ML20095J120

NPDES Noncompliance Notification:On 920322,cooling Tower Blowdown Water Discharged Into Possum Hollow Creek.Caused by Procedure Deficiency.Sys Operating Procedure S09.4.A Expected to Be Revised by 920501

ML20095J120
Person / Time
Site:	Limerick
Issue date:	04/23/1992
From:	Doering J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Bauer R PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9205010111
Download: ML20095J120 (3)

Text

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PHILADELPHIA ELECTRIC COMPANY LIMERICK GENER ATING f.TATION j P. O. DOX A l T.AN ATOG A. PENNSYLV ANI A 19464 (215) 327 1200 E x t. ,000 YS ,".'.".h .'.'

• Apri123, 1992 Mr. Robert Bauer, Jr.

Department of Environmental Resources Bureau of Water Quality Manaavment Suite 6010, Lee Park 555 North Lane Conshohocken, PA 19428

Subject:

Noncompliance with NPDES Permit No. PA-0051926, Limerick Generating Station; Cooling Tower Blowdown Manhole Overflow to Possum Hollow Creek

Dear Mr. Bauer:

DESCRIPTION OF THE EVENT On March 22, .'992, a noncompliance of the NPDES permit for the Limerick Generating Station occurred after Unit 1 Cooling Tower basin drcin water in conjunction with Unit 2 Cooling Tower blowdown water was discharged into the Possum Hollow Creek resulting in an unpermitted discharge. This condition resulted in the release of chemically treated water from an unmonitored

[ discharge point.

On March 21, 1992, System (S) Operating Procedure S09.4.A,

" Cooling Tower and Circulating Water System Drain," was being implemented by operations personnel in conjunction with a clearance. application on the circulating water system. At 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br />, on March 21, 1992,'the Unit 1 Cooling Tower basin drain valve, 09-1001, was opened to begin draining the Unit 1 Cooling Tower basin into the blowdown line. Additionally at 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br />, the Unit 2 Cooling Tower blowdown was being maintained at a flow of 5,200 gpm. On March 22, 1992, at approximately 0130 hours0.0015 days <br />0.0361 hours <br />2.149471e-4 weeks <br />4.9465e-5 months <br />, operations personnel discovered water discharging from a manhole on the Cooling Tower blowdown line and flowing directly into the

, Possum Hollow Creek.- Main Control Room (MCR) personnel were

': unaware of the excessive blowdown flow rate because the drain line from the Unit 1 Cooling Tower basin connects into the blowdown line downstream of the flow element for the MCR flow recorde . FR-09-201. Flow recorder FR-09-201 records and monitors cooling Tower blowdown flow rates and not Cooling Tower ,

l basin drain flow rates. . At 0215 hours0.00249 days <br />0.0597 hours <br />3.554894e-4 weeks <br />8.18075e-5 months <br />, operations personnel l reduced the Unit-2 Cooling Tower blowdown flow and secured the Unit 1 Cooling Tower basin drain to terminate the overflow from the manhole. The system engineer later estimated approximately 350,000 gallons of circulating water was discharged into the l g g l 9205010111-920423 PDR ADOCK 05000352 I}O S PDR

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. l Possum Hollow Creek. 'The combination of the Unit 1 Cooling Tower l basin drain flow and the Unit 2 Cooling Tower blowdown flow, resulted in exceeding the Cooling Tower blowdown line capacity.

The chemical makeup of the water discharged into the Possum Hollow Creek was analyzed on March 22, 1992. The pH of the discharge was approximately 7.7, total zinc concentration was 0.7 ppm, and the PEco 5 usage rare for the Unit 2 Cooling Tower was being maintained at 806.4 lbs/ day. All values were within permit ,

limits.

CAUSE OF THE NONCOMPLIANCE The cause of the noncompliance was procedure deficiency in that the' System operating procedure SO9.4.A failed to take into consideration the capacity of the Cooling Tower bloudown line.

Guidance was tiot present to remind operations personnel that the Cooline Tower drain flow bypasses the blowdown flow element.

This allowed.tha blowdown line capacity to be exceeded through

'the combination of Unit 1 Cooling Tower basin drain flow and Unit

-2 Cooling Tower blowdown flow.

PREVENTIOd OF FUTURE OCCURRENCES The followioi corrective actions will be implemented to prevent the recurrence of a similar event.

1. System operating procedure S09.4.A is expected to be revised by May 1, 1992, to provide.' sufficient procedural guidance to ensure that operations personnel closely. monitor and control this evolution. This procedura: guidance will warn operations personnel that Cooling Tower basin drain flow indication does not exist, and the subsequent importance of properly-controlling Cooling Tower basin draining.

2. A review of other applicable system' operating procedures will be performed to determine if other similar deficiencies exist. This review is expected to be completed by May 1, 1992, and appropriate actions will be implemented as necessary. .

l- 3. An engineering evaluation will be performed to determine if

! the blowdown and basin-drain designs for the Cooling Towers can be improved or modified. This evaluation is expected to .

. be completed by September 30, 1992.

p Sincerely, .

Q+

/

DMS:cah

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Page 3 I cc: -U.S. Nuclear Regulatory Commission

-Document Control Desk Docket Nos. 50-352/50-353 Washington, D.C. 20555 T.-T. Martin i Administrator, Region I, USNRC. . j Docket Nos. 50-352/50-353  ;

T. J. Kenny l USNRC Senior Resident Inspector. LGS Docket Nos. 50-352/50-353 Program Management Section-(3HMS2)

Permits. Enforcement Branch Water-Management Division Environmental Protection Agency Water Permits Section. -

Region III 841 Chestnut Building Philadelphia, PA 19107

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