Wiki about cosmic particles says vast vast majority are alpha, and you say it's absorbed by the skin.. Furthermore, something tells me the fuselage would have some stopping effect. There's some beta too, but almost no gamma as I understand, so.. What is harmful there? Do the crews keep track of it?

Didn't all of you know that the yellow lines are long pieces of tape that hold the road together?

It's mostly protons, actually.

First off, cosmic rays have vastly greater energies than particles produced through simple radioactive decay. The helium nuclei produced by alpha decay typically have energies in the order of 5 MeV or so. Cosmic ray helium nuclei OTOH can have energies up to the order of TeV...

Anyway. The answer is "various kinds of secondary radiation: mostly neutrons" (at cruising altitude, neutrons make up more than 50% of the equivalent dose^[1]). AFAIK, the neutrons are mostly produced through a process called spallation, when high energy cosmic rays strike nuclei in the atmosphere.

[EDIT]
Kyodo News: All 6 Fukushima reactors reconnected to external power

The official death toll has risen to 10000, with 17000 still missing, and 240000 still living in temporary shelters.

Also, three workers at Fukushima aiming for a Darwin Award have suffered radiation burns.

What I've learned from this is we need to do a better job building nuclear plants.

Oh, there are really so many reasons to trust them, including this:
(Wikipedia:)

Business as usual

There was this interesting report about TEPCO having been hiring unskilled workers for years, firing them after their radiation dose was reached... Unfortunately, I can't find it in English.

At some point, they'll become too expensive...

I forgot to mention: No insurance-company has ever covered nuclear accidents at power plants. I guess they know why, AFAIK they're pretty good at estimating risks.

Question: Why aren't nuclear reactors built underground?

Interesting. I admit I didn't word my claim carefully enough. ^^
At any rate, that's no regular insurance company doing business. It's a construct of/encouraged by the government and it can only exist because it is backed by tax-money. There's no private insurance company which will insure nuclear plants up to a reasonable amount insured.

BTW, risk estimates are roughly at 1 "beyond design basis accident" every 30 years with about 400 reactors in the world. So, it is actually a bit too early.

http://www.theatlantic.com/infocus/2011/03/japan-earthquake-two-weeks-later/100034/

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But what about daylight savings time? And abandoning light bulbs? Clearly a lot is being done to reduce energy consumption.

Just think of the uproar that would ensue if the 10,000 deaths were due to unclear energy instead of a natural cause.