Event Notification Report for November 13, 2007
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/12/2007 - 11/13/2007
EVENT NUMBERS
43780
Power Reactor
Event Number: 43780
Facility: THREE MILE ISLAND
Region: 1 State: PA
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] B&W-L-LP
NRC Notified By: BOYD
HQ OPS Officer: JOHN MacKINNON
Region: 1 State: PA
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] B&W-L-LP
NRC Notified By: BOYD
HQ OPS Officer: JOHN MacKINNON
Notification Date: 11/13/2007
Notification Time: 07:08 [ET]
Event Date: 11/13/2007
Event Time: 06:32 [EST]
Last Update Date: 11/13/2007
Notification Time: 07:08 [ET]
Event Date: 11/13/2007
Event Time: 06:32 [EST]
Last Update Date: 11/13/2007
Emergency Class: UNUSUAL EVENT
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
Person (Organization):
MARIE MILLER (R1)
JOHN LUBINSKI (NRR)
BRIAN McDERMOTT (IRD)
SAM COLLINS (R1RA)
JIM DYER (NRR)
MARIE MILLER (R1)
JOHN LUBINSKI (NRR)
BRIAN McDERMOTT (IRD)
SAM COLLINS (R1RA)
JIM DYER (NRR)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Refueling | 0 | Refueling |
UNUSUAL EVENT DECLARED DUE TO UNEXPECTED REACTOR VESSEL WATER LEVEL CHANGE DURING A REFUELING OUTAGE WITH IRRADIATED FUEL IN THE CORE
While in a drained down condition the reactor vessel experienced an unexplained loss of reactor coolant system inventory with irradiated fuel within the vessel. Licensee entered Emergency Action Level MU-9, Unusual Event at 0632 EST. Within a few minutes after entering EAL MU-9 reactor vessel water level returned to its initial water level of 13.7 inches above the centerline of the Hot Legs of the Reactor vessel. Licensee is investigating why reactor vessel water level changed.
Chairman Klein's Comm. Assist. (Bill Orders), Comm. Jaczko's Assist (T. Hipschman), Comm. Lyons Assist (S. Baggett), R1DO (M. Miller), R2DO (M. Lesser), R3DO (M. Phillips), R4DO (V. Campbell) , DHS (A. Ackers), FEMA (Sullivan), DOE (S. Bailey), USDA (Watts), HHS (C. Harper) , EPA (NRC) Chief Brown were notified.
* * * UPDATE ON 11/13/07 AT 1025 EST FROM J. BOYD TO MACKINNON * * *
Termination of Unusual Event.
"EAL classification of MU9 is no longer applicable. Investigation of the unplanned Reactor vessel level showed no indication of leakage into any building containing RCS piping. The apparent cause of the event is due to a slight negative pressure in the RCS. When the OTSG lower manways were installed with HEPA filters fan units running, the indicated RCS level lowered and stabilized due to the HEPA units drawing air from the RCS. No actual RCS inventory loss occurred. When the HEPA units were turned off the RCS level returned to the indicated Reactor vessel level prior to the event. In accordance with station procedures this EAL event was terminated at 0929 on 11/13/07."
The licensee notified the Resident Inspector, State and Local Officials of this event update
R1DO (D. Holody), NRR EO (J. Dozier), IRD (B. McDermott) , DHS ASWO (Ed Hoisinton) and FEMA (D. Sullivan) were notified of the termination of the Unusual Event.
While in a drained down condition the reactor vessel experienced an unexplained loss of reactor coolant system inventory with irradiated fuel within the vessel. Licensee entered Emergency Action Level MU-9, Unusual Event at 0632 EST. Within a few minutes after entering EAL MU-9 reactor vessel water level returned to its initial water level of 13.7 inches above the centerline of the Hot Legs of the Reactor vessel. Licensee is investigating why reactor vessel water level changed.
Chairman Klein's Comm. Assist. (Bill Orders), Comm. Jaczko's Assist (T. Hipschman), Comm. Lyons Assist (S. Baggett), R1DO (M. Miller), R2DO (M. Lesser), R3DO (M. Phillips), R4DO (V. Campbell) , DHS (A. Ackers), FEMA (Sullivan), DOE (S. Bailey), USDA (Watts), HHS (C. Harper) , EPA (NRC) Chief Brown were notified.
* * * UPDATE ON 11/13/07 AT 1025 EST FROM J. BOYD TO MACKINNON * * *
Termination of Unusual Event.
"EAL classification of MU9 is no longer applicable. Investigation of the unplanned Reactor vessel level showed no indication of leakage into any building containing RCS piping. The apparent cause of the event is due to a slight negative pressure in the RCS. When the OTSG lower manways were installed with HEPA filters fan units running, the indicated RCS level lowered and stabilized due to the HEPA units drawing air from the RCS. No actual RCS inventory loss occurred. When the HEPA units were turned off the RCS level returned to the indicated Reactor vessel level prior to the event. In accordance with station procedures this EAL event was terminated at 0929 on 11/13/07."
The licensee notified the Resident Inspector, State and Local Officials of this event update
R1DO (D. Holody), NRR EO (J. Dozier), IRD (B. McDermott) , DHS ASWO (Ed Hoisinton) and FEMA (D. Sullivan) were notified of the termination of the Unusual Event.