United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for January 11, 1999

                       Headquarters Daily Report

                         JANUARY 11, 1999

***************************************************************************
                    REPORT             NEGATIVE            NO INPUT
                    ATTACHED           INPUT RECEIVED      RECEIVED

HEADQUARTERS                           X
REGION I            X
REGION II                              X
REGION III                             X
REGION IV                              X
PRIORITY ATTENTION REQUIRED  MORNING REPORT - REGION I  JANUARY 11, 1999

Licensee/Facility:                     Notification:

Northeast Utilities                    MR Number: 1-99-0003
Millstone 3                            Date: 01/11/99
Waterford,Connecticut                  1/8/99 SRI PHONE CALL
Dockets: 50-423
PWR/W-4-LP

Subject: UPDATE CONCERNING SMALL UNMONITORED RELEASE OF RADIOACTIVITY
         INTO NIANTIC BAY

Reportable Event Number: 35219

Discussion:

As previously reported in morning report 1-99-0001, a small amount of
radioactivity was inadvertently released into Niantic Bay from the Unit 3
"A" waste test tank (WTT). The leak occurred when a 3/4" instrument line
froze, and subsequently thawed, allowing leakage past a pressure
instrument's damaged O-ring and gasket. A berm, which was constructed
around the WTT, failed to keep the leakage from reaching the yard drain
system, and eventually Niantic Bay. Although the licensee had a permit to
release the contents of the WTT to Niantic Bay through an authorized and
monitored release path, the leakage through the yard drain system, which
is an unauthorized and unmonitored release path, was reportable to the
State of Connecticut.

Independent NRC assessment of the licensee's analysis and dose projection
confirmed that there was no actual health and safety consequence
associated with this leak. Based on the licensee's measurements of the
concentrations of radionuclides in the WTT at the time of the leak
(predominately tritium, with trace concentrations of other
radionuclides), and conservative assumptions with respect to dilution and
exposure pathways, the NRC confirmed that the dose projection to a
maximumly exposed individual was 0.000000219 millirem whole body, and
0.00000207 millirem organ. The regulatory limit specified in the
licensee's technical specifications is 3 millirem whole body in a year,
and 10 millirem organ in a year.  In comparison, the average United
States individual receives about 360 millirem whole body per year from
background sources.  Accordingly, no on-site or off-site radiological
risk is expected from this event.

Regional Action:

Routine Resident Inspector Followup.

Contact:  Richard Urban              (610)337-5271
          John White                 (610)337-5114
_
Page Last Reviewed/Updated Thursday, March 29, 2012