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Why I am not worried about Japan’s nuclear reactors

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

#81

Earlier quoted context omitted.

Interesting also that in the INES pdf on that site, the requirement for INES4 is at least one death from radiation. Perhaps the declaration of INES level four was in error, or the requirement is not strict. Another interesting link just found: http://en.wikipedia.org/wiki/List_of_civilian_nuclear_accide...

There is one confirmed death (a crane operator, but I didn't find any clear cause of death) and several injuries.

As he is already dead, it won't be radiation that killed him. Radiation poisoning needs days to do its ugly work. For the person to die within hours, the containment must have failed to allow sufficient radiation out. Since this has not happened, the person in question hasn't died from radiation.

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

#82

The article is mostly correct, but a few corrections from a nuclear engineer: 1. What he refers to as "moderator rods" are actually control rods. The term "moderator" refers to a material that is unlikely to absorb neutrons, but likely to scatter them. This helps lower the average neutron speed inside the reactor, which actually increases the fission rate. Since water serves this purpose just fine, most reactors do n…

for 4. Tritium is a beta emitter. Wherever it ends up when it decays, the radiation won't get very far.

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

#83

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 h…

> ...nuclear power is the only viable option that is available today...

Nuclear power in itself is unlikely to solve our energy problems. It is only a part of the solution. We will not be able to supply the world with enough energy using nuclear power alone given the length of time it takes to design, approve, build, and certify a nuclear power station.

The Sun is by far our greatest source of energy.

Have a look at http://en.wikipedia.org/wiki/World_energy_resources_and_cons...

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

#84

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.

I would be interested in how tidal generators can cause >100.000 deaths.

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

#85
The light from the Sun that strikes this planet, (the largest fusion based nuclear reactor in the Solar System) produces more energy in one day than all the nuclear, oil, or coal based power plants on the planet.

One has to wonder why governments insist on building poisonous, fragile, radioactive generators on earth, when we can safely harness solar, wind, and wave energies without such horrifying risk.

Will it be the lack of common sense that is cited as the primary downfall of civilization when we are long gone, due to our less than intelligent decisions about energy? Who among us wishes to have children play along the Gulf coast of the United States this summer? Oil illness anyone? Or along the coast of Northern Japan for the next 25,000 years or so...

Does anyone seriously believe that a "shoot for the moon" style campaign like the one we held to create nuclear power plants, would not result in workable alternative energy programs?

One point is certain. Earthquakes WILL continue to happen.

One other point is certain. Nuclear energy is inherently dangerous. You can only minimize the chance of catastrophic failure. Not eliminate it. And once the genie is out of the containment vessel, the penalty last 25,000+ years.

No amount of carefully considered analysis changes the science of this issue. It's time to give alternative energy solutions the same level of serious treatment we have lent to coal and nuclear systems or prepare for a future where meltdowns and frantic efforts to prevent them are more common place.

A future where more than a few locations become permanent exclusion zones for thousands of years. A future for your children where the increased incidence of cancer and mutation is part of every day living.

Or not if we come to our senses and throw every effort into fully developing alternate energy systems. We have a fusion reactor handy just 93 million miles away with billions of years of energy to come. Lets use it.

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

#86
post #79

The article is mostly correct, but a few corrections from a nuclear engineer: 1. What he refers to as "moderator rods" are actually control rods. The term "moderator" refers to a material that is unlikely to absorb neutrons, but likely to scatter them. This helps lower the average neutron speed inside the reactor, which actually increases the fission rate. Since water serves this purpose just fine, most reactors do n…

Would you provide more detail on #4? I'm curious but not quite getting what the consequences of this are.

It means there are isotopes, including tritium, whose half-lives are long enough that they pose a risk to the health of anyone who happens to inhale or ingest them. The OP's dismissal of such risks is a bit facile.

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

#87
post #85

The light from the Sun that strikes this planet, (the largest fusion based nuclear reactor in the Solar System) produces more energy in one day than all the nuclear, oil, or coal based power plants on the planet. One has to wonder why governments insist on building poisonous, fragile, radioactive generators on earth, when we can safely harness solar, wind, and wave energies without such horrifying risk. Will it be th…

Unfortunately good will isn't the strongest driving factor in all this, it's a whole lot of paychecks, and solar energy is still behind.

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

#88

Earlier quoted context omitted.

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.)

As far as the steam is concerned this puts my mind at a rest. Quote from http://allthingsnuclear.org/post/3792741638/containment-at-f... "In this situation, the vented air would be routed through a high-efficiency particulate air (HEPA) filter, charcoal beds, and another HEPA filter to remove as much radioactivity as possible before being released from a very tall stack to dilute the flow as much as possible."

When you say the contaminated water can be kept in the containment, does that mean that they are basically flooding the containment with seawater? My impression was that the there is still a need for cooling (i.e. cool water in, hot water out) in case of a total melt down.

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

#89
post #82

The article is mostly correct, but a few corrections from a nuclear engineer: 1. What he refers to as "moderator rods" are actually control rods. The term "moderator" refers to a material that is unlikely to absorb neutrons, but likely to scatter them. This helps lower the average neutron speed inside the reactor, which actually increases the fission rate. Since water serves this purpose just fine, most reactors do n…

for 4. Tritium is a beta emitter. Wherever it ends up when it decays, the radiation won't get very far.

Still not good when it ends up in your body.

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

#90

Great article. This seems to be a great story in the media because "normal people" are not as pessimistic as engineers, and see an explosion at a nuclear reactor to be something that is extremely bad and that could be ending the world soon. After all, atomic bombs are nuclear, and those are bad, right? But in reality, while not great, failures are accounted for in the design of the reactor, and can be managed. It's s…

" but the environment and the reactor core are still both fine."

How confident are you in that statement?

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