Event Notification Report for July 24, 2015

PART 21 - MOUNTING BRACKET SEISMIC QUALIFICATION

The following information was excerpted from a facsimile from FLOWSERVE:

"In accordance with the provisions of 10CFR Part 21, [Flowserve] has identified a potential issue and is submitting our evaluation of the event.

"DESCRIPTION: Entergy Design Specification, SPEC-09-0001-P, paragraph 3.1.1 a, requires that position indicators remain operable during a seismic event. The seismic analysis performed [for installation at Pilgrim Station] did not include mounting brackets for the position indicators. Later review of these brackets found them to be inadequate for the application.

"SCOPE: The engineering evaluation searched all instances of the use of safety related Topworx C7 position indicators, base part number 04126889, by the Flowserve, Raleigh facility.

"PROPOSED ACTION: Flowserve will provide seismically analyzed replacement mounting brackets to Entergy Pilgrim Station at no charge. To prevent reoccurrence of this situation, additional training on the use of nuclear order checklists will be performed.

TEXAS AGREEMENT STATE REPORT - UNABLE TO RETRACT RADIOGRAPHY CAMERA SOURCE

The following information was obtained from the State of Texas via email:

"On July 24, 2015, the Agency [Texas Department of State Health Services] was notified by the licensee's radiation safety officer (RSO) that one of his crews was unable to retract a 39 curie Iridium-192 source into QSA 880 D camera. The RSO stated the radiographers had completed their first shot of the day in a shooting bay and noted the lock on the camera did not trip when the source was retracted. The RSO stated the radiographers noted the dose rate where they were standing was 30 millirem per hour after they attempted to retract the source. The radiographers notified the RSO of the event. The RSO responded to their location. The RSO is authorized to recover disconnected sources.

"The RSO stated he recovered the source by disconnecting the source guide tube and shaking the source out of the guide tube and into a shield they have designed for this purpose. The RSO was able to connect the source pig tail to the drive cable and retract the source into the camera. The RSO stated he received 15 millirem during the source retrieval. No member of the general public received a dose as a result of this event. The RSO stated they cycled the source in and out of the camera several times without incident. The RSO stated he remained at the work site and monitored the radiographers for several shots and did not note any issues. The RSO is not sure at this time if a source disconnect or misconnect occurred. The RSO is continuing to investigate the event.

"Additional information will be provided as it is received in accordance with SA-300."

The event location was Wedge Measurements Systems located in Joshua, TX.

Texas Incident #: 1-9327

AUTOMATIC REACTOR TRIP DUE TO TURBINE TRIP ON MAIN GENERATOR LOCKOUT

"At 1351 EDT on 7/24/2015, Sequoyah Unit 1 reactor/turbine automatically tripped.

"Following the reactor trip, all safety-related equipment operated as designed. Auxiliary Feedwater automatically initiated as expected from the Feedwater Isolation Signal.

"Unit 1 is currently being maintained in Mode 3 at NOT/NOP, approximately 548 F and 2235 psig, with auxiliary feedwater supplying the steam generators and decay heat removal via the condenser steam dumps. The immediate cause of the trip was an electrically-induced turbine trip. There was no associated work in progress related to this and all systems were normally aligned.

"There is no indication of any primary/secondary leakage. All rods fully inserted on the reactor trip and remain inserted. The electrical alignment is normal with shutdown power supplied from off-site power. The 2B-B Emergency Diesel Generator is currently in service for the performance of an unrelated surveillance. There is no operational impact to Unit 2. Unit 2 continues to operate in Mode 1 at 100%.

"There was no impact on public health and safety. Post-trip investigation is in progress and planned restart timeline has not yet been determined.

"The licensee notified the NRC Resident Inspector."

The cause of the main generator lockout is under investigation.

PART 21 - ACTUATOR SHAFT DID NOT MEET DIMENSIONAL REQUIREMENTS

The following information was excerpted from a facsimile provided by Flowserve:

"In accordance with the provisions of 10CFR Part 21, [Flowserve] has identified a potential issue and is submitting our evaluation of the event.

"DESCRIPTION: Energy Northwest - Columbia Station reported a replacement actuator shaft for 6-900 Anchor/Darling swing check was different than the one removed and could not be installed. After consultation with Flowserve, it was determined the actuator shaft did not meet the dimensional requirements of the manufacturing drawing. The shaft includes an off-set lug that engages the hinge and allows testing or exercising the valve disc. The shaft diameter opposite the lug was too large but must be equal to or less than the basic diameter adjacent to the lug in order to allow free disc swing.

"SCOPE: Replacement actuator shafts supplied by Flowserve using manufacturing drawings that do not definitively specify the radius/diameter at the lug. Applies to Anchor/Darling swing check valves with levers or actuators.

"PROPOSED ACTION: Flowserve will revise actuator shaft drawing to clearly define the radius/diameter at the lug. Flowserve will notify the customers of the attached evaluation of the defect and will request that the actuator shafts be returned to Flowserve for evaluation and/or replacement at no charge.

"SUBJECT: Actuator Shaft supplied for 6-900 Exercisable Swing Check Valve, Drawing No. 3489-3 manufactured by Anchor/Darling Valve Co. and installed at Energy Northwest (ENW) - Columbia Station.

"ROOT CAUSE: The actuator shaft was machined by a Flowserve subvendor which incorrectly interpreted the machining drawing and produced the shaft with a large, out of tolerance radius around the lug. The drawing was not clear to the subvendor. Flowserve inspection did not discover the discrepancy during subsequent dimensional inspection.

"POTENTIAL EFFECT: An excessively large diameter at the lug will not allow installation of a replacement actuator shaft. A shaft with a diameter opposite the lug that is greater than design but still small enough to allow installation could retard or prevent free disc swing and adversely affect check valve function.

"EVALUATION: Swing check valves normally operate automatically reacting to fluid flow and do not include external operating mechanisms. Some valves include external mechanisms to confirm valve operation using an external lever or actuator to cycle the disc. Normally these check valves are allowed to swing freely and the external mechanism is not engaged. The external mechanism is only engaged for testing or exercising. The engagement is accomplished by a lug on the actuator shaft that rides in a cut out in the hub of the hinge. The hinge rotates on the actuator shaft during normal, free operation therefore the clearance between the hinge hub bore and shaft is a critical design feature and can affect operation. Proper operation of valve assemblies are verified during production testing therefore are not within the scope of this evaluation.

"CONCLUSION: Although the ENW actuator shaft could not be installed due to the excess material, inadequate removal to allow installation could affect the function. In addition shafts manufactured to similar manufacturing drawings supplied as replacement parts could be capable of installation but not allow complete free disc / hinge swing."

Affected plants include Exelon - Limerick, Exelon - Quad Cities, and Energy Northwest - Columbia.