New York Times: US Navy Helicopter Exposed to Radiation

This almost sounds scary, but I have a feeling that when the details omitted in the article emerge from the Navy it will not be as scary as the New York Times article suggests.

The Pentagon was expected to announce that the aircraft carrier Ronald Reagan, which is sailing in the Pacific, passed through a radioactive cloud from stricken nuclear reactors in Japan, causing crew members on deck to receive a month’s worth of radiation in about an hour, government officials said Sunday.

The officials added that American helicopters flying missions about 60 miles north of the damaged reactors became coated with particulate radiation that had to be washed off.

The key detail missing in all of these stories is the levels of radiation being detected measured in micro sievert (mSv). Instead of using the popular media comparison of average over a year, lets use the example of a CT scan which runs about 2,000 - 2,200 micro sieverts in one use.

As best we have been informed to date, the radiation levels at the Fukushima power plant run about 100 to 1,200 microsieverts per hour, and have peaked around the time of the explosions. While you can read the New York Times article and be alarmed, I actually quoted the safety measure necessary for this radiation exposure from the article - wash it off.

According to various news reports, the maximum level detected so far around the Fukushima plant is 1,557.5 micro sievert logged Sunday. In the open atmosphere, this number would drop considerably due to disipation. We will likely learn details of the Navy exposure and remedy taken, and I do think the Navy will take an abundance of caution, but if the Navy is smart they will also use this opportunity to educate regarding nuclear power - since the Navy is an organization with many thousands of nuclear specialists.

The New York Times article goes on to say this:

The plume issue has arisen before. In 1986, radiation spewing from the Chernobyl disaster in Ukraine was spread around the globe on winds and reached the West Coast in 10 days. It was judged more of a curiosity than a threat.

The comparison to Chernobyl remains popular, but is also good way to identify if someone talking about Fukushima knows what they hell they are talking about. If someone suggests any comparison between the two based on the current data, they are an idiot - not an expert.

Here is how to put Fukushima in the context of Chernobyl. The radiation levels at Chernobyl were of the order of 30,000 roentgens per hour near the plant.

30,000 roentgens is 3,579 sieverts. One million micro sieverts to one sievert. Doing a little quick math, if we are comparing the magnitude of radiation levels coming from 'meltdown' at the Fukushima power plant to the 'meltdown' at Chernobyl we get 1 / 3,579,000

Again, doing the math, a relative comparison suggests Fukushima is 0.00002% of the Chernobyl levels of radiation. These 'meltdowns' have nothing in common, unless you believe .000002% - below the mSv of a CT scan - is a public health threat.

For the record, 7th Fleet is repositioning ships after the contamination detection. This is a wise precaution, because as many have pointed out, it is one thing to trust the Japanese numbers but it is more important to verify them.

Updated:

The New York Times has already followed up with another article on the topic. 17 Navy personnel were exposed to radiation according to the report.

Cmdr. Jeff A. Davis, a spokesman for the American Seventh Fleet in Japan, said the Navy personnel — who apparently had flown through a radioactive plume from a damaged nuclear power plant — had been ordered to dispose of their uniforms and to undergo a decontamination scrub that had successfully removed radioactive particles.

“They received very, very low levels of contamination,” Commander Davis said in a telephone interview from Japan early Monday.

“It certainly is not cause for alarm,” he said. “It is something we have to watch very carefully and make sure we are able to monitor, and to mitigate against this environmental hazard.”

Like I said, the Navy will take an abundance of caution dealing with this issue. You do not discuss nuclear power without also discussing safety. I also note that on the nuclear powered USS Ronald Reagan (CVN 76), the detection systems for radiation are very good.

I once read an article that suggested the US Navy has more nuclear trained engineers than the Department of Energy. I don't know if that is actually true, but I do know that there are probably hundreds of nuclear trained US Navy readers who visit here daily and if I get something wrong regarding nuclear issues - I am going to get a hurricane of email and comments that will highlight my mistakes.