THE THERMOCHEMICAL PIPELINE

Such potential applications of the HTGR are now under study at General Atomic Co (the US manufacturer of the HTGR), by Gas Cooled Reactor Associates (a user group of utilities), both at San Diego, and by the Advanced Reactor Systems Dpt. of General Electric at Sunnyvale, Calif.

One of the fascinating concepts, the feasibility of which is now under study by General Electric, is the thermochemical pipeline. It would carry energy over distances of up to 300 miles with smaller losses than electricity and with the possibility of lossless storage.

Some chemical reactions need (and absorb) heat to take place; they are called endothermic. Others, exothermic reactions, release heat when they take place.

The thermochemical pipeline carries gases loaded with energy to the destination where they give up their heat in a chemical reaction and are piped back to the HGTR, which uses heat to "charge them up" again.

Specifically, methane (from the return pipeline) and steam are converted into hydrogen and carbon monoxide. This "steam reforming of methane" is done at 1700 degrees F, but it should be understood that the resulting gases in the pipeline are quite cool; the energy absorbed by them is stored in the bonding of their molecules.

At the destination, this energy is released at about 1100 degrees F by "methanation," i.e., by turning the H-CO mixture into methane (and water), a process commonly used in the production of high-BTU gas from coal. The low energy return product is thus itself a fuel, which is incidental in the transmission process, but can be used for versatility in storage and additional energy conversion.

There are other possibilities, such as using this HTGR-"Reformer" for producing base load electric power (just as if it were an HTGR-"Steamer") while producing synthetic fuel for peaking service.

Another design under study is the HTGR Gas Turbine, which would eliminate the need for cooling water and would raise the efficiency of power generation to beyond 40%, and possibly to 50% by using a bottoming cycle (utilizing the low-temperature heat rejected by the turbine).

These and other applications are now in the feasibility study stage, and pessimists say nothing will ever come of them. With General Atomic having to withdraw from the commercial market after a $250 million loss, with a single HTGR running commercially in the country, and that of a design that will never be built again (after learning its lessons), who would be crazy enough to point to the HTGR as the fission reactor of the future?

We would.

And there are other crazies around. Britain, Japan and Switzerland have intensive HTGR development programs going. West Germany spent six times as much on HTGR development in 1980 as the US.

[Sources: Mostly General Electric Advanced Reactor Systems Dpt. documents (not widely published); see also article in Energy Daily, 8 Sept. 1980.]