Cringley: Japan may have just permanently lost 20% of its electricity supply • Hacker News Board

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#51

Post by VMG » Sat, Mar 12, 2011, 1:45 PM UTC

ugh wrote: post #45

gimpf wrote: post #43

Earlier quoted context omitted.

Hmm. Here in Central Europe this would probably read: "However the events unfold we can rest reassured that scientists have to acknowledge that any use of nuclear technology for electrical power generation is inherently unsafe and therefore irresponsible." And then we build a new coal power plant.

Not even probably. In Germany, opposition parties already (and once again) demanded of the government to rethink their nuclear strategy. (No new nuclear power plants are built or planned in Germany but the coalition government recently extended the runtime of existing nuclear power plants.) I'm a bit annoyed that the only two options in Germany seem to be to either shut all nuclear power plants down or to extend the…

It is worth mentioning that France is still big on nuclear and we will likely be buying French power from nuclear plants.

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#52

Post by gonzo » Sat, Mar 12, 2011, 1:49 PM UTC

lambda wrote: post #25

I don't know much about nuclear reactors. To my untrained ear, what Cringely says sounds fairly reasonable. But then, having read a bunch of articles of his linked in the past on computer hardware and software, which I do know something about, I find that what he writes usually falls into one of two categories: (1) stuff that's obvious to anyone who knows what they're talking about and are paying any attention at all…

he lied a number of years ago about what he'd supposedly done with wifi, a couple high-gain antennas and a corner reflector.

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#53

Post by gonzo » Sat, Mar 12, 2011, 1:50 PM UTC

FUKUSHIMA DAIICHI-1 was already scheduled to be shutdown this month.

http://www.icjt.org/plants/uni/a/uni194a.html

neutronicus has even more reasons why what Bob says is very likely wrong.

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#54

Post by gonzo » Sat, Mar 12, 2011, 1:55 PM UTC

Groxx wrote: post #6

ugh wrote: post #4

Earlier quoted context omitted.

“I trust Japanese engineering more than Cringley predictions.” What does that even mean?

That Cringely is less reliable than Japanese manufactured / designed goods.

While true, this reactor was built by General Electric in the late 1960s.

http://www.icjt.org/plants/uni/a/uni194a.html

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#55

Post by gonzo » Sat, Mar 12, 2011, 1:56 PM UTC

MichaelApproved wrote: post #38

TomOfTTB wrote: post #30

Earlier quoted context omitted.

I think you're right but I give him credit for drawing attention to a big issue that everyone else is ignoring which is Japan's diminished production capacity (rather than focusing on the doomsday meltdown scenarios most of the media are fixated on). Even if they return to service eventually there's going to be downtime. That's going to force Japan to use more fossil fuels which will drive up the price (even more). A…

Oil isn't used to make electricity. The major options are nat gas and coal. This disaster will likely drive DOWN oil prices since Japan will likely need less of it in the short term.

maybe not in Japan, but here in Hawaii, oil is used to make electricity.

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#56

Post by gonzo » Sat, Mar 12, 2011, 1:57 PM UTC

JoelUpchurch wrote: post #49

I suspect the decision to use sea water to cool the reactor means that they have decided to write off the plant. It was 40 years old anyway and nearing the end of it's service life.

the end of its service life was this month!

http://www.icjt.org/plants/uni/a/uni194a.html

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#57

Post by gonzo » Sat, Mar 12, 2011, 1:59 PM UTC

nathanhammond wrote: post #28

rdl wrote: post #16

Earlier quoted context omitted.

They could probably fly or ship or truck in some smallish diesel generators to accomplish the same thing -- they're just pumps, so I find it hard to believe any individual load is bigger than your average transportable diesel genset. It shouldn't be too difficult to divide a load connected hydraulically vs. electrically across a bunch of generators quickly (switchgear is otherwise fairly custom).

The backup diesel generator at Oconee Nuclear Station (Oconee, SC) is fashioned out of a pair of modified diesel train engines ... it isn't exactly a simple "throw more power at it" problem. Even if it were trivially possible to add power as if you were filling up a tank of gas the bigger problem would be mating the power output and frequency of these generators with the rated values for the plant's electric system (…

the generators in question are used to run pumps. you wouldn't need to phase match them to the plant's electric system, per se. (you would need to phase match them to the other generators, but that is straight-forward)

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#58

Post by rospaya » Sat, Mar 12, 2011, 3:03 PM UTC

http://en.wikipedia.org/wiki/Robert_X._Cringely

Robert X. Cringely is the pen name of both technology journalist Mark Stephens and a string of writers for a column in InfoWorld, the one-time weekly computer trade newspaper published by IDG.

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#59

Post by neutronicus » Sat, Mar 12, 2011, 3:12 PM UTC

masklinn wrote: post #42

neutronicus wrote: post #15

Like they wouldn't have boron near a nuclear reactor. I'm a PWR man myself, but I am 99% sure that GE BWR designs have a couple of big tanks of borated water specifically for a LOCA. I highly doubt they're having reactivity problems, it's probably just managing the decay heat, and now the radiation leaks, that's the problem. "Just" is a relative word, here, of course. Boiling water reactors are simpler, cheaper, but…

> Like they wouldn't have boron near a nuclear reactor. They probably do, the question is whether they can carry it to the site faster than the US navy, and whether the boron tanks have not been compromised.

The question is also, and I didn't make it clear enough in my original post:

"Wait, they need boron?"

Boron is a neutron absorber, and is therefore used to control the fission rate. You add boron when you're afraid of the fission rate getting out of control (e.g. Chernobyl). This is a legitimate concern here for two reasons:

1) A BWR is significantly more reactive (conducive to a high fission rate) at cold zero power than at hot full power, because cold water is a better neutron moderator than steam.

2) Xenon-135 and Samarium-149 are by-products of nuclear fission that have an effect on reactivity similar to boron. Their half-lives are on the order of hours, so when you crank down the fission rate, a couple hours later you also crank down the concentrations of Xe-135 and Sm-149, which, if you're not careful, can cause the reactor to go supercritical (and possibly prompt supercritical - a form of criticality in which everything happens approximately a thousand times faster - pretty much the worst-case reactivity excursion scenario) again a few hours after shutdown.

So, basically, you need enough negative reactivity from somewhere, either control rods or borated water, to counteract these two reactivity insertions. The Japanese reactor is almost certainly designed so that inserting all of the control rods into the core will kill any and all reactivity increases after shutdown.

What is most likely occurring is that there is very little nuclear fission inside the reactor right now. All the power inside the reactor is coming from decaying fission products, and it's probably on the order of kilowatts, it's just that the when the flow rate through the core drops from gallons per second to essentially nothing, a few kilowatts per cubic foot will get you pretty damn hot pretty damn quick. At this point some of the fuel rods have probably failed as well (if not melted), so the water in the reactor may be nastier than usual.

Unless the control rods have failed or are in the process of failing, I doubt that boron is even necessary for reactivity control, except as insurance. My educated guess is that their problems are entirely thermal- and containment-related, and that there is no danger of a reactivity accident, since a xenon transient or a condensation transient would have run its course by now, so the control rods probably have enough reactivity worth to keep the reactor subcritical indefinitely.

Re: Cringley: Japan may have just permanently lost 20% of its electricity supply

#60

Post by jsavimbi » Sat, Mar 12, 2011, 3:12 PM UTC

masklinn wrote: post #42

neutronicus wrote: post #15

Like they wouldn't have boron near a nuclear reactor. I'm a PWR man myself, but I am 99% sure that GE BWR designs have a couple of big tanks of borated water specifically for a LOCA. I highly doubt they're having reactivity problems, it's probably just managing the decay heat, and now the radiation leaks, that's the problem. "Just" is a relative word, here, of course. Boiling water reactors are simpler, cheaper, but…

> Like they wouldn't have boron near a nuclear reactor. They probably do, the question is whether they can carry it to the site faster than the US navy, and whether the boron tanks have not been compromised.

Someone's under the impression that the US Navy is capable of doing whatever they want, whenever they want. In actuality, it took a very long time for US-Japanese relations to get to the point where the Navy would be able to station a nuclear-powered aircraft carrier, the USS George Washington, at the fleet activities base in Yokosuka. Prior to that, only the conventional carriers Midway, Independence and Kitty Hawk were allowed, and nuclear-powered carriers making a port of call were sometimes diverted due to tensions with the civilian population. Nuclear weapons themselves were banned and the forward carriers were weaponized at sea, in secret, from other vessels.

So, no, given the state of relations between the countries and the general lack of experience in civilian application, not to mention the improbability of possessing the resources, I'd highly doubt that the US Navy would be instrumental in assisting the qualified and experienced staff at a nuclear power plant located in a highly developed country such as Japan. I think the author was just throwing that in there to add some ominous weight to his argument.