ML20198B134

Revised Special Rept:On 980505,discovered That Certain Fire Barriers Appeared to Be Degraded.Caused by Removal of Firestop Damming Boards.Hourly Fire Watches Established in Affected Areas

ML20198B134
Person / Time
Site:	Catawba
Issue date:	12/14/1998
From:	Gordon Peterson DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9812180070
Download: ML20198B134 (10)

Text

' Duke Energy Corporation Catawba Nudear Station 4800 Concord Road

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Y York. SC 29745 (803) 831-4251 OFFICE 3

Gary R. Iwerson (go3) g31342Gux Vice hesident December 14, 1998 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

Duke Energy Corporation Catawba Nuclear Station Units 1 and 2 Docket Nos. 50-413 and 50-414 Special Report: Fire Protection Program Inoperable Fire Barrier Penetrations Revision 1 l

I Pursuant to Facility Operating License Section 2F, License Conditions 2.c. (8) for Unit 1 and 2.c. (6) for Unit 2, and Selected Licensee Commitment 16.9.5; attached is Revision i 1 of a Special Report concerning inoperable fire barrier I penetrations. Revision 0 of this Special Report, issued j ,

on June 2, 1998; addressed a condition that was discovered l on May 5, 1998. The only commitments contained in this I document are listed in the " Corrective Actions" section of I the attached report. There are no additional commitments I ,

I contained'in revision 1. l l

Questions regarding this Special Report should be addressed to J.W. Glenn at (803) 831-3051. I i

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Very trul urs, G. R. Peterson .I I

Attachment . P.C 9812180070 981214 P '

PDR ADOCK 05000413 .

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5 U.S. Nuclear Regulatory Commission December 14, 1998 V Page 2 4 Attachment  :

Special. Report l

Inoperable Fire Barrier Penetrations e

i Abstract: ,

On May 5, 1998 both Units were in Mode 1 (Power Operation) at

approximately 100% power. During a Triennial Fire Protection

Audit, it was discovered that certain. fire barriers appeared to be degraded. Investigation by Engineering determined that

' one fire barrier in a masonry block wall in the Auxiliary 4 Building was degraded and sixty penetration seals in the fire barrier in the Control Room floor were inoperable. Since these

fire barriers had been in this condition for an indeterminate  !

l time, it was determined that the requirements of Selected Licensee Commitment (SLC) 16.9.5 had not been met in the past history of the plant and the appropriate remedial actions had

. not been taken. The root cause of the problem in the Auxiliary Building was shrinkage of the firestop foam and damage that occurred when a forming board was removed. The root cause for the problem with the Control Room floor

firestops was improper installation during the construction ,

l- of the plant. Corrective actions were posting the required firewatches and repair of the Auxiliary Building firestop.

I Planned corrective actions include further inspections to j determine the extent of these problems and either removing

the Control Room floor as a committed fire barrier or '

! repairing the firestops.

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! During inspections per Planned Corrective Action #2 of l j Revision 0 of this Special Report, additional problems were l l

noted with void areas in large rectangular block out fire l z penetrations. These problems were caused by poor I installation practices and inadequate installation i procedures during the construction of the plant. I

! Catawba Nuclear Station Units 1 and 2 Facility Operating License NPF-35 and NPF-52 require that Duke Energy Corporation implement and maintain in ef'v:t all provisions of the

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approved Fire Protection Program as amended. It was i determined that the degradation described in this report constitutes a noncompliance with this license condition.

• j Consequently, this occurrence was reported within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of

discovery pursuant to the provisions of Facility Operating

! License Section 2F (Reference Event #34208, reported on May l 12, 1996 and updated on May 19, 1998 and November 13, 1998). l j Revision'1.of this Special Report is being provided within l  !

30

days of.the November 13, 1998 Update. l

U.S. Nuclear Regulatory Commission December 14, 1998 p Page 3 Introduction i

! Catawba Nuclear Station Units 1 and 2 are four loop

Westinghouse Units. Selected Licensee Commitment (SLC) 16.9.5, Fire Barrier Penetrations; is a part of the Catawba Fire ,

4 Protection (EIIS:KP) Program and is subject to the provisions I of the Catawba Facility Operating License Condition 2.c.(8)for NPF-35 (Unit 1) and License Condition 2.c. (6) for NPF-52 (Unit I 2). SLC 16.9.5 requires that all fire barriers and all

] sealing devices in fire barrier penetrations shall be operable

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such that fires would be confined or adequately retarded so i that the following criteria is achieved:

1. Fire will not spread from non-safety related areas to safety related areas,

, 2. Fire will not damage redundant analyzed post fire safe ,

j shutdown equipment, a 3. Fire will rot spread from the balance of plant to the

{ control complex (control room, cable rooms and j battery rooms),

! 4. Fire will not spread from non-containment areas to l containment areas.

Firestop number F-AX-348-W-134 is located in a masonry block

] wall that separates the Unit 1 A Train Component Cooling Pumps

from the Unit 1 B Train Component Cooling Pumps.

Firestops of the K-AX-657-F-XXX series (where XXX represents a sequential number) are located in the floor of the Control Room and separate the Control Room from the Cable Spreading Rooms. There are 79 of these penetrations of which 60 were found to be inoperable.

An audit of the fire protection program is required every three years. The audit is called the " Triennial Fire Protection Audit". This audit was performed at Catawba from 5-4-98 to 5-8-98. The Audit Number was SA-98-100(A11). The problems described in this Special Report were discovered as a result of this audit.

Description of Event 5-5-98 During a triennial fire protection audit 18:15 walkdown insp~ection it was noted that there

l U.S. Nuclear Regulatory Commission 1 December 14, 1998 y Page 4 4 was an excessive gap at the top of wall ,

firestop F-AX-348-W-134. The gap extended l completely through the barrier. Engineering verified that the firestop was inoperable, Operations was notified and a firewatch was posted.

5-5-98 Work request 98021525 (Work order 98044764-18:30 01) was generated for repair of the firestop.

5-6-98 The triennial fire protection audit team i

11:30 noted an excessive gap on the ".nderside of floor firestop numbers K-AX-657-F-104 and K-AX-657-F-109. When viewed from the upper side it appeared that the required eight inch minimum depth of foam had not been achieved.

5-6-98 Work request 98021617 (Work Order 98044845-15:00 01) was initiated to have the depth of foam measured in all circular sleeves in the Control Room Floor.

5-6-98 Hourly firewatenes were established for the 16:00 Control Room - Cable Spreading Rooms Area.

l 5-7-98 Maintenance completed the inspection of firestop foam in the Control Room Cloor penetrations and forwarded the data to Engineering.

5-7-98 Engineering notified Operations of Control 10:30 Room floor firestops with inadequate depth of foam. (A firewatch was already in place).

5-7-98 Maintenance completed repair of wall firestop 13:45 F-AX-348-W-134.

5-18-98 Additional inspections along with an 15:40 Engineering followup evaluation identified 24 additional inadequate floor firestops in six other committed barriers. These penetrations were declared inoperable. Hourly firewatches were established.

U.S. Nuclear Regulatory Commission December 14, 1998 g Page 5 11-12-98 During inspections per planned corrective I action #2 of Revision 0 of this Special l Report, problems were found that appeared I to be generic to all large block out I penetrations through committed fire I boundary walls. l 11-13-98 Engineering declared the 218 fire barriers I of this type inoperable and fire watches I were posted. l Cause Of Event The root cause of the problem for the auxiliary building wall penettation was determined to be shrinkage of the foam such that it pulled away from the top of the penetration blockout.

After the installation of a silicone foam penetration seal, some shrinkage is expected to occur. The installation procedure requires a new foam seal to be inspected 3 to 7 days after installation to ensure the seal is acceptable. The amount of shrinkage noted with this firestop was greater than the normal post installation shrinkage. There was also some apparent damage from the removal of firestop damming boards. I Other firestops were inspected for similar damage and no additional cases were found.

The root cause of the problem with the Control Room floor penetrations was determined to be improper installation of firestop foaming material during the construction of the plant. The Control Room Penetration seals were in embedded sleeves, which project four inches above the floor. Firestop foam was placed in the sleeve up to the top of the four-inch projection. The firestop foam should have been installed within the sleeve in the area of the floor slab instead of the area within the sleeve above top of the floor slab.

While performing intrusive inspections of fire penetrations I (removal of outer fiberboard and visually inspecting the I foam) per planned corrective action 2 of Revision 0 of this l Special Report, several types of deficiencies were I discovered with large rectangular block out fire stop i penetration seals. The type of deficiencies found include I the following: I I

1) Inadequate foam fill in the opening l

2) Shrinkage of foam away from the top edge of the opening i

3) " Cold Joint" gaps between layers of foam fill l

4) Voids created by gas bubbles I i

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U.S. Nuclear Regulatory Commission December 14, 1998 g Page 6 The first two deficiency types (1 and 2 above) ware created I because the large block out type openings are " foamed" with I a damming board installed on both sides of the opening. This I prevents the installer from being able to see the final I results of the foam injection. The penetration seal design I specifications and installation procedures were intended to I require a 3 to 7 day post installation inspection by I removing the top portion of the damming board on at least I one side of the penetration. Based on the inspections I completed thus far, it appears that the post installation I inspection was not performed consistently. l The second two deficiency types (3 and 4 above) are a result I of the placement of new layers of foam prior to allowing i adequate cure time of the previous layer. This results in l

, the entrapment of hydrogen gas bubbles as the foam layer is l curing. The installation instructions supplied by the I manufacturer of the foam recommends a 15 minute wait time l

, between layers. This wait time apparently was not adhered te I consistently. I 1

An Engineering review of the drawings for large rectangular l block out openings in committed fire barriers identified a I total of 218 locations where large block out penetrations I are installed. Further intrusive inspections on these 216 I block out openings will continue.

The root cause of the problem with the large block out wall I penetrations has been determined to be poor installation I practices and inadequate installation procedures during the I construction of the plant.

Fire watches are in place for all of the affected locations. I Any problems found during inspection of the penetration l seals are being repaired as they are discovered. l There are no EPIX failures associated with this event. This I is not considered to be a recurring problem. However, I similar problems have been noted at all Duke Energy Nuclear l Stations. 1 Corrective Actions Subsequent

1. Engineering personnel evaluated the items discovered by the audit team and notified Operations of conclusions.

U.S. Nuclear Regulatory Commission Dacember 14, 1998 ,

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2. Operations posted the required fire watches.

3. Firestop F-AX-348-W-134 was repaired by Maintenance.

4. Additional inspections were initiated to identify other problems.

Planned

1. Engineering will evaluate a modification to delete the Control Room Floor as a committed fire barrier. This is based on a study that was performed as a part of the

" Cost Beneficial Licensing Action" initiative. This study identified a new technical criteria for maintaining committed fire barriers. One criterion addressed barriers that separate areas of the control complex from other areas of the station. Since the control room and cuble spreading rooms are both within the control complex, it may be possible to remove the barriers between the two areas as committed fire barriers. If this approach is not feasible, the affected firestops will be repaired.

2. Additional inspections of similar configurations will continta and repairs will be made as necessary.

Additional Information The wall firestop in the Component Cooling Pump Area is a part of a boundary that is used to separate redundant Component Cooling Pumps and is intended to prevent a single fire from damaging redundant pumps and motors so as to allow repairs necessary to achieve cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after a fire event.

The firestops as installed in the Control Room floor (and similar) penetrations still afford some level of fire protection. The Control Room and Cable Spreading Rooms have lou combustible loadings, both areas are supplied with fire detection, and the Control Room is continuously occupied.

The current safety significance of the degradation of the I large penetration seals is mitigated by establishing l l compensatory measures consisting of hourly fire watches in I the affected areas and by the fire protection defense in I l

O.S. Nuclear Regulatory Commission December 14, 1998

/ Page 8 depth program. The fire protection program defense in depth I program includes the following: I I

Fire Prevention l I

A program for controlling activities that have I a potential to cause fires (hot work program). I I

Fire Control l I

Control of work activities including control of I combustible materials and housekeeping. I I

Designated storage areas for combustible material. I I

Fire Mitigation Elements l I

Early warning fire detection systems. I Fixed fire suppression systems. I Fire Brigade intervention. l Passive fire protection features including walls and I remaining installed portions of penetration seals. 1 I l In addition, Catawba Nuclear Station has a stand alone Safe 1 Shutdown Facility with an independent diesel generator and I i control room for mitigating 10CFR50 Appendix R Fire Events I and Security Events, i The health and safety of the public were not affected by this event.

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U.S. Nuclear Regulatory Commission December 14, 1998

/ Page 9 xc: L. A. Reyes U. S. Nuclear Regulatory Commission Regional Administrator, Region II Atlanta Federal Center 61 Forsyth S* , SW, Suite 23T85 Atlanta, GA 93 P. S. Tam NRC Senior Project Manager (CNS)

U. S. Nuclear Regulatory Commission Mail Stop O-14H25 Washington, DC 20555-0001 D. J. Roberts Senior Resident Inspector (CNS)

U. S. Nuclear Regulatory Commission Catawba Nuclear Site i

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U.S. Nuclear Regulatory Commission December 14, 1998

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bxc: ELL EC050 KE Nicholson PIP 0-C98-4396 NCPMPA-1 RGC Licensing File NCEMC PMPA SREC CN-801.01 CN04DC Electronic Distribution i

WM Hogan GD Gilbert PR Herran SL Bradshaw GR Peterson RA Jones BJ Horsley GH Savage PR Newton

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