ML20005D682

LER 89-005-01:on 890518 & 25,damping Board Removed from Penetration Containing Cable Tray.On 890531,voids Noted in Penetration Seals.Caused by Erroneous Vendor Procedures. Penetrations Restored & Procedures revised.W/891201 Ltr

ML20005D682
Person / Time
Site:	Arkansas Nuclear
Issue date:	12/01/1989
From:	Ewing E, Millar D ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2CAN128905, IEB-88-056, IEB-88-56, LER-89-005, LER-89-5, NUDOCS 8912140118
Download: ML20005D682 (6)

Text

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. . ; j Aruns,as Power & UpM Congany t.,, _j /ma mas twe:: Ox

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! December 1, 1989 l 2CAN128965 L

l U. S. Nuclear Regulatory Commission L- Document Control Desk {

Mail Station P1-137 Washington, D. C. 20555

SUBJECT:

Arkansas Nuclear One - 1. nit 2 Docket No. 50-368 License No. NPF-6 Licensee Event Report No. 50-368/89-005-01 Gentlemen:

In accordance with 10CFR50.73(c)(2)(1)(B), attached is the subject supplemental report concerning inadequate procedural guidance which resulted in voids in the sealant material of penetration fire barriers, rendering the barriers non-functional. Arkansas Power & Light Company previously committed to provide a supplemental report of additional discoveries of penetration fire barriers which did not meet the requirements of Technical Specifications upon completion of the inspections.

Very truly yours, a_.

E. C. wing General Manager, Technicti Support and Assessment ECE/DM/sgw Attachment i cc: Regional Administrator l Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 INPO Records Center 1500 Circle 75 Parkway ,

Atlanta, GA 30339-3064 pl 8912140118 891201 t I I PDR AI'OCK 05000368 S PDC.

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• I Form 1062.01 A i NRC Fore 366 U.S. Nuclear Regulatory Commission

-(9 83) Approved One No. 3150-0104 Expires: 8/31/85 LICEN5EE EVENT REPORT (LE R)

FACILITY NAME (1) Arkansas Nuclear One, Unit Two (DOCKET NUMBER (2) IPAGE (3) 10161010101 31 61 81)LQf,19J} i TITtt (4) Inadequate Procedural Guidance Resulted in Voids in sealant Material of i Penetration Fire Barriers Rendering the Barriers Non Functional IVENT DATE (5) LE R NUMBE R (6) i REPORT DATI (7) OTHER F ACILITIES INv0tvED (8) 1 l 15equentiell IRevisioni  !

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I Month! Day lYear lYear l l Number l l Number Monthi Day lYear 1 Facility Names )ocket Number (s) l i i i i l )1 0 0101 1 ,1 , j I i i 1 I >

0! 51 11 81 81 91 Of 91--! 01 01 61--I Of 1 11 21 01 11 81 91 i)I ,

0 10101 I l_

OPERATING 1 ITH15 REPOR1 15 5UBMIT1ED PUR5uANT "O THE REQUIREMEN16 0F 10 CFR 5:

MDDI (9) i 11 (Check one or more of the followinn) (11)

POWERI l _ I 20.402(b) I,,_,1 20.405(c) l_ I 60.73(a)(2)(iv) 1.,,,1 7 3. 71(b) ,

LEVEll 1 ,,,1 20.405(a)(1)(1) 1.,,,1 60. 36(c)(1) l _ l 50.73(a)(2)(v) l_l 73.71(c)

(10) 1110101 1 20.40$(a)(1)(11) l_ l 50.36(c)(2) l _l 60.73(a)(2)(vii) l_ l Other (Specify in '

l _ l 20.405(a)(1)(111) 1 JI 60.73(a)(2)(1) I,,,,,1 60,73(a )(2)(v111)( A)1 Abstract below and I,,,1 20.40$(a)(1)(iv) l . ,,,1 50. 73(a)(2)( t i ) l_l 60.73(a)(2)(viti)(B)1 in Text, NRC Form I l 20.40$fa)(1)(v) I i 60.73:o)(2)(111) 1 I b0.73:o)(2)(x) 1 366A)

LIC iNSEL C0h1ACT FOR TH15 L :R (2) ,

home 1 Telephone Nweber lArea 1 ]

Dana Millar, Nuclear Safety and Licensing Specialist l Code l l

$10111916141 13111010 i COMPLETE ONI tlNE FOR EACH COMPONENT F AltVRE DESCRIBED IN THIS REPORT (J) l l l lReportablel l l l l lReportablel Causel5ystool Component IManufacturerl to NPRD5 I ICouselsysteel Comoonent (Manufacturer to NPRDS I l l 1 1 1 1 I i ,

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I I l l l 1 l l 1 l i I I I I I I I I I I l I fiUPPLEMEN" REPORT EXPECTCD (la) l EXPECTEI) i Month Day Year

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l $UBMISSION 1 l l Yes (If ves. conolete Exoected Subsission Date) III No I DATE (15) I i I i l l ABSTRACT (Limit to 1400 spaces, i.e. , approximately fif teen single space typewritten lines) (16) l in May 1989 AP&L initiated a plan to conduct non-routine inspections of penetration fire barriers l located in wall blockouts that contain silicone foam material with fire-retardant (damming) boards on both sides of the penetration as a result of NRC Information Notice 88*b6,

• Potential Problems with j Silicone foam Fire Barrier Penetration Seals". As a result of the inspections, twenty-four penetrations l l located in various fire barriers separating plant fire areas were identified with voids in the silicone i i foam material, rendering each penetration f f re barrier non-functional. As required by Technical

( 5pecifications, a fire watch was established within one hour of discovering the degradation in the seals.

i in each affected area fixed fite detection systems and fire suppression equipment are available to help  ;

l prevent the spread of a fire, therefore, the safety significance is minimal. Additionally, trained fire brigade personnel are continuously available. Initial seal installation procedures used to install the '

l I silicone foes material were inadequate to ensure voids did not exist. Procedure revisions have been made to require removing of the damming boards on both sides of the barrier when performing repairs to previously sealed blockouts. Additional procedure revisions for new seal installations are in progress.

Repairs have been completed to restore each of the identified seals to the functional capability required by Technical Specifications. The ins. sections of the penetration fire barriers have been completed.

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. l Firm 1062.018

.NRC Foin 366A U.S. Nuclear Regulatory Commission (9 63) Approved OMB No. 3150 0104 LICEN5ft EVENT REPORT (LER) T[XT CONTINUATION FACILITY MAME (1) IDOCKCT NUMBER (2) l ttR NUMM R (6) l PAGE (3) l l l 15equentiell l Revision]

Arkansas Nuclear One, Unit Two i I Yearl I Number l l Number l 10151010I0I 31 61 et et 9f--t 01 01 bi--I of Il01210F10lb l TEXT (If more space is required, use additional NRC Form 3660 s) (17) l A. Plant Status At the time of discovery of the findings discussed in this report, Arkansas Nuclear One, Unit 2 l (AND-2) was in Operational Mode 1 (Power Operations). Reactor power level varied between 70 percent i and 100 percent full power. The seventh refueling outage on AND-2 began September 25, 1989 and ]  !

ended November 22, 1989. I B. Event Description ]

In May 1989 special non-routine inspections of penetration fire barriers located in wall blockouts l I that contain fire-retardant (damming) boards on both sides of a penetration were initiated as a l j result of NRC Information Notice 88-56, " Potential Problems with 5tlicone foam Fire Barrier "

i Penetration Seals". The Information Notice discussed the potential that 60ew of the installed fire t'arrier penetration seals (PEN / SEA Q , specifically silicone foam, may not meet minimum requirements due to voids, gaps, splits or lack of fill material. Previous inspections of penetrat o fire barriers were those required by Technical Specifications, which require a visual inspection 91 the barriers at 1sast once per 18 months. While performing visual inspections, if a damming I coord is present, the integrity of the board is inspected, however, the inspection procedure does I I

not required the removal of the damming board and the inspection of the sealing material found i between the damming boards (e.g., st11 cone foam). Therefore, any degradation of a fite barrier.

due to the silicone foam material being inadequate, would not be identified during a routine visual inspection of a penetration tire barrier. A plan was established to inspect approximately )

twenty-five percent of the penetration fire barriers located in wall blockouts. 1 On May 18, 1989, when the damming board was removed from a penetration located in a well separating a corridor from an Engineered Safety Features switchgear room, a void was found in the silicone foam material. The penetration, containing a cable tray, is a twenty-two inch by ten inch opening ,

in a three-hour rated fire well, which is approximately twelve inches thick. The void in the  !

silicone fome material was approximately seven inches in depth in a seal that contains ten inches j of silicone foam material, and apparently had existed since plant construction. Upon discovering i the void after the damming board was removed, the penetration fire barrier was comidered non-functional l i

and a fire watch was appropriately es i lished within one hout as required by Technical Specifications.

l On Nay 25, 1989, when the damming board was removed from e penetration located in a well separating a corridor from the turbine building, a void was found in the silicone foam material. The penetration,  ;

containing a cable tray, is an opening thirty-six by eighteen inches located in a three-hour rated J fire wall approximately eighteen inches thick. The degradation consisted of a hole aproximately '

two inches in diameter and eight inches in depth in a seal that contains ten inches of silicone I i foam material. Plant modifications had been made in April 1985 which required the seal to be i repaired. At the time the void was identified, a fire watch was already established in the affected area.

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On May 31, 1989, while continuing the inspections, two additional penetration seals were identified i l

with voids in the silicone fomm material. Both penetrations are located in a three-hour rated )

I fire wall, which is approximately twenty-four inches thick, that separates an electrical equipment 1 room from the cable spreading room. Each seal contained approximately ten incnes of silicone  ;

l foam material. One penetration, containing a cable tray, is a forty-tvo by fourteen and one half j

inch opening, The void, located below the cable tray, was approximately four inches in diameter .

and nine inches deep. Plant modifications were made in October 1984 which breached the seal and required repair to the seal. The other penetration, containing a cable tray and conduit, is an opening approximately forty-two by seventeen inches. The void was approximately two inches in diameter and six inches deep. Although, plant modifications were made that required the seal to ,

be breached in a refueling outage in 1986, the location of the void would not have been af facted (

by the modification, therefore, the void apparently existed since plant construction. A fire watch was already established in the area when the voids were identified.

As the non-routine inspections of penetration fire barriers that contain fire retardant damming boards on both sides of a ponctration were continued, between July and September 1989, twenty additional fire barriers were identified as degraded. AP&L has inspected one hundred percent of 1 the penetration fire barriers located in wall blockouts that contain fire-retardant damming boards 1 on both sides of a penetration. See Table 1 for a listing of the penetrations, date identified, locations, void sizes and available fire detection and suppression equipment. The inspections and repairs of the identified barriers have been completed. When each penetration fire barrier was identified to be degraded, a fire watch was established as required by Technical Specifications.

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• I Form 1062.01B WRC Fore 366A U.$. Nuclear Regulatory Commission ,

-(9-83) Approved OMB No. 3150-0104 d Expires: 8/31/85  !

LIC[NSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY MAME (1) (DOCAET NUSER (2) l L(R NUMB [R (6) l PAGE (3) )

l l l lhequentiell IRevisionl i Arkansas Nuclear One, Unit Two l l Yearl i Number 1 1 Number.l j 10t$t010101 St 61 81 81 9t--I 01 Of St--I of Il01310F10lb i TEXT (If more space is required, use additional NRC Form 366A's) (17) l l

C. Safety significance i The effected plant fire eress and the adjacent areno (with the exception of the turbine building), i to each identified penetration which was ditcovered to have degraded silicone foam material, are l equipped with fixed fire detection systew (ionization type smoke detectors) with annunciation in I the AMO-2 Control Room. A protective wire fire detection cystem also existed in the cable spreading room. Each of these fire detection systems is required to be operable by Technical $pecifications.

Additionally, fire suppression equipment is located in each af fected area, in the form of fire i extinguishers or fire water hese reels. The cable spreading room, also, has a fixed automatic I suppression system that is required by Technical specifications. Fire Brigade personnel, specifically trained in fire fighting, are available at all times in the unlikely event a fire were to occur.

Also, the affected areas are easily accessible by personnel. Although the seals were degraced, considering the combination of the fixed detection, suppression equipment availability, and the response of the fire brigade personnel, significant protection against the spread of a fire existed. Therefore, the safety significance of the degraded seals is minimal.

D. Root Cause During initial plant construction, vendor procedures were used for the insteilation of silicone foam fire barrier sealant material and damming boards. The instructions included in the procedure did not specifically require an inspection of either side of the foam material after it was injected into the penetration. A plant specific procedure for seal installation was written and implemented in October 1985. Also, a training program was established to train personnel on j installation of seals. However, the procedure required that only one side of the foam seal be  !

inspected for voids prior to the final damming board being installed. Inspection of only one side I of the seal was not adequate to identify a problem with voids in the material, j

[ach of the identified rsnetrations that was found degraded had silicone foam material installed I per the vendor procedure and therefore, post installation inspections were not required to be i performed. Without inspections any voids that may have been present in the silicone foam material j would not be identified.

E. Basis for Reportability Technical Specifications requiee that all penetration fire barriers protecting safety related I areas shall be functional at all times. If one or more of the required penetration fire barriers is non-functional, a continuous fire watch shall be estabitshed on at least one side of the affected penetration within one hour. When each of the barriers was identified as being non-functional, a fire watch was established within one hour as required by Technical Specifications. However, the barriers had been non-functional for greater than one hour, therefore, these events are reportable i per 10CFR$0.73(a)(2)(1)(B).

F. Corrective Actions Repairs have been completed to restore each identified penetration to the functional capability require.' by Technical Specifications. Procedure revisions have been made to require the removal i of the damming 1. cards on bu*at sides of the barrier when performing repairs to previously sealed l blockouts. To ensure both sides of the sealant material are inspected when performing new seal installations, an evaluation of the procedure is in progress and final revisions will be completed by December 31, 1989.

G. Additional Information There are no previously reported similar events related to degraded silicone foam material in penetration fire barriers.

Inspections of penetration fire berriers on Arkansas Nuclear One, Unit One have been initiated and no degraded seals have been identified to date. Only one barrier remains to be inspected and I it will be inspected by December 31, 1989 I Energy Industry Identification System (EII5) codes are identified in the text as (XX).

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. I Firm 1042.013 l NRC Fem 366A U.S. Nuclear Regulatory Coenlission +

j (9 83) Approved 006 No. 3150-0104 l

tapires: 8/31/85 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION l FACILITY NME (1) l DOCKET NVISER (2) l .ER WUDGER (6) l PAGE (3) l l I i i Lequentiali IRevisioni Arkansas Nuclear One. Unit Two I i Yearl i Number I i Number i  ;

10151010101 31 61 81 8) J,j,- I Of 01 51--I 01 Il01410F1015 TEKT (If more space is required, use additional NRC Fore 366A's) (17) J l

Table 1 ]

Date Fire 8errier Location - Void Size Fire Detection / Fire l Note 3 Number Fire Zone Note 1 Suppression Eouipment q 1

7 10-89 2104-08-133 Diesel Generator Access Three Voids ionization Type Smoke i l

Corridor and Notor Control 1) 10x3x10 Detectors and Protectowire Center 372 Elevation 2) 2x2x3 with Control Room Auxiliary 8u11 ding (A8) 3) 2x2x2 Annunciation. Open head sprinkler system.

Note 2.  ;

1 10-89 2104 07-0115 64x14x6 i 7 12-89 2104-02-0073 2x5x10 2104-02-0083 24x24x10 7-31 89 2104 07 0121 Two Voids

1) 4x8x6

2) 2x2x6 7 10-89 2098-04 0072 Cable Spreading Room 6x14x6 Protectowire and ionization 372 Elevation AB type smoke detectors with Control Room Annunciation.

Closed and open head sprirkler systems. Note G.

7 25-89 2098-07-0091 2x2x10 7-28 89 2098-06-0089 Unknown-2098-06 0093 Airflow between rooms 1 I

7-31 89 2111-05-0001 Lower South Electrical 3x1x10 lonization Type Smoke Penetration Room. Detectors with Control Roon 372 Elevation AB annunciation. Pre-action closed head sprinkler systes. ,

Note 2.

8-7 89 2111 07-0017 Two Veids

1) 4xbx10

2) 4x5x10 8-9-89 2076-02-0057 Electrical Equipment 4x4x10 lonization Type Smoke (Notor Generator Set) Detectors with Control Room Room. 354 Elevation annunciation. No fixed fire A8 suppression equipment. Note 2. ,

8-10-89 2073-05 0140 Access Corridor; Pump %x3x10 lonization Type Smoke Detectors 2073-05-0152 and Tank Area 1x20x10 with Control Room annunciation.

354 Elevation AB No fixed fire Suppression.

Note 2.

4-15-89 2073-05-0135 4x10x10

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. s Form 1062.018 NRC Forn 366A U.S. Nuclear Regulatory Commission (9-83) Approved 04 No. 3150-0104 Empires: 8/31/85 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY M4NE (1) 100CKET NUS ER (2) l '.ER NLSSER (6) l PAGE (3) l l l l3equentiell lRevisioni Arkansas Nuclear Otse. Unit Two l l Yearl Number i Number l 10151010101 31 61 el el 91-- 01 01 5 --t Ot it01510F1015 TEXT (If more space is required, use additional NRC Fors $66A's) (17)

Table 3 Date Fire terrier Location Void Site Fire Detection / Fire Note 3 Number Fire Zone Note 1 Suporession Eouisment 9*29 89 2081-04-0037 Upper North Pipin0 3x,20x9 fonfration Type Smoke Penetration Area. Detectors with Control 354 Elevation AB Room annunciation. No fixed fire suppression equipment. Note 2.

8 13-89 2017-05-0063 Access Corridor, Boron 4x24x10 Ionization Type Smoke Mana0ement System Detectors with Control Area (Fire Zone 2040) Room annunciation. No 335 Elevation AB fixed fire suppression equipment. Note 2.

9-13-89 2055-05-0049 Lower South Piping 3x13x9h Iontratien Type Smoke Penetration Room Detectors with Control 335 Elevation AB Room annunciation. No fixed fire suppression equipment. Note 2.

9 14 89 2055 02-0137 4x4x9 9-14 89 2055 07-0173 14x14x9%

NOTE 1: Each void site is listed in inches with the last dimension being depth. The approximate thickness of the silicone foam material in each penetration is ten inches.

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NOTE 2: Manual fire suppression equipment in the form of portable fire extinguishers and fire hose reels are available. The area is easily accessible by fire brigade personnel.

NOTE 3: The identified date is the date of discovery of the degraded fire barrier.

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