"An academic reactor or reactor plant almost always has the following basic characteristics: It is simple. It is small. It is cheap. It is light. It can be bui

"An academic reactor or reactor plant almost always has the following basic characteristics: It is simple. It is small. It is cheap. It is light. It can be built very quickly. It is very flexible in purpose (“omnibus reactor”) Very little development is required. It will use mostly “off-the-shelf” components. The reactor is in the study phase. It is not being built now. On the other hand, a practical reactor plant can be distinguished by the following characteristics: It is being built now. It is behind schedule. It is requiring an immense amount of development on apparently trivial items. Corrosion, in particular, is a problem. It is very expensive. It takes a long time to build because of the engineering development problems. It is large. It is heavy. It is complicated. " The above still seems to be relevant, it spells out the differences between paper exercises and the finished product. On paper the many thousands of subtleties of real things are rarely taken into account i.e. frictionless, motionless, perfectly rigid, etc., spherical cows are the norm.