|PART 21 - FAILED OIL PUMP DUE TO IMPROPER MOTOR ASSEMBLY
The following was received via facsimile:
"Duke Energy via Mr. James M. Smith issued a letter to Carrier Corporation's Customer Service Organization on November 21, 2019 reporting that on November 4, 2019, a Carrier 17FA999-1200-107 Oil Pump (Duke Energy UTC Number 30110654) failed rendering one train of the Control Room Area Chilled Water System inoperable. A failure investigation by Duke Energy representatives determined that the oil pump, which had been in service for less than two months, had a broken shaft and failed due to improperly assembled oil pump motor assembly. The failed oil pump and a replacement (spare) oil pump in the warehouse (Duke Energy UTC Number 30078287) both had loose fasteners and unstaked alignment pins.
"Prior to Duke Energy's November 21, 2019 notice, Carrier issued a corrective action to their supplier on April 28, 2017 to address failures with a different non-safety related oil pump (Carrier Model 17FA512- 968) at a non-nuclear facility. The corrective action applied to all 17FA oil pump assemblies supplied to Carrier after April 28, 2017, including both safety and non-safety related oil pumps. The corrective action consisted of cleaning of threaded holes and application of red Loctite, ensuring specified torque requirements are met using a calibrated digital torque wrench, and verifying the staking operation. Both oil pump issues described by Duke Energy in the November 21, 2019 notice concerned oil pumps built prior to the April 28, 2017 corrective action. Carrier is not aware of reports of any other defects in pumps in the same series in either nuclear or non-nuclear applications built since the corrective action.
"Carrier will provide a final report to the U.S. Nuclear Regulatory Commission no later than March 11, 2020. If you have questions regarding this matter, please contact the undersigned."
David Kwasigroch, Associate Director of Engineering, (315) 432-3461, firstname.lastname@example.org.
This issue affects McGuire Nuclear Station.
* * * UPDATE ON 3/9/20 AT 1102 EDT FROM DAVID KWASIGROCH TO BETHANY CECERE * * *
The following is a synopsis of the additional information in the final report, as received via fax:
"Carrier issued a corrective action to our supplier on April 28, 2017 to address failures with a different non-safety related oil pump (Carrier Model 17FA5l2-968) at a non-nuclear facility. The corrective action was applied to all 17FA oil pump assemblies supplied to Carrier after April 28, 2017, including both safety and non-safety related oil pumps. The corrective action consisted of cleaning of threaded holes and application of red Loctite, ensuring specified torque requirements are met using a calibrated digital torque wrench, and verifying the staking operation.
"Additional design modifications are being implemented, which consist of: adding an additional set screw with Nylok Patch into the motor housing to secure the stator, installing pressed in dowel pins to hold the pump cover and pump housing together, and the addition of lock tab washers with TorQ-Patch cover bolts to keep the bolts more secure.
"Carrier's records indicate that four affected pumps were supplied to three nuclear facilities: the two pumps that were the subject of Duke Energy's notice; one pump supplied to Dominion Energy, Inc.; and one pump supplied to Susquehanna Nuclear, LLC. Carrier mailed letters to the three nuclear facilities on March 5, 2020, to coordinate replacement of the affected pumps. It is not known whether the pumps supplied to Dominion Energy, Inc., or Susquehanna Nuclear, LLC were improperly assembled."
Notified R1DO (Finney), R2DO (Davis), and Part 21/50.55 Reactors Group (by email).