ML053350512
| ML053350512 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 12/01/2005 |
| From: | House J, Steven Orth NRC/RGN-III |
| To: | |
| References | |
| FOIA/PA-2006-0115, FOIA/PA-2010-0209 PNO-III-05-016 | |
| Download: ML053350512 (2) | |
Text
December 1, 2005 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-RIII-05-016 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region III staff on this date.
Facility Licensee Emergency Classification Braidwood 1 and 2 Notification of Unusual Event Exelon Generation Co. Alert Braceville, Illinois Site Area Emergency Docket: 50-456 and 50-457 General Emergency License: NPF-72; NPF-77 X Not Applicable
SUBJECT:
POTENTIAL OFF-SITE MIGRATION OF TRITIUM CONTAMINATION DESCRIPTION:
On November 30, 2005, the licensee informed the resident inspectors and Region III (Chicago) that elevated levels of tritium (the radioactive isotope of hydrogen) had been measured in groundwater on the Braidwood site and that the tritium may have moved in groundwater off the site.
The licensee believes that the tritium in the groundwater is a result of past leakage from a pipe which normally carries non-radiation circulating water discharge to the Kankakee River, about five miles from the site. Significant leakage occurred from the pipe in November 1998 and December 2000, flooding a portion of the plant site with an estimated 3 million gallons of water in each occurrence. A small leak of a few gallons also occurred in May 2005.
The discharge pipe is also used for planned liquid radioactive effluent releases with the effluent mixing with the non-radiation circulating water being discharged. (Braidwood, like most nuclear plants, releases small concentrations of radioactive liquids under controlled and monitored conditions and within limits imposed by the NRC.) Planned releases were made at the time the leakage occurred in 1998 and 2000 which accounts for the presence of tritium in the groundwater. There have been no planned releases from the plant which exceeded NRC discharge limits.
The licensee has measured tritium levels in shallow onsite monitoring wells as high as 58,000 picocuries per liter. This level of tritium, if released from the site, would be a small fraction of NRC limits for radioactive effluent releases to the environment.
In the vicinity of the onsite monitoring wells where elevated tritium levels have been measured, there are three homes and a larger parcel of vacant land with undeveloped lots. The licensee believes the movement of the groundwater is away from the homes and toward the vacant CONTACTS:
John House Steven Orth 630/829-9824 630/829-9827
PNO-RIII-05-016 property. The licensee has contacted the homeowners and collected well water samples to be analyzed by an independent laboratory. The licensee is also drilling monitoring wells on the vacant site. The initial sample results are expected to be available on December 2, 2005.
The licensee has notified local officials and the State of Illinois of the elevated tritium measurements. The licensee is also planning to issue a news release.
Region III has dispatched a radiation specialist to the site to assist the resident inspectors in their review of the circumstances surrounding the elevated measurements and the licensees plans to address the elevated tritium levels.
Region III was notified of the elevated measurements on November 30, 2005. The information in this preliminary notification has been reviewed with licensee management and is current as of 3:30 p.m. on December 1, 2005.