NRC NEWS

 U.S. NUCLEAR REGULATORY COMMISSION

 801 Warrenville Road

 Lisle IL 60532

 Web Site: http://www.nrc.gov 

No. III-03-045 June 25, 2003

CONTACT: Jan Strasma (630) 829-9663 E-mail: opa3@nrc.gov

 Viktoria Mitlyng (630) 829-9662 

NRC PROPOSES $60,000 FINE AGAINST EXELON FOR INACCURATE INFORMATION

The Nuclear Regulatory Commission staff has proposed a $60,000 fine against Exelon

Generation Company for providing incomplete and inaccurate information to the NRC staff concerning

the condition of a pipe support at the Unit 3 of the Dresden Nuclear Power Station. The two-reactor

facility is located near Morris, Illinois.

In September 2001 the NRC staff held a telephone conference call with Dresden officials to

discuss the potential that a water hammer caused damage to a support for piping in one of the plant’s

emergency reactor cooling systems, the high pressure coolant injection system. A water hammer is a

pressure shock wave that occurs in pipes when there is a sudden change in flow and can be due to a

variety of circumstances such as excessive air in the piping or water suddenly flashing to steam.

The licensee had found that the pipe support was damaged following the automatic shutdown

of the reactor on July 5, 2001. During the conference call on September 27, 2001, the Dresden

officials explained that there was no indication that a water hammer had occurred because the peak

pressure observed during the shutdown was not high enough, there was no damage to adjacent pipe

supports, and, based on the system’s alignment, there was no air in the piping. However, a Dresden

employee had found that an adjacent pipe support was loose during an inspection the previous day. 

This information was not provided to the NRC during the conference call.

Ultimately, the Dresden engineers determined that a water hammer had occurred, after finding

that air was trapped in the piping and that pressure had spiked to more than 1000 pounds following the

automatic shutdown on July 5. Licensee calculations eventually showed that the high pressure coolant

injection system had been inoperable, and to meet NRC requirements, the damage should have been

repaired or the reactor shut down within 2 weeks of discovering the damaged support on July 19.

NRC inspection findings are evaluated using a four-level scale of safety significance, ranging

from "green" for a finding of very low significance, through "white" and "yellow" to "red," for a

finding of high safety significance. The agency has determined that the inoperability of the high

pressure coolant injection system was “white,” meaning a finding of low to moderate safety

significance.

The NRC’s Office of Investigations conducted an investigation into the information provided

by Exelon to the NRC staff during its evaluation of the operability of the high pressure coolant 
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injection system. Based on the results of the investigation, the NRC staff determined that the failure of

the company to disclose the condition of the loose pipe support was a willful violation.

The company has until July 23 to pay the fine or to protest it. If the fine is protested and

subsequently imposed by the NRC staff, Exelon may request a hearing.

The notice to the company of the proposed fine and notice of violation will be available from

the Region III Office of Public Affairs and on the NRC’s web site at: 

http://www.nrc.gov/reading-rm/doc-collections/enforcement/actions/reactors/

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