Development of specialised remote application tools for non-destructive testing in reactor pressure vessel at OKG saves valuable down-time.

The nuclear power plant OKG AB located on the Swedish east coast, is one of the Nordic Region's largest energy companies. Its three boiling water reactors account together for 10% of the total electricity generation in Sweden.

For more than 15 years, the plant has used FORCE Technology to carry out inspections. In urgent need for an alternative non-destructive testing method of level measuring nozzles located under water, the choice of nuclear reactor specialist was easy.

The challenge and goal was to present an imprint of areas in the reactor pressure vessel and its internals, which are submerged under water. The imprints are to be viewed in a microscope for reporting of possible surface flaws down to 1.5 mm long and 3 µm wide.

Development across departments

In order to achieve the goal a group of engineers and technicians across departments at FORCE Technology were leading the development. The personnel are proficient when it comes to mechanical testing systems and known to use only cutting edge equipment.

The specialised remote application tool should be utilised for fast inspection of simple and complex geometries, which are impossible to inspect with other inspection techniques e.g. weld surfaces in restricted areas under water.

The engineers and technicians succeeded in the development of the tools for remote application in the reactor pressure vessel and its internals. And the tools were approved and qualified for field work by the Swedish Qualification Centre, SQC.

OKG saves down-time

As owner of the new remote application tools for e.g. under water inspection of level measuring nozzles, auxiliary feed water nozzles etc. in nuclear reactor pressure vessels, FORCE Technology can provide the inspection services throughout the world. ”FORCE Technology is pleased to provide our services with a short notice. All preparations and qualifications of the moulding tools for visual inspection have been worth the efforts”, says Hans-Ole Olsen, FORCE Technology.

”We are pleased that FORCE Technology managed to mobilise engineers and technicians within 24 hours from Denmark so we saved valuable down time”, says Lars Johansson, OKG AB. ”The moulding was performed fast and efficiently with a very high quality” and he continues: ”The moulding was carried out on two level measuring nozzles to our satisfaction and we would like to thank all involved personnel for a well performed work”.