Information Notice No. 83-69: Improperly Installed Fire Dampers at Nuclear Power Plants
SSINS No.: 6835
IN 83-69
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, DC 20555
October 21, 1983
Information Notice No. 83-69: IMPROPERLY INSTALLED FIRE DAMPERS AT
NUCLEAR POWER PLANTS
Addressees:
All nuclear power reactor facilities holding an operating license (OL) or
construction permit (CP).
Purpose:
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
required.
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
Systems.
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.
8308300797
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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
Attachment:
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Page Last Reviewed/Updated Tuesday, March 09, 2021