Event Notification Report for February 13, 2006
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
02/12/2006 - 02/13/2006
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 42334
Facility: SUSQUEHANNA
Region: 1 State: PA
Unit: [1] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: MARTIN LICHTNER
HQ OPS Officer: BILL HUFFMAN
Region: 1 State: PA
Unit: [1] [2] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: MARTIN LICHTNER
HQ OPS Officer: BILL HUFFMAN
Notification Date: 02/13/2006
Notification Time: 17:18 [ET]
Event Date: 02/13/2006
Event Time: 09:33 [EST]
Last Update Date: 02/21/2006
Notification Time: 17:18 [ET]
Event Date: 02/13/2006
Event Time: 09:33 [EST]
Last Update Date: 02/21/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
Person (Organization):
PAUL KROHN (R1)
PAUL KROHN (R1)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
LOSS OF SINGLE POWER SUPPLY COULD RESULT IN LOSS OF VENTILATION FOR DC SUBSYSTEMS IN BOTH UNITS
"At 09:33 on February 13, 2006, a Susquehanna field operator inadvertently tripped an essential instrument AC panel breaker, while applying an energy control tag. He immediately communicated this condition to the control room, and then closed the breaker to restore power. During the subsequent investigation to determine applicable technical specifications, control room operators discovered that the tripped breaker resulted in a momentary loss of both battery room exhaust subsystems. To comply with the required actions for a loss of both battery room exhaust subsystems, Susquehanna declared all Unit 1 and Unit 2 DC subsystems inoperable, which resulted in LCO 3.0.3.
"Although the entry into LCO 3.0.3 is not reportable, Susquehanna did discover an unanalyzed condition on both units that significantly degrades plant safety, which is reportable in accordance with 10CFR50.72(b)(3)(ii). The loss of a single power supply could result in the loss of ventilation and cooling for all DC subsystems on both units, leading to degradation of essential DC power sources. This condition does not meet single failure criteria for safety-related equipment."
The licensee notified the NRC Resident Inspector.
* * * UPDATE 1342 EST ON 2/21/06 FROM GORDY ROBINSON TO S. SANDIN * * *
The licensee is retracting this report based on the following:
"At 0933 hours on February 13, 2006, a Susquehanna field operator inadvertently tripped an essential instrument AC panel breaker while applying an energy control tag. The field operator immediately communicated this condition to the control room and was directed to close the breaker to restore power. The breaker trip resulted in a momentary loss of exhaust flow from the Class 1E 125 VDC and 250 VDC battery rooms. In response, operators declared all Unit 1 and Unit 2 batteries inoperable. An ENS notification (# 42334) was initiated in accordance with 10CFR50.72(b)(3)(ii)(B), Unanalyzed Condition that Significantly Affects Plant Safety, because the loss of a single power supply rendered the status of all station essential DC power sources (Batteries) indeterminate and, thus, inoperable. It was believed that this condition did not meet single failure criteria for safety-related equipment.
"Subsequent analysis of this event has revealed that the battery room exhaust system acted per design. The system's design is consistent with intended logic that ensures single failure proof isolation of the system, in compliance with the single failure criterion, in response to a toxic gas release. The single failure proof design of the battery exhaust system ensures isolation, not continued operation, in the presence of a single failure. The analysis further concluded that a short term loss of battery room exhaust does not compromise a battery's ability to function. The insights obtained through this analysis provide the basis for retraction of the ENS report of February 13, 2006."
The licensee informed the NRC Resident Inspector. Notified R1DO(Henderson).
"At 09:33 on February 13, 2006, a Susquehanna field operator inadvertently tripped an essential instrument AC panel breaker, while applying an energy control tag. He immediately communicated this condition to the control room, and then closed the breaker to restore power. During the subsequent investigation to determine applicable technical specifications, control room operators discovered that the tripped breaker resulted in a momentary loss of both battery room exhaust subsystems. To comply with the required actions for a loss of both battery room exhaust subsystems, Susquehanna declared all Unit 1 and Unit 2 DC subsystems inoperable, which resulted in LCO 3.0.3.
"Although the entry into LCO 3.0.3 is not reportable, Susquehanna did discover an unanalyzed condition on both units that significantly degrades plant safety, which is reportable in accordance with 10CFR50.72(b)(3)(ii). The loss of a single power supply could result in the loss of ventilation and cooling for all DC subsystems on both units, leading to degradation of essential DC power sources. This condition does not meet single failure criteria for safety-related equipment."
The licensee notified the NRC Resident Inspector.
* * * UPDATE 1342 EST ON 2/21/06 FROM GORDY ROBINSON TO S. SANDIN * * *
The licensee is retracting this report based on the following:
"At 0933 hours on February 13, 2006, a Susquehanna field operator inadvertently tripped an essential instrument AC panel breaker while applying an energy control tag. The field operator immediately communicated this condition to the control room and was directed to close the breaker to restore power. The breaker trip resulted in a momentary loss of exhaust flow from the Class 1E 125 VDC and 250 VDC battery rooms. In response, operators declared all Unit 1 and Unit 2 batteries inoperable. An ENS notification (# 42334) was initiated in accordance with 10CFR50.72(b)(3)(ii)(B), Unanalyzed Condition that Significantly Affects Plant Safety, because the loss of a single power supply rendered the status of all station essential DC power sources (Batteries) indeterminate and, thus, inoperable. It was believed that this condition did not meet single failure criteria for safety-related equipment.
"Subsequent analysis of this event has revealed that the battery room exhaust system acted per design. The system's design is consistent with intended logic that ensures single failure proof isolation of the system, in compliance with the single failure criterion, in response to a toxic gas release. The single failure proof design of the battery exhaust system ensures isolation, not continued operation, in the presence of a single failure. The analysis further concluded that a short term loss of battery room exhaust does not compromise a battery's ability to function. The insights obtained through this analysis provide the basis for retraction of the ENS report of February 13, 2006."
The licensee informed the NRC Resident Inspector. Notified R1DO(Henderson).
General Information or Other
Event Number: 42341
Rep Org: TEXAS DEPARTMENT OF HEALTH
Licensee: TEXAS INSTRUMENTS
Region: 4
City: DALLAS State: TX
County:
License #: G1800
Agreement: Y
Docket:
NRC Notified By: RUBEN CORTEZ
HQ OPS Officer: BILL HUFFMAN
Licensee: TEXAS INSTRUMENTS
Region: 4
City: DALLAS State: TX
County:
License #: G1800
Agreement: Y
Docket:
NRC Notified By: RUBEN CORTEZ
HQ OPS Officer: BILL HUFFMAN
Notification Date: 02/15/2006
Notification Time: 18:04 [ET]
Event Date: 02/13/2006
Event Time: 00:00 [CST]
Last Update Date: 02/15/2006
Notification Time: 18:04 [ET]
Event Date: 02/13/2006
Event Time: 00:00 [CST]
Last Update Date: 02/15/2006
Emergency Class: NON EMERGENCY
10 CFR Section:
10 CFR Section:
Person (Organization):
DAVID GRAVES (R4)
E. WILLIAM BRACH (NMSS)
DAVID GRAVES (R4)
E. WILLIAM BRACH (NMSS)
AGREEMENT STATE - LOSS OF CONTROL OF POLONIUM SOURCE
The State of Texas reported that a static eliminator with 20 millicurie Polonium-210 source (based on a January 2005 assay) was inadvertently shipped to Taiwan without radioactive material controls or the knowledge of the RSO for the licensee. The RSO received a Po-210 source for renewal of the source in a static eliminator and discovered that the eliminator was missing. The licensee determined that the static eliminator with the depleted Po-210 source had been shipped to Taiwan without consideration of the Po-210 source in the eliminator. There is currently no indication that the source is lost - but it is no longer under the licensee's control. Investigation into this event is ongoing.
THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL
Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks.
The State of Texas reported that a static eliminator with 20 millicurie Polonium-210 source (based on a January 2005 assay) was inadvertently shipped to Taiwan without radioactive material controls or the knowledge of the RSO for the licensee. The RSO received a Po-210 source for renewal of the source in a static eliminator and discovered that the eliminator was missing. The licensee determined that the static eliminator with the depleted Po-210 source had been shipped to Taiwan without consideration of the Po-210 source in the eliminator. There is currently no indication that the source is lost - but it is no longer under the licensee's control. Investigation into this event is ongoing.
THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL
Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks.