ML19354D482

Special Rept:On 890720,Halon Sys for Unit 1 Switchgear Room Inoperable.Caused by Personnel Error.Hourly Firewatch Established.Solenoid Functionally Tested Satisfactorily, Declared Operable & Connected to Halon Bank

ML19354D482
Person / Time
Site:	Calvert Cliffs
Issue date:	10/30/1989
From:	Russell L BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8911090311
Download: ML19354D482 (6)

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'OAS AND V n ,< ELECTRIC jj CHARLES CENTER . P.O. BOX 1475 BALTIMORE. MARYLAND 21203 ,

[,, s ' , t. EON B. RUSSELL

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,, . 3, CAtytRT CLIFFS NUCLEAR POWER PLANT DEPARTMENT x.

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' October 30,1989

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U. S. Nuclear Regulatory Cornmission Washington, DC 20555 m

' ATTENTION: Document Control Desk

SUBJECT:

Calvert Cliffs ' Nuclear Power Plant i Unit Nos. I _ & 2; Docket Nos. 50-317 & 50-318 '

. Halon Systems Special Report '

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q- Technical Snecification 3.7.11.3a "

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' Gentlemen:-

, . Per . ' the requirements of Technical Specification 3.7.ll.3a, we hereby submit the. l following Special Report . .concerning an inoperable Halon ' system ' for the ~ Unit' I Switchgear Rooms.

Should you have any further questions regarding this matter, we will be pleased to discuss them with you.

Very truly yours, eD t

LBR/GLB/bjd (

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' 8911090311 891030 PDR ADOCK 05000317

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_, Docriment Contril Desk ' '

. , October 30, 1989

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.i L cc: 'D. ' A.' Brune, Esquire

, J. E. Silberg, - Esquare -

- R.4 A. Capra, NRC S. A.McNeil,NRC ,

W. T. Russell, NRC .

J. ' E. Beall, NRC I T. Masette, DNR 4  !

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4 HALON SYSTEM SPECI AL REPORT BACKGROUND At approximately 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> on July 20. 1989, with Unit I shutdown (MODE 5 Cold 1 Shutdown), a Fire and Safety Technician (FAST) discovered that a master solenoid to the Unit i Switchgear Room Halon System was disconnected. This solenoid actuotes the discharge of Halon from three of nine Halon cylinders located on the west wall of the 45-foot elevation Switchgear room. This disconnected solenoid was discovered during the routine performance of Surveillance Test Procedure (STP) M-291-0, "Halon System Valve Position Verification." However, the Halon System Master Solenoids are not checked as part of this STP and, therefore, the performance of the STP did not directly contribute to the discovery of this event.

Upon discovery of the disconnected solenoid, the Shift Supervisor was informed and the Halon System was immediately declared inoperable. The ACTION STATEMENT for Technical Specification 3.7.11.3, "Halon Systems," was entered and an hourly fire watch was established. The solenoid was inspected for damage and returned to its normal position, however, the ACTION STATEMENT remained in effect until an OPERABILITY determination could be made.

Even though there was no indication of damage to the solenoid or associated equipment, a functional test was performed to verify OPERABILITY. A maintenance order was initiated and OPERABILITY of the solenoid was verified by performing Section VII of STP-M-699-1, " Functional Test of 27' and 45' Switchgear Rooms Automatic Halon Release Solenoll Circuit." Upon satisfactory completion of the test, the Halon System was decle.rtd OPERABLE and the ACTION STATEMENT was exited at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> on July 20, 1989.

Further investigation into the event showed that the solenoid was last documented to be out-of-service ' between approximately 0830 and 0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br /> on June 29, 1989. A FAST had performed a fire system impairment tagout at this time in accordance with Calvert Cliffs Instruction CCI-133, "Calvert Cliffs Fire Protection Plan". The Halon System for the 27-foot and 45-foot Switchgear rooms was disabled by disconnecting each of the '

three master solenoids from its associated Halon cylinder bank. This is the standard  !

l. procedure for disabling a Halon system when work being performed in a room might cause j an inadvertent actuation of the Halon System. In this instance, maintenance I technicians wanted to heat a motor-generator coupling on the 27-foot level Switchgear room.

l~ The FAST who performed the tagout on June 29, 1989 believes that tit was unlikely that l

he left one master solenoid diconnected. However, CCI-133 did not require independent i

verification of the fire system impairment tagout. Therefore, there was no independent l

verification by any other personnel that all three master solenoids were actually reconnected on June 29. During the investigation, it was also reported that the master solenoids were observed to be in place on July 14, 1989. This observation occurred during an informal walkdown of the Halon System which was being conducted for the purposes of procedure development. However, this observation was not documented. No l maintenance or other activities were identified during the period between June 29 and l July 20 which would require the Halon System to be disabled in the 27-foot or 45-foot levels of the Switchgear Room. Consequently, since it cannot be determined beyond a reasonable doubt that the master solenoid was reconnected on June 29, we conclude from lL _ _ - . - . _. .

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HALON SYSTEM SPECIAL REPORT the documented evidence that 'the solenoid was inadvertently left disconnected.

This tevent was reported in a four hour report under 10 CFR 50.72(b)(2Xi) and in Licensee Event Report (LER) 89-12-Ol* under 10 CFR 50.73(aX2XiXD) as a condition prohibited by the plant's Technical Specifications.

CAUSE OF INOPERABILITY The root cause of this event was determined to be personnel error resulting from the lack of an approved, written procedure for rendering the Ilalon System inoperable by disabling the three master solenoids. Activities which modify fire protection systems i described in the Technical Specifications are required to be prescribed and accomplished in accordance with documented instructions, procedures, and drawings.

This task was incorrectly considered to be within the skills normally possessed by qualified personnel of the craft and, therefore, the FAST was unaware that a procedure was required. Contributing causes to this event are as follows.

CCI-133, "Calvert Cliffs Fire Protection Plan" does not adequately address the method for taking fire detection or suppression systems out-of-service. CCI-133 does not reference CCI-I l 7, " Temporary Modification Control." The purpose of CCI-ll7 is to ensure that the disabling, bypassing, or changing af systems, sub-systems, or components by some form of temporary modification will be properly reviewed for safety consequences, documented, and controlled. The task of disconnecting the solenoids was not recognized as a temporary modification to the plant. The use of CCI-il7 would have required an independent verification to ensure that all of the master solenoids had been returned to service before declaring the Halon System OPERABLE.,

in addition, CCI-133 does not adequately address when Safety Tagging is required or I its relationship to Fire System impairment Tagging. CCI-Il2, " Safety Tagging" is not I referenced by CCI- 133. The purpose of CCI-il2 is to establish procedures for the tagging of equipment to ensure the safety of personnel and to ensure no adverse effect on operating equipment. Fire System Impairment Tags are placed on fire detection and

suppression equipment whenever they are taken out-of-service for maintenance. Due to ,

l the ambiguity of these instructions, a Safety Tag was considered not to be required for '

l this task.

l l EFFECT ON UNIT OPERATION l An evaluation of Halon concentration with the three-bottle bank unavailable was l performed. An initial concentration of approximately 6% - was calculated as available for the 45-foot elevation Switchgear room and approximately 3.45% was calculated for the 27-foot Switchgear room. It can be concluded that the Halon system, even with the three-bottle bank inoperable, would have prevented fire spreading within the room as NOTE: Revision 1 of LER 89-12 issued October 27, 1989, revised the event date from July 20, 1989 to June 29, 1989. As a result, the Halon System was declared inoperable for greater than 14 days, (i.e., June 29 - July 20, 1989) and the special report has subsequently been submitted late.

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is-L HALON SYSTEM SPECIAL REPORT '

P well as outside the room. Our bases for this conclusion are provided below:

In the 45-foot Switchgear room the initial discharge concentration of 6% is ,

above the recommended extinguishing concentration of 5% for this type of room.

In the 27-foot Switchgear room the initial discharge concentration of 3.45%, while below the recommended extinguishing concentration, would have ,

stopped flaming combustion and thereby prevented a fire from spreading.

• l The detection systems which actuate the Halon systems were functional.

These systems provide an alarm indication to the Control room. In addition, these systems utilize smoke detectors which respond much faster to fire conditions than heat detectors. Therefore any fire leading to discharge of the Halon system would have still been in an l' incipient stage.

i The plant fire brigade would respond to a fire in time to provide extinguishment . of glowing combustion still remaining after the llalon discharge.

Therefore, there is reasonable assurance that the safety of the plant and the public was not significantly compromised by the event.

1)(MEDIATE CORRECTIVE ACTIONS TAKEN

The following corrective actions were taken on July 20, 1989

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L . Upon discovery of the event, the I-lalon system was declared INOPERABLE and an hourly. fire watch was established in accordance with Technical li Specification 3.7.11.3. .

. After inspecting the solenoid for any noticeable damage, the solenoid was L connected back to its Halon bank. Therefore, though remaining inoperable

l. by Technical Specifications, the Halon system was functional.

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. The solenoid was functionally tested satisfactorily and declared OPERABLE, CORRECTIVE ACTIONS TAKEN TO PRECLUDE REOCCURRENCE The following corrective actions have been taken as a result of this event:

p . CCI-133 has been revised to discontinue the use of fire system impairment L

tags and, instead, will reference CCI-i l2 Safety Tagging requirements.

CCI-133 will also require the use of CCI-il7 for temporary modifications to fire : detection and suppression sy:;tems.

. STP-M-291-0 has been revised to require verification that llalon actuator l

solenoids are properly installed. This STP and STP-M-699-1 have also been revised to have distinct verification and sign-offs for each Halon System station.

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i i 15ALON SYSTEM SPECIAL REPORT

. Identification tags have been installed on llalon master solenoids.

. . Warning signs have been placed near llalon. cylinder banks which state, TIRE SUPPRESSION SYSTEM DO NOT DISTURB WITilOUT PERMISSION, CALL FIRE PROTECTION UNIT: X-4755/4931."

1 The following corrective actions will be taken as a result of this event:

. A Quality Assurance Surveillance will be conducted to: (1) evaluate if CCI-ll2 and 117 are applicable to any other plant activities not currently being applied to these CCis and (2) determine if plant personnel (sample selected from cognizant disciplines) have an adequate working knowledge of 3

CCis i12, i17, and 133.

. Fire and Safety personnel will receive training on the revised requirements. j of CCI-133 and CCI-il7.  !

. A written procedure will be established for disabling and restoring the Halon System master solenoids.

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