The following information was provided by the licensee via email:
Identification of the manufacturer of the component that contains the defect:
Diversified Machine Components- Howden Part Number 00900490-00114N
LOCKNUT/NYLON
INSERT 1-1/8-12 STL-ZINC NUCLEAR
Howden PO075865
During assembly of the nuts onto a rotor, Westinghouse stripped a nut. After removal it was discovered that the nut that stripped had a machined bore with incorrect thread length. The nuts supplied on the above purchase order were all supplied from one heat. Diversified Machine Components and Howden have been and continue to be in communication on this matter. The nuts on PO075685 have been returned to Howden for evaluation and remain on hold as nonconforming product.
Howden issued NCR 3589 for Part Number 00900490-00114N Lock Nut which was received by Diversified Machine on 8/31/22. Howden has also issued Corrective Action request #HACAR336 also received by Diversified Machine on 8/31/22.
At this time, based on initial evaluations Diversified Machine Components has supplied Howden with a total of five purchase orders which have been identified and submitted to Howden for review. The five purchase orders identified are: 16 Pcs. on PO052609, 16 pcs on PO052645, 16 pcs on PO056804, 16 pcs on PO068879 and 16 pcs on PO075685. The nuts on PO075685 have been segregated and the returned to Howden for evaluation.
A Nonconformance Report has been issued which describes with as much information as possible to give a clear understanding and description of the nonconforming condition as found. The evaluation of the nonconformance report and the corrective action to be taken shall be completed by authorized personnel at Diversified Machine in a timely manner.
Diversified Machine shall continue to communicate with Howden as required. If there are any questions pertaining to this communication, please feel free to contact me at 440-942-5701.
The following information was provided by Diversified Machine Components via email:
The basic component that contains the defect is part number 00900490-00114N. The lock nut has been machined with a counterbore removing half of the threads from the nut.
After removal they discovered the nut that stripped was miss machined and only had threads in less than 1/2 of the bore.
Known affected plants:
Ameren Callaway Plant
ASCO NPP (Howden Customer - Ergytech, Inc.)
Notified R1DO (Defrancisco), R3DO (Orlikowski), R4DO (Pick) and via email: Part 21 Materials and Part 21 Reactors