Tuesday, March 15, 2011

Into the Breach

Things took a very bad turn last night in Japan. Unit #2 did breach containment. Levels of radiation that are dangerous local to the plant have been released.

Unit #4, which had been in cold shutdown, suffered what is believed to be a hydrogen explosion. I am reading and hearing reports that the spent fuel pool became uncovered at some point and caught fire here as well - trying to confirm.  That would be extremely bad news.  There are other reports saying that the fuel did not catch fire.  Here's hoping that is the case.

We have gone deep into the wilderness of worst case scenario for this type of plant. I must admit I never would have thought that something like this could have happened in Japan. We are now talking about events that I have only studied in theoretical problems when I was in school.

Radiation Exposure Terms

Here is a quick reference for you regarding the language and terms used to describe radiation dose.

Japan and most of the rest of the world uses a unit called a "sievert" to measure dose to the body.  In the U.S. we use the term "rem."

1 sievert (Sv) = 100 rem (R)

100 millisieverts (mSv) = 10 rem (R) = 10,000 millirem (mR)

Here is a link to a quick calculator to convert the values between rem and sievert.  This might be necessary as reports in the U.S. media may cite units in rem and in international media they will cite dose in terms of sieverts.

NOTE:  The doses that have been provided so far have all be in terms of dose per hour.  This is important.  The rate of absorption drives how long you can work safely in a specified radiation field.  Always try and confirm the rate of the dose being provided in a media account.

Effects of Radiation

In the U.S. a radiation worker is allowed to take 5 rem per year.  Normal members of the public are limited to 100 millirem (mR) per year.  These figures are dose allowed above normal background radiation.

For perspective, in a report out of the NYT this morning, we see that radiation levels of 400 mSv/hr were recorded at the plant.  That is 40 rem/hr.  That can produce measurable and negative effects to health.

Check out this table on Wikipedia for a list of effects of radiation poisoning and the levels it takes to induce them.

Thoughts

At the end of this crisis, the death or sickness toll from the radioactive release will probably be minimal compared to the loss of life from the earthquake and tsunami, but the fear factor involved in radiation will drive a disproportionate response.

The long-term effects should be minimal - with the plant sealed off, the reactors entombed in concrete and lingering radiation low if not normal background.

This disaster is going to have a lot of long term effects around the world.  Remember that energy use drives economies.  I'll hold off on speculating at the moment.  There are other things to worry about.

4 comments:

David said...

As you know, Prechter has forecast that electricity production was apt to decline during the supercycle decline, and this lines up nicely with that.

Turmoil in the oil-producing region combined with what will likely be a 20 year period of excess fear of nuclear power generation seems like fertile soil from which to grow a lot less usable energy.

Karl Denninger has spent a lot of time discussing the connection between economic (living standard) growth and power production. All these threads are part of the same unpleasant tapestry, unfortunately.

Flagg707 said...

Funny you mention that. I was just thinking of a quote I recall from a science fiction author, Heinlein, I think it was, who was probably quoting someone else when he said, "you get steam engines when it comes to steam engine time." I think the point was that societies and economies must be in a place where they can take advantage of and nurture technological and social leaps before they can occur.

Well, it looks like it works in reverse as well. When it comes to shattering optimism time, something comes along to do just that. When it comes to knee-capping the economy time, something comes along for that as well.

And when it comes to Supercycle decline time, well, here we go...

TheEngineer said...

Great post, and great blog. Seems like we have similar interests -- and please see the schematics of the reactor plant here.

We should have a beer when this is over.

But has a breach of the primary piping been confirmed? I agree that it's Not Good, but I haven't seen any reliable reports that there's a hole in the reactor somewhere.

Flagg707 said...

@TheEngineer: Thanks for the comment. I am still basing the thought that contaiment was breached on the pressure drop TEPCO reported in Unit 2 after a big "explosion" - which they theorize was a breach down into the Suppression Pool - but I am not a BWR guy, so I could be wrong, but that pressure drop is bad.

And to let the spent fuel pool become uncovered at Unit 4! Unbelievable. Call the effing US Navy and have them airlift in pallets of diesel fuel, diesel generators and pumps if you have to. Ugh.