Event Notification Report for May 04, 2004
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/03/2004 - 05/04/2004
Power Reactor
Event Number: 40724
Facility: OCONEE
Region: 2 State: SC
Unit: [1] [] [3]
RX Type: [1] B&W-L-LP,[2] B&W-L-LP,[3] B&W-L-LP
NRC Notified By: RANDY TODD
HQ OPS Officer: ARLON COSTA
Region: 2 State: SC
Unit: [1] [] [3]
RX Type: [1] B&W-L-LP,[2] B&W-L-LP,[3] B&W-L-LP
NRC Notified By: RANDY TODD
HQ OPS Officer: ARLON COSTA
Notification Date: 05/04/2004
Notification Time: 19:08 [ET]
Event Date: 05/04/2004
Event Time: 16:55 [EDT]
Last Update Date: 05/04/2004
Notification Time: 19:08 [ET]
Event Date: 05/04/2004
Event Time: 16:55 [EDT]
Last Update Date: 05/04/2004
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Person (Organization):
KERRY LANDIS (R2)
KERRY LANDIS (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 3 | N | Y | 100 | Power Operation | 100 | Power Operation |
UNANALYZED CONDITION AND POTENTIAL LOSS OF CONTAINMENT SAFETY FUNCTION
"NOTE: Oconee Unit 2 is DEFUELED (No Mode) in a refueling outage.
"Oconee has discovered a new scenario where the double ended guillotine rupture addressed by IE Bulletin 80-04 is not the worst case with respect to containment pressure following a Main Steam Line Break (MSLB). Therefore this scenario is being reporting as an Unanalyzed Condition and a potential loss of the containment safety function. This new scenario involves a range of MSLB break sizes smaller than the double ended guillotine rupture addressed by IE Bulletin 80-04, with the break located inside containment, and with a concurrent Loss Of Offsite Power (LOOP).
"This event scenario is still being evaluated but it appears to result in containment pressures in excess of the 59 psig limit discussed in the UFSAR. Preliminary results indicate that pressure would not exceed the containment 'ultimate capacity' of 144 psig.
"Analysis has shown that the Steam Generator tube stresses remain within acceptable limits for this event scenario so that no additional RCS leakage would occur. As a result, the offsite dose for this scenario is bounded by previous scenarios for a MSLB outside containment.
"Background
The AFIS (Automatic Feedwater Isolation System) Circuitry required by Tech Specs 3.3.11, 3.3.12, and 3.3.13 is intended to isolate Feedwater from the steam generators in the event of a Main Steam Line Break (MSLB) by closing the Feedwater Control Valves and preventing operation of the Emergency Feedwater Pumps. Tech Spec 3.7.3 requires the Feedwater Control Valves to be operable and provides an 8 hour Allowed Outage Time (AOT) if they are not. If the AOT is exceeded, the affected unit must be in Mode 3 within an additional 12 hours. The Feedwater Control Valves are air operated and fail as-is on loss of Instrument Air. Low MS pressure causes AFIS to signal the valves to close. Emergency Feedwater Pumps are interlocked based on rate of MS pressure drop.
"Scenario:
ONS identified a new scenario involving a MSLB smaller than the double ended guillotine rupture addressed by IE Bulletin 80-04, located inside containment, and occurring concurrent with a LOOP.
"In this scenario, the LOOP results in the loss of power to the permanently installed plant instrument air compressors, so that instrument air pressure would begin to decay. The smaller MSLB break size slows the rate of pressure loss from the affected MS line. Break sizes exist such that by the time the MS system pressure decays to the AFIS actuation setpoint, instrument air pressure might become inadequate to close the Feedwater Control Valves. Also, the low rate of change of MS pressure might not satisfy the AFIS rate based setpoint for actuating the EFW pump interlock. If the control valves remain open or if the EFW pumps are allowed to operate, additional inventory would reach the steam generators and flash to steam. Since the scenario requires the break to be located inside containment, this would result in increased containment pressures.
"Initial Safety Significance:
The Main Steam Line Break inside containment is a low probability event. Also, although the MSLB scenario includes the assumption of some primary to secondary leakage, the analysis shows that Steam Generator tube stresses remain within acceptable limits for these break sizes, so that no additional RCS leakage would occur. As a result, the offsite dose for this scenario is still bounded by the scenario for a break outside containment. Therefore this event is not significant with respect to the health and safety of the public.
"Corrective Action(s):
A diesel compressor connected to the Instrument Air header has been placed in operation to assure a source of instrument air in the event of a LOOP. Additional actions for permanent resolution are being evaluated."
The licensee will notify the NRC Resident Inspector.
"NOTE: Oconee Unit 2 is DEFUELED (No Mode) in a refueling outage.
"Oconee has discovered a new scenario where the double ended guillotine rupture addressed by IE Bulletin 80-04 is not the worst case with respect to containment pressure following a Main Steam Line Break (MSLB). Therefore this scenario is being reporting as an Unanalyzed Condition and a potential loss of the containment safety function. This new scenario involves a range of MSLB break sizes smaller than the double ended guillotine rupture addressed by IE Bulletin 80-04, with the break located inside containment, and with a concurrent Loss Of Offsite Power (LOOP).
"This event scenario is still being evaluated but it appears to result in containment pressures in excess of the 59 psig limit discussed in the UFSAR. Preliminary results indicate that pressure would not exceed the containment 'ultimate capacity' of 144 psig.
"Analysis has shown that the Steam Generator tube stresses remain within acceptable limits for this event scenario so that no additional RCS leakage would occur. As a result, the offsite dose for this scenario is bounded by previous scenarios for a MSLB outside containment.
"Background
The AFIS (Automatic Feedwater Isolation System) Circuitry required by Tech Specs 3.3.11, 3.3.12, and 3.3.13 is intended to isolate Feedwater from the steam generators in the event of a Main Steam Line Break (MSLB) by closing the Feedwater Control Valves and preventing operation of the Emergency Feedwater Pumps. Tech Spec 3.7.3 requires the Feedwater Control Valves to be operable and provides an 8 hour Allowed Outage Time (AOT) if they are not. If the AOT is exceeded, the affected unit must be in Mode 3 within an additional 12 hours. The Feedwater Control Valves are air operated and fail as-is on loss of Instrument Air. Low MS pressure causes AFIS to signal the valves to close. Emergency Feedwater Pumps are interlocked based on rate of MS pressure drop.
"Scenario:
ONS identified a new scenario involving a MSLB smaller than the double ended guillotine rupture addressed by IE Bulletin 80-04, located inside containment, and occurring concurrent with a LOOP.
"In this scenario, the LOOP results in the loss of power to the permanently installed plant instrument air compressors, so that instrument air pressure would begin to decay. The smaller MSLB break size slows the rate of pressure loss from the affected MS line. Break sizes exist such that by the time the MS system pressure decays to the AFIS actuation setpoint, instrument air pressure might become inadequate to close the Feedwater Control Valves. Also, the low rate of change of MS pressure might not satisfy the AFIS rate based setpoint for actuating the EFW pump interlock. If the control valves remain open or if the EFW pumps are allowed to operate, additional inventory would reach the steam generators and flash to steam. Since the scenario requires the break to be located inside containment, this would result in increased containment pressures.
"Initial Safety Significance:
The Main Steam Line Break inside containment is a low probability event. Also, although the MSLB scenario includes the assumption of some primary to secondary leakage, the analysis shows that Steam Generator tube stresses remain within acceptable limits for these break sizes, so that no additional RCS leakage would occur. As a result, the offsite dose for this scenario is still bounded by the scenario for a break outside containment. Therefore this event is not significant with respect to the health and safety of the public.
"Corrective Action(s):
A diesel compressor connected to the Instrument Air header has been placed in operation to assure a source of instrument air in the event of a LOOP. Additional actions for permanent resolution are being evaluated."
The licensee will notify the NRC Resident Inspector.
General Information or Other
Event Number: 40725
Rep Org: OHIO BUREAU OF RADIATION PROTECTION
Licensee: TIMKEN COMPANY
Region: 3
City: CANTON State: OH
County:
License #: 31-201770025
Agreement: Y
Docket:
NRC Notified By: MIKE SNEE
HQ OPS Officer: JEFF ROTTON
Licensee: TIMKEN COMPANY
Region: 3
City: CANTON State: OH
County:
License #: 31-201770025
Agreement: Y
Docket:
NRC Notified By: MIKE SNEE
HQ OPS Officer: JEFF ROTTON
Notification Date: 05/05/2004
Notification Time: 11:28 [ET]
Event Date: 05/04/2004
Event Time: 15:00 [EDT]
Last Update Date: 05/05/2004
Notification Time: 11:28 [ET]
Event Date: 05/04/2004
Event Time: 15:00 [EDT]
Last Update Date: 05/05/2004
Emergency Class: NON EMERGENCY
10 CFR Section:
10 CFR Section:
Person (Organization):
CHRISTINE LIPA (R3)
THOMAS ESSIG (NMSS)
CHRISTINE LIPA (R3)
THOMAS ESSIG (NMSS)
AGREEMENT STATE RADIOACTIVE CONTAMINATION DUE TO MELTED SOURCE
State of Ohio reported that a Cs 137 source was destroyed in a furnace at the Timken Steel Company. The initial detection of a problem occurred with high radiation being detected in the bag house exhaust system. Dose rates are 660 micro R/hr in the bag house. It is not known at this time the origin of the radioactive material. The licensee is conducting surveys to determine if there is contamination anywhere else in the facility. The licensee is also conducting an inventory of their radioactive material to determine if it was their material. It is suspected that the radioactive material may have been in a load of scrap steel that was being melted for reprocessing. The licensee has contacted a contractor to perform decontamination activities.
Licensee notified the NRC Agreement States representative (J. Lynch).
State of Ohio reported that a Cs 137 source was destroyed in a furnace at the Timken Steel Company. The initial detection of a problem occurred with high radiation being detected in the bag house exhaust system. Dose rates are 660 micro R/hr in the bag house. It is not known at this time the origin of the radioactive material. The licensee is conducting surveys to determine if there is contamination anywhere else in the facility. The licensee is also conducting an inventory of their radioactive material to determine if it was their material. It is suspected that the radioactive material may have been in a load of scrap steel that was being melted for reprocessing. The licensee has contacted a contractor to perform decontamination activities.
Licensee notified the NRC Agreement States representative (J. Lynch).
Other Nuclear Material
Event Number: 40722
Rep Org: TES CONSULTANTS
Licensee: TES CONSULTANTS
Region: 3
City: FARMINGTON HILLS State: MI
County:
License #: 21-32150-01
Agreement: N
Docket:
NRC Notified By: NICK HUCHINSON
HQ OPS Officer: ARLON COSTA
Licensee: TES CONSULTANTS
Region: 3
City: FARMINGTON HILLS State: MI
County:
License #: 21-32150-01
Agreement: N
Docket:
NRC Notified By: NICK HUCHINSON
HQ OPS Officer: ARLON COSTA
Notification Date: 05/04/2004
Notification Time: 13:34 [ET]
Event Date: 05/04/2004
Event Time: 08:00 [EDT]
Last Update Date: 05/07/2004
Notification Time: 13:34 [ET]
Event Date: 05/04/2004
Event Time: 08:00 [EDT]
Last Update Date: 05/07/2004
Emergency Class: NON EMERGENCY
10 CFR Section:
10 CFR Section:
Person (Organization):
CHRISTINE LIPA (R3)
THOMAS ESSIG (NMSS)
CHRISTINE LIPA (R3)
THOMAS ESSIG (NMSS)
DAMAGED TROXLER MOISTURE DENSITY GAUGE
At approximately 0800 EDT on 05/04/04, an equipment operator backed an excavator over a Troxler density gauge model 3430, Serial No. 29858, containing an 8 millicurie Cs-137 and a 40 millicurie Am-241:Be source. The exterior cover of the gauge was damaged, the source rod was bent and stuck in the exposed position at the time the incident occurred. The technician removed personnel from the area and contacted the local Hazmat fire department which placed the damaged gauge in a steel drum. The licensee is in possession of the steel drum containing the damaged gauge and has plans to return it to the manufacturer for disposal. The licensee believes that based on the structure of the damaged gauge, there was no source leakage and they are in process of performing personnel exposure calculations as warranted. The licensee contacted Region 3 and will submit a written report of this incident, as required.
* * * UPDATE AT 0937 EDT ON 05/07/04 TO JOHN MACKINNON FROM NICK HUTCHINSON * * *
Correct gauge serial number mentioned above should be 30162 instead of 29858. R3DO (Christine Lipa) & NMSS (Roberto Torres) notified.
At approximately 0800 EDT on 05/04/04, an equipment operator backed an excavator over a Troxler density gauge model 3430, Serial No. 29858, containing an 8 millicurie Cs-137 and a 40 millicurie Am-241:Be source. The exterior cover of the gauge was damaged, the source rod was bent and stuck in the exposed position at the time the incident occurred. The technician removed personnel from the area and contacted the local Hazmat fire department which placed the damaged gauge in a steel drum. The licensee is in possession of the steel drum containing the damaged gauge and has plans to return it to the manufacturer for disposal. The licensee believes that based on the structure of the damaged gauge, there was no source leakage and they are in process of performing personnel exposure calculations as warranted. The licensee contacted Region 3 and will submit a written report of this incident, as required.
* * * UPDATE AT 0937 EDT ON 05/07/04 TO JOHN MACKINNON FROM NICK HUTCHINSON * * *
Correct gauge serial number mentioned above should be 30162 instead of 29858. R3DO (Christine Lipa) & NMSS (Roberto Torres) notified.