Category: The environment

Atmosphere, biosphere, lithosphere, hydrosphere, etc – everything about life and the state of this planet

Stanford to divest from coal

Stanford University has announced that it will be divesting its $18.7 billion endowment from direct holdings of coal company stock.

This is great news for the campaign at U of T, given the size of the endowment and the credibility of the school.

The divestment campaign in general has huge potential to snowball, as each decision to divest makes it easier for other schools to make the same choice.

Sea-based nuclear power stations

Sea-based nuclear power stations would offer some advantages over the terrestrial sort:

For one thing, they could take advantage of two mature and well-understood technologies: light-water nuclear reactors and the construction of offshore platforms… The structures would be built in shipyards using tried-and-tested techniques and then towed several miles out to sea and moored to the sea floor…

Offshore reactors would help overcome the increasing difficulty of finding sites for new nuclear power stations. They need lots of water, so ideally should be sited beside an ocean, lake or river. Unfortunately, those are just the places where people want to live, so any such plans are likely to be fiercely opposed by locals.

Another benefit of being offshore is that the reactor could use the sea as an “infinite heat sink”… The core of the reactor, lying below the surface, could be cooled passively without relying on pumps driven by electricity, which could fail…

At the end of its service life, a floating nuclear power station could be towed to a specially equipped yard where it could be more easily dismantled and decommissioned. This is what happens to nuclear-powered ships.

The article mentions the Akademik Lomonosov, a Russian ship-based nuclear power system with an output of 70 megawatts. It uses the same kind of reactors that power the Taymyr-class icebreakers. Unfortunately, several such stations are intended to provide power for offshore oil and gas development.

The earliest floating nuclear power station went critical in 1967, inside the hull of a Liberty ship. It provided 10 megawatts to the Panama Canal Zone from 1968 to 1975.

Open thread: thorium-fueled nuclear reactors

Whenever the many problems with nuclear power are raised, there are people who suggest that everything could be fixed with a substantial technical change: moving to generation IV reactors, for instance, or the ever-elusive fusion possibility.

Another common suggestion is that using thorium for reactor fuel could limit concerns about proliferation, as well as (modest) concerns about uranium availability.

I have read a lot of contradictory things on the subject of thorium, so it seems useful to have a thread tracking information on the issue.