Carnot's theorem dictates the irreducible minimum heat that has to be given out to the heat sink for a given temperature of the heat source. Nuclear power stations do not reach this limit but their performance is not very different to conventional coal fired power stations.

At a steam temperature of 540°C and a cooling water temperature of 27°C the theoretical thermal efficiency is 63% meaning that 0.57MW of heat has to be given out to the environment for every 1MW of electricity generated. In practice coal and nuclear power stations achieve about 33% efficiency at those sorts of temperatures meaning that 2MW of heat is given out to the environment for each 1MW of electricity generated.

High temperature reactors could increase this efficiency and also open the possibility of the direct production of the hydrogen needed for the hydrogenation the tar using the sulfur-iodine process circumventing the further losses in electrolysis. .

jhm,

Peter Huber has written many kind words about nuclear power in the past but your ad hominem dismissal is disengenuous.  Calling him a shill or a true believer is just a way to insult.  Stick to the arguments.

That said, I was disappointed with the quotations presented here - it's not up up to Huber's usual quality.

In fact, compressed natural gas can be and is used for transport fuel.  Several US gas utilities have actively promoted its use for vehicles by sponsoring and subsidizing public and prive refuel stations.

Note that methane has an octane number of about 120.  An engine optimized for burning methane would then use a much higher compression ratio and achieve a higher thermal efficiency and therefore better milage.  Few vehicle conversions go to that much trouble and so are sub-optimal.  The range is also driven by the on-board gas storage capacity but that is a bigger burden than a gasoline tank so is a negative.

As to nuclear's waste heat, the inefficiencies that result in waste heat are driven by the physical characteristics of the water used to cool the core.  We're stuck at about 33% efficiency.  The only way to substantially improve that is to go to liquid metal cooling where efficiency would improve to roughly 40% or to helium cooling using nuclear rocket engine technology and gas turbines where 55% efficiency would be possible.

A possible use of the waste heat from current reactor designs would be for desalinization, producing potable water.  In Asia, the waste heat is sometimes used for public swimming pools located adjacent to the plants.