Molten salt reactors greatly ease fears, expense of nuclear power
PHOENIX — The use of current-type nuclear reactors — light water reactors, or LWR — is valid for all the points mentioned in the Herald’s editorial about Duane Sand and his idea for a Red River Valley nuclear power plant (“Nuclear power plant deserves study,” Page F1, Dec. 20).
But there are much better designs of nuclear reactors than LWR, some demonstrated successfully in the 1960s but killed by politicians. Our national priorities have changed since then, especially our need to eliminate the pollution and health issues of coal and oil.
Molten salt reactors have none of the safety issues or nuclear waste problems LWR have.
Molten salt reactors use molten fuel, and the temperature always is far too low to melt the reactor materials.
Light water reactors use about 3 percent of the fuel because of the structure of the fuel pellets. Plus, the very high temperatures inside the pellets will melt the reactor materials if cooling fails.
Molten salt reactors use no fuel pellets, but molten fuel. The fuel is dissolved in the coolant; thermal expansion and contraction strongly regulate the fission rate (it has been shown to be a very stable reactor design); and nowhere in the reactor is there anything that can get hot enough to melt the materials.
Molten salt reactor designs can use more than 99 percent of the fuel, so there essentially is no long-term nuclear waste. A thousand kilograms of uranium or thorium would produce more than 1 gigawatt-year of electricity (vs. 35,000 kilograms in LWR), leaving 830 kilograms of fission products to store for 10 years, 170 kilograms to store for 350 years and nothing to store for longer.
Molten salt reactors use no water (OK, the bathrooms, coffee maker and window-washing use a little). There’s no high-temperature, high-pressure water, so there’s no chance of a steam explosion. Nor is there a chance of a hydrogen explosion, all of which means there’s no need for a very expensive steam-containment building.
Oak Ridge National Laboratories developed and operated a molten salt reactor in the 1960s and early 1970s. It ran successfully for more than 20,000 hours before Congress shut it down instead of building the commercial-scale version.
Why didn’t we use MSR? Because Congress got to pick what type of nuclear reactor we used, and even though the nuclear physicists and designers and the Atomic Energy Commission all said to use liquid metal fast breeder reactors and/or molten salt reactors, the fossil fuel “energy friends of Congress members” picked light water reactors because there was no chance these would ruin the coal and oil companies.
Molten salt reactors are cooled by salt at far below its boiling temperature, so there are no high pressures. Likewise, the reactors use no water, so there’s no high-pressure safety equipment.