Friday, March 11, 2011

Quick lesson in radioactivity

This is a bit out of my area of expertise. I've never had a need to take another 120 hours of specialty training to work at Hanford but some of my cohort have.

The Nuclear Regulatory Commission, the United States Environmental Protection Agency, and other U.S. and international agencies, require that licensees limit radiation exposure to individual members of the public to 1 mSv (100 mrem) per year, and limit occupational radiation exposure to adults working with radioactive material to 50 mSv (5 rem) per year, and 100 mSv (10 rem) in 5 years.

What the hell does all this mean you might be asking? As simply as I can say it works like this. We are being exposed to radiation on a regular basis from what's called background radiation. That can be naturally occurring radiation from radon gases, X-rays from the doctor or dentist and other sources like the burning of coal just to name a few. Fortunately most of these doses are very small in the fractions of an Sv. Radiation used to be measured in rads but that didn't take into account what was being exposed and what possible damage it might be doing to a human body. An Sv is a Sievert is named after Rolf Sievert, a Swedish medical physicist famous for work on radiation dosage measurement and research into the biological effects of radiation. It takes into account what part of the body or combination of body parts are effected. Were the exposures from ingestion, inhalation, or skin contact? Not something you can put your finger on with ease but easily measure with a photo sensitive badge like the type atomic workers are required to wear.

So should we be concerned about the releases in Japan? That will depend on many factors but judging from the distance from here to Japan it's likely that most of the radiation will dissipate before it reaches our shores. Rain would wash it into the ocean which would dilute it further. Remember the Russians were noted for dumping their nuclear waste in the oceans off their coast for years. Not a good thing I know but a fact none the less.

On the matter of nuclear power plants I've always been against them. Not that I'm a purist in terms of environmental issues but even from a economic sense they make no sense. The amount of energy and materials required to build, operate and then dismantle a plant is far more than the amount of energy they can produce in 25 years (their lifespan). There are several such plants that are ticking time bombs operating well beyond their useful lives. Then there's the issue of the waste because no body wants it in their backyard.

An Update on the Fukushima Daiichi plant: Seems the 40 year old plant had some safety violations in the past. 29 violations to be exact. And the president and several of his board members were forced to resign because of this. A few things to consider are that the plant is operating beyond its' life span as I pointed out earlier and that safety inspections were falsified. A nice invitation for disaster. But as we all know money and profits come first even in a global market place.

Update 2: Here's a video from Russia Today of the explosion hope it works.

6 comments:

BBC said...

If a big one hits here it's going to be damn interesting but it sure won't be the mess they have over there.

I'll bet that a few hours before it hit that many of them were fussing that it was boring or there was nothing interesting going on. That can damn sure change in a hurry.

Interesting times....

dana said...

I always felt safe (geographically speaking) in Indiana. Nothing could get me there! The sunshine couldn't get me either. So we're now in Florida, only a very COUNTRY type of Florida. No tourists. "Move along folks. There's nothing to see here."

On the other hand, we're sticking off the bottom of America on a sandbar.

Randal Graves said...

Yeah, yeah, cost, blah blah blah. The real danger comes from the inevitable swarm of radioactive mutants.

The Blog Fodder said...

Doesn't sound like the reactor itself is damaged. The explosion was most likely hydrogen gas build up. The reactors were shut down well before the explosion so it was not a meltdown. Not Chernobyl 2. Yet.

BBC said...

I heard that it was a hydrogen gas build up that blew the building up, the reactors inside them have domes over them.

Oh hell, something is going to get all of us someday anyway, eat dessert first.

Murr Brewster said...

Speaking for myself, I don't want the nuclear waste in anyone's back yard. Remember Mork? When he found out we didn't have "Nuke-B-Gone" and were still building reactors? Shocking.