ThorCon generates reliable electric power cheaper than coal, competitive with natural gas, cheaper than LNG, cheaper than storage-buffered wind and solar.

Power plant capital costs

ThorCon and standard supercritical coal-fired plants both make high temperature steam. They both use the same Rankin-cycle power conversion systems. These can be purchased from a half-dozen competitive suppliers for $500/kW, including the massive, precision turbogenerator, itself costing $120/kW. The difference is the steam generator. Compare the size of this modern 660 MWe coal plant’s steam boiler and associated gear to ThorCon’s 500 MWe steam generating fission island.

Coal steam generation vs ThorCon steam generation

Coal plants must handle massive amounts of fuel and ash.

Coal-fired power plant costs vary by country, type of coal burned, local conditions, and local environmental requirements. New coal power plants may require costly flue gas scrubbers to remove sulfur oxides that cause acid rain. High temperature pulverized coal plants create more nitrogen oxides to be removed. Fly ash is to be captured, including particulates smaller than 2.5 microns. US costs are high at $3500/kW. In Indonesia SourceWatch reports costs for six coal plants averaging about $1800/kW. New plants at Paitan are proposed at $1400/kW.

1 GW ThorCon: 280 tons fuelsalt every 8 years
1 GW coal plant: 10,000 tons coal every day

Coal plants require more steel, concrete, and money.

The steam generator part of a 500 MW supercritical coal plant requires about 45,000 tons of steel for massive boiler, coal handling, flue gas treatment, and ash handling systems. It  uses about 135,000 cubic meters of reinforced concrete. Almost all the coal plant work is done on site.

Almost all the ThorCon work is done in a controlled, assembly line environment. ThorCon’s steam generator is its small fission island, requiring about 8,000 tons of steel. The entire ThorCon including fission island, hull, and turbine-generator has about 50,000 tons of steel. The bulk of ThorCon steel is simple flat plate panels, which shipyards can produce and erect for less than $1,000 per ton. ThorCon uses non-structural concrete for its mass in the seismic-isolating turbine-generator platform, and optionally in place of sand for ballast in the 1 meter thick steel-sandwiched hull sidewalls.

The ThorCon steam generation side does require some costly items that a coal plant does not need. The fission island Cans requires 700 tons of very high quality graphite, and 800 tons of SUS 316 and 304. But these and other adjustments add a little more than 50 million dollars to the cost of a 500 MW plant. Overall the resource cost of the ThorCon is half that of the coal plant. Assuming efficient regulation, ThorCon capital cost will be cheaper than coal.

ThorCon and coal use the same steam-to-electricity power conversion systems. The sources of high temperature steam differ. 

ThorCon capital cost confirmation

The basic ThorCon design specification was completed in 2018 and shared with potential suppliers and shipbuilders. A renowned South Korean engineering and shipbuilding firm estimated the cost for production of 500 MW ThorCons. Their estimate excluded costs for some items such as feedwater reheaters, which we added back in.  The shipyard estimate supports our estimates that ThorCon power plants can be mass produced by shipyards at costs of $800/kW to $1000/kW.

ThorCon generates energy cheaper then coal.

Thermal coal is shipped and delivered at competitive prices; $80 per ton is as good as it gets for coal delivering thermal energy of 25 MJ/kg. A 1-GW coal plant operating at 90% capacity factor and 45% thermal efficiency requires 2,500,000 tons per year. The coal fuel alone costs $200 million, or 2.5 cents/kWh of generated electricity. This excludes operating costs such as disposing of 300,000 tons of coal ash.

ThorCon generates electricity cheaper than coal because its capital costs are less and its fuel costs are less.

Natural gas and LNG power costs

Fracked natural gas fuel pipelined to US power plants costs $3 to $4 per million BTU, leading to costs of 3 to 4 cents/kWh of generated electricity. Natural gas generators are displacing coal-fired generators in the US by generating less expensive electricity. ThorCon liquid fission power can be competitive with natural gas in the US, and more competitive in Eurasia where natural gas is more expensive. 

LNG (liquified natural gas) can be delivered by ship to regions where pipelined natural gas is not available. The cost of cryogenic liquefaction, insulating, transporting, and re-evaporating methane adds a premium of 2-3 cents/kWh to the cost of electricity. The US FERC reported the December 2018 LNG prices in dollars per million BTU plotted on the map above. ThorCon generated electricity is cheaper than LNG sourced electricity.

Wind and solar power costs

Prosperous economies require reliable energy when needed, so power generation must be dispatchable on demand. Intermittent wind and solar source generators can temporarily supply low-cost electric power to the grid, but with a capacity factor of about 30%. This has created demand for redundant natural gas turbine generators to provide “back up” power when there is no wind or sun. The natural gas turbine-generators spin full time, reducing fuel consumption when weather permits wind or solar generation. Paying for both the intermittent and natural gas power sources means their average electricity cost is more than ThorCon electricity cost.

Batteries have been proposed to replace CO2-emitting natural gas generators. Storing intermittent electric energy for later dispatch adds expensive storage buffering costs. A 2018 Science article by Steven Davis and 32 other renowned scientists analyzed storage costs. Using low-cost, mass-market, lithium-ion batteries for daily buffering raises electricity costs from 3.5 cents/kWh  to 14 cents/kWh. For weekly buffering the cost grows to 50 cents/kWh. Even if future battery costs are halved, that cost will be 29 cents/kWh. Even free intermittent electricity would not significantly reduce storage-buffered, dispatchable electricity costs. ThorCon generated electricity is cheaper than storage-buffered wind and solar electricity.

ThorCon can penetrate the market for electric power.

ThorCon can supply power plants at the competitive cost levels of large ships, rather than at the extraordinary high costs of building today’s nuclear power plants. This changes everything. It makes fission power competitive with natural gas and cheaper than coal or LNG.

ThorCon electric power cost:

  • Lower capital cost and lower fuel cost than coal.
  • Competitive with pipelined natural gas.
  • Lower electricity cost than shipped LNG (liquified natural gas).
  • Cheaper than solar and wind including natural gas backup.
  • Cheaper electricity than storage-buffered wind and solar sources.

Should-cost vs Did-cost

Most people will automatically scoff at the claim that a nuclear power plant should cost less to build than a coal plant. It is received wisdom that nuclear plants are outrageously expensive. And most recent nuclear projects confirm that belief. But why? ThorCon clearly consumes less resources than a coal plant of the same capacity, and is easier to build. Even a standard nuclear plant requires about the same amount of steel and concrete as a coal plant. Why is nuclear so expensive?

Economists tell us that in a reasonably competitive market with: multiple providers, nil price power, no big secrets, no major barriers to entry, and no big externalities, market cost measures the value of the planet’s precious resources consumed by an activity. This is the should-cost. In situations where there are little or no competitive pressures, the difference between should-cost and the dollars actually expended, the did-cost, can be quite remarkable. The Tale of Two Ships offers an example. Naval ships can be built with exactly the same technology as commercial ships. Yet they can easily cost 20 to 30 times their commercial counterparts.

Where does all this money go? The Navy ship has extensive design calculations of every detail, interminable design reviews, careful certification of yards, vendors, materials, welders, janitors. Ubiquitous documentation of everything with strictly followed sign off procedures, all sorts of prescriptive standards and procedures which must be precisely adhered to. Meticulous review of the tiniest of changes. Nothing is too good for our sailors.

The commercial ship has little of this. There are heavy penalties if the ship is not delivered on time or does not perform per spec in actual trials; but the cost of owner, classification society, and flag state review and inspection is less than 5% of the shipyard price. As a result, a commercial ship will be unavailable on average about 15 days per year, an availability of 96%. Most ships do better, but a few do worse. A ship that is unavailable more than 30 days per year is a lemon and will probably cost the builder a customer.

Astonishingly, the availability of Navy ships is much worse. The Tale of Two Ships offers an egregious but not uncommon example. Availability is often 60% or less, construction schedules are expected to slip, and the ships frequently do not perform per spec. All that process, all that paperwork, all those rules, often — if not usually — results in a badly flawed product. 

ThorCon requires less resources than a coal plant. One third less in construction; four time less in fuel. ThorCon is simpler and can be built almost entirely on an assembly line at shipyard productivity and quality. ThorCon power should-cost about half as much as coal where coal is cheap. But the did-cost depends on how we regulate nuclear power. The bottom line is simple: will we build nuclear power plants the way the U.S. Navy builds ships or the way the Koreans build ships? If it’s the former, then nuclear will never beat coal regardless of the technology. If it’s the latter, then ThorCon is easily cheaper than coal.