RD&D-Programme 2004 - SKB

A method and equipment based on laser technology have been developed in cooperation with
the Royal Institute of Technology in Stockholm for measuring the dimensions of the copper
tubes. The equipment is mobile and can be transported to different suppliers of copper tubes
to measure straightness, inside diameter and ovality along the entire length of the tube. The
method provides much more accurate results than was previously possible.
The results obtained after computer simulations and tool optimization in forging of blanks for
lids and bottoms have shown that this is now a workable method.
Programme
Fabrication of seamless copper tubes and blanks for lids and bottoms will continue in order to
verify and further optimize tools, process parameters, inspection methods and technical specifications.
Seamless copper tubes will be fabricated by means of extrusion in order to verify this
method. Continued fabrication trials will be done with pierce and draw processing and forging.
The development work on fabrication of copper tubes with integral bottoms by pierce and draw
processing will continue.
Fabrication will be carried out primarily for a wall thickness of five centimetres, but also on a
limited scope for four centimetres in order to gain experience and gather data as a basis for a
possible later decision on a change.
In the continued work on tube fabrication, the advantages and disadvantages of the different
methods will be compared. It is likely that more than one of these methods will be able to be
used for future serial production.
Development of laser technology for dimension measurement of copper tubes will continue.
Methodology and equipment for nondestructive testing by means of ultrasound as an inspection
method will be developed. Besides detection of discontinuities in the casting, the possibilities
of using ultrasound to determine the grain size in the fabricated copper components will be
examined, see also section 5.5.
5.5 Nondestructive testing of canister components
The different parts of the canister will be examined by means of different methods for
nondestructive testing (NDT) in order to show that they fulfil the fabrication requirements.
Conclusions in RD&D 2001 and its review
The lessons learned from the trial fabrication of all canister parts will be applied to and
influence the further development of the fabrication technology. The work of investigating and
establishing acceptance criteria and testing methods will make it possible to specify equipment
for NDT and other quality inspection more precisely. A more thorough evaluation of modified
machinery and testing equipment for the canister factory will be carried out in cooperation with
potential suppliers.
The viewpoints of the regulatory authorities are presented in section 7.2.
Newfound knowledge since RD&D 2001
See also section 7.2.
The methods used by the fabricators to test the components have been surveyed. Furthermore,
the methods used by the suppliers to test similar items in their production have also been
studied.
60 RD&D-Programme 2004