Posted: Mar 16, 2011 3:44 PM by Rob Perillo
I have received a number of phone calls, emails, tweets and Facebook messages this week from concerned viewers about the potential radiation leaks from the earthquake/tsunami crippled nuclear power plants in Northeastern Japan. Fortunately, I do have a background in forecasting radiation and can tell you there should be absolutely no concerns for anywhere in North America including Hawaii.
The current radition releases by steam and any possible future melt down (or downs) will keep all dangerous radiation levels local to Japan and generally less than 50 miles of the plant.
In the mid-1980s I worked at the James A. FitzPatrick Nuclear Power Plant in upstate New York and consulted with Niagara Mohawk's 9-mile Point nuclear facilities, both of which are in Lycoming, New York. I worked as an Emergency Planning Meteorologist which involved computer modeling of potential radiation releases in case of an accident. This was a period that came shortly after the Three Mile Island accident in the late 1970s that prompted much more stringent procedures for developing accident plans for earthquakes and possible terrorist attacks etc at nuclear power generating facilities.
It was my job to take potential radiation release scenarios and incorporate local meteorological conditions and then forecast where any potential radiation would go and how it would disperse. At the time, there was no off-site facility at the power plant, so if radiation was released, it was my job to travel to the plant and forecast where the radiation would go...not at a palatable job scenario!
The bottom line with the dire ongoing situation in Japan, and steam or meltdown related radiation releases, while certainly extremely hazardous and potentially deadly, will likely be confined to less than 50 miles within the plant's radius depending on low level winds and weather. Radioactive iodine and cesium (which generally released in these scenarios) are relatively heavy when compared to that of the properties of air so they "precipitate" out of the atmosphere rather quickly.
Normally any deadly amount will be confined to within 20-30 miles of the point source but could travel a little farther is there is actually a low-level stable atmospheric layer.
In all the scenarios I have ever worked rarely would deadly/hazardous radiation be transported beyond 30 miles beyond the point source...this however, does not mean that radiation could travel further than that.
But the thought that this radiation could get to the upper atmosphere and get carried hundreds of miles is nearly impossible, unless a summer-like thunderstorm could co-locate right over the facility at it's maximum radiation release time...highly unlikely (less than .001% chance). Therefore any concerns outside of Japan is unfounded.
Some of us may remember the atomic bomb tests of the 1950s and 1960s in South Pacific. Those radiation releases did get into the upper atmosphere and got carried by the jet stream as the bomb process itself and the ensuing mushroom clouds certainly brought high radiation levels up to 50,000-60,000 feet. The process of a nuclear melt down at a power plant is very different process and much more localized and considered a "lower atmospheric level" event.
In addition, from the literature I studied at the time, any radiation that may be deposited in the ocean nearby Japan, will likely sink as well, but transport in the ocean theoretically could be a slightly greater distance than atmospheric dispersion.
The localized effect (within 30 miles) of high/deadly radiation amounts in Japan nearby these plants however, cannot be understated.