Repair of hydropower station turbine casings to a tight deadline
Background
As part of a contract with First Hydro, Kvaerner Boving undertook an on-site Engineering Critical Assessment of the spiral casing of turbines at Ffestiniog Power Station. Defects were found in 2 units which required repair within the maintenance outage period.Objective
Kvaerner Boving were required to project manage the removal of the defects and the completion of the repairs within 10 days.Approach
TWI were contracted by Kvaerner Boving to provide assistance and technical support in undertaking the following:- to review all existing materials data and non-destructive examination results
- to develop defect removal and welding repair procedures
- to test and approve the procedures
- to identify and commission suitable welding contractor
- to project manage and supervise the on-site repair activities
Benefit
Repair completed in 8 days allowing First Hydro to return the 2 units, each capable of generating 90 MW of electricity, to full and unrestricted operation within the outage period.Conclusion
Use of personnel with broad welding engineering and industrial experience enabled the repairs to be completed within the outage period, with decisions being taken on-site in real time.
Non-nuclear case studies index
Copyright © 2001, TWI Ltd
Information and advice from TWI and its partners are provided in good faith and based, where
appropriate, on the best engineering knowledge available at the time and incorporated into TWI's
website in accordance with TWI's ISO 9001:2000 accredited status. No warranty expressed or implied
is given regarding the results or effects of applying information or advice obtained from the
website, nor is any responsibility accepted for any consequential loss or damage.