United States Nuclear Regulatory Commission - Protecting People and the Environment

Event Notification Report for April 17, 2012

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
04/16/2012 - 04/17/2012

** EVENT NUMBERS **


47833 47838 47840

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Part 21 Event Number: 47833
Rep Org: MITSUBISHI NUCLEAR ENERGY SYSTEMS
Licensee: MITSUBISHI HEAVY INDUSTRIES, LTD
Region: 1
City: ARLINGTON State: VA
County:
License #:
Agreement: Y
Docket:
NRC Notified By: EI KADOKAMI
HQ OPS Officer: JOHN KNOKE
Notification Date: 04/13/2012
Notification Time: 15:58 [ET]
Event Date: 04/13/2012
Event Time: [EDT]
Last Update Date: 04/16/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
21.21(a)(2) - INTERIM EVAL OF DEVIATION
Person (Organization):
BLAKE WELLING (R1DO)
KATHLEEN O'DONOHUE (R2DO)
DAVID HILLS (R3DO)
VINCENT GADDY (R4DO)
PART 21 GROUP (EMAI)

Event Text

PART 21 INTERIM REPORT - STEAM GENERATOR TUBE WEAR

This interim Part 21 is in regard to San Onofre Nuclear Generating Station, Unit 2, Steam Generator replacement.

"During the first refueling outage following steam generator replacement, eddy current testing identified ten total tubes with depths of 90 to 28 percent of the tube wall thickness. Some of the affected tubes were located adjacent to retainer bars. The retainer bars are part of the floating anti-vibration bar (AVB) structure that stabilizes the u-bend region of the tubes.

"Other tubes in the two steam generators had detectable wear associated with support points elsewhere in the AVB structure. Each steam generator has 9727 tubes with an 8 percent (778 tubes) design margin for tube plugging.

"Discovery Date: February 13, 2012

"Evaluation completion schedule date: May 31, 2012"

"Those Mitsubishi Heavy Industries customers potentially affected by this issue have been notified and will receive a copy of this interim report."

Reference Document: UET-20120089
Interim Report No: U21-018-IR (0)

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Power Reactor Event Number: 47838
Facility: HARRIS
Region: 2 State: NC
Unit: [1] [ ] [ ]
RX Type: [1] W-3-LP
NRC Notified By: CURTIS BULLOCK
HQ OPS Officer: VINCE KLCO
Notification Date: 04/16/2012
Notification Time: 07:38 [ET]
Event Date: 04/16/2012
Event Time: 08:00 [EDT]
Last Update Date: 04/16/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
KATHLEEN O'DONOHUE (R2DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 92 Power Operation 92 Power Operation

Event Text

PLANNED MAINTENANCE ON THE TECHNICAL SUPPORT CENTER NORMAL POWER SUPPLY

"At approximately 0800 [EDT] on April 16, 2012, the Harris Nuclear Plant (HNP) Technical Support Center (TSC) normal power feed will be removed from service for scheduled maintenance.

"The maintenance will consist of first switching the TSC to the TSC backup power supply. The normal supply will be disconnected and replaced with another offsite power source which is independent of the Harris switchyard. This power arrangement will remain in place while maintenance is performed on the TSC normal power supply and is expected to last approximately two months. A backup diesel generator is stationed near the TSC which can be connected if necessary during an emergency.

"An update will be provided when the TSC normal power supply has been returned to its normal alignment

"This event is reportable per 10CFR50.72(b)(3)(xiii) as described in NUREG-1022, Rev. 2, since this work activity affects an emergency response facility for the duration of the maintenance.

"The [NRC] Senior Resident Inspector has been informed."

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Power Reactor Event Number: 47840
Facility: HARRIS
Region: 2 State: NC
Unit: [1] [ ] [ ]
RX Type: [1] W-3-LP
NRC Notified By: CURTIS BULLOCK
HQ OPS Officer: JOHN SHOEMAKER
Notification Date: 04/16/2012
Notification Time: 17:11 [ET]
Event Date: 04/16/2012
Event Time: 09:32 [EDT]
Last Update Date: 04/16/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
KATHLEEN O'DONOHUE (R2DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 92 Power Operation 92 Power Operation

Event Text

UNAVAILABILITY OF TECHNICAL SUPPORT CENTER RADIATION MONITOR

"At 0932 EDT on April 16, 2012, the Harris Nuclear Plant (HNP) Technical Support Center (TSC) normal power feed was removed from service for scheduled maintenance.

"Upon restoration of power to the TSC, it was identified that the TSC radiation monitor (RM-3653C) did not return to service as expected. Following discovery, Radiation Protection technicians were dispatched to investigate the cause of RM-3653C not operating properly.

"At 1627 EDT, the TSC radiation monitor has been returned to service and is operable.

"This event is reportable per 10CFR50.72(b)(3)(xiii) as described in NUREG1022, Rev. 2 due to the loss of the TSC radiation monitor.

"The NRC Senior Resident Inspector has been informed"

The cause of the radiation monitor failure was related to a dead back-up battery which did not allow the radiation monitor to properly re-boot after power was restored.

Page Last Reviewed/Updated Tuesday, April 17, 2012
Tuesday, April 17, 2012