Event Notification Report for August 26, 2000
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
08/25/2000 - 08/26/2000
Other Nuclear Material
Event Number: 37260
Rep Org: US STEEL, GARY WORKS
Licensee: US STEEL, GARY WORKS
Region: 3
City: GARY State: IN
County:
License #:
Agreement: N
Docket:
NRC Notified By: BRIAN CONKEL
HQ OPS Officer: BOB STRANSKY
Licensee: US STEEL, GARY WORKS
Region: 3
City: GARY State: IN
County:
License #:
Agreement: N
Docket:
NRC Notified By: BRIAN CONKEL
HQ OPS Officer: BOB STRANSKY
Notification Date: 08/26/2000
Notification Time: 10:14 [ET]
Event Date: 08/26/2000
Event Time: 03:00 [CDT]
Last Update Date: 08/26/2000
Notification Time: 10:14 [ET]
Event Date: 08/26/2000
Event Time: 03:00 [CDT]
Last Update Date: 08/26/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
10 CFR Section:
Person (Organization):
PATRICK HILAND (R3)
JOSEPHINE PICCONE (NMSS)
PATRICK HILAND (R3)
JOSEPHINE PICCONE (NMSS)
TWO NUCLEAR GAUGES DISPLACED ON MANUFACTURING LINE
Two nuclear gauges (2061T and 2061B) were displaced from their mountings on the #6 East galvanizing line when a strip of sheet steel broke. These gauges are both Nucleonic Data Systems model 200 devices, each containing 2.001 Ci of Am-241. The sources are generally licensed under Valmet license GA458-3G.
The gauges came to rest on a roll of steel approximately one foot from their mounting positions. A health physics consultant responded to the site and performed surveys and wipe samples, but no damage or leakage was detected. A full investigation of the event is currently being conducted.
Two nuclear gauges (2061T and 2061B) were displaced from their mountings on the #6 East galvanizing line when a strip of sheet steel broke. These gauges are both Nucleonic Data Systems model 200 devices, each containing 2.001 Ci of Am-241. The sources are generally licensed under Valmet license GA458-3G.
The gauges came to rest on a roll of steel approximately one foot from their mounting positions. A health physics consultant responded to the site and performed surveys and wipe samples, but no damage or leakage was detected. A full investigation of the event is currently being conducted.
Power Reactor
Event Number: 37261
Facility: PALO VERDE
Region: 4 State: AZ
Unit: [] [2] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: DAN MARKS
HQ OPS Officer: FANGIE JONES
Region: 4 State: AZ
Unit: [] [2] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: DAN MARKS
HQ OPS Officer: FANGIE JONES
Notification Date: 08/26/2000
Notification Time: 22:37 [ET]
Event Date: 08/26/2000
Event Time: 15:39 [MST]
Last Update Date: 08/26/2000
Notification Time: 22:37 [ET]
Event Date: 08/26/2000
Event Time: 15:39 [MST]
Last Update Date: 08/26/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
Person (Organization):
LARRY YANDELL (R4)
LARRY YANDELL (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | A/R | Y | 100 | Power Operation | 0 | Hot Standby |
AUTOMATIC REACTOR TRIP DUE TO UNEXPECTED CLOSURE OF ALL MAIN STEAM ISOLATION VALVES
"The following event description is based on information currently available. If through subsequent reviews of this event, additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
"On August 26, 2000, at approximately 15:39 MST Palo Verde Unit 2 experienced an automatic reactor trip (RPS actuation) from approximately 100% rated thermal power due to pressure exceeding the high pressurizer pressure reactor trip setpoint. The high pressure resulted from the closure of all main steam isolation valves (MSIVs) coincident with the annunciation of a loss of 'A' train power to the MSIV control cabinet. The unit was at normal temperature and pressure prior to the trip. All CEAs inserted fully into the reactor core. No ESF actuations occurred and none were required. An investigation has commenced to determine why the MSIVs closed.
"Due to the MSIV closure, main steam safety valves lifted for a short period. Operators restored reactor coolant system heat removal using atmospheric dump valves and the main steam safety valves reseated. Feedwater to the steam generators was initiated using the 'B' motor driven essential auxiliary feedwater pump and is now maintained by the 'N' motor driven non-essential auxiliary feedwater pump.
"Safety related buses remained energized during and following the reactor trip. The offsite power grid is stable. Power distribution for one of the two non-safety buses did not automatically transfer to offsite power. Condenser vacuum was lost and has not yet been restored, thus heat removal remains via the atmospheric dump valves. Unit 2 Operations entered LCO 3.4.17(A) for RCS specific activity greater than 1.0 µCi/gm. No other significant LCOs have been entered as a result of this event. No major equipment was inoperable prior to the event nor contributed to the event.
"Unit 2 is stable at normal operating temperature and pressure in Mode 3. The event did not result in any challenges to the fission product barrier. There were no adverse safety consequences or implications as a result of this event. The event did not adversely affect the safe operation of the plant or the health and safety of the public.
"Steam generator tube leakage was approximately 0.07 gpd prior to the reactor trip, (0.047% of the technical specification limit.
"RCS dose equivalent iodine was approximately 4.28E-02 µCi/gm prior to the reactor trip. (4.28% of the technical specification limit.)
"The first post-trip RCS dose equivalent iodine sample indicated 2.06 µCi/ml.
"RCS chemistry continues to be monitored."
The licensee has notified the NRC Resident Inspector.
"The following event description is based on information currently available. If through subsequent reviews of this event, additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
"On August 26, 2000, at approximately 15:39 MST Palo Verde Unit 2 experienced an automatic reactor trip (RPS actuation) from approximately 100% rated thermal power due to pressure exceeding the high pressurizer pressure reactor trip setpoint. The high pressure resulted from the closure of all main steam isolation valves (MSIVs) coincident with the annunciation of a loss of 'A' train power to the MSIV control cabinet. The unit was at normal temperature and pressure prior to the trip. All CEAs inserted fully into the reactor core. No ESF actuations occurred and none were required. An investigation has commenced to determine why the MSIVs closed.
"Due to the MSIV closure, main steam safety valves lifted for a short period. Operators restored reactor coolant system heat removal using atmospheric dump valves and the main steam safety valves reseated. Feedwater to the steam generators was initiated using the 'B' motor driven essential auxiliary feedwater pump and is now maintained by the 'N' motor driven non-essential auxiliary feedwater pump.
"Safety related buses remained energized during and following the reactor trip. The offsite power grid is stable. Power distribution for one of the two non-safety buses did not automatically transfer to offsite power. Condenser vacuum was lost and has not yet been restored, thus heat removal remains via the atmospheric dump valves. Unit 2 Operations entered LCO 3.4.17(A) for RCS specific activity greater than 1.0 µCi/gm. No other significant LCOs have been entered as a result of this event. No major equipment was inoperable prior to the event nor contributed to the event.
"Unit 2 is stable at normal operating temperature and pressure in Mode 3. The event did not result in any challenges to the fission product barrier. There were no adverse safety consequences or implications as a result of this event. The event did not adversely affect the safe operation of the plant or the health and safety of the public.
"Steam generator tube leakage was approximately 0.07 gpd prior to the reactor trip, (0.047% of the technical specification limit.
"RCS dose equivalent iodine was approximately 4.28E-02 µCi/gm prior to the reactor trip. (4.28% of the technical specification limit.)
"The first post-trip RCS dose equivalent iodine sample indicated 2.06 µCi/ml.
"RCS chemistry continues to be monitored."
The licensee has notified the NRC Resident Inspector.