Comparing radiation intensity

[wtmusic]

Very difficult with the flood of information to compare how much radiation is being released. This is compounded by the several different units being used, as well as inaccurate information being disseminated by media.

The graph below shows a comparison of radiation intensity. All data is expressed the same units = millirems/hour, with other units below for comparison. In some cases it's based on an extrapolation of estimated yearly exposure. A Japanese government website (http://www.bousai.ne.jp/eng/) shows the current nuke plant measurements, although Fukushima - the important one - is listed as "under survey". It's important to note that the Fukushima measurement below was a maximum reading which quickly declined - but it was a hell of a blast.



Sources:
http://web.mit.edu/newsoffice/1994/safe-0105.html
http://www.hss.energy.gov/csa/analysis/rems/

[jpak]

1. The current dose rate at Onagawa is 21 µSv/hr = 0.021 mSv/hr - off that chart

FYI

[FBaggins]

2. Off THAT chart... but that's a chart well below any real risk. (on edit - NOT off the chart)

21 µSv/hr is right about the in-cab limit for trucks that transport radioactive materials.

On edit - It's actually well below the normal exposure level... and thus no real risk. Though, of course, a reading at that level tens of miles away from the source implies higher levels elsewhere... they would need to be many MANY times higher for real concern... and many MANY times higher than THAT to even warrant mentioning in the same sentence with the devestation in Japan right now.

[jpak]

3. There is no safe dose of ionizing radiation - and Japan's threshold for declaring an emergency is

5 µSv per hour

The longer people are exposed - the greater the risk

yup

[FBaggins]

4. All true.

But also irrelevant.

We're still subject to radiation constantly in our daily lives. The goal may be "NO additional exposure" above background levels (and that "emergency" level is set with that in mind), but the question here is "what level repesents a real danger?"

That "emergency" level would imply that most people who fly long distance deal with emergencies all the time. :)



And you may wish to check your units against that chart again. Is the mesures level really off the chart? I edited my reply for relevance.

[txlibdem]

5. Now it says "under survey"

Radiation levels had been dropping. I wonder if they've leveled off or are still going down.