"Greenpeace now supports Nuclear as a clean energy source.....I wonder what their hidden agenda is?"
I do not think there is any thing hidden about their agenda, they have merely woken up to an alternative that is more sensible than many that are currently in practice.

My education was engineering, I mean to say practical application of scientific knowlege.

So nuclear is not ideal but it is way more practical than carbon based energy sources which are cheap but as we now well know has immediate costly consequences and a limited source.

'BUT nuclear has the waste as a profound consequence' you say?

Ah Yes, but that waste will not be waste for thousands or tens of thousands of years as some would have you believe.
The expansion of knowlege is exponential.
Today we are looking for Higgs boson, the 'God particle'. Probably during this century we will achieve practical super conductors, enough to produce strong enough magnetic fields to make fusion practical.
With greater knowlwge of fundamental nuclear particles we will be able to irradiate that nuclear 'waste' not only to make it safe but very likely as continued fuel to be reduced to the point of basic neutrons and protons, i.e. most types of matter to energy, 100%.

Nuclear is not my favourite. Natural sources such as wind, geothermal, solar and sea waves are most preferred as sources for electricity which should replace most hydrocarbon energy sources.
( I am even against use of petroleum sources for production of plastic packaging. Petroleum being limited, should only be used for absolutely necessary needs where there are no alternatives.)
That electricity to produce hydrogen for fuel cells for vechicles that can not run on electricity directly. By directly I mean recharged batteries from grid for cars.

Environmentalists got it wrong due to incomplete understanding or scare tactic re: Industrial civilization to collapse.
Abuse of science, industralization and politics are the problem while proper use is a saviour for the planet. I am ever hopefull on that subject.

Ed.