NRC NEWS

 U.S. NUCLEAR REGULATORY COMMISSION

 2443 Warrenville Road

 Lisle IL 60532

 Web Site: http://www.nrc.gov E-mail: opa3@nrc.gov

No. III-06-026 June 30, 2006

CONTACT: Jan Strasma (630) 829-9663 

Viktoria Mitlyng (630) 829-9662 

NRC ISSUES A WHITE FINDING TO EXELON FOR THE HANDLING 

OF UNPLANNED TRITIUM RELEASES AT BRAIDWOOD

The Nuclear Regulatory Commission staff has issued a final white finding to Exelon for

multiple failures to properly evaluate the radiological impacts of unplanned releases from a pipe which

goes from the Braidwood Nuclear Power Plant to the Kankakee River. The plant is operated by Exelon

Generation Co.

On November 30, 2005, Braidwood staff informed the NRC that elevated levels of tritium were

found on plant property. The discovery was made as additional monitoring wells were installed by

Braidwood staff. 

All radioactive discharges into the circulating water blowdown line, which takes nonradioactive water from the cooling lake to the river, were stopped when the contamination was

discovered. 

Subsequently, Braidwood expanded its sampling beyond the plant boundary, including

residential wells. Outside of the plant, tritium was found in one residential drinking water well. The

tritium levels there were significantly less than the U. S. Environmental Protection Agency (EPA)

drinking water standard of 20,000 picocuries per liter. The remaining residential well samples had no

tritium above normal background levels. The plant staff found that the area of contaminated

groundwater extended 2000 to 2500 feet north of the plant boundary.

The NRC conducted inspections to characterize and evaluate the tritium contamination on plant

property and in the public domain. The inspectors collected independent and confirmatory samples for

independent analysis, reviewed plant procedures and records, and observed activities related to the

contamination.

The NRC confirmed that unplanned releases from the pipe, which is about 5 miles long and has

11 vacuum breaker valves, occurred between 1996 and 2005. The releases were due to leakage from

the vacuum breakers. The inspectors concluded that the largest leaks occurred in 1996 (about 250,000

gallons of water); 1998 and 2000 (about 3,000,000 gallons of water) during the radioactive releases

through the pipe and led to the tritium contamination onsite and offsite.
The NRC’s findings are not based on the radiological impact of the unplanned releases on

public health. The NRC estimated the doses from the contamination to be a small fraction of the

NRC’s limit for doses to members of the public.

The NRC staff identified three violations of NRC regulations related to significant deficiencies

in Braidwood’s environmental control programs: failure to perform necessary radiological surveys;

failure to adequately implement a program to assess the cumulative dose of the releases; and failure to

conduct an adequate monitoring program to provide data on measurable levels of radiation and

radioactivity in the environment resulting from the releases. 

“We recognize that the radiological impact of these releases on public health is not a concern

here,” said James Caldwell, NRC Regional Administrator. “However making sure that nuclear material

doesn’t end up where it’s not supposed to be is important. It is also important to analyze the situation

and to mitigate it quickly and efficiently when an unplanned release occurs.”

Exelon has performed extensive monitoring since the discovery of the contamination and has

taken steps to mitigate the impact of the unplanned releases.

The NRC uses color-coded inspection findings and performance indicators to assess nuclear

plant performance. The colors start with “green” and then increase to “white,” “yellow” or “red,”

commensurate with the safety significance of the issues involved. 

White findings normally result in additional NRC inspections and meetings with the utility.

Based on the white finding, the NRC issued a Notice of Violation to Exelon Generation Co. for its

failures to perform surveys following the historical leaks, to assess the environmental impacts, and to

account for potential impact on the public, and to control licensed material. The company is required to

respond to the Notice of Violation within 30 days, describing its corrective actions and steps it is

taking to prevent a recurrence of the violation.

The letter notifying Exelon of the white finding will be available from the NRC’s

Region III Office of Public Affairs or in the NRC’s online document library at:

http://www.nrc.gov.reading-rm/admas/web-based.html .

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