ML20059G455

NPDES Noncompliance Notification:On 900715 & 17,five of Seven Samples from Discharge Point 001 Exceeded Limit. Acid Injection Sys Adjusted Immediately & Mod Designed to Automate Acid Feed Sys on Both Units

ML20059G455
Person / Time
Site:	Limerick
Issue date:	08/21/1990
From:	Mccormick M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Bauer R PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9009120318
Download: ML20059G455 (3)

Text

. . . -_

• s t PHILADELPHIA ELECTRIC COMPANY' -

2301 MARKET STREET f

P.O. BOX 8699 f

PHILADELPHI A. PA.19101 i i

i ms: e414000  ;

August 21, 1990 i Mr. Robert Bauer, Jr.  !

Department of Environmental Resources l Bureau of Water Quality Management ,

1875 New Hope Street  ;

Norristown, PA 19401 5

SUBJECT:

Noncompliance with NPDES Pemit Limerick Generating Stations i NPDCS Permit No. PA-005192i Dear Hr. Bauer QtSCRIPTION OF NONCOMPLIANCE During the period between 7/15/90 and 7/17/90 seven samples were i collected from Discharge Point 001 and sent to our Corporate Chemistry  !'

Laboratory to be analyzed for total zinc. Five of the seven samples taken exceeded the pemit limit of 1.0 mg/1, Four of the samples were  :

l collected on 7/26/90 and the results were 1.3 mg/l at 1045,1.4 mg/l at

1145, 1.3 mg/l at 1735, and 1.3 mg/l at 1940. The fifth sample was  !

l collected at 0345 on 7/17/90 and its result was 2.0 mg/1. The results  ;

of two samples taken later on 7/17/90 indicated the.t the' total zine i concentration was again below the pemit limit of 1.0 mg/1. ,

CAUSE OF THE NONCOMPLIA)_lgJ At 0930 on 7/15/90 the Unit 2 reactor shutdown due to low vacuum in I the main condenser. Tha shutdown eliminated the heat load'on the Unit 2 circulating water system which minimized evaporation in the cooling tower and caused the pH to start decreasing. The acid feed system, which is needed to maintain circulating water pH between 8.0 and 8.5 l when Unit 2 is aperating, was not taken out of service after the reactor l had shutdown. Acid feed to the Unit 2 circulating water system was l

stopped at 0920 on 7/16/90 after it was determined that the pH of- this water was 4.6'i. (A Discharge 001 sample that was collected at 1030 'on

• l 7/16/90 had a' pH of 7.38.) This lower than normal pH in the Unit 2 j circulating water increased the solubility of zinc in that system which caused the concentration of total zine to increase. The blowdown- i contribution from Unit 2 was sufficient, when combined with the other flows in Discharge 001, to increase the total zine concentration above  ;

our 1.0 mg/l discharge limit.

t 9009120316 900821

• A  !

PDR ADCICK 05000353 I S PDC (/ ,

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DURATION OF THE NONCOMMMf]

The period of noncompliance began on 7/15/90 at approximately 1300 when the increased total :ine concentration in Unit 2 circulating water caused the level of total zine in Discharge 001 to exceed 1.0 mg/1.

Based on the zinc analysis results from 7/16/90 and 7/17/90, the noncompliance period ended on 7/17/90 at approximately 1100 when the total :inc concentration had decreased to below 1.0 mg/1. The duration t of the noncompliance was less than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, during which about 19.5 '

million gallons of cooling water were released from Discharge 001 diffuser into the Schuylkill River. .

CORPECTIVE ACTION Initially, upon determination of pH in Unit 2 circulating water on the morning of 7/16/90, acid feed was immediately taken out of -service '

to allow the pH to increase to normal makeup water range. Sampling for total zine by our on-site spectrophotometric method. indicated that the concentration in Unit 2 circulating water was not decreasing significantly, therefore, the zine chemical injection to both cooling towers was shut off. The blowdown rates of both cooling towers were adjusted to further reduce the total inc level at Discharge 001. These corrective actions were sufficient to lower the total :ine concentration.

down to 1.0 mg/l by 1100 on 7/17/90.

9 pREVENTICN OF FUTURE OCCURRENCES plant and system shutdown procedures are being revised to' minimi:c, ^

, the potential for recurrence of this incident. These revisions will be l in place by 9/15/90. This noncompliance incident was also discussed at

! Chemistry staff and technician meetings. These discussions were to make I

all staff aware of the event. Information was also added to Chemistry l Night Orders to provide interim direction. On August 19, 1990, Unit 2 was shutdown due to EHC leaks.- Due to the information that had been provided, the acid in$ection system was adjusted immediately following shutdown and a repeat violation was avoided. A modification is- being designed to automate the acid feed systems on both units. The modification is expected to - be installed by the end of 1991.

Additionally, station personnel are evaluating the feasibility of '

modifying the chemical feed systems of both units to add ' automatic control.  ;

Sincerely, ,

nto h (\l

'ts SA. /a

/k, H.J. McCormick, Jr.

-f plant Manager JCE/jee t

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l 9 v O *

, i cci U.S. Nuclear Regulatory Commission /

Document control Desk Washington, D.C. 20555 i J

Administrator Region I U.S. Nuclear Regulatory Commission j 475 Allendale Road  :

King of Prussia, PA 19406 4 i

i Station Resident NRC Inspector Tom Kenny, H.C.# NRC j Program Management Section (3WM52)

Permits Enforcement Branch Water Management Division Environmental-Protection Agency Water Permits Section Region III l 841 Chestnut Building ,

Philadelphia, PA.19107 i

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