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Event Notification Report for March 15, 2005

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
03/14/2005 - 03/15/2005

EVENT NUMBERS
4149641497

Power Reactor
Event Number: 41496
Facility: KEWAUNEE
Region: 3     State: WI
Unit: [1] [] []
RX Type: [1] W-2-LP
NRC Notified By: HAROLD PROKASH
HQ OPS Officer: CHAUNCEY GOULD
Notification Date: 03/15/2005
Notification Time: 22:48 [ET]
Event Date: 03/15/2005
Event Time: 16:30 [CST]
Last Update Date: 03/15/2005
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION 50.72(b)(3)(v)(A) - POT UNABLE TO SAFE SD
Person (Organization):
MONTE PHILLIPS (R3)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N N 0 Refueling 0 Refueling
Event Text
KEWAUNEE PLANT DESIGN FOR FLOODING EVENTS MAY NOT MITIGATE THE CONSEQUENCES OF PIPING SYSTEM FAILURES


The following was provided by the licensee:


"While reviewing Nuclear Regulatory Commission's (NRC) memorandum regarding Task Interface Agreement (TIA), TIA 2001-02,'Design Basis Assumptions For Non-Seismic Piping Failures at Prairie Island Plant,' Kewaunee staff determined that the Kewaunee plant design for flooding events may not mitigate the consequences of piping system failures. As a minimum, and as a consequence of assuming failure of non-seismically qualified piping systems as prescribed in the TIA, water has been assumed to collect in the turbine building from a circulating water system piping failure that would result in substantial damage to Engineered Safeguards (ESF) and Safe Shutdown (SS) plant equipment, most notably electrical equipment. As a consequence of high water level in the turbine building, water could flow into the ESF equipment rooms that contain the Auxiliary Feedwater pumps, Emergency Diesel Generators and both the 480 volt and 4160 volt electrical switchgear. Water is assumed to flow into the equipment rooms by way of leakage past non-water-tight doors and the plant's unchecked floor-drain system. The expected water levels In the safeguards and electrical equipment rooms are assumed to increase to the point of causing multiple trains of both ESF and SS equipment to be unavailable to safely shutdown the plant."

"Kewaunee's primary mitigation strategy to combat flooding events is to recognize the event and initiate manual actions to open doors/ barriers. Opening the barriers to flooding directs the water out of the turbine building through the safeguards equipment rooms and returns it to the lake. Normally the manual actions would be expected to be performed before water level accumulates to a point of causing equipment damage. However, under the seismic failure assumptions, water levels are assumed to accumulate faster than the plant's ability to identify and react in order to assure protection of equipment required to initiate and complete a safe plant shutdown.

"Coincidental to the condition being reported, the plant had recently implemented additional precautionary measures to combat internal flooding events that lesson the significance of the condition being reported. Temporary pumping equipment, temporary sandbag barriers and additional personnel have been staged to minimize the consequences of previously questioned flooding events. Furthermore, a number of plant equipment design changes are being processed to further improve Kewaunee's defenses against internal flooding events. However, given the event being reported, the full scope of any additional actions is still to be determined."

The NRC Resident Inspector was notified.


Power Reactor
Event Number: 41497
Facility: PALO VERDE
Region: 4     State: AZ
Unit: [1] [] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: TIM GAFFNEY
HQ OPS Officer: MIKE RIPLEY
Notification Date: 03/15/2005
Notification Time: 23:07 [ET]
Event Date: 03/15/2005
Event Time: 18:51 [MST]
Last Update Date: 03/15/2005
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(xi) - OFFSITE NOTIFICATION
Person (Organization):
TOM FARNHOLTZ (R4)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 100 Power Operation 100 Power Operation
Event Text
OFFSITE NOTIFICATIONS DUE TO CAUSTIC SPILL

The following information was provided by the licensee via facsimile (licensee text in quotes):

"The following event description is based on information currently available. If through subsequent reviews of this event, additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.

"On March 15, 2005 at approximately 18:51 Mountain Standard Time (MST), the Palo Verde Nuclear Generating Station informed another government agency, the EPA/DOT National Response Center, of a caustic spill, related to the protection of the environment. Notification was also made to the Arizona Department of Environmental Quality and the Arizona Department of Public Safety (State Police). No news release is planned or expected.

"A commercial tanker truck was transferring caustic sodium hydroxide at Unit 1 when a drip was observed from the transfer hose at approximately 16:54 MST. The spill was limited to approximately one quart outside of the spill containment berm. The evolution was terminated and the tanker truck was driven out of the Protected Area.

"A drip trail was later discovered at approximately 18:00 along the path of the truck out of the Protected Area, including a puddle of approximately 3 gallons in the sally port (access point). The truck was returning to Phoenix, AZ. The spill quantity on-site is not estimated to have approached a reportable quantity (1,000 pounds), but due to the evidence that the truck was leaking while in transit to Phoenix, the Palo Verde Hazardous Materials Emergency Coordinator conservatively elected to make the government notifications. Additionally, Palo Verde notified the trucking company which ultimately located the truck upon its return to the company yard. No leak existed at that time, suggesting the leakage was limited to the caustic that remained in the truck's discharge pipe after the transfer was stopped.

"There was no impact to control room habitability and no safety systems, including essential ventilation, were actuated or required. The spill did not hamper site personnel in the performance of duties necessary for the safe operation of the nuclear power plant.

"The NRC Resident inspector was notified of the chemical spill and this ENS notification."