Dismantling Techniques for Steel Components

Summary

In this research programme we looked out for possibilities to solve the dismantling problems in the reference BWR reactor with thermal cutting techniques.

It was shown that the stainless steel plated wall of the reactor pressure vessel with a thickness of 600 mm, can be dismantled by plasma-autogen-combination-cutting.

Further research work was done to find out the efficiency of oxygen lance piercing and powder flame cutting, specially at parts which cannot be done or only with great difficulties by flame cutting. It was carried out that the oxygen lance piercing gives the best results, when it is done by mankind.

A special dismantling problem was the recirculation inlet tube at the vessel wall with only a small clearance between tube and wall. It was solved by using the plasma arc cutting in air as well as under water.

The mastering of the dust and aerosol emission by application of the thermal cutting techniques is a serious problem for the future. The comparison of the dust and aerosol emission by plasma arc cutting in air and under water gave a remarkable reduction of the emissions by cutting under water.