Why I am not worried about Japan’s nuclear reactors • Hacker News Board

Re: Why I am not worried about Japan’s nuclear reactors

#61

Post by chernevik » Sun, Mar 13, 2011, 4:03 PM UTC

drtse4 wrote: post #33

ars wrote: post #3

Excellent writeup. I've been telling people this all day, but it's great to have a PhD confirm it. BTW, with Chernobyl the control rods were not able to be inserted all the way, which is one of the main reasons it was so bad - the chain reaction never stopped, and the heat just kept building up.

The description he makes of how a plant works is nice, but being "a PhD" in an unrelated field doesn't mean much to me... if he had been a nuclear physicist with nice publications or nuclear engineer working at the xxx plant AND if he had access to additional information on what it's really happening/ed i would have cared more for his conclusions... Looking at the comments [1] (guy from Japanese Atomic Energy Agency)…

Frankly I don't entirely credit the conclusions of any "authority" right now -- everyone outside the plant management loop is making educated guesses, and many of them have powerful institutional biases shaping their thinking.

And if we set aside conclusions, this is the best orientation to the problem that I've seen so far. I'm not worried about his credentials, as this is internally consistent, and externally consistent with what I know of physics. Maybe the plant lacks a third containment, or is using a different fuel, but I can adjust my understanding of the system for those facts as they come along.

Re: Why I am not worried about Japan’s nuclear reactors

#62

Post by billswift » Sun, Mar 13, 2011, 4:13 PM UTC

wedesoft wrote: post #25

ars wrote: post #3

Excellent writeup. I've been telling people this all day, but it's great to have a PhD confirm it. BTW, with Chernobyl the control rods were not able to be inserted all the way, which is one of the main reasons it was so bad - the chain reaction never stopped, and the heat just kept building up.

Also Chernobyl uses graphite as a moderator instead of water. I.e. the chain reaction continued even after the water boiled away.

Also, from what I remember from the coverage at the time and right after, the graphite caught fire and the plume of smoke helped to carry even more fallout into the air and to spread it even farther.

Re: Why I am not worried about Japan’s nuclear reactors

#63

Post by miles » Sun, Mar 13, 2011, 4:18 PM UTC

Grateful for the explanation, but the author's bias is questionable at best. He suggests,

"If you want to stay informed, please forget the usual media outlets and consult the following websites"

and goes on to list 3 nuclear lobbying websites.

So, ignore the independent media and get all of your information from pro-nuclear lobbies?

More: https://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-w...

Re: Why I am not worried about Japan’s nuclear reactors

#64

Post by dfox » Sun, Mar 13, 2011, 4:20 PM UTC

ugh wrote: post #50

ck2 wrote: post #40

Earlier quoted context omitted.

I think you are missing some documentation http://www.southernstudies.org/images/sitepieces/wing_tmi_ca...

There have been several studies of health effects in the aftermath of the Three Mile Island incident, some (like this one) found effects, some didn’t. But that’s not even that important to the point I was trying to make. The amount of radioactivity released into the atmosphere was very low, in a real disaster (like in Chernobyl) much, much more radioactivity is released – more than any one coal power plant could ever…

Point is that you are comparing effects of relatively unlikely accident with effects of normal operation.

Re: Why I am not worried about Japan’s nuclear reactors

#65

Post by CWuestefeld » Sun, Mar 13, 2011, 4:21 PM UTC

I suppose that my fears for this particular situation are mostly allayed. But I think that's only the tip of the iceberg.

In the face of the world's need for energy, nuclear power is the only viable option that is available today. I wonder how much this incident is going to weigh against using that option?

The power plants in operation today use technology that's quite obsolete. The design of the older plants is an historical accident. Because of the war-driven necessity of developing nuclear technology for weapons, the understanding of the technology that informed the currently-operational reactors was largely bomb-centric. But we know better today, there exists designs for reactors that are orders of magnitude safer, both in terms of operational dangers as well as its waste byproducts.

I'm afraid that sound-byte driven media and activists who aren't willing to evaluate newer ideas will cause such prejudice that newer, better technology will never see the light of day, and thus we'll see worse environmental problems (or economic problems) because our current energy problems can't be fixed otherwise.

Re: Why I am not worried about Japan’s nuclear reactors

#66

Post by waterlesscloud » Sun, Mar 13, 2011, 4:24 PM UTC

ars wrote: post #17

weinzierl wrote: post #6

He says that even in the case of a total meltdown (which hopefully will not happen in Fukushima) we will be save because everything will be contained in the third containment. What I don't get is how cooling is supposed to happen in this case. I think they still would have to pump sea water into the containment which would then get contaminated not only by neutron activation but also with Uranium, Cesium, Iodine etc.…

You filter out the other elements, and release the water. Water pretty much can't get radioactive. (For more than a few minutes.) The longest radioactive oxygen you can make in a reactor has a half life of 26 seconds. For hydrogen, deuterium is not radioactive, and tritium can't be made in a light water reactor. So water effectively can't get radioactive.

And they have these filters right there, handy and ready to use just in case they started pumping in sea water?

Re: Why I am not worried about Japan’s nuclear reactors

#67

Post by eliasmacpherson » Sun, Mar 13, 2011, 4:26 PM UTC

PaulHoule wrote: post #46

Kilimanjaro wrote: post #36

Earlier quoted context omitted.

Earthquake destroys nuclear plant: thousands killed. Tsunami destroys tidal power plant: none killed. You are the PM of Japan, you make the call.

Actually, hydroelectric plant failures can cause 100+ kilodeaths. In terms of prompt fatalities, hydroelectricity is by far the deadliest power source.

Am I right in thinking that your figure is for inland hydroelectric power plants, not Tidal power generators?

Re: Why I am not worried about Japan’s nuclear reactors

#68

Post by hollerith » Sun, Mar 13, 2011, 4:30 PM UTC

weinzierl wrote: post #23

ars wrote: post #17

Earlier quoted context omitted.

You filter out the other elements, and release the water. Water pretty much can't get radioactive. (For more than a few minutes.) The longest radioactive oxygen you can make in a reactor has a half life of 26 seconds. For hydrogen, deuterium is not radioactive, and tritium can't be made in a light water reactor. So water effectively can't get radioactive.

That's why I wrote " get contaminated not only by neutron activation but also with Uranium, Cesium, Iodine ". I doubt that in the current situation there would be the necessary facilities to filter out those elements, but I would be interested in having more information on this.

Well, the OP says there are such facilities. (The contaminated water can be kept in the containment till the facilities have recovered from the earthquake if they are currently down.)

Re: Why I am not worried about Japan’s nuclear reactors

#69

Post by ugh » Sun, Mar 13, 2011, 4:37 PM UTC

dfox wrote: post #64

ugh wrote: post #50

Earlier quoted context omitted.

There have been several studies of health effects in the aftermath of the Three Mile Island incident, some (like this one) found effects, some didn’t. But that’s not even that important to the point I was trying to make. The amount of radioactivity released into the atmosphere was very low, in a real disaster (like in Chernobyl) much, much more radioactivity is released – more than any one coal power plant could ever…

Point is that you are comparing effects of relatively unlikely accident with effects of normal operation.

It looks to me as though one or two Chernobyl sized disasters per century can very much upset that balance.

Deaths obviously still matter but I don't think looking only at radioactivity is good enough. I would very much like to know the deaths per kWh for energy produced from coal and nuclear energy. It is certainly possible that infrequent nuclear disasters are, well, worth it.

(A single airplane crash kills many more people than a single car crash. Airplanes are still much safer than cars since they crash so infrequently compared to cars. Nuclear energy might very well be in a similar position, I honestly don't know.)

Re: Why I am not worried about Japan’s nuclear reactors

#70

Post by samlevine » Sun, Mar 13, 2011, 4:44 PM UTC

miles wrote: post #63

Grateful for the explanation, but the author's bias is questionable at best. He suggests, "If you want to stay informed, please forget the usual media outlets and consult the following websites" and goes on to list 3 nuclear lobbying websites. So, ignore the independent media and get all of your information from pro-nuclear lobbies? More: https://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-w...

>So, ignore the independent media and get all of your information from pro-nuclear lobbies?

The msm usually doesn't have any idea what they're talking about when they report on computer related issues, why do you expect them to be any better when it comes to nuclear power?