal Regulations requires that each operating nuclear power plant have a fire protection plan that satisfies General Design Criterion (GDC) 3, "Fire protection," in Appendix A to 10 CFR Part 50. GDC 3 requires that "structures, systems, and components important to safety shall be designed and located to minimize, in a manner consistent with other safety requirements, the probability and effects of fires and explosions. Noncombustible and heat resistant materials shall be used wherever practical throughout the unit, particularly in locations such as the containment and control room." NRC-approved plant fire protection programs referenced by the plant operating license and Section III.G, "Fire protection of safe shutdown capability," of Appendix R to 10 CFR Part 50, require one train of systems necessary to achieve and maintain hot shutdown conditions from either the control room or emergency control stations to be free from fire damage. Section III.G.2 of Appendix R permits separation by a horizontal distance of more than 6.1 meters [20 feet] with no intervening combustibles or fire hazards as one of several methods to ensure that cables and equipment and associated circuits of redundant safe shutdown trains located outside containment are maintained free from fire damage. If this method is used, fire detection and automatic fire suppression must be installed in the area of the redundant safe shutdown trains. Some licensees use Thermo-Lag fire barrier material to enclose intervening combustibles to achieve 6.1 meters [20 feet] of separation free of intervening combustibles between the redundant safe shutdown trains. Section III.G.2.f of Appendix R allows licensees to separate cables and equipment and associated circuits of redundant trains inside noninerted containments by installing a noncombustible radiant energy shield as one of several methods to achieve required fire protection for these circuits. Some licensees use Thermo-Lag to construct radiant energy heat shields inside containment. Related Generic Communications Attachment 2 is a list or recently issued generic communications concerning Thermo-Lag 330-1 fire barrier systems. . IN 92-82 December 15, 1992 Page 3 of 3 This information notice requires no specific action or written response. If you have any questions about the information in this notice, please contact one of the technical contacts listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager. ORIGINAL SIGNED BY Brian K. Grimes, Director Division of Operating Reactor Support Office of Nuclear Reactor Regulation Technical contacts: Ralph Architzel, NRR (301) 504-2804 Patrick Madden, NRR (301) 504-2854 Attachments: 1. Report of Test FR 3989, Analysis Of Barrier Material For Noncombustibility 2. List of Recently Issued Generic Communications Concerning Thermo-Lag 330-1 Fire Barrier Systems 3. List of Recently Issued NRC Information Notices . Attachment 2 IN 92-82 December 15, 1992 Page 1 of 1 List of Recently Issued Generic Communications Concerning Thermo-Lag 330-1 Fire Barrier Systems 1. Information Notice 91-47, "Failure of Thermo-Lag Fire Barrier Material to Pass Fire Endurance Test," August 6, 1991 2. Information Notice 91-79, "Deficiencies in the Procedures for Installing Thermo-Lag Fire Barrier Materials," December 6, 1991 3. Information Notice 92-46, "Thermo-Lag Fire Barrier Material Special Review Team Final Report Findings, Current Fire Endurance Tests, and Ampacity Calculation Errors," June 23, 1992 4. Bulletin 92-01, "Failure of Thermo-Lag 330 Fire Barrier System to Maintain Cabling in Wide Cable Trays and Small Conduits Free from Fire Damage," June 24, 1992 5. Information Notice 92-55, "Current Fire Endurance Test Results for Thermo-Lag Fire Barrier Material," July 27, 1992 6. Bulletin 92-01, Supplement 1, "Failure of Thermo-Lag 330 Fire Barrier System to Perform Its Specified Fire Endurance Function," August 28, 1992 .
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