ML20011E205

Forwards Response to Generic Ltr 89-13, Svc Water Sys Problems Affecting Safety-Related Equipment. New Chlorination Sys Installed Using Hypochlorite Rather than Gaseous Chlorine & Test Program Will Be Developed

ML20011E205
Person / Time
Site:	Clinton
Issue date:	01/29/1990
From:	Holtzscher D ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-051, REF-GTECI-NI, TASK-051, TASK-OR GL-89-13, U-601574, NUDOCS 9002090076
Download: ML20011E205 (5)

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, JDocket No. 501461f

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Washington,: D,C. 20555 .

i Subj ect: i Clinton Power Station.-  ;

J Response to Service Water. System Problems Affecting-1afetv-Related Eauinment'(Generic Letter 89-13) .

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Dear' Sir:

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j This letter is in response to Generic = Letter 89-13 which requested l Illinois-Power Company (IP) to confirm that theLsafety functions of-the service water; systems are being met and to assure NRC that IP is in ,

&  : compliance with the: applicable regulations, i

.. Attached'is'the evaluation.of Clinton Power Station (CPS)' Service j

,. , . Water System for.conformance toLthe requirements of Items I through V of  ;

the generic. letter. : CPS intends to develop.a' program that addresses the

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y s  ; recommendations-of the Generic Letter prior to' restart after the C refueling. outage' scheduled to end in December of 1990. ,

u Sincerely yours, Q N}

D.1. Iloitzscher r pf Acting Manager'-

Licensing and Safety 4

liSFB/krm i f',, .-Attachment .;

, cc: .NRC Regional Administrator, Region III -I NRC Clinton Licensing Project Manager.

NRC Resident Office p: Illinois Department of Nuclear Safety I

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9002090076 900129 o d PDR ADOCK 05000461 N, P PDC 4, p. f

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Attechm2nt-to U-601574 Page 1 of 4 ILLINOIS POWER COMPANY RESPONSE TO GENERIC LETTER 89 13

-SERVICE WATER SYSTEMS AFFECTING SAFETY RELATED EOUIPMENT. ,

' INTRODUCTION The Clinton Power Station (CPS) Operating License states that the license was ,

issued with the support of the Safety Evaluation Report (SER) NUREG-0853.

• Revision 0 of the SER, Section 9.2.1 states, ". . . the staff concludes that' the service water-system meet the requirements of GDC 2, 44, 45 and 46 with~

respect to the system's protection against natural phenomena, capability for transferring the required heat 11oads, inservice inspection, and functional

. testing, .and the guidelines of Regulatory Guide 1.29 with respect to the system's seismic classification, and is therefore acceptable."

-According to NRC Staff review, CPS has been found to meet all the regulations

- referred to by Generic Letter (GL) 89-13. which assures the safe operation of I the safety related service water system. However, also in accordance with the GL, CPS has conducted a review of the Recommended Actions.

RECOMMENDED ACTION I For open cycle service water systems, implement and maintain an ongoing program of surveillance and control techniques to significantly reduce the i

incidence of flow blockage problems as a result of biofouling. A program acceptable to the NRC is described in " Recommended Program to Resolve Generic j Issue 51" (Enclosure 1). It should be noted that Enclosure 1 is provided as guidance for an acceptable program. An equally effective program to preclude biofouling would also be acceptable.- -

i POSITION I CPS is cooled by Clinton Lake, which is classified as clam waters.

CPS is developing a program to implement the requirements of Generic Letter 89-13. This program will be placed in effect a within the time frame provided in the Generic Letter, r

RECOMMENDED ACTION I.A The intake structure should be visually inspected, once per refueling cycle, q for macroscopic biological fouling organisms.

• POSITION I.A The screen house is required to be inspected by divers at each refueling outage and, if necessary, cleaned. Thus far, it has not been necessary to clean the screen house or pump bays. Procedure revisions with respect to acceptance criteria will be necessary to meet the recommendations of the generic letter.

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• Page 2 of 4 RECOMMENDED ACTION I.B .

The service l vater system should be continuously (for example, during spawning) chlorinated -(or' equally effectively treated with another biocide) whenever_ the' potential for a macroscopic biological fouling species exists.

l POSITION I.B

-ALnew chlorination system has been installed that uses hypochlorite rather than gaseous chlorine. The new system is-currently being tested.for release to'the plant operating staff.

Additional modifications are being developed to improve the  ;

performance of the system due to performance problems. Clinton Power Station will evaluate the recommendations of the generic letter with respect to chlorination of the water source.

RECOMMENDED ACTION I.C

. Redundant and infrequently used cooling loops should be flushed and flow tested periodically at the' maximum design flow to ens':re that they are not fouled or clogged. Service water cooling. loops should be filled with chlorinated or equivalently treated water before layup. Systems that use raw service water as a. source, such as_some fire protection systems, shoulo also- i be chlorinated or equally effectively treated before layup to help prevent microbiological 1y induced corrosion.

POSITION I.C

-CPS procedures will be reviewed to assure periodic flush and flow tests are performed as necessary.  ;

The service water system at CPS will be chlorinated using the hypochlorite system. The shutdown service water piping and loads may be treated with chlorine by use of the normally open cross-tie valves with the service water system if normally isolated shutdown service water loads are placed in service during periods of chlorination, The fire protection system will be treated automatically with chlorine through a system that is activated when the fire system diesel pump is started.

Procedure revisions with respect to chlorination frequency, concentration, and proper layup methods may be necessary to meet the recommendations of the generic letter.

Recent events at CPS have prompted the discovery of microbiological 1y induced corrosion (MIC).in safety related heat exchangers. IP is pursuing corrective actions including inspections, mechanical cleaning, and chemical treatment.

Corrective actions also include repairs where corrosion may have already degraded long term reliability, a

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. .~~ Attich:Snt-to U 601574 Page 3 of 4-RECOMMENDED ACTION I .D _

T o Samples of. water and substrate should be collected annually to determine if Asiatic' clams have populated the water source. Water and substrate sampling F is only necessary at freshwater plants that have not previously detected the presence of Asiatic clams in their source water bodies. If Asiatic clams are detected,l utilities may discontinue this sampling activity, if desired, and ,

the chlorination (or equally effective) treatment program should be modified to'be in agreement with Paragraph B, above, r POSITION I.D CPS has a procedure for inspecting the presence of clams; however,.

since clams have been found at CPS, this inspection procedure may be discontinued in which case chlorination would be used as

- described in Recommended Action I.B.

RECOHMENDED ACTION II Conduct a test program to verify the heat transfer capability of all safety-related heat- exchangers cooled by service water. '

POSITION II CPS will develop a test program to address the recommendation of the generic letter. ;The purpose of the program will be to review

. the heat transfer capability of the Shutdown Service-Water (SX) heat exchangers to verify that they will perform their intended function. The test program will be documented and will consist of a baseline program and a periodic re test program.

Testing will: include sufficient instrumentation (permanent and portable) to verify heat transfer capabilities; but in some cases, ,

inspection or frequent maintenance may be utilired in lieu of testing.

'RECOHMENDED ACTION III Ensure by establishing a routine inspection and maintenance program that corrosion, erosion, protective coating failure, silting, and biofouling cannot degrade the performance of .the safety-related systems supplied by service water.

POSITION III Maintenance procedures will be established for erosion inspections, removal of excessive accumulations of biofouling agents, corrosion products and silt. Repair of corroded service water system piping and components will be conducted in accordance with approved procedures.

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- RECOMMENDED ACTION IV Confirm that the service water system will perform its intended' function in

- accordance with the licensing basis for the plant.

i y' POSITION IV The SX system configuration was field. verified as part of_ initial-plant startup. -This also included a design review by CPS and the- '

i NRC staff which determined that the system was,not. vulnerable to a

/ single _ active failure. The staff review is documented in the SER,  ;

l JSection 9.2.1.

-To address the recommendation of the generic letter, CPS will

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review'the ability of the system to perform its intended function with a walkdown and single active failure review of all design i

- changes to the~SX system.since initial plant start-up.

RECOMMENDED ACTION V Confirm that maintenance practices, operating and emergency procedures,~and training are adequate to ensure that safety-related equipment will function as.

intended and that operators of this equipment will perform' effectively, j POSITION V r

It will be ne'essary c to develop'and revise maintenance procedures, operation procedures and emergency procedures to address the recommendations of the_ generic letter. A review of operator and.

maintenance training revealed that the programs meet the requirements of the generic letter; however retraining on procedure changes identified above will be conducted as necessary.

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