Event Notification Report for October 29, 2014

STUCK SOURCE IN A VARIAN HIGH DOSE RATE AFTERLOADER

Staff at the New Milford Cancer Center in New Milford, CT were performing their daily quality assurance checks on their Varian Medical Systems high dose rate (HDR) afterloader when the 7.2 Ci (estimated) Ir-192 source became stuck in the safe position. New Milford contacted the vendor who dispatched a support team to investigate.

The Varian RSO surveyed the area and found the dose rate at 5 cm was 1.5 mR/hr which was within normal parameters with the source in the shielded position. While attempting to free the source, it became stuck outside of the shielded position. Dose rates increased to 20 mR/hr at the entrance to the maze, 280 mR/hr at the turn (approximately 15 feet from the HDR) and 5.4 R/hr at 0.5 meters. The service manager was able to use the emergency hand crank to return the source to its shielded position. During the retrieval, the RSO received 9 mR while the service manager received 27 mR.

Based on past issues and current symptoms, Varian technicians replaced the drive mechanism and will be installing a new source wire.

Once all repairs are made, the HDR will be placed into service with the Varian team on hand during the first post-maintenance use.

Varian, an NRC licensee, is making this report since New Milford Cancer Center (license number 0617892-01) did not exceed any reporting thresholds due to this event.

The vendor has notified R1 (Modes). See similar events in Event Notifications 46695 and 46758.

UNANALYZED CONDITION DUE TO MATERIAL IN A THERMOCOUPLE HOUSING

"While performing troubleshooting on a thermocouple, uranium-bearing material was found inside the sealed housing containing the wiring block for the thermocouple. A very small amount (less than one ounce) of wet paste-like material was removed from the housing for analysis. The leak appears to be low concentration material that has penetrated the enclosed thermocouple well. The material was contained within the housing; however, the electrical conduit exiting the housing connects to an electrical panel that is an unfavorable geometry.

"Potential health and safety consequences: "No actual safety consequences occurred due to this event. The potential consequences would result if a sufficient volume of HEU solution were to leak through the thermocouple well and drain through the electrical conduit into an unfavorable geometry electrical panel, which could under worst case conditions lead to a criticality accident. The leaked material was contained within the instrument housing and no personnel exposures resulted.

"Sequence of occurrences leading to the event: "The integrity of a thermocouple well failed allowing a very small quantity of low concentration material to enter the housing containing the thermocouple connections. The leak was identified during troubleshooting operational issues with the system. At this point, the failure mechanism of the thermocouple well is unknown.

"Additional actions taken in response to the event: Similar systems are being inspected to determine if additional failures are present. Also, corrective actions to include modification of the unfavorable geometry electrical panels that have not been previously modified are underway to eliminate this failure pathway.

"What is the safety significance of the event? Low safety significance due to limited quantity as well as geometry of container.

"The licensee has notified the NRC Resident Inspector."

MAXIMUM ALLOWABLE PRIMARY CONTAINMENT LEAKAGE RATE EXCEEDED

"This notification is to report a condition involving higher than allowable through-seat leakage of two redundant feedwater system check valves (28A and 96A). Unit 2 is currently shut down and primary containment is not required to be operable. Therefore, there is currently no safety impact due to this discovered condition.

"This leakage was identified as a result of planned local leak rate testing of the feedwater primary containment isolation valves for the 'A' feedwater line being performed during the current P2R20 refueling outage. At approximately 1100 EDT, Engineering determined that the primary containment penetration pathway leakage through the redundant check valves resulted in a condition where the maximum allowable primary containment leakage rate (La) was exceeded. In accordance with NUREG-1022, Rev. 3, Event Report Guidelines 10 CFR 50.72 and 50.73, Section 3.2.4, this occurrence is an example of a reportable condition. Therefore, this notification is being made pursuant to 10CFR 50.72(b)(3)(ii)(A).

"This condition has been entered in the plant corrective action program (IR 2402909).

"The NRC Resident Inspector has been informed of this notification."

LOSS OF CONTROL ROOM EMERGENCY AIR CONDITIONING SYSTEM OPERABILITY

"At 0711 EDT, Salem Unit 2 entered TSAS [Technical Specification Action Statement] 3.0.3 due to the Salem Unit 1 - 1B Vital instrument bus inverter failing which resulted in a loss of the Unit 1 - 1B Vital instrument bus. The loss of power to the 1B Vital instrument bus resulted in Salem Unit 2 initiating the accident pressurized mode of control room ventilation. All dampers and fans repositioned correctly with the exception of the Unit 1 Control Room Emergency Air Conditioning System (CREACS) intake dampers, 1CAA48, 50, and 51. The 1CAA48 was pinned closed to support Unit 1 - 1A125VDC scheduled maintenance. The 1CAA50 and 51 failed to move to the open position (required for Unit 2 accident pressurized mode) due to the loss of power to the 1B Vital Instrument Bus. With the 1CAA48, 50 and 51 dampers closed, this isolated the Unit 1 CREACS intake in the closed position. For an accident in Unit 2, the CREACS intake for Unit 1 is required to open.

"Salem Unit 2 exited TSAS 3.0.3 at 0822 EDT when the 1CAA50 and 51 were pinned in the open position to implement accident pressurized mode for Salem Unit 2 in accordance with S1/S2.OP-SO.CAV-0001, Control Area Ventilation Operation.

"Salem Unit One is Defueled.

"This event is being reported under the requirements of 10 CFR 50.72(b)(3)(v)(D) as 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of systems that are needed to perform mitigation of the consequences of an accident.'

"The licensee has notified the NRC Resident Inspector. No one was injured as a result of the failure of 1B Vital instrument inverter."

The licensee notified Lower Alloways Township.

* * * RETRACTION FROM BILL MUFFLEY TO HOWIE CROUCH AT 1529 EST ON 12/22/14 * * *

"A subsequent review of the condition reported on 10/29/2014 in EN 50573 determined that the Control Room Emergency Air Conditioning System (CREACS) was operable and capable of performing its safety function. Therefore, there was no reportable condition.

"Circuit analysis identified that the Unit 2 Control Room Intake Isolation (CRIX) Train B circuit remained fully functional and able to respond to a Unit 2 Safety Injection (SI) signal or actuation from radiation monitor 2R1B Channel 1 (radiation levels in the Unit 2 normal Control Area Ventilation intake). The loss of the 1B vital instrument bus did not affect the normal actuation circuitry. The appropriate Unit 1 dampers would have received an open
signal and the appropriate Unit 2 dampers would have received a closed signal, thereby isolating the Unit 2 CREACS intake and opening the Unit 1 CREACS intake. Thus, the CREACS would have been capable of mitigating the consequences of an accident.

"The NRC Resident Inspector has been notified."

Notified R1DO (Ferdas).

POSITIVE FITNESS FOR DUTY TEST RESULTS

A contractor employee had a confirmed positive for alcohol during a for-cause fitness-for-duty test. The contractor employee's unescorted access to the plant has been terminated.

The licensee notified the NRC Resident Inspector.

PART 21 NOTIFICATION - BALDOR AC MOTORS WITH POTENTIAL BEARING END CAP ALIGNMENT ISSUES

The supplier, Baldor Electric Company, identified a potential fitment issue between the motor shaft journal, bearing cap and bracket that could allow the bearing cap to cock in the bracket. This misalignment would cause the motor to fail within hours of being placed in service. Therefore, all motors in service for greater than 24 hours would not be affected by the defect.

The supplier has notified its vendor and provided corrective actions and/or parts replacement as appropriate.