ML20212H189

NPDES Noncompliance Notification:On 861209,main Outfall Chlorine Limit of 0.1 Ppm Exceeded During Routine Chlorination of Svc Water Sys.Caused by Failure of in-use Sodium Bisulfite Pump.Npdes Rept for Dec 1986 Encl

ML20212H189
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	01/14/1987
From:	Hess R PORTLAND GENERAL ELECTRIC CO.
To:	OREGON, STATE OF
Shared Package
ML20212H193	List: ML20212H189 ML20212H201
References
ES-572-87L, NUDOCS 8701210298
Download: ML20212H189 (3)

Text

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- llll Portland General Electric Company ES-572-87L ,

TROJAN f

GOV REL 9C l January 14, 1987 Oregon Department of Environmental Quality NW Region 811 SW Sixth Ave Portland OR 97204 Gentlemen:

Attached is the December 1986 NPDES report for the Trojan Nuclear Plant. Also attached are data required to be submitted in addition to that en standard NPDES forms. The plant maintained power operation for the entire month.

The main outfall chlorine limit of 0.1 ppm was exceeded on December 9 during a routine chlorination of the Service Water System. The chlorination was initiated at 1637 hours0.0189 days <br />0.455 hours <br />0.00271 weeks <br />6.228785e-4 months <br /> with no chlorine detected in the main outfall until 1658 hours0.0192 days <br />0.461 hours <br />0.00274 weeks <br />6.30869e-4 months <br /> when analysia indicated 0.7 ppm total residual chlorine. The spare sodium bisulfite (dechlorination) pump was immediately started and chlorine concentration was reduced to less than 0.1 ppm by 1702 hours0.0197 days <br />0.473 hours <br />0.00281 weeks <br />6.47611e-4 months <br />. The cause of the high chlorine concentration was the failure of the in-use sodium bisulfite pump. This pump was checked prior to the start of chlorination and was functional, but failed after the start of chlorination.

A pH value of 4.3 was indicated on the main outfall pH recorder at 1701 hours0.0197 days <br />0.473 hours <br />0.00281 weeks <br />6.472305e-4 months <br /> on December 23. The pH indication was below permit limitations (6.0) for approximately 4 minutes. An investigation concluded the pH limit was not violated and the erroneous indiention was due to equipment failure. The low pH occurred during service water chlorination. Investigation revealed a failure of a check valve on the sodium bisulfite pump discharge.

8701210298 870114 PDR ADOCK 05000344

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ES-572-87L January 14, 1987 Page 2 The valve failure allowed bisulfite flow directly to the main outfall pH monitor. This resulted in an erroneous low pH indication. This was verified by laboratory analysis which determined the quantity of sodium bisulfite discharged to the main outfall could not have depressed the pH to less chan 6.0, but a direct flow of bisulfite to the main pH monitor would have resulted in a pH of approximately 4.3.

The "B" cire water train was drained to the recreation lake from 0110 to 1015 hours0.0117 days <br />0.282 hours <br />0.00168 weeks <br />3.862075e-4 months <br /> on December 10. This drainage was necessary to repair a condenser leak and was performed at reduced power. The ODEQ was notified, as required, by telephono prior to this event.

The effluent temperature was approximately 95'F. The elevated temperature in the bermed area of the recreation lake (designated i mixing zone) killed 54 fish. Species composition, size range, and numbers are given below:

Species Size Range Fork Number Length in mm Bluegill (Lepomis macrochirus) 117-180 46 Largemouth Bass (Micropterus salmoides) 155 1 Carp (Cyprinus carpio) 215-255 3 Yellow Perch (Perca flavescens) 180-200 2 Goldfish (Crassius auratus) 135-145 _2 TOTAL 54 There was no visible impact on the recreation lake outside of the mixing zone.

To prevent a recurrence of this situation, future drainage of the cire water system will be diluted with water from the fire mains to reduce the thermal impact to fish.

All required samples for the cire water draining were taken and were within permit specifications.

The pH monitor was out of service from 0600 to 1205 hours0.0139 days <br />0.335 hours <br />0.00199 weeks <br />4.585025e-4 months <br /> on December 1 for pump repair and from 0040 to 1215 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.623075e-4 months <br /> on December 30 to repair a check valve on the sample pump. The pH monitor was out of service from 0815 to 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> on December 31 to tighten loose recorder adjustment and pen cables. All required backup samples were taken during the periods of outage.

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ES-572-87L January 14, 1987 Page 3 If you have questions, please contact Stan Katkansky at 226-8409.

Sincerely, N

R. J. Hess, Manager Environmental Sciences RH/SK:by es.737 et Trojan Distribution David Kish, ODOE USNRC, Docuawnt Control Desk John B. Martin, USNRC Cary C. Kellund. USNRC, Trojan s

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