If you really needed the shale oil and you didn't have fossil fuels to do the extraction you could run the extraction process using a nuclear plant.
http://web.mit.edu/newsoffice/...
The last of these ideas would locate a nuclear plant near a deposit of oil shale -- a type of deposit, technically known as kerogen, that has not been used to date as a source of petroleum. Heated steam from a nuclear plant, in enclosed pipes, heats the shale; the resulting oil can be pumped out by conventional means.
At first glance, that might sound like a "dirty" solution, enabling the use of more carbon-emitting fuel. But Forsberg suggests that it's quite the opposite: "When you heat it up, it decomposes into a very nice light crude oil, and natural gas, and char," he explains. The char -- the tarlike residue that needs to be refined out from heavy crude oils -- stays underground, he says.
Today, the heating of the rock is usually accomplished by burning fossil fuels, making the process less efficient. That's where the excess heat from a nuclear plant comes in: By coupling the plant's steam output with a shale-oil well, the oil can be recovered without generating extra emissions. The process also does not need regular heat input: The nuclear plant can operate at a steady rate, providing electricity to the grid when needed, and heating oil shale at times of low electricity demand. This enables the nuclear plant to replace the burning of fossil fuels in producing electricity, further reducing the release of greenhouse gas.
The world's largest oil-shale deposits are concentrated in the western United States. "We lucked out," Forsberg says. "This has the lowest carbon footprint of any source of liquid fossil fuel."
The resource that could be unlocked is enormous, he says: "Some of these deposits would yield a million barrels per acre. There's no place else on Earth like it."
Actually you could view the current extraction process as being a sort of pump priming - right now fossil fuels are used to run things. Counter intuitively it becomes more economic when fossil fuel prices are high. Now if fossil fuel prices fell you could imagine using a nuclear plant to supply the heat. Or, if fossil fuels became unavailable - e.g. due to a major war in the Middle East - you could use nuclear too. Once people have started to make money out of extracting shale oil the odds are they will use that money to stay in business.
It seems like if you could use the waste heat from a reactor to extract oil you can get even better energy efficiency than merely using the heat to generate steam to generate electricity. Also thorium means that we're not in any danger of running out of fuel for nuclear reactors.