ML20079B918

Special Rept 1-91-005:on 910515,fire Barrier Assemblies Inoperable for Longer than 14 Days.Caused by Personnel Error.Penetration Declared Inoperable & Required Hourly Fire Watch Established

ML20079B918
Person / Time
Site:	Hatch
Issue date:	06/14/1991
From:	Beckham J GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1-91-005, 1-91-5, HL-1682, NUDOCS 9106180176
Download: ML20079B918 (5)

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n-i ,; 1 HL-1682 001794 June 14, 1991 U.S. Nuclear Regulatory Comission ATIN: Document Control Desk  :

l Washington, D.C. 20555 i

PLANT HATCH - UNIT 1 NRC DOCKET 50-321 OPERATING LICENSE DPR-57 SPECIAL REPORT l-91-005 FIRE BARRIER ASSEMBLIES IN0PERABLE E0R A PERIOD _LORGER_HiMLl4_ DAYS Gentlemen:

In accordance with Plant Hatch Unit 1 Technical Specifications section 6.9.2 and Appendix B of the Fire Hazards Analysis, Georgia Power Company is submitting the enclosed Special Report concerning fire barrier assemblies which were inoperable for a period greater than 14 days.

Sincerely, W/ / ]

J. T. Beckham, Jr.

OCV/cr

Enclosure:

Special Report 1-91-005

( cc: Georaia P1wer Company l

Mr. H. L. Sumner, General Manager - Nuclear Plant Mr. J. D. Heidt, Manager Engineering and Licensing - liatch l

NORMS V.S. Nuclear Regulatory CommissionJutshinaton. 0.C.

Mr. K. Jabbour, Licensing Project Manager - Hatch U.S. Nuclear. Regulatory Commission. Reaion 11 Mr. S. O. Ebneter, Regional Administratur Mr. L. D. Wert, Senior Resident inspector - Hatch 9106180176 910614 LL y f, DOC F. 0500 1

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ENCLOSURE PLANT HATCH - UNIT 1 NRC DOCKETS 50-321 OPERATING LICENSE DPR-57 SPECIAL REPORT l-91-005 flRE BARRIER ASSEMBLIES IN0PERABLE FOR LONGER THAN 14 DAYS RESULTS 111 A SPECIAL REPORT g AS E QQlM Q_BY THE flRE HAZARDS ANAL 111S a

A. REQVIREMENT FOR REPORT This report is required by Unit 1 Technical S ecifications section 6.9.2 which states that Special Reports shal be submitted as required by the fire Hazards Analysis (FHA) and its Appendix B requirements.

Appendix B of the fitA, section 1.1.1 states that fire-rated assemblics and sealing devices in fire-rated assembly penetrations separating fire areas must be operable. Action statement (b) requires that inoperable fire-rated assembly (s) and/or sealing device (s) must be restored to operable status within 14 days or prepare and submit a Special Report to the Commission within the next 30 days per Technical Specifications section 6.9.2. In the event described in this report, a cable penetration seal was found to be inoperable. Investigations showed that this condition had existed for longer than 14 days; therefore, this Special Report is required.

B. UNIT STATUS AT TIME Of EVENT On 5/15/91, at 0900 CDT, Unit I was in the Run mode at a power level of 2436 CHWT (100 percent of rated thermal power).

C. DESCRIPTION Of EVENT On 5/15/91, at approximately 0900 CDT, nonlicensed personnel reviewing Design Change Request (DCR)84-217 determined that cable penetration seal IT54-Z2A12 was inoperabis. Specifically, the cable penetration seal assembly, known as a Nelson frame, was not installed in accordance with the manufacturer's instructions. The penetrations are sealed with Nelson blocks, mechanical devices which slip over the cables and seal the penetration. In place of four of thirty-five Nelson blocks, a silicone scalant known as RTV-106 was used in approximately a 0.4 square foot area of the penetration. Even though the RTV-106 has fire resistive characteristics, the material has not been tested as a substitute for the Nelson blocks in the seal assembly. Consequently, the three-hour fire rating of the pe.1etration seal assembly was jeopardized.

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ENCLOSURE PLANT HATCH - UNIT 1 NRC DOCKETS 50-321 OPERATING LICENSE DPR-57 SPECIAL REPORT l-91-005 flRE BARRIER ASSEMBLIES IN0PERABLE FOR LONGER idAN 14 DAYS RESULTS IN A SPECIAL REPORT AS RE0VIRED BY THE FIRE HAZARDS ANALYSIS A. REQUIREMENT FOR REPORT This report is required by Unit 1 Technical Specifications section 6.9.2 which states that Special Reports shall be submitted as required by the fire Hazards Analysis (FHA) and its Appendix B requirements.

Appendix B of the FHA, section 1.1.1 states that fire-rated assemblies and sealing devices in fire-rated assembly penetrations separating fire areas must be operable. Action statement (b) requires that inoperable fire-rated assembly (s) and/or sealing device (s) must be restored to operable status within 14 days or prepare and submit a Special Report to the Commission within the next 30 days per Technical Specifications section 6.9.2. In the event described in this report, a cable penetration seal was found to be inoperable. Investigations showed that this condition had existed for longer than 14 days; therefore, this Special Report is required.

B. UNIT STATUS AT TIME OF EVENT 1 On 5/15/91, at 0900 ;DT, Unit I was in the Run mode at a power level of 2436 CHW1 (100 percent of rated thermal power).

C. DESCRIPTION Of EVENT On 5/15/91, at approximately 0900 CDT, nonlicensed personnel reviewing Design Change Request (DCR)84-217 determint.d that cable penetration seal IT54-Z2Al2 was inoperable. Specifically, the cable penetration seal assembly, known as a Nelson frame, was not installed in accordance with the manufacturer's instructions. The penetrations are sealed with Nelson blocks, mechanical devices which slip over the cables and seal l the penetration. in place of four of thirty-five Nelson blocks, a silicone sealant known as RTV-106 was used in approximately a 0.4 square foot area of the penetration. Even though the RTV-106 has fire resistive characteristics, the material has not been tested as a substitute for the Nelson blocks in the seal assembly. Consequently, the three-hour fire rating of the penetration seal assembly was jeopardized.

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ENCLOSURE (Continued) l SPECIAL REPORT l-91-005 flRE BARRIER ASSEMBLIES IN0PERABLE FOR LONGER THAN 14 DAYS RESULTS IN A SPECIAL REPORT AS RE0VIRED BY THE FIRE HAZARDS ANALYSIS Investigations into the event revealed that a walkdown of Nelson frame penetration seal assemblies had been performed in November of 1983 at which time deviations regarding the installation of Nelson frame penetration seal assemblies were identified. At that time, appropriate t.ompensatory actions were taken in accordance with the plant's Technical Specifications. These deviations were noted by the l Commission during an inspection in August of 1984 and addressed in l Report 50-321, 3G6/84-32, dated 9/17/84. One of the deviations noted in the 1983 walkdown involved the improper use of silicone in the ,

Nelson frame for penetration IT54-Z2Al2. OCR 84-217 was developed to i address the noted discrepancies including that associated with penetration IT54-Z2A12. The DCR was implemented during the Fall 1984 Jnit 1 Refueling outage. During implementetion of the DCR, it was determined that a permanent repair to penetration IT54-Z2Al2 seal assembly could not be completed by the end of the outage. The number of cables being routed through the penetration was more than the Nelson assembly could accommodate using the Nelson insert blocks. four of the thirty-five Nelson blocks could not be pro >erly installed without one of the cables being removed and rerouted tarough another penetration.

Consequently, a temporary resolution was incorrectly approved and implemented. The Nelson frame was reassembled and RTV-106 was used to provide a fire barrier around five of the cables routed throuch the penetration. The RTV was used to fill an area of approximateTy0.4 square feet. A permanent repair was planned for the following Unit 1 Refueling outage; however, actions were not taken to ensure the change was implemented.

Upon discovery of the condition on 5/15/91, # ficiency Card (DC) 1-91-2262 was written and licensed personnel were notified.

Subsequently, an hourly fire watch was established for the affected areas in accordance with the requirements of FHA, Appendix B, section 1.1.1.

D. CAUSE OF EVENT The cause of the event was cognitive personnel error on the part of nonlicer. sed personnel in that they failed to adequately evaluate the temporary repair to penetration IT54-Z2Al2 seal to ensure that the

! thred-hour fire rating of the seal was not jeopardized. Specifically, i per the manufacturer's instructions, RTV-106 is recommended for use as I a sealant between Nelson blocks and cable conduit with irregular l

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ENCLOSURE (Continued)

LPECIAL REPORT l-91-005 FIRE BARRIER ASSEMBLIES IN0PERABLE FOR LONGER THAN 14 DAYS RESULTS IN A SPECIAL REPORT AS RE0Q1RIQ BY THE flRE HAZARDS ANALYSIS surfaces, it is ap>arent that the involved engineering personnel concluded from this t1at it was acceptable to use RTV-106 as a fire barrier material in place of the Nelson blocks. Consequently, the involved personnel did not perform an adequate evaluation to ensure that RTV-106 itself actually had a three-hour fire rating.

E. ANALYSIS OF EVENT Fire-rated cable penetration seal assemblies are designed to prevent the propagation of a fire from one fire area to another, in the event described in this report, a fire-rated penetration assembly was rendered inoperable because it was assembled in an untested configuration. When this condition was discovered, licensed shift personnel implemented the compensatory actions of FHA, Appendix B, section 1.1.1, which requires verification that the applicable fire detection equipment was operable and the establishment of an hoLrly fire watch.

This fire-rated assembly is located on the west wall of the Unit 1 Reactor Building, and separates the Reactor Building (fire area 1104) from the east cableway (fire area 1205F) of the Unit 1 Turbine Building. Both fire areas are equipped with fire detection and suppression systems. Fire area 1205F is equipped with both linear thermal detectors and smoke detectors, and fire area 1104 is equipped with smoke detectors. Both fire areas are equipped with wet pipe automatic fire suppression systems, water hoses, and portable carbon dioxide fire extinguishers, in the unlikely event of a fire in either of these areas, it would be promptly detected and subsequently extinguished by the automatic fire suppression systems and/or the site's trained fire brigade.

Based on the above analysis, it is concluded that this event had no adverse affect on nuclear safety.

F. CORRECTIVE ACTIONS

1) The affected penetration was declared inoperable and the required hourly fire watch for the appropriate fire area was initiated.

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ENCLOSURE (Continued)

SPECIAL REPORT l-91-005 flRE BARRIER ASSEMBLIES INOPERABLE FOR LONGER THAN 14 DAYS RESULTS IN A SPECIAL REPORT ALRWHRED BY THE FIRE HA7AROS ANALYSIS

2) The affected penetration has been covered with a thermolag fire barrier material in accordance with approved plant procedures. The material provides a three-hour fire rated barrier for the penetration.

3) The Nelson frame seal assembly for the affected penetration will be  ;

restored in conformance with the manufacturer's instructions which will restore its three-hour fire rating, This will be performed during the next Unit I refueling outage, At that time, the ,

thermolag fire wrap will be removed. This action is currently i scheduled to be completed by 12/10/91.

4) GPC will review the Nelson frame seal assemblies modified during implementation of DCR 84-217, and will submit a revision to this special report if further problems are identified. This action is currently scheduled to be completed by 12/10/91.

No disciplinary action will be taken within Georgia Power Company I because the engineer responsible for approving the temporary repair is no longer employed by the Company, Current administrative controls governing the design change process and the fire protection program should be sufficient to help preclude a recurrence of this event, I

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