ML20086D462

Approves Use of Tolytriazole at Dosage Rate Requested in 950522 Ltr

ML20086D462
Person / Time
Site:	Pilgrim
Issue date:	06/30/1995
From:	Mcsweeney E ENVIRONMENTAL PROTECTION AGENCY
To:	Boulette E BOSTON EDISON CO.
References
NUDOCS 9507100161
Download: ML20086D462 (2)

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y UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION I l ,

J.F, KENNEDY FEDERAL BUILDING, BOSTON, MASSACHUSETTS 02203-2211

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j June 30, 1995 E.T. Boulette, PhD j Senior Vice President - Nuclear Boston Edison Pilgrim Nuclear Power Station Rocky Point Road Plymouth, Massachusetts 02360 Re: Pilgrim Nuclear Power Station (PNPS),

NPDES Permit No. MA0003557 Use of Tolytriazole as a Corrosion Inhibitor

Dear Dr. Boulette:

In your letter of May 22, 1995, you have requested approval to add Tolytriazole, a corrosion inhibitor, to the reactor building and turbine building closed cooling-water systems; station-heating and the emergency diesel generator cooling-water systems.

This material has been recommended for use by the Institute of Nuclear Power Operations (INPO) for corrosion control of copper alloys.

Initial conditioning of the cooling systems would require a Tolytriazole maximum concentration 20 mg/1, after which

! concentrations would be maintained at 2 mg/1. The ma:41 mum

! concentration would be in the neutralizer sump.

At the facility, Tolytriazole would be discharged from PNPS' Outfall 011 only during scheduled plant outages, and during any unplanned system maintenance evolutions. In a " worst--case scenario", 200 GPM (maximum flow) of the Tolytriazole effluent would be diluted with 1500 GPM (minimum flow) of service water, 1

prior to discharge to Cape Cod Bay. The Tolytriazole i concentration of the effluent would be approximately 2.35 mg/1.

If one of the circulating water pumps is operational during an outage, the Tolytriazole discharge would further be diluted with 155,000 GPM of Bay water, yielding an effective Tolytriazole discharge concentration of 0.03 mg/1.

Acute and chronic toxicity testing results in the vendor's Material Safety Data Sheets (MSDS) on Tolytriazole (or COBRATEC, TT-50-S], indicate that the Tolytriazole concentration in a

" worst-case scenario" discharge is below both the acute and chronic toxicity levels.

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I Based cm actual acute and chronic toxicity testing results, the

" worst-case scenario" discharge concentrations, additional dilution from the circulating water pump, the use of Tolytriazole is approved at the requested dosage rate. Any change in the dosage rate or active ingredient concentration must be approved by EPA and the State prior to usage.

Should you have any questions, please contact Nick Prodany of my staff at 617-565-3587.

Sincerely, 4 - 4 Edward K. McSw eney, Chief i

Wastewater Management Branch i cc: R. Anderson, PNPS j Paul Hogan, MA DEP S. Silva, EPA L'

Region,I, NRC 4 Document ~ Control 2 Desk';';NRC O

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