A New Class of Nuclear Reactors

prunedude tips this quote from a post at Freakonomics about Japan's nuclear crisis: "The folks over at IV Insights, the blog associated with Nathan Myhrvold's Intellectual Ventures, point out that it was the complete loss of power that disabled the cooling systems protecting the plant's reactors. Which raises the question: Is there nuclear technology that could withstand such a catastrophe? Possibly. TerraPower, an Intellectual Ventures spin-off that also boasts Bill Gates as an investor, is working on a new reactor design called a traveling wave reactor that uses fast reactor technology, rather than the light water technology used at the Fukushima Daiichi plant. The two biggest advantages of the fast reactor design is that it requires no spent fuel pools and uses cooling systems that require no power to function, meaning the loss of power from the tsunami might not have crippled a fast reactor plant so severely."

Comments

Same as it ever was

[drsmack1]

Of course any new reactors designed will have safeguards against any previous disaster - it's the ones that never happened before that fuck us.

Re:Same as it ever was

[ColdWetDog]

See above for the comments on Pebble Beds. It appears that even after decades of research and engineering into nuclear reactors, we still don't know enough to be confident that any particular design or implementation will behave the way the designers expect. Not exactly surprising since anything more complicated than a paper towel seems to have those same issues but it does mean that any progress will have to come slowly and hopefully carefully.

Just because it looks good in Autocad doesn't mean it will actually work correctly.

Is there nuclear technology?

[ShakaUVM]

"Is there nuclear technology that could withstand such a catastrophe? Possibly."

Yeah, as in all other modern designs.

Passive cooling has been the hot new thing since, you know, the 80s.

Dumb question...

[sideslash]

If nuclear power plants are used to power cities, why can't they power their own cooling? Seems like keeping the darn thing running would be safer than watching it sit there unpowered and on the verge of blowing up. (Don't get me wrong; I'm sure there's a good reason. I'm just curious.)

Re:Dumb question...

[XiaoMing]

I'm sorry, but that is one of the most misleading and misinformed sequence of words to get marked up regarding this whole issue.

First off, it should be noted that this reactor was in the middle of what can be considered by the general public as three chronological regimes of reactors:

1. Very unsafe reactors that have little or no passive safeguards (i.e. reactors reminiscent of Chernobyl or Simcity2k's 50 year kaboom)
2. Relatively safe reactors that have many passive safeguards (multiple layers of containment, and spill region with unfavorable fission geometry etc.) but that still rely on external containment measures (active cooling in the situation we're discussing now)
And finally
3. Very safe reactors that have many passive safeguards built in for every foreseeable (keyword, so no need to go thinking up magical exceptions to this category) circumstance (such as the capability to snuff themselves out via high concentrations of neutron absorbing daughters etc). As these reactors were being constructed and developed during a period of nonproliferation and disarmament, you see mixed results as many in operation were also once-off prototypes, but there are many places (Japan, France, Canada, etc.) where standarization and continued development/production means that most of the public fear is about as accurate as the tea party's propaganda regarding Kenyan birth records.

As an aside, it's also a good time to note that nuclear power plants are still nothing more than a fancy way to boil water. I.e. after a few heat exchange processes, the steamy water from these reactions is still used to do what water flowing downhill is used for, to drive a turbine.

Now the important part: Shutting down the reactors was by far the correct thing to do here because cooling was necessary for the daughter isotopes.
That is, the stuff we've been cooling all this time is the result of decay from before the plant was shut down.

What does this mean? Now here comes the simple part: It means that if you took the exact same situation, but kept the reactors running critically (i.e. no full insertion of control rods), you'd not only continue to generate heat from the primary fission reaction itself, but ALSO continue to generate more heat from the fission of the daughter products.

So sure, you might have had a few hours, hell maybe a day to generate additional energy before the subsequent tsunami--that managed to wipe out: the national electrical grid, thirteen backup diesel generators; and backup batteries that last for eight hours--is now expected to leave your steam turbine energy generation system completely untouched and functional. (http://www.voximate.com/blog/article/1058/failover-backup-systems-redundant/)
And in the very very likely case that it doesn't? Well now you have all that additional heat as well as even more daughter products to take care of.

No manuals will be rewritten, if this shit happens again they'll shut down the plants just like they did this time, only get plugs that fit rather than risking a full blown meltdown while hoping that a damaged powerplant can supply its own cooling somehow.

And of-course, if these defunct cores are replaces with newer designs after this is all over, we'll be in much better shape regardless.

THESE reactors should't have had a problem

[unassimilatible]

It can't believe nobody has mentioned this, but the reactor designs were not the problem. All of these cooling problems could have been solved by some sort of waterproof backup power, even if it had to be stored 50 miles away and delivered via an underground cable that comes up under the reactors. Some of these reactors' cooling systems failed because the battery backup power was in the farking basement for crissakes! Below sea level on an Island! Totally flooded. I'm a social science (excuse the contradiction of terms) and I know better than that.

How hard would it be to either 1) keep battery backup at a high point above a nuke plant* (I know, weight, whatever, engineer around it) or 2) the plan I mentioned above, the same redundancy that data centers have, redundant power located elsewhere. Either would have likely saved these reactors.

*Patent pending.