Event Notification Report for March 10, 2000
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
03/09/2000 - 03/10/2000
Power Reactor
Event Number: 36785
Facility: KEWAUNEE
Region: 3 State: WI
Unit: [1] [] []
RX Type: [1] W-2-LP
NRC Notified By: TOM WEBB
HQ OPS Officer: BOB STRANSKY
Region: 3 State: WI
Unit: [1] [] []
RX Type: [1] W-2-LP
NRC Notified By: TOM WEBB
HQ OPS Officer: BOB STRANSKY
Notification Date: 03/10/2000
Notification Time: 18:13 [ET]
Event Date: 03/10/2000
Event Time: 16:20 [CST]
Last Update Date: 03/10/2000
Notification Time: 18:13 [ET]
Event Date: 03/10/2000
Event Time: 16:20 [CST]
Last Update Date: 03/10/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(1)(ii) - DEGRAD COND DURING OP 50.72(b)(1)(ii)(A) - UNANALYZED COND OP
10 CFR Section:
50.72(b)(1)(ii) - DEGRAD COND DURING OP 50.72(b)(1)(ii)(A) - UNANALYZED COND OP
Person (Organization):
ROGER LANKSBURY (R3)
ROGER LANKSBURY (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
SHIELD BUILDING VENTILATION FILTER TRAIN FLOW OUTSIDE OF SPECIFICATION
While performing an administrative review of the results of surveillance test SP 24-122, "Shield Building Vent Filter Testing," performed on 7/27/1999, the licensee determined that train "B" was outside of specification for fan flow rate. The required flow rate is 6200 SCFM +/- 10%, while measured flow was 5427 SCFM. The Updated Final Safety Analysis Report (UFSAR) assumes a flow rate of 5000 SCFM. Shield building vent train "B" was declared inoperable at 1620 on 3/10/2000, and the unit entered 7-day Technical Specification Limiting Condition for Operation (LCO) 3.6.b.1. The NRC resident inspector has been informed of this event by the licensee.
While performing an administrative review of the results of surveillance test SP 24-122, "Shield Building Vent Filter Testing," performed on 7/27/1999, the licensee determined that train "B" was outside of specification for fan flow rate. The required flow rate is 6200 SCFM +/- 10%, while measured flow was 5427 SCFM. The Updated Final Safety Analysis Report (UFSAR) assumes a flow rate of 5000 SCFM. Shield building vent train "B" was declared inoperable at 1620 on 3/10/2000, and the unit entered 7-day Technical Specification Limiting Condition for Operation (LCO) 3.6.b.1. The NRC resident inspector has been informed of this event by the licensee.
Power Reactor
Event Number: 36786
Facility: CLINTON
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: MARSHALL FUNKHOUSER
HQ OPS Officer: BOB STRANSKY
Region: 3 State: IL
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: MARSHALL FUNKHOUSER
HQ OPS Officer: BOB STRANSKY
Notification Date: 03/10/2000
Notification Time: 20:05 [ET]
Event Date: 03/10/2000
Event Time: 18:45 [CST]
Last Update Date: 03/10/2000
Notification Time: 20:05 [ET]
Event Date: 03/10/2000
Event Time: 18:45 [CST]
Last Update Date: 03/10/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(1)(ii)(B) - OUTSIDE DESIGN BASIS
10 CFR Section:
50.72(b)(1)(ii)(B) - OUTSIDE DESIGN BASIS
Person (Organization):
ROGER LANKSBURY (R3)
ROGER LANKSBURY (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
POTENTIAL TO DAMAGE EDG WHEN PARALLELED TO OFFSITE POWER SOURCE
"It has been determined that there exists the potential for an unanalyzed interaction between the Static VAR Compensators and a diesel generator when paralleled with an offsite power source. This unintended interaction has been determined to constitute an event or condition during operation that results in the nuclear power plant being in a condition that is outside the design basis of the plant. This condition has been documented in a Condition Report and entered into the plant corrective action program.
"Discussion:
"Static VAR compensators (SVCs) are installed on the secondary side of the reserve auxiliary transformer (RAT) and the emergency reserve auxiliary transformer (ERAT) to address potentially inadequate grid voltage conditions assuming a loss of coolant accident (LOCA) and unit trip. One SVC is installed on the secondary (4.16 kV) side of the RAT and one SVC is installed on the secondary side (4.16 kV) side of the ERAT. The RAT is associated with the offsite 345 kV transmission system and the BRAT is associated with the offsite 138 kV transmission system. These two transmission systems constitute the two required offsite electrical power sources for the plant's three Class 1E 4.16 kV buses, Each Class 1B 4.16 kV buses is also capable of being supplied by a dedicated diesel generator.
"The design of the SVC is described in a Design Report that was included as Attachment 5 to the CPS license amendment submittal dated May 4, 1998 (letter U602972). During parallel operations between the diesel generator and the offsite power source via either the RAT or the ERAT, the SVCs are designed to 'freeze' such that their design function of regulating voltage on the secondary side of the RAT and the BRAT does not result in detrimental interaction between its control circuits and the control circuits of the diesel generator. The action of freezing the SVC control circuit ensures that the SVCs do not attempt to counter bus voltage transients inherent in the process of synchronizing the diesel generator to its respective Class 113 bus. The freeze signal is derived from auxiliary contacts on die diesel generator output breaker and the Class 1E bus feeder breakers.
"During the root cause investigation into the damage incurred by the Division III diesel generator during a routine surveillance (apparently involving a synchronization attempt with an out-of-synchronization condition), it was determined that a small time delay inherent in the electrical interlock circuitry for the freeze signal allowed the SVC to detrimentally interact with the diesel generator since the SVC freeze condition is not immediately effected upon closure of the diesel generator output breaker. The damage to the Division III diesel generator was previously reported in event number 36736. Although the potential for interaction had been recognized and compensated for in the design, the effect of the longer than expected time delay had not been recognized. Therefore, the effects of the unanalyzed time delay introduced an increased probability of malfunction of equipment important to safety resulting in a design configuration that constitutes an unreviewed safety question as defined in 10 CFR 50.59.
"This configuration has been determined to constitute a condition that is outside the design basis of the plant. The design requirement for the SVCs is to assist in maintaining secondary side voltages on the RAT and ERAT within acceptable values consistent with the offsite source 'capacity and capability' requirements of General Design Criterion (GDC) 17. A second requirement was that the SVCs not negatively impact plant structures, systems, and components such that an increase in the probability of a malfunction of equipment important to safety exists. Contrary to the above requirements, the current design of thc SVC controls is such that during synchronization of the diesel generator to its Class 1E bus the potential exists for the SVC to negatively impact bus voltage. As a consequence of the adverse voltage control during the diesel generator synchronization, the potential exists for the SVC response to degrade or impair the function of the diesel generator resulting in an increased probability of malfunction of equipment important to safety.
"This design deficiency exists only under the limited circumstances during the conduct of diesel generator surveillances in which the diesel is paralleled with the offsite power source. The postulated duration of the unanalyzed condition is a fraction of a second following the closure of the diesel generator output breaker. This is the approximate length of time required for the SVC control circuits to enter the freeze mode after closure of the diesel generator output breaker. Prior to the breaker closure and following the small time period of the unanalyzed condition, the diesel generators and the offsite power circuits are capable of performing their intended design functions during parallel operations. The Onsite AC Sources Limiting Conditions for Operation (LCO) specified in Technical Specifications 3.8.1 and 3.8.2 are satisfied.
"AmerGen is currently pursuing a plant modification to resolve this design deficiency as soon as possible to support testing of the diesel generators."
The NRC resident inspector will be informed of this notification by the licensee.
"It has been determined that there exists the potential for an unanalyzed interaction between the Static VAR Compensators and a diesel generator when paralleled with an offsite power source. This unintended interaction has been determined to constitute an event or condition during operation that results in the nuclear power plant being in a condition that is outside the design basis of the plant. This condition has been documented in a Condition Report and entered into the plant corrective action program.
"Discussion:
"Static VAR compensators (SVCs) are installed on the secondary side of the reserve auxiliary transformer (RAT) and the emergency reserve auxiliary transformer (ERAT) to address potentially inadequate grid voltage conditions assuming a loss of coolant accident (LOCA) and unit trip. One SVC is installed on the secondary (4.16 kV) side of the RAT and one SVC is installed on the secondary side (4.16 kV) side of the ERAT. The RAT is associated with the offsite 345 kV transmission system and the BRAT is associated with the offsite 138 kV transmission system. These two transmission systems constitute the two required offsite electrical power sources for the plant's three Class 1E 4.16 kV buses, Each Class 1B 4.16 kV buses is also capable of being supplied by a dedicated diesel generator.
"The design of the SVC is described in a Design Report that was included as Attachment 5 to the CPS license amendment submittal dated May 4, 1998 (letter U602972). During parallel operations between the diesel generator and the offsite power source via either the RAT or the ERAT, the SVCs are designed to 'freeze' such that their design function of regulating voltage on the secondary side of the RAT and the BRAT does not result in detrimental interaction between its control circuits and the control circuits of the diesel generator. The action of freezing the SVC control circuit ensures that the SVCs do not attempt to counter bus voltage transients inherent in the process of synchronizing the diesel generator to its respective Class 113 bus. The freeze signal is derived from auxiliary contacts on die diesel generator output breaker and the Class 1E bus feeder breakers.
"During the root cause investigation into the damage incurred by the Division III diesel generator during a routine surveillance (apparently involving a synchronization attempt with an out-of-synchronization condition), it was determined that a small time delay inherent in the electrical interlock circuitry for the freeze signal allowed the SVC to detrimentally interact with the diesel generator since the SVC freeze condition is not immediately effected upon closure of the diesel generator output breaker. The damage to the Division III diesel generator was previously reported in event number 36736. Although the potential for interaction had been recognized and compensated for in the design, the effect of the longer than expected time delay had not been recognized. Therefore, the effects of the unanalyzed time delay introduced an increased probability of malfunction of equipment important to safety resulting in a design configuration that constitutes an unreviewed safety question as defined in 10 CFR 50.59.
"This configuration has been determined to constitute a condition that is outside the design basis of the plant. The design requirement for the SVCs is to assist in maintaining secondary side voltages on the RAT and ERAT within acceptable values consistent with the offsite source 'capacity and capability' requirements of General Design Criterion (GDC) 17. A second requirement was that the SVCs not negatively impact plant structures, systems, and components such that an increase in the probability of a malfunction of equipment important to safety exists. Contrary to the above requirements, the current design of thc SVC controls is such that during synchronization of the diesel generator to its Class 1E bus the potential exists for the SVC to negatively impact bus voltage. As a consequence of the adverse voltage control during the diesel generator synchronization, the potential exists for the SVC response to degrade or impair the function of the diesel generator resulting in an increased probability of malfunction of equipment important to safety.
"This design deficiency exists only under the limited circumstances during the conduct of diesel generator surveillances in which the diesel is paralleled with the offsite power source. The postulated duration of the unanalyzed condition is a fraction of a second following the closure of the diesel generator output breaker. This is the approximate length of time required for the SVC control circuits to enter the freeze mode after closure of the diesel generator output breaker. Prior to the breaker closure and following the small time period of the unanalyzed condition, the diesel generators and the offsite power circuits are capable of performing their intended design functions during parallel operations. The Onsite AC Sources Limiting Conditions for Operation (LCO) specified in Technical Specifications 3.8.1 and 3.8.2 are satisfied.
"AmerGen is currently pursuing a plant modification to resolve this design deficiency as soon as possible to support testing of the diesel generators."
The NRC resident inspector will be informed of this notification by the licensee.
Power Reactor
Event Number: 36787
Facility: SOUTH TEXAS
Region: 4 State: TX
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: SCOTT HEAD
HQ OPS Officer: JOHN MacKINNON
Region: 4 State: TX
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: SCOTT HEAD
HQ OPS Officer: JOHN MacKINNON
Notification Date: 03/11/2000
Notification Time: 08:24 [ET]
Event Date: 03/10/2000
Event Time: 11:48 [CST]
Last Update Date: 03/11/2000
Notification Time: 08:24 [ET]
Event Date: 03/10/2000
Event Time: 11:48 [CST]
Last Update Date: 03/11/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
10 CFR Section:
Person (Organization):
DAVID LOVELESS (R4)
DAVID LOVELESS (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Refueling | 0 | Refueling |
ELECTRICAL SEPARATION REQUIREMENTS WERE VIOLATED
This event notification was called under License Condition 2.G. - 24 hour License Notification
On Monday, March 6, 2000 defueling operations were ongoing at South Texas Project Unit 1 to support the current refueling outage. A temporary modification was installed on that date in a Safety Related "B" Train Load center to supply non-class power to one of the two spent fuel pumps. This modification was installed to ensure "B" train related pump remained available while fuel was being loaded into the spent fuel pool. The other pump was supplied with Class 1E power and was backed up by a diesel.
The modification involved running non-class cables in and around the Class 1E load center. On March 10th it was determined that since electrical separation requirements [class to non-class] were violated the load center was rendered inoperable as well as the electrically supported equipment. One component affected was the "B" Train containment isolation valve for normal purge. If the valve is inoperable Technical Specification 3.9.9, Containment Ventilation Isolation System, requires that the normal purge penetration be closed during core alterations.
During the time frame that the valve was inoperable fuel movement took place with the normal purge in operation (I.e., the penetration was open). This is in violation of Technical Specification requirements.
The NRC Resident Inspector will notified of this event by the licensee.
This event notification was called under License Condition 2.G. - 24 hour License Notification
On Monday, March 6, 2000 defueling operations were ongoing at South Texas Project Unit 1 to support the current refueling outage. A temporary modification was installed on that date in a Safety Related "B" Train Load center to supply non-class power to one of the two spent fuel pumps. This modification was installed to ensure "B" train related pump remained available while fuel was being loaded into the spent fuel pool. The other pump was supplied with Class 1E power and was backed up by a diesel.
The modification involved running non-class cables in and around the Class 1E load center. On March 10th it was determined that since electrical separation requirements [class to non-class] were violated the load center was rendered inoperable as well as the electrically supported equipment. One component affected was the "B" Train containment isolation valve for normal purge. If the valve is inoperable Technical Specification 3.9.9, Containment Ventilation Isolation System, requires that the normal purge penetration be closed during core alterations.
During the time frame that the valve was inoperable fuel movement took place with the normal purge in operation (I.e., the penetration was open). This is in violation of Technical Specification requirements.
The NRC Resident Inspector will notified of this event by the licensee.