The accompanying research covers the feasibility investigations and choice of technology in principle; it does not cover items that need validation after detailed design. It has been suggested to separate the R&D items which are concerned with the principal physics feasibility (PF) from those that are concerned with the technical feasibility (TF). Although this idea has been followed in a coarse way one must realise that there is no clear distinction possible and that the picture blurs the more one goes into details, therefore this expresses only a tendency. As an example we would quote the main and spallation loop heat exchangers. Whereas heat exchangers have been studied and built for hundreds of years and the heat exchanging principles are well known the combination with the requirements of withstanding heat transients, i.e. Megawatt swings, in the 1 second time domain (beam trips) and the unusual contact with liquid Lead Bismuth Eutectic (LBE) of some corrosive nature puts so many additional criteria on their design, some of principal physical (e.g. materials) some of technical nature, that a clear distinction cannot reasonably be made. More R&D information |