United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-69: Improperly Installed Fire Dampers at Nuclear Power Plants

                                                            SSINS No.: 6835 
                                                            IN 83-69       

                                UNITED STATES
                            WASHINGTON, DC 20555
                              October 21, 1983

                                   NUCLEAR POWER PLANTS 


All nuclear power reactor facilities holding an operating license (OL) or 
construction permit (CP). 


This information notice is provided as notification of three related 
potentially generic problems involving the improper installation of fire 
dampers in ventilation ducts which penetrate fire barriers in safety-related
areas. Any one, or all three problems may exist at a facility. It is 
expected that recipients will review this information notice for 
applicability to their facilities. No specific action or response is 

Description of Circumstances: 

On June 13, 1983, at the Crystal River Station, while moving duct work to 
accommodate a plant modification, the licensee's personnel discovered that a 
required fire damper had not been installed in a ventilation duct between 
the Auxiliary Building and the Control Building. In evaluating and 
implementing corrective actions, the licensee identified two additional 
problems. The design drawings called for 3-hour fire rating on the dampers, 
but the procurement documents specified only 1-1/2-hour rating. Thus, 56 
dampers installed in safety-related areas did not have the required fire 
rating. Further investigation revealed that 21 of the 56 identified fire 
dampers were not properly located within the duct system. These dampers were
installed within the ducts in the fire area and not within the fire wall 
penetration as required by the design and Installation Code, National Fire 
Protection Association Standard 90A, Air Conditioning and Ventilating 

The situation may also exist at other facilities. Improperly installed fire 
dampers have been identified during recent NRC inspections at other nuclear 
power plants including Bellefonte, Farley, Grand Gulf, McGuire, and Watts 
Bar. These discrepancies existed primarily because of inadequate design data
or because the design documents did not conform to the criteria of NFPA-90A 
or of the damper manufacturer. 


                                                           IN 83-69        
                                                           October 21, 1983 
                                                           Page 2 of 2     

Redundant safety-related equipment and components at nuclear power plants 
are required to be separated by distance or by fire-resistant walls, floors,
enclosures, or other types of fire barriers. All penetrations in the fire 
barriers are required to be protected against the spread of fire in order 
for the barriers to be effective. Ventilation duct penetrations of fire 
barriers are required to be protected by means of fire dampers which are 
arranged to close in the event of fire. Improperly installed fire dampers 
could permit the passage of fire through a fire barrier and thereby 
jeopardize redundant safety-related systems. 

Licensees are encouraged to review the fire damper installations at their 
facilities and determine whether the correct dampers are installed and 
whether the damper installation is in accordance with relevant criteria. No 
written response to this notice is required. If you have any questions 
regarding this matter, please contact the Regional Administrator of the 
appropriate NRC Regional Office, or this office. 

                                   Edward L. Jordan Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contact:  J. B. Henderson, IE
                    (301) 492-9654

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