U-601756, Submits Revised Response to Generic Ltr 89-13, Svc Water Sys Problems Affecting Safety-Related Equipment

Submits Revised Response to Generic Ltr 89-13, Svc Water Sys Problems Affecting Safety-Related Equipment

ML20066C115
Person / Time
Site:	Clinton
Issue date:	12/31/1990
From:	Spangenberg F ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-13, U-601756, NUDOCS 9101090250
Download: ML20066C115 (2)

Text

i U 601756 ILLINDIS POWER 1d3 " """'

CLIN'lON l'OWER ST ATION. I'.O. ILOX 078, CLIN' ION, ILLINOIS 61727 0678. TELEI' HONE (217) 168881 December 31, 1990 Docket No. 50 461 Nuclear Regulatory Commission Docuroent Control Desk Washington, D.C. 20555

Subject:

Clinton Power Station Revised Response to Generic Letter 8913 Service Water System Problems Affecting Safety.

Related Eaulpment

Dear Sir:

On January 29, 1990, Illinois Power Company (IP) provided a response (letter U 601574) to the recommended actions in Generic Letter (CL) 89 13. The purpose of this letter is to revise the Clinton Power Station (CPS) response to recommended actions 1.B and IV of the original response.

In response to recommended action I.B. CPS discussed the new chlorination system which had been installed and committed to evaluating the recomriendations of CL 8913 with respect to chlorination of the water source prior to the end of the current refueling outage. During the evaluation of using chlorination as a treatment, it was discovered that chlorine alene would not be totally offective in the control of microscopic biological species. This is due to the high pit content of Clinton Lake. Therefore, CPS is currently evaluating various chemicals and injection tnethods to provide micro and macro biofouling protection. The injection method vil1 provide system treatment and ensure that service water loops are treated prior to layup, At this time, due to the complexity of the design, chemical testing and the need for state approval, a schedule to iniplement a new design is not available. Therefore, IP will not be able to fulfill the commitment of addressing this issue prior to the end of the current refueling outage, lloweve r , to protect the Shutdown Service Water system from biofouling, an interim chemical treatment program has been implemented. This program has been approved by the Illinois Enviroraental Protection Agency to treat each division of the Shutdown Service Water system. The treatment using the interim program was conducted in October 1990, and was successful in demonstrating no environmental impact. As a result of this success, an application is being made to perform interim chemical treatments on a quarterly basis until a final design is implemented. In j addition, various heat exchangers will be periodically opened and f visually inspected for biofouling. 0 9101090250 901231 POR (\ DOCK 0500ggi 08c120 A&p

Based on the above, IP's revised response to recommendation I.B is to develop and impicment a design to provide system chemical treatment. The interim chemical treatment program discussed above will be used to control biofouling until the design is implemented.

IP will provide a report by March 31, 1991, updating the status of the new design.

In IP's initici response to recommended action IV, CPS committed to review the ability of the Shutdown Service Water system to perform its intended function with a system walkdown and single active failure review of all design changes to the Shutdown Service Water system since initial plant startup. This commitment was to be complete prior to the end of the current refueling outage.

IP is presently verifying the ability of the Shutdown Service Water system at CPS to perform its intended function in the event of the failure of a single active component; however, it has been determined that a system walkdown is not necessary. The rationale which led to this conclusion is as follows:

A) The CPS Safety Evaluation Report (SER) documents the Shutdowr Service Water system design as being singic failure proof.

B) The Shutdown Service Water system walkdowns, as required by CPS Procedure No. 1340.01, " Review of System Release Packages,"

verified the system was built in accordance with the design at the time it .as released to IP operations from IP startup.

C) The CPS modification program was instituted prior to June, 1986, and all subsequent modifications to the SX system were installed and released for operations in accordance with the modification program.

D) As stated in Item V.I of supplement 1 to the Generic Letter, an ef fective modification program is an acceptable justification l

for not performing the walkdown.

l Based on the above, performance of a walkdown of the Shutdown Service Water system is not required.

Clinton Power Station shall continue to implement the actions stated in our original response to Ceneric Letter 89 13 and the revisions discussed above.

Sincerely yours, F. A. Sp ng erg, I Manager Licensing and Safety WTD/alh ec: NRC Regional Administrator, Region III NRC Clinton Licensing Project Manager NRC Resident Office Illinois Department of Nuclear Safety

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