ML19325F212

Corrected Supplemental Response to Violations Noted in Insp Rept 50-458/89-24.Corrective Action:Operations Personnel Secured Standby Water Svc Sys to Isolate Leak

ML19325F212
Person / Time
Site:	River Bend
Issue date:	11/07/1989
From:	Booker J GULF STATES UTILITIES CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RBG-31731, NUDOCS 8911170039
Download: ML19325F212 (5)

Text

'

ig , I

?% , '

, - A .

(;'dN '

, GULF STATES ' UTELITIES COMPANY m ,n, m ,a n ,m, wmm m o ,, - - w m ,a m ,,

i m a cu,m mw m em j i

November 7,1989  ;

RBG- 31731 _

File Nos. G9.5, G15.4.1 l

n O. S. Nuclear Regulatory Commission  !

Document Control Desk i Washington, D.C. 20555 -

i

^

i Gentlemen:

i River Bend Station - Unit l' 'i

. Refer to: Region IV ,

Docket No. 50-458/ Report 89-24  ;

r Gulf States UtilitiesCompany(GSU)isprovidingourcorrectedsupplemental }

> response to Notice of . Violation- 8924-01, " Failure' to Provide Adequate Procedures for Control of a Special Process," as discussed with Messrs. W. y n Paulson, D. Nottley and G. Constable of your staff on August 24 and September i 12 1989. This supplement provides grammatical corrections to the supplement

~

- dated October 17, 1989. These changes were discussed with your Messrs. W. A. r Paulson and G. L. Constable on October 31, 1989.  !

Should you'have any questions, please contact Mr. L. A. England at (504) 381- l 4145. , ,

Sincerely, j

. F.M!

J. E. Booker i

' Manager-River Bend Oversight l River Bend Nuclear Group  :

JEB/ / / CMC /ch ,

Attachmentt l

cc: U.'S. Nuclear Regulatory Commission  ;

Region IV^

611 Ryan Plaza Drive Suite 1000 Arlington, TX 76011 ,

NRC Senic,r Resident Inspector P. O. Box 1051 St. Francisv111e, LA 70775 8911170039 spitoy

[60f g'DR ADOCK 05000458 I t PDC P

4 ,. - ---

. e .

. ATTACHMENT Response to Notice of Violation 50-458/8924-01 Level IV REFERENCES,:

Notice of Violation - i.etter from J. L. Milhoar to J. C. Deddens, dated June 30, 1989.

Licensee Event Report 89-020 from J. E. Booker to Document Control Desk, dated May 19, 1989.

Augmented Inspection Team - Inspection Report No. 50-458/89-20 from L. J.

Callan to J. C. Deddens, dated May 16, 1989.

FAILURE TO PROVIDE ADEQUATE PROCEDURES FOR CONTROL OF A SPECIAL PROCESS:

River Bend Station Technical Specification 6.8.1.a requires that procedures be established, implemented, and maintained covering the activities recommended in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978.

Appendix A of Regulatory Guide 1.33. Revision 2. February 1976, Paragraph 9, requires that maintenance activities that can affect the performance of safety- related equipment and that require skills not normally pussessed by qualified maintenance personnel be properly preplanned and performed in accordance with detailed procedures.

Contrary to the above, Corrective Maintenance Procedure (CMP)-9186, Revision 4, " Freeze Seal " did not require the use of a temperature detecting device in the sleeve of the freeze seal chamber to monitor the freeze plug integrity and the procedure did not prohibit supplying more than one freeze plug from the same nitrogen bottle. These procedural inadequacies contributed to the loss of freeze seal event on a 6-inch service water line on April 19, 1989.

, REASON FOR THE VIOLATION:

Gulf States Utilities Company (GSV) has reviewed Inspection Report No.

50-458/89-20 concerning the NRC Augmented Inspection conducted April 21-24, 1989, and has found the facts contained therein to be factual and accurate.

Licensee Event Report (LER)89-020 was submitted May 19, 1989 and discussed this event as well. GSU believes that there were several contributing factors which led to the occurrence of this event:

1. An insufficient supply of liquid nitrogen coolant to the freeze plug resulted in a failure of the freeze plug.

2. Both freeze plugs were fed from the same nitrogen supply line. This system did not provide for independent control of liquid nitrogen flow to each of the two plugs.

Page 1 of 4

I 3. Corrective Ma htenance Procedure (CMP)-9186, Rev. 4 was ambiguous with

respect ta the temperature monitoring requirements for freeze plugs.

l Also, t'ni s procedure did not prohibit the use of an adequate coolant

! supply to feed multiple freeze plugs.

4. Inadequate freeze plug monitoring resulted in the failure of the personnel involved to detect the onset and continuation of thawing of the freeze plug. The lack of freeze plug temperature monitoring was '

the major weakness identified.

5. Maintenance personnel had limited experience applying freeze plugs and ,

a lack of formal training on freeze plugs may also be contributory f

! factors to the incident. l

6. Operators lacked pertinent information as to the exact location of the freeze plug activity in progress and the lack of contingency plans to i mitigate consequences of freeze plug failure hampered the control c room s ability to respond to the failure. However, given the L

circumstances surrounding the incident, plant personnel responded  ;

commendably. *

CORRECTIVE STEPS WHICH HAVE BEEN TAKEN AND THE RESULTS ACHIEVED: ,

Immediate corrective actions taken included: operations personnel secured the Division Il standby service water system to isolate the leak; reactor '

protection system power was transferred to its alternate power supply; the shutdown cooling mode of the residual heat removal system was restored within approximately 17 minutes with an insignificant increase in reactor coolant  ;

temperature; and, GSU management dictated that freeze plugging activities would no longer be performed by GSU personnel. ,

The standby)for ISWP*VF0525 service water1HVR*UC11B unit cooler supply and return isolation valves were successfully (ISWP*VF0524 repaired under a and revised maintenance work order (MWO) using another pair of freeze plugs installed and maintained by a contractor (Freeze Technologies, Inc.) ,

specializing in this service. Freeze Technologies, Inc. performed subsequent freeze seals during the second refueling outage.

The Equipment Qualification and Specification Group of Design Engineering performed a walkdown of the affected areas of the auxiliary building to identify those equipment items susceptible to moisture ingress. All Class IE switchgear inspected was dry internally, and there were no water lines noted on the structures. MW0s were written to perform internal inspections of the equipment in other areas where it was suspected that moisture ingress was ,

possible. The devices located within the equipment was cleaned, dried, and returned to its qualified condition where moisture was found internally. The documentation action of this inspection is contained in Equipment Qualification Impact Summary (EQIS) No. X-388.

Corrective Maintenance Procedure (CMP)-9186, " Freeze Seal," was revised on May 3, 1989 via Temporary Change Notice (TCN) 89-0462 to emphasize the requirement of temperature monitoring during freeze plugging. This TCN also prohibited the setting of multiple freeze plugs using an inadequate coolant supply.

Page 2 of 4

An existing Engineering Evaluation and Assistance Request (EEAR) 86-R0093 for water proofing of all non-safety related switchgear equipment in the  !

. . auxiliary building was dispositioned to initiate Modification Request (MR)  :

'. 89-0135 to address the floor electrical penetrations in'. motor control centers, IEHS*MCC2J and 1EHS*MCC2L and to prevent future' electrical failures ,

of Auxiliary Building 13.8KV switchgear due to flooding.

The Independent Safety Engineering Group (ISEG) prepared Operating Experience Report (OER)89-008, dated June 13, 1989. This report reviewed the freeze

' plug failure event and the corrective actions taken. Based on those corre:tive actions taken, no additional ISEG recommendationc were made.

Quality Assurance performed six surveillances as a result of this event:

1. OS-89-04-49, " Conduct of Operations After Freeze Seal Transient",

l,

2. 05-89-04-48, " Loss of Freeze Plug Incident",

3. 05-89-05-35, " Follow-up on 05-89-04-48" l

4. 03-89-05-18, " Freeze Seal", and '

5. 05-89-04-61, " Unscheduled Surveillance on Freeze Technology i International Inc."

6. ES-89-04-64, " Moisture Intrusion in Electrical Equipment" recommended i EEAR 86-R0093 be completed. The EEAR is finalized and MR 89-0135 has  ;

been initiated.

1 Condition Reports (CR) 89-0492 and 89-0493 were issued to document the 4

reconrnendations of these surveillances. CR 89-0492 describes the procedural deficiencies and CR 89-0493 discusses the training deficiencies previously l identified.

, Gulf States Utilities has reviewed the effects of discharging the fire water spray system ~on the 141' elevation of the auxiliary building. This study considered the effect of ponding water on the protected elevation as well as all elevations below. Also included was the effect of water, in the form of i sprinkler discharge or floor runoff, on safe shutdown equipment. The basis i for this investigation was the original design criteria established for the fire hazards analysis (FHA) and the moderate energy line crack (MELC) analysis.

Neither analysis took credit for the floor drain system, assuming water discharging underneath stairvell doors and down the elevator shaft. The latest study showed that the depth of water on the 141' elevation due to fire water flow is less than 0.75". Therefore, no safe shutdown equipment is affected by flooding due to fire water discharge since all safety related equipment is elevated at least 1.375".

Water spray effects on the safe shutdown equipment were also reviewed, using the MELC guidance. Two potential targets were identified on the fringe of the sprinkled area, panel ISCV*PNL2C1 and transformer ISCV*X02C. The MELC analysis required the conduit entering this equipment to be sealed for water Page 3 of 4 l

y .4 o

entry and notes shielding is provided by adjacent equipment. Due to the l small amount of spray, protected conduit entry and shielding, this equipment i will not be damaged by sprinkler discharge. Below the 141' elevation, water

. depths are bounded by the MELC analysis, due to the much larger flows l typically found. Therefore, no safe shutdown equipment is affected by either i fire water discharge spray or fire water sprinkler runoff to a lover i elevation.  ;

CORRECTIVE STEPS WHICH WILL BE TAKEN TO AVOID FURTHER VIOLATIONS: [

Freeze plug training requirements were added to Maintenance Section Procedure  ;

(MSP)-0009 3 " Qualification of Maintenance Personnel," requiring maintenance  ;

personnel to be trained in freeze plug installation techniques in order to '

install freeze plugs at River Bend Station (RBS), i i

CMP-9186 has been formally cancelled ensuring that RBS personnel will not '

perform freeze sealing until a proper procedure is developed and training '

completed. .

The Operations Department issued Standing Order #76 on April 23, 1989, which requires contingency plans to be provided to the main control room for all i future freeze plugs. These contingency plans include pertinent details about the freeze plugs and the actions to be taken to mitigate the consequences of the failure. (

Electrical floor penetrations in motor control centers 1EHS*MCC2J and ,

IEHS*MCC2L~will be sealed in accordance with MR 89-0135 to prevent future  !

electrical failures of Auxiliary Building 13.8KV switchgear due to flood 4ng.  ;

i When GSU implements its freeze plugging program, the procedures and trainin g  ;

will address the necessity of a sufficient supply of nitrogen, the !

independence of the nitrogen supplies for multiple plugs, and the necessity for equipment and personnel monitoring during maintenance and installation of the plug. j DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED: [

GSU will perform training to maintenance personnel required to install and I maintain freeze plugs prior to GSV performing any freeze plug activities in -

the future. .

i MR 89-0D5 will be completed prior to the end of the third refueling outage, scheduled to begin September 15, 1990.  ;

i Page 4 of 4