ML19305B075

Final Deficiency Rept Re Defective Vertical Fire Dampers. All Fire Damper Units Will Be Modified & Operationally Cycled Prior to or During Installation

ML19305B075
Person / Time
Site:	Wolf Creek, Callaway
Issue date:	02/12/1980
From:	BECHTEL GROUP, INC.
To:
Shared Package
ML19305B071	List: ML19305B070 ML19305B075
References
NUDOCS 8003190109
Download: ML19305B075 (5)

Text

{{#Wiki_filter:- m ws-Final Report on Vertical Fire Dampers ' for the ShTFPS Project Bechtel Power Corporation Gaithersburg, Maryland February 12, 1980 e 9 9 e

TABLE OF CONTD!TS 1.0 Introduction , 2.0 Description of Deficiency 3.0 Analysis of Safety Icpl cations 4.0 Corrective Action 5.0 Conclusi.on e e G .

1.0 INTRODUCTION

in compliance with 10CFR50.55(e), this report is being issued due te failure of vertical fire da=pers supplied to SNUPPS Project (Callaway , and Wolf Creek Jobsites) by Ruskin Manuf acturing Company, Grandview, Missouri, to close cocpletely. The dampers had been delivered to Union Electric's Callaway Unit No. I and Kansas Gas & Electric's Wolf Creek Jobsites.

2.0 DESCRIPTION

DEFICIENCY A nonconfor:ance report generated at Callaway Jobsite indicated failure of the lower end of the dacper blade closure spring (flat ribbon coil type) to remain in place, resulting in incocplete closure of the vertical dacpers. This failure was identified while the dampers were being operationally cycled. One end of spring, on dampers designed for vertical installation, becomes disconnected during cycling. Release of the spring interferes with full closure of the damper. A bracket at the lower end of the vertical da=pers holds the spring which is connected to the da per blade. The brackets were originally designed to be installed as shown in the left hand sketch of Ruskin Manufacturing Cocpany Drawing No. 5398 (copy attached). To provide extra support for the bracket, Ruskin decided to tack weld the top edge of ' the bracket to the dacper blade guide, as shown in the middle sketch on Ruskin Drawing No. 5396. The tack welding resulted in widening of the gap in the brackets and allowing the springs, in some instances, to slip out while they were recoiling during closure of the damper. 3.0 ANALYSIS OF SAFETY DLDLICATIONS Fire dampers are provided for all HVAC systec penetrations of fire rated walls to prevent spread of a fire through the ductwork free one area of the plant to another. Many of the fire rated walls provide , separation of redundant safe shutdown equipment. Approximately 85 l vertical fire dampers are used in the Auxiliary Building, 22 in the Fuel i Building, 117 in the Control Building, and 2 in the Reactor Building in each of the SNUPPS Units. Failure of a damper to fully close during a fire situation could l potentially permit the fire to spread from one fire area to another

        -   area containing safety related equipment.

 ,     4.0  CORRECTIVE ACTION                                                        ,

l A #6 screw using a washer, star lockwasher, and hex nut, will be  ! installed in the narrow portion of the spring slot, as shown in the , l Ruskin Manufacturing Company Drawing No. 5398. The verticsl fire  ! dampers for Callaway Jobsite have been returned to Ruskin for i necessary' modification. Fire dampers for Wolf Creek, not yet installed, will either be returned to Ruskin for the necessary  ; modification or else modiffad on site. Dampers already installed at Wolf Creek will be modified at the jobsite. Vertical fire dampers, not yet shipped to SNUPPS Units, will be modified prior to delivery. All vertical fire dampers modified per this report will be operationally cycled, prior to or during installation, to confirm acceptability. This deficiency has been reported to the NRC by Ruskin Manufacturing Company as a JZFR Part 21 defect. The Rus's.in report has provided the necessary generic information, required by 10CFR Part 21 reporting requirements.

5.0 CONCLUSION

After modification, all vertical fire dampers will close completely, as intended, and will prevent spread of fire from one fire area to another a;ea containing safety related equipment. o b i i

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