Information Notice No. 89-52: Potential Fire Damper Operational Problems

                                  UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                             WASHINGTON, D.C.  20555

                                  June 8, 1989



All holders of operating licenses or construction permits for nuclear power 


This information notice is being provided to alert addressees to potential 
problems affecting the closing reliability of curtain-type fire dampers under 
ventilation system operational air flow conditions.  It is expected that 
recipients will review the information for applicability to their facilities 
and consider actions, as appropriate, to avoid similar problems.  However, 
suggestions contained in this information notice do not constitute NRC 
requirements; therefore, no specific action or written response is required. 

Description of Circumstances: 

On November 6, 1984, Ruskin Manufacturing transmitted a 10 CFR Part 21 notifi-
cation to the NRC regarding seven of its curtain-type fire dampers that failed
to close during ventilation duct air flow tests.  The tests were performed at 
the Palo Verde nuclear plant and were conducted to determine the ability of 
the curtain-type fire dampers to close under operational air flow conditions, 
as designed. 

On January 18, 1985, Northern States Power Company (NSP) notified the NRC of 
several curtain-type fire dampers that failed to fully close under ventilation
system air flow conditions during ventilation duct system operability tests 
performed by NSP.  The fire damper testing method used remote trip wires in 
place of the thermal links and the ventilation ducts were fully closed with no
open duct access panels, thus representing the actual air flow and pressures 
that would be present during operating conditions. 

On May 14, 1986, Wisconsin Public Service Corporation (WPSC) notified the NRC 
of two curtain-type fire dampers manufactured by Action Air that were tested 
and that failed to close completely under normal air flow conditions.

On December 27, 1987, Alabama Power Company notified the NRC that control room
fire dampers at Farley Unit 1 were inoperable because of failure to close 
during testing under air flow conditions.  

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                                                                 June 8, 1989
                                                                 Page 2 of 3

On February 23, 1988, Alabama Power Company reported to NRC that a number of 
fire dampers at Farley Unit 2 failed to close when tested under air flow.

Until quite recently, the only industry standard governing the design, fabri-
cation, and testing of fire dampers was Underwriters Laboratories, Inc. (UL) 
Standard 555, "Fire Dampers and Ceiling Dampers."  The 1979 edition states in 
part that "the closing reliability of fire evaluated on the basis
that...ventilating systems are automatically shut down when a fire occurs...
therefore, the UL ratings are applicable to fire dampers...installed in 
systems where air movement is effectively stopped at the start of a fire...." 
The standard does not evaluate whether or not fire dampers will close under 
air flow conditions.  Therefore, the UL fire damper rating only indicates 
whether a fire damper in the closed position will main-tain its integrity under
fire conditions for a specific time period, typically rated for 1� or 3 hours. 


NRC requirements and guidelines for fire damper configurations are contained 
in various documents, including Appendix A to the Branch Technical Position 
(BTP) APCSB 9.5-1, "Guidelines for Fire Protection for Nuclear Power Plants 
Docketed Prior to July 1, 1976," (NUREG-75/087; NUREG-0800) and Standard 
Review Plan (SRP) 9.5.1, "Fire Protection Program" (NUREG-0800).  The extent 
to which these guidelines apply to a specific plant depends on licensee 
commitments and license requirements that are applicable to the fire 
protection program.  The objective of these guidelines is to provide a fire 
damper that will close and latch as required to ensure that those systems and 
components important to safe shutdown will be capable of performing their 
intended functions. 

Licensees should be aware that fire damper testing methods that do not 
simulate the actual total differential pressure at the damper (i.e., visual 
inspection or drop testing with duct access panels open) may not show 
operability under air flow conditions.  If licensees depend on the UL product 
listing and do not sufficiently model air flow during surveillance testing, 
they cannot be sure that the dampers will close fully when called upon to do 
so unless air flow is stopped first. 

Licensees who have adequately addressed this issue have either (1) type tested 
"worse-case" air flow conditions of plant-specific fire damper configurations; 
(2) tested all dampers installed in required fire barriers; or (3) administra-
tively shut down the ventilation systems to an area upon confirmation of a 
fire.  The last approach has been incorporated into plant emergency 

Because all curtain-type fire dampers currently installed at nuclear power 
stations are of a similar design, all stations having these fire dampers 
should consider the 10 CFR Part 21 report, which specifically references 
Ruskin dampers, to be applicable to curtain-type fire dampers manufactured by 
other companies.  This type of fire damper, as installed in nuclear power 
stations, is typically used to protect redundant trains of safe shutdown 
systems and should be capable of closing and latching under anticipated air 
flow conditions. 

.                                                                 IN 89-52
                                                                 June 8, 1989
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No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact one of the techni-
cal contacts listed below or the Regional Administrator of the appropriate 
regional office. 

                              Charles E. Rossi, Director
                              Division of Operational Events Assessment
                              Office of Nuclear Reactor Regulation

Technical Contacts:  Dennis J. Kubicki, NRR 
                     (301) 492-0825 

                     Joseph J. Petrosino, NRR 
                     (301) 492-0979

                     Joseph M. Ulie, Region III
                     (312) 790-5712

Attachment:  List of Recently Issued NRC Information Notices
.                                                            Attachment 
                                                            IN 89-52 
                                                            June 8, 1989 
                                                            Page 1 of 1

                             LIST OF RECENTLY ISSUED
                             NRC INFORMATION NOTICES
Information                                  Date of 
Notice No._____Subject_______________________Issuance_______Issued to________

89-51          Potential Loss of Required    5/31/89        All holders of OLs
               Shutdown Margin During                       or CPs for nuclear
               Refueling Operations                         power reactors. 

88-88,         Degradation of Westinghouse   5/31/89        All holders of OLs
Supp. 1        ARD Relays                                   or CPs for nuclear
                                                            power reactors. 

89-50          Inadequate Emergency          5/30/89        All holders of OLs
               Diesel Generator Fuel                        or CPs for nuclear
               Supply                                       power reactors. 

89-49          Failure to Close Service      5/22/89        All holders of OLs
               Water Cross-Connect                          or CPs for nuclear
               Isolation Valves                             power reactors. 

89-48          Design Deficiency in the      5/22/89        All holders of OLs
               Turbine-Driven Auxiliary                     or CPs for nuclear
               Feedwater Pump Cooling                       power reactors. 
               Water System 

89-47          Potential Problems With       5/18/89        All holders of OLs
               Worn or Distorted Hose                       or CPs for nuclear
               Clamps on Self-Contained                     power reactors and
               Breathing Apparatus                          fuel facilities. 

89-46          Confidentiality of            5/11/89        All holders of 
               Exercise Scenarios                           licenses for fuel 
                                                            cycle facilities 
                                                            and byproduct 
                                                            material licensees
                                                            having an approved
                                                            emergency response

89-45          Metalclad, Low-Voltage        5/8/89         All holders of OLs
               Power Circuit Breakers                       or CPs for nuclear
               Refurbished with Sub-                        power reactors. 
               standard Parts 

89-44          Hydrogen Storage on the       4/27/89        All holders of OLs
               Roof of the Control Room                     or CPs for nuclear
                                                            power reactors. 
OL = Operating License
CP = Construction Permit 

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