Could nuclear US Navy ships provide emergency backup power to Japan? | Hacker News Reader

Could nuclear US Navy ships provide emergency backup power to Japan?

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Former US Navy submarine officer here. The easy answer is no. The turbine generators are much smaller than the main engines and are designed to take much less load. Also, the cables, breakers, and connections can't handle that kind of electrical load.

But the longer answer is that yes, it is possible. When subs and other ships tie up to the pier, we connect cables to connect the boat to "shore power." Reverse the flow, and the boat powers the shore facilities. It's just that the power that can get from the boat to the shore is nowhere near the amount of power that's needed.

Specific data:

S6G full power: ~165 MW (A fraction of that available for electrical power) - http://en.wikipedia.org/wiki/S6G_reactor

Affected Japanese reactors: 785 MW each (All available for electrical power) - http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant

Cool, thanks for that!

I wasn't thinking that a sub could completely replace all of the power lost by the nuclear power plant, just that one could provide enough for emergency services. It's really just a thought experiment.

And this is the power plant in the USS Ronald Reagan nearby (I guess there are 2 which each provide 104MW): http://en.wikipedia.org/wiki/A4W_reactor

It was proposed in Northern Ireland during a power workers strike. Although considering the limited electrical power you can pull from even a nuclear sub and the 'security implications' of parking one in Belfast during the euphemisms it never got very far

I'd say the real problem is that the power circuitry _within_ the boats/ships are designed to handle quite a bit of load. But the physical connections _on/off_ the boat are likely not designed to carry it. To do this properly would require some redesign of Navy ships/boats.

Former (non-nuke, non-electrician) US Navy carrier sailor here. :)

According to Wikipedia, the output for a Los Angeles-class attack sub is around 150-165 MW and the output for a Nimitz-class carrier is around 194 MW.

The damaged Fukushima reactors have a total output of 2,812 MW, so even in a best case scenario it seems like you would only be able to use naval reactors to power emergency and critical services.

Of course, there are probably a lot of emergency and critical services needed right now.

100% of that 194 MW isn't used for electrical power generation. The total MW output is split between propulsion and the generators. If I had to guess, I'd say that bulk of the wattage is used for propulsion. Moving a carrier through the water at 30 knots is no small feat.

After the "World Series Earthquake" (aka 1989 Point Loma Earthquake), nuclear subs from Alameda crossed the bay and provided power to San Francisco.

If you're asking if this could be used to help with the failing Japanese reactors, it's too late. If U.S. nuclear ships had somehow managed to get up there and get connected in time to provide power before the plant's battery backups ran out, then uninterrupted cooling could have been maintained and the meltdowns prevented. Things are now well past that point, and now it's just a matter of keeping the radiation contained to the greatest degree possible as the meltdown continues, and finding a way to seal everything up permanently without killing anyone.

Yeah, once the reactors are doused with seawater they're done.

But there are plenty of other facilities that need emergency power now - hospitals, water treatment plants, the other reactors that aren't yet ruined.

It would be useful and awesome if US ships and subs carried the necessary equipment and were trained in how to provide emergency power to disaster-stricken places.

Every U.S. ship has the necessary connections to connect to land-based power grids. Normally these are used to draw power into the ship, but they can be made to work both ways. Even non-nuclear ships can push power, at least until they run out of fuel. The big problem is that the power grid is usually deavily damaged by the disaster (or non-existent to begin with in some countries), so there's nothing for the ship(s) to hook up to.

Even without tying up at the pier to push power, an aircraft carrier or large amphibious ship can provide tremendous support: desalinization plants capable of producing thousands of gallons of fresh water each day, helicopters capable of conducting search and rescue and/or transporting relief supplies, doctors and corpsmen trained in field medicine, command and control aircraft to tame all of the chaos listed above, etc.

Thank you all for the feedback, glad to have found this thread. I've been curious about the ability to provide enough power and fresh water to avert disaster in some of the reactors not beyond repair. Have yet to hear much about this in the news, is there any information that this has been discussed; as well, why the lack of nuclear experts/techs on site as opposed to a seemingly small number of private employees. Certainly hope a sense of pride/responsiblity is not impeding help and safety.

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