| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
09/08/2011 - 09/09/2011 ** EVENT NUMBERS ** |
 | !!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!! | | Power Reactor | Event Number: 47086 | Facility: COMANCHE PEAK
Region: 4 State: TX
Unit: [1] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MIKE NIEMEYER
HQ OPS Officer: MARK ABRAMOVITZ | Notification Date: 07/21/2011
Notification Time: 20:39 [ET]
Event Date: 07/21/2011
Event Time: 11:53 [CDT]
Last Update Date: 09/08/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
| Person (Organization):
VIVIAN CAMPBELL (R4DO)
|
| 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 | Event Text VULNERABILITY FROM A POTENTIAL CONTROL ROOM FIRE ON "A" SAFEGUARDS BUS
"A potential scenario has been identified that has not been analyzed in the Comanche Peak Nuclear Power Plant Fire Safe Shutdown Analysis (FSSA). This situation is described below for Unit 1, but also applies to Unit 2. Listed below is the configuration for 1EA1. The basic configuration is typical for 1EA2, 2EA1 and 2EA2 as well (ref. E1-0001)
- Safeguard Bus 1EA1 is a 6.9 kV switchgear with a Main-Tie-Main configuration.
- The normal lineup has one feeder breaker closed, the other feeder breaker open and the tie breaker closed.
- 1EA1 receives normal power from the secondary side of Startup Transformer XST2 through breaker 1EA1-1.
- 1EA1 receives alternate power from the secondary side of Startup Transformer XST1 through breaker 1EA1-2.
- 1EA1 receives emergency power from diesel generator 1EG1 through breaker 1EG1.
- An alternate source of power for 1EA1 is also available from Train C through breaker 1EA1-3.
"The control wiring for the 1EA1-1 circuit breaker contains the following attributes that are important to understand the issue:
- Switch 43/1EA1-1, located in the Shutdown Transfer Panel (STP) is used to transfer control of 1EA1-1 from the Control Room (1-CB-11 switch CS-1 EA1-1) to the Hot Shutdown Panel (HSP) switch CS-1 EA-1 L. (Ref. E1-0031-01&02)
- There is a trip circuit fuse located in the 6.9 kV switchgear compartment for 1EA1-1 for control of the trip circuit when the breaker is controlled at 1CB-11 and a separate fuse for the trip circuit when the breaker is controlled by the HSP.
- The trip circuit for 1EA1-1 has a contact routed through the Control Room to the Solid State Protection System (SSPS) Cabinet. This contact is in the trip circuit when control is from the Control Room or when control is from the HSP. (Ref. E1-0031-01)
"The scenario is based on a fire in the Control Room. If the fire in the Control Room causes a ground in the wiring routed in the Control Room to the SSPS cabinet, the fuse for the 1E1-1 trip circuit would open. In the event of a fire in the Control Room, control of the plant is transferred to the HSP. When the control of breaker 1EA1-1 is transferred to the HSP and the ground condition in the SSPS wiring still exists, the second 1EA1-1 trip circuit would open. At this time there would be no way to remotely trip open 1EA1-1. The breaker could still be tripped mechanically at the breaker. Therefore, if 1EA1-1 is closed, 1EA1 could remain energized if off-site power is available. If off-site power is not available, but 1EA1-1 remains closed, bus 1EA1 would remain electrically connected to XST2. As part of the transfer of control from the Control Room to the HSP, operators start up the diesel generator and close 1EG1 to place 1EA1 loads on the generator. If 1EG1 is closed and 1EA1-1 breaker is still closed with off-site power available, the generator will be immediately connected to grid power through XST2 without synchronizing. If 1EG1 is closed and 1EA1-1 breaker is still closed with off-site power not available, the generator will be immediately connected to XST2 and attempt to energize XST2. This large current draw associated with energizing XST2 would likely stall and damage diesel generator 1EG1.
"Compensatory Action is being implemented through procedure revisions to preclude damage to the diesel generator during this scenario."
The licensee will notify the NRC Resident Inspector.
* * * RETRACTION FROM TOM RUCKER TO PETE SNYDER AT 1713 ON 9/8/11 * * *
"At 1939 central daylight time on July 21, 2011, Luminant Power notified the NRC (Event No. 47086) of a Unanalyzed Condition per 50.72(b)(3)(ii)(B) regarding the vulnerability from a potential control room fire on 'A' Safeguards bus. The event report described a portion of a cable running from the Hot Shutdown Panel (HSP) to the Solid State Protection System (SSPS) cabinet in the Control Room (CR) that was not protected from a CR fire scenario for which a worst case Control Room/Cable Spreading Room fire induced short could result in the 1EA1-1 circuit breaker, connecting the 345 kV Startup Transformer to the grid, not tripping and damaging the EDG.
"Upon further review it has been determined that the Fire Safe Shutdown Analysis (FSSA) modeled that cable in the analysis since CPNPP began commercial operation. Additionally, the FSSA accounted for the fire-induced circuit ground on this cable and one of the specified manual actions is to trip the 1EA1-1 circuit breaker to assure the EDG would load the 'A' Safeguard bus to support the required fire scenario. The EDG output breaker is designed to auto close once the 1EA1-1 circuit breaker is tripped open. The previous version (prior to compensatory actions) of ABN-803A/B, the procedure used should a fire occur in the Control Room, directed the Reactor Operator to trip 1EA1-1 circuit breaker once the diesel was verified running, then ensure the EDG breaker closed. There is no procedural step directing personnel to manually close the EDG breaker. Since, in this scenario, indication for the 1EA1-1 circuit breaker at the Hot Shutdown Panel would be lost, it would be expected that the RO would direct the RRO to verify 1EA1-1 circuit breaker position.
"Based on the above, Luminant Power has concluded that the FSSA adequately modeled the plant and procedures were written which would not direct any action that would have caused the condition stated in the CR description. Based on the above, the conclusion is that CPNPP did not have an unanalyzed condition that significantly degraded plant safety per 50.72 (b)(3)(ii)(B) regarding the vulnerability from a potential control room fire on 'A' Safeguards bus. Therefore, this event is retracted."
The licensee will notify the NRC Resident Inspector.
Notified R4DO (Lantz). |
| Agreement State | Event Number: 47243 | Rep Org: ILLINOIS EMERGENCY MGMT. AGENCY
Licensee: EQUISTAR CHEMICALS, LP
Region: 3
City: MORRIS State: IL
County:
License #: IL-01737-01
Agreement: Y
Docket:
NRC Notified By: DAREN PERRERO
HQ OPS Officer: BILL HUFFMAN | Notification Date: 09/06/2011
Notification Time: 12:38 [ET]
Event Date: 09/02/2011
Event Time: [CDT]
Last Update Date: 09/06/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
CHRISTINE LIPA (R3DO)
ANGELA MCINTOSH (FSME)
| Event Text AGREEMENT STATE - FIXED PROCESS GAUGE FAILED SHUTTER CHECK
The following report was received from the State of Illinois via e-mail.
"While performing routine shutter checks of fixed gauges at the licensee's site, a device failed to perform as expected. As a result, the Radiation Safety Officer contacted the Agency and made the required report. The failed Ohmart/Vega Model SH-F2 gauge is used for level detection on a high temperature, high pressure vessel. The vessel is located on a roof 50 feet above grade with the nearest workstation approximately 300 feet away. The gauge was left in the 'on' position so as to allow continued routine operation of the process line. Shift supervisors and site personnel were advised of the situation and any entry into the vessel has been prohibited should the line become disabled or shut down. The manufacturer has been contacted and arrangements are pending for repair of the device at the first available opportunity. Should the gauge mounting fail and it become necessary, additional shielding material is available on-site to cover the open beam port and personnel have adequate training to perform that task. No threat to health and safety exist at this time and there are no associated exposures."
The Ohmart Gauge Model SH-F2, Serial Number 7306GK contains an 0.3 Ci sealed Cs-137 source.
Illinois Report Number IL11120 |
| Agreement State | Event Number: 47245 | Rep Org: TEXAS DEPARTMENT OF HEALTH
Licensee: IRIS NDT INC
Region: 4
City: DEER PARK State: TX
County:
License #: 04769
Agreement: Y
Docket:
NRC Notified By: ART TUCKER
HQ OPS Officer: BILL HUFFMAN | Notification Date: 09/06/2011
Notification Time: 17:42 [ET]
Event Date: 09/06/2011
Event Time: [CDT]
Last Update Date: 09/06/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
JAMES DRAKE (R4DO)
PAUL MICHALAK (FSME)
| Event Text AGREEMENT STATE - RADIOGRAPHY CAMERA SOURCE DISCONNECT FROM DRIVE CABLE
The following event was provided by the State of Texas Health Services Radiation Branch via facsimile:
"On September 6, 2011, the [State of Texas Radiation Branch] was notified by the licensee that while using a Spec 150 radiography camera (serial number 1154, containing a 47.2 Curie Iridium -192 source), the source disconnected from the drive cable. The licensee's Radiation Safety Officer stated the radiographer was starting to crank the source out for the eighth shoot of the day when he noted that the guide tube had come loose from the camera and that the drive cable had began to spool in front of the camera. The radiographer attempted to return the source to the locked position in the camera, but it would not lock. The radiographer went to investigate at the front of the camera and saw the source lying on the ground in front of the camera. The radiographer contacted the RSO and a source recovery team went to the location. Lead shot was placed over the source to reduce the area dose rates. The source recovery team was able to reconnect the source to the drive cable and return the source into the camera and lock it in place. The licensee has returned the camera to its storage location and will conduct a leak test of the source and inspect the guide tube and crank-outs. The RSO stated that it appears that the quick disconnect on the camera failed. No significant exposure was received by the source recovery team or any member of the general public. Additional information will be supplied as it is received in accordance with SA-300."
Texas Report Number I-8882 |
| Power Reactor | Event Number: 47249 | Facility: SEQUOYAH
Region: 2 State: TN
Unit: [ ] [2] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MATT LOVITT
HQ OPS Officer: JOHN SHOEMAKER | Notification Date: 09/08/2011
Notification Time: 10:34 [ET]
Event Date: 05/05/2011
Event Time: 15:20 [EDT]
Last Update Date: 09/08/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
| Person (Organization):
DANIEL RICH (R2DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 2 | N | Y | 85 | Power Operation | 85 | Power Operation | Event Text INVALID SPECIFIED SYSTEM ACTUATION
"This report is a 60-day telephone notification in lieu of a written licensee event report being made under 10CFR50.73(a)(2)(iv)(A) and 10CFR50.73(a)(1). The event was an invalid actuation of a Unit 2 Containment Ventilation Isolation (CVI). At the time of the event Unit 1 was at 100% power and Unit 2 was at 85% power.
"At 1520 EDT on 5/5/2011, an 'A' train CVI signal was inadvertently initiated during a surveillance test for containment purge air exhaust radiation monitor 2-RM-90-130. The inadvertent CVI signal was initiated due to incorrect connection of test equipment. The signal caused the 'A' train containment upper and lower compartment radiation monitor isolation valves to close. Unit 2 entered Technical Specification Limiting Condition for Operation (LCO) 3.3.3.1 Action 27 and LCO 3.4.6.1 Action b, due to the isolation of lower compartment radiation monitor 2-RM-90-106. The inadvertent CVI signal was also received by the containment vent system, but the containment vent system was not in service and no valves were actuated.
"The radiation monitoring (system 90) and the containment vent (system 30) systems received a complete 'A' train CVI signal. The 'A' train radiation monitoring isolation valves closed as designed. The containment vent system was not in service, and since the valves were already closed, no valves were actuated. Actual plant conditions did not exist that required a CVI signal. Therefore, this actuation was invalid.
"The delay in reporting this event was due to an initial interpretation that the event did not result in an actuation of the systems listed in paragraph 10CFR50.73(a)(2)(iv)(B), because only one system was in service which was affected by the actuation. Subsequent discussions noted that while only one system was in service, both systems received the CVI signal. The event is reported as a 60-day telephone notification in lieu of a written licensee event report being made under 10CFR50.73(a)(2)(iv)(A) and 10CFR50.73(a)(1)."
The date, when the final determination of the invalid system actuation was made, was not provided.
The licensee notified the NRC Resident Inspector. |
| Power Reactor | Event Number: 47252 | Facility: SAN ONOFRE
Region: 4 State: CA
Unit: [ ] [2] [3]
RX Type: [1] W-3-LP,[2] CE,[3] CE
NRC Notified By: PHYLLIS DOMINGUEZ
HQ OPS Officer: VINCE KLCO | Notification Date: 09/08/2011
Notification Time: 19:08 [ET]
Event Date: 09/08/2011
Event Time: 15:38 [PDT]
Last Update Date: 09/08/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
| Person (Organization):
RYAN LANTZ (R4DO)
|
| 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 | | 3 | A/R | Y | 100 | Power Operation | 0 | Hot Standby | Event Text AUTOMATIC REACTOR TRIP DUE TO A GRID DISTURBANCE
On September 8, 2011 at 1538 PDT, the San Onofre Units 2 and 3 reactors tripped due to a grid disturbance. All control rods fully inserted. The EFAS (Emergency Feed Actuation System) initiated as expected for a reactor trip. Steam generators are being fed by the main feedwater system and decay heat is being removed through the steam bypass system to the main condensers. There is no primary to secondary leakage and no safety relief valves lifted. Site electrical power sources are being fed from off-site power and both units are in a normal shutdown configuration. The emergency diesel-generators are in standby/operable status and were not required during the event. Both units are stable (NOT/NOP) and in Mode 3. The reactor trip response is considered uncomplicated.
The licensee has notified the NRC Resident Inspector. | |