ML19347A853

RO 80-070/01P:on 800922,born Dilution Discovered During RCS Initial Fill & Vent,Causing Unplanned Reactivity Insertion to Exceed Tech Specs Limits.Caused by Procedural Deficiency.Boric Acid Blender Total Flow Setpoint Changed

ML19347A853
Person / Time
Site:	Beaver Valley
Issue date:	09/23/1980
From:	Werling J DUQUESNE LIGHT CO.
To:
References
80-070-01P, 80-70-1P, NUDOCS 8009300412
Download: ML19347A853 (2)

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- Post Office Box 4 Shippingport, PA 15077 September 23, 1980 BVPS: JAW:981 Scaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 LER 80-070/01P Mr. B. H. Grier, Director of Regulation United States Nuclear Regulatory Commission Region 1

• 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

l In accordance with Appendix A, Beaver Valley Technical Specifications, l Licensee Event Report LER 80-070/01P, Technical Specification 6.9.1.8.d, l Administrative Controls, is submitted. This occurrence was reported to the Beaver Va.11ey NRC Resident Inspector Mr. D. A. Beckman at 0110 hours0.00127 days <br />0.0306 hours <br />1.818783e-4 weeks <br />4.1855e-5 months <br /> on September 23, 1980.

Prom 0545 hours0.00631 days <br />0.151 hours <br />9.011243e-4 weeks <br />2.073725e-4 months <br /> to 1240 hours0.0144 days <br />0.344 hours <br />0.00205 weeks <br />4.7182e-4 months <br /> on September 22, 1980, the Reactor Coolant System initial fill and vent was in progress. The reactor coolant sample taken at 1648 hours0.0191 days <br />0.458 hours <br />0.00272 weeks <br />6.27064e-4 months <br /> on September 22, 1980 showed a boron concentration of 1701 ppm while the previous day's sample showed 1964 ppm. This dilution resulted in a reactivity insertion of 3% ak/k which is greater than the 0.5% ak/k Technical Specification administrative limit for an unplanned reactivity insertion.

The shutdown margin was calculated to be 6.8% Ak/k which is greater than the administrative minimum of 5% ak/k and the Technical Specification minimum of 1% Ak/k.

})oo35 8000800 N

O Mr. B. H. Criar September 23, 1980 BVPS: JAW:981 Page 2 ,

This dilution was caused by a procedural deficiency. The manual emergency boration flow path was open for Train "A" priority. This flow path allows the boric acid pump discharge flow to bypass the boric acid blender. The boric acid blender procedure did not account for this condition and the blender's automatic controls raised the primary grade water flow to an amount equal to the missing boric acid flow. This extra primary grade water caused the unplanned dilution.

The total flow setpoint of the blender has been changed to produce the desired water flow for the calculated mix. The blender operating procedure has been changed to require a setpoint change when the manual emergency boration flow path is in service.

Very truly yours, 0 .

, J. A. Werling Superintendent

()

I cc: Director Of Management & Program Analysis United States Nuclear Regulatory Commission Washington, D. C. 20555 W. J. Ross, BVPS Licensing Project Managerw/ #

United States Nuclear Regulatory Commission Washington, D. C. 20555

• D. A. Beckman, Nuclear Regulatory Commission, BVPS Site Inspector P. Higgins, Secretary, Prime Movers Committee - EEI Nucle'ar Safety Analysis Center, Palo Alto, California Mr. John Alford, PA Public Utilities Commission, Harrisburg, PA 9

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