ML17251A730

Assessment of Removal of Raised Floor & Mod to Fire Detection Zones for Plant Process Computer Sys (PPCS) Computer Room at Ginna Nuclear Plant, Informal Rept

ML17251A730
Person / Time
Site:	Ginna
Issue date:	05/31/1986
From:	Phillips K IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY
To:	NRC
Shared Package
ML17251A729	List: ML17251A728 ML17251A730
References
CON-FIN-D-6023 EGG-NTA-7266, TAC-60800, NUDOCS 8608190229
Download: ML17251A730 (12)

Text

EGG- NTA-7266 May 1986 INFORMALREPORT Idaho ASSESSMENT OF REMOVAL OF THE RAISED FLOOR AND National MODIFICATION TO THE FIRE DETECTION ZONES FOR En gineering THE PLANT PROCESS COMPUTER SYSTEM (PPCS)

Laboratory COMPUTER ROOM AT THE GINNA NUCLEAR PLANT Managed by the U.S. K. Phillips Oepartment of Energy 0

+Q E &Pi& Idaho Prepared for the Work performed under U, S, NUCLEAR REGULATORY COPINISSION DOE Conrrecr No. DE-A C07-76IDOf570 86081'70229 860604 PDR ADOCK 05000244 F PDR

ASSESSMENT OF REHOVAL OF THE RAISED FLOOR AND MODIFICATION TO THE FIRE DETECTION ZONES FOR THE PLANT PROCESS COMPUTER SYSTEN (PPCS) COHPUTER ROON AT THE GINNA NUCLEAR PLANT IREL R Lead NRC Rev i ewer H. Fa irti1 e I"RL I RI I TAC No. 60800 Docket No. 50-244 EGM Idaho, Inc.

Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Under DOE Contract No. DE-AC07-76ID01570 FIN No. D6023

ABSTRACT This EGKG Idaho, Inc. report assesses the effect of removal of the raised floor and modif1cation to the fire detection zones for the Plant Process Computer System (PPCS) Computer Room at the Ginna Nuclear Plant of Rochester Gas and Electric Corporation (RGKE). Th1s assessment is specific to this one computer 1nstallat1on and determines that there is no compromise of NRC f1re protection requirements by the removal of the raised floor.

II

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CONTENTS ABSTRACT ... ..........

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1. INTRODUCTION ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 1

2. REVIEW REQUIREMENTS 4 ~ ~ ~ ~ ~ ~ ~ ~ ~ 2

3. EVALUATION ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 3

4. CONCLUSIONS 6 5 REFERENCES ....................................................... 7

ASSESSMENT OF REMOVAL -OF RAISED FLOOR AND MODIFICATION TO THE FIRE DETECTION ZONES FOR THE PLANT PROCESS COMPUTER SYSTEM PPCS COMPUTER ROOM AT THE GINNA NUCLEAR PLANT OF ROCHESTER GAS AND ELECTRIC CORPORATION RGSE

l. INTRODUCTION Rochester Gas and Electric Corporation (RGSE) 1s 1nstalling a new Plant Process Computer System (PPCS) at the G1nna Nuclear Plant 1n the Spring of 19S6. The PPCS 1s necessary to support the new Safety Assessment System requ1red by NUREG-0737. As part of this installation the existing computer room will be mod1fied. The ra1sed computer floor will be removed, and w1ring and cables for the computer will be relocated to a wire way under the new PPCS. The fire detection zone at the computer room ceiling will be used to activate the Halon F1re Suppression System for the computer room.

2. REVIEM REQUIREMENTS The removal of the raised floor and modification of the fire detector zones for the Plant Process Computer System {PPCS) Computer Room at the Ginna Nuclear Plant of Rochester Gas and Electric Corporation was evaluated against the requirement and recommendations of the following documents.

1. Title 10, Code of Federal Regulations, Part 50.48, Fire Protection.

2. Title 10, Code of Federal Regulations, Part 50, Appendix R - Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979.

3. National Fire Protection Association's National Fire Code, NFPA 12A Standard for "Halon 1301 Fire Extinguishing Systems, 1985."

In general, these requirements and recommendations outline the fire protection necessary to protect the PPCS against a ma]or fire loss. They outline the requirement for proper installation and operation of a total flooding Halon 1301 Fire Suppression System to protect the PPCS Computer Room at Ginna Nuclear Plant of RG&E.

3.. EVALUATION Title lO, CFR 50.48 requires a fire protection plan to be in place and have specific features for using automatic and manually operated fire detection and suppress1on systems to limit fire damage to structure, systems, and components 1mportant to the safety of the plant'.

Appendix R to 10 CFR 50 states: the fire protect1on program shall extend the concept of defense in depth to fire protect1on in fire areas important to safety, w1th the following ob]ectives:

o to prevent fires from starting o to detect rapidly, control, and extinguish promptly those fires that do occur o to provide protection for structure, systems, and components important to safety so that a fire that is not promptly extingu1shed by the fire suppression act1v1ties w1ll not prevent the safe shutdown of the plant.

The NFPA 12A standard 1s a gu1de for the installat1on, operation, and maintenance of Halon 1301 Fire Suppress1on Systems in order that such equipment will function as intended throughout 1ts life.

This evaluat1on is based on the assumption that the existing fire detection zones and Halon Suppression System fully meet the requirement outline above.

The current det'ection consists of two detection zones 1n the computer room, zone S07 under the ra1sed floor and zone 217 at the ceiling.

Zone Z17 at the ceiling provides alarm only and will not actuate the Halon System. The under-floor zone S07 will send alarm and activate the halon on

the operation of a second detector in the floor detector zone. The system has a two-out-of-four logic for operation. The Halon System 1s a total flooding system cover1ng the complete 20' 25' 8'omputer room including the under-floor area of the computer room. The modification to

'the computer room, detection system, and halon suppress1on system will consist of the following:

l. The raised floor will be totally removed.

2. The four detectors in Zone S07 under the ra1sed floor will be removed.

3. The four detectors at the ceiling in Zone Zl7 will be rewired so as to provide a two-out-of-four logic for operating the Halon System. Alarm will be provided by the first detector to operate, and halon will be discharged by the second detector to operate.

4. The halon container for the room, control system,,and quantity of agent will not be changed in any way. The system will be mainta1ned as a total flooding system covering the complete computer room. The concentration of halon discharged into the room will not be changed.

l. This modif1cation,will not increase the probability or sequences of an accident, but will decrease the probability by removing an area where detection does not function well, the under-floor area.

2. This mod1fication will not create the possibility of a new or different kind of accident from any acc1dent previously evaluated.

The potential is the same as that of a computer fire. The suppression is expected to operate faster from the ceiling detectors. Past experience has shown that ceiling detectors w1ll operate faster than under-floor detectors.

3. This modification will not involve a reduction in the margin of safety. The detector at the ceiling will provide faster detection, and maybe more reliable detection than the under-floor detection provided. The actuat1on of the halon will probably respond faster from the ceiling detector than it would have from the under-floor detectors.

This modificat1on to the PPCS Computer Room, Detection System, and Halon Suppression System will not change their ability to meet the NRC or NFPA requirements as mentioned above. Hith this modification the facility should still be fully acceptable from a fire protect1on standpoint.

4. .CONCLUSION It's concluded that the modification of the PPCS Computer Room at the Ginna Plant of Rochester Gas and Electric Corporation (RG&E) will not decrease the fire protection of this room in any way. If anything,'it will shorten the response time of the Fire Suppression System.

5. REFERENCES

1. Rochester Gas and Electric Corporation letter, Roger M. Kober to Harold R. Denton, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission "RGhE R. E. Ginna Nuclear Plant Docket No. 50-244," February 12, 1986.

2. EG&G Idaho, Inc. telecom, Ken C. Phillips to Mort Fairti le, NRC and Bob Allis, RGKE, "Modification to Fire Protection for Plant Process Computer Room at Ginna Plant of RG8E," May 12, 1986.

NRC FOAM 22$ U.S. NUCI.EAR RKQULATORY COMMISSION l. REPORT NUMBER IANgnrdhp TIOC, rdd Vol IYo.. i(nnYI 12 Bnl NRCM 1102, 220 t. 2202 BIBLIOGRAPHIC OATA SHEET EGG-NTA-7266 SEE INSTRUCTIONS ON THE A EVE ASK,

2. TITLE ANO SUBTITLE 2. LEAVE BLANK Assessment of Removal of the Raised Floor and Nodification to the Fire Detection Zones for the Plant Process Computer System (PPCS) Computer Room at the O OATE REPORT COMPLKTEO Ginna Plant MONTH YEAR

5. AUTHORISI May 1986 8, OATS REPOAT ISSUEO K. Phillips MONTH YEAR Hay 1986 T. PERFOAMING ORGANIZATION NAME ANO MAILINGAOOAESS((notuooZVICodol S. PROIECTITASK(Y(ORK UNIT NUMBER EGBG Idaho, Inc. 9, FIN OR GRANT NUMBER Idaho Falls, ID 83415 D6023

10. SPONSORING ORGANIZATIONNAME ANO MAILINGAOOAKSS (IncludoZio Codr( lll.TYPE OF AEPORT Division of PWR Licensing - B Informal Office of Nuc 1 ear Regul a tory Commission Washington, DC 20555 O. PERIOO COVERFO (Ineuoro dnlnl N/A

'I2. SUPPI.EMENTAAY NOTES

12. ASSTAACT (200 unudl or Inul This EG8G Idaho, Inc. report assesses effect of removal of the raised floor and modification to the fire detection zones for the Plant Process Computer System (PPCS) Computer Room at the Ginna Plant of Rochester Gas and Electric Corporation (RG8E). This assessment is specific to this one computer installation and determines there is no compromising of NRC fire protection requirements by the removal of the raised floor.

In. OOCUMENT ANAI.YSIS ~. KEYY(OAOSIOESCRIPTORS IS. AVAILABILITY STATEMENT Limited IS. SECVAITYCLASSIFICATION ITho onon(

O. IOENTIFIEASIOPKN KNOEO TERMS Unclassified ITho rooonl Unclassified 17,NUMBER OF PAQKS

'IS. PAICE