L-2008-206, Unusual or Important Environmental Event - Unanticipated Water Discharge

Unusual or Important Environmental Event - Unanticipated Water Discharge

ML082690602
Person / Time
Site:	Saint Lucie
Issue date:	09/18/2008
From:	Katzman E Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EPP 4.1, L-2008-206
Download: ML082690602 (3)

Text

0 Florida Power & Light Company, 6501 S. Ocean Drive, Jensen Beach, FL 34957 September 18, 2008 FPL L-2008-206 10 CFR 50.4 10 CFR 50.36.b EPP 4.1 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE: St. Lucie Units 1 and 2 Docket Nos. 50-335 and 50-389 Environmental Protection Plan Report Event Date: August 19, 2008 Unusual or Important Environmental Event - Unanticipated Water Discharge On August 19, 2008, excessive rainfall from Tropical Storm Fay necessitated pumping an estimated volume of 43,000,000 gallons of storm water from approved outfall 008 and approximately 22,000 gallons from the Unit 1 condenser bay directly to the plant intake canal.

The attached report is being submitted pursuant to the requirements of Section 4.1 of the St.

Lucie Units 1 and 2 Environmental Protection Plans to provide the description of the event.

Very truly yours, Eric S. Katzman Licensing Manager St. Lucie Plant ESK/KWF Attachment c~3 an FPL Group company

St. Lucie Units 1 and 2 L-2008-206 Docket Nos. 50-335 and 50-389 Attachment Environmental Protection Plan Report Page 1 of 2 Unusual or Important Environmental Event - Unanticipated Water Discharge EVENT DESCRIPTION Guidance for pre-storm activities and preparation prior to the arrival of severe weather is provided by internal plant procedures. Pre-storm preparations were initiated and completed on August 19, 2008 as per plant procedure AP 0005753. Preparations were based on a forecast of 3-4 inches of expected precipitation. The actual amount of precipitation experienced at the plant and surrounding area was between 13-15 inches. Empirical data indicates that 1 inch of precipitation equals a 4 inch rise of water level in the site percolation basins and the site Storm Water Drainage System (SWDS). Due to the magnitude of this rain event the SWDS was compromised and did not operate as expected. The compromise of the SWDS resulted in the inundation of the Unit 1 condenser bay which included several submerged electric motors. The fact that electric equipment was inundated posed a significant personnel safety risk as well as a risk to plant equipment.

In order to reduce the volume of water in the Unit 1 condenser bay and mitigate the safety risk the plant commenced pumping activities from the Unit 1 condenser bay and directed the discharge to the plant intake canal. The following morning the local Florida Department of Environmental Protection office was contacted to inform them of the mitigation activities and acquire permission to continue pumping from the Unit 1 condenser bay to the intake canal as well as to commence pumping storm water from approved outfall 008.

An estimated volume of 43,000,000 gallons of storm water was pumped from the approved outfall 008 from the south east percolation basin, and approximately 22,000 gallons were pumped from the Unit 1 condenser bay directly to the plant intake canal. Sampling from both locations were consistent with the requirements stated in the site Industrial Wastewater Permit, FL0002208.

CAUSE OF EVENT Severe storm weather preparation procedures and protocols for a tropical storm were inadequate for a precipitation event of this magnitude. The inability of the SWDS and site percolation basins to process 13-15 inches of precipitation resulted in elevated component and personnel safety risks. In order to mitigate said risk the plant discharged the accumulated storm water from the Unit 1 condenser bay to the intake canal and from outfall 008 to the intake canal.

CORRECTIVE ACTIONS

1) The site storm water drainage system and percolation basin volumes are reduced from 5.5 feet depth to 3.6 feet prior to a severe weather event.

2) Temporary pumps are now deployed in the Unit 1 condenser bay at the tropical storm alert level.

St. Lucie Units 1 and 2 L-2008-206 Docket Nos. 50-335 and 50-389 Attachment Environmental Protection Plan Report Page 2 of 2 Unusual or Important Environmental Event - Unanticipated Water Discharge

3) Chemistry samples-storm water discharge three days prior to a severe weather event to expedite pumping activities if required.

4) Chemistry to expedite all sampling activities to allow the plant flexibility in pumping activities.

5) Maintenance department to deploy, test, and secure pumping equipment at outfall 008 three days prior to a severe weather event. This will facilitate pumping during severe weather events.

AGENCIES NOTOFIED The local St. Lucie County office of the Florida Department of Environmental Protection was contacted on August 20, 2008.