NUCLEAR WORKER WEAR: A Toronto firefighter wears a self-contained breathing apparatus, similar to gear worn by workers at the Fukushima Daiichi nuclear power plant in Japan.
Image: Wikimedia Commons, Joshua Sherurcij
-
The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
Read More »
Braving explosions and invisible hydrogen fires as well as bursts of radiation at least eight times higher than government hourly safety standards, a cohort of 50 or so workers has returned to the embattled Fukushima Daiichi nuclear power plant in Japan. The workers represent the last line of defense in cooling the overheating reactors and spent fuel pools, such as reactor No. 3, which is still billowing white smoke or steam—a possible indication of a breach in the thick steel and concrete that contains the nuclear core or of water boiling off its spent fuel pool.
Tokyo Electric Power Company (TEPCO) has evacuated all non-essential personnel due to radiation pulses spiking as high as 400 milli-Sieverts per hour—and readings at the border of the power plant site of roughly 6 milli-Sieverts per hour, enough for an individual worker to reach the maximum exposure allowed by standard Japanese regulation for a full year in less than 9 hours. In fact, the Japanese Health Ministry has raised the legal limit on radiation exposure to 250 millisieverts a year—five times that standard level, which is also the legal limit in the U.S.—to enable the 50 or so workers efforts to bring the nuclear power plant back under control. Those workers continue to struggle to cool overheating nuclear reactors by pumping seawater through fire extinguishing system lines—while necessarily exposing themselves to the dangerous radioactive particles released by hydrogen explosions and even a series of fires on the power plant grounds.
"There are basically three strategies for reducing radiation exposure: time, distance and shielding," explains health physicist Peter Caracappa of Rensselaer Polytechnic Institute, who is also the radiation safety officer for that university's research reactor and radioactive materials and equipment. "If you spend less time, you get a smaller dose. The further away you are from the source, the intensity drops off quickly. If there is a shielding material between you and the radiation source, the radiation dose is reduced."
In the case of the workers at Fukushima Daiichi, it is likely only time—if anything—that can be controlled, via limiting the amount of time workers spend working in radioactive areas, which have now likely spread to cover much of the nuclear power plant. Of course, the Japanese operators at the controls of these or any nuclear reactors benefit from the shielding provided by thick concrete construction of the power plant buildings. In addition, operators at the Browns Ferry nuclear power plant in Alabama—which employs a modified version of the same reactors that are at the Fukushima power plant—enjoy a ventilation system with both a filter to keep radioactive particles out and pressurization so that air always flows out rather than in, producing a stiff breeze—a protection that may also be available to the Japanese workers. "If there was a material like smoke or radioactive material, the tendency would be for it to be repelled," says Ray Golden, a spokesman for the Tennessee Valley Authority (TVA), a U.S. government-owned corporation that runs the nuclear power plant.
Nuclear power plant workers in the U.S. and Japan also have access to self-contained breathing apparatus—like scuba gear—that prevents them from inhaling radioactive particles, such as cesium-137 and iodine-131, when working outside the control room and other more secure areas. "You can walk away from an external source," Caracappa says. "Radioactive material deposited in the body you carry around with you, you can't walk away from that."
The skeleton crew of workers flit like ghosts through the nuclear power plant, wearing simple white suits used to keep them from tracking radioactive material beyond certain areas. These suits also have the benefit of partially blocking alpha radiation, essentially helium nuclei released during the breakdown of other, larger radioactive elements.
But it would take cumbersome lead suits or the like to block more energetic radiation, the most familiar of which are known as X-rays and gamma rays. So the TEPCO workers are likely relying on either shielding themselves behind other equipment—though all the equipment involved in power generation at a boiling water reactor like those at Fukushima is radioactive to some extent—or limiting the time spent receiving radiation doses.
Even those TEPCO workers who receive a significant dose of radiation—more than 2 Sieverts, or high enough to cause immediate radiation sickness characterized by skin redness, hair loss, nausea and even burns—could be treated with drugs. But all those still in the nuclear power plant will face at least a slight increase in risk for cancers, according to Caracappa. "It's not simple to quantify," he notes. "The most commonly accepted value for the risk is that the increased risk of cancer is 4 percent per Sievert."
The radioactive material that has escaped from one or more of the reactors will be around for years after the Fukushima Daiichi power plant crisis is resolved. For example, cesium-137 has a half-life of 30 years, meaning it will take three decades for it to lose half its radiation punch. At the same time, however, such radioactive material can be simply washed off before it penetrates the skin or cleaned off surfaces. "It's just stuff, you can wash off dirt or whatever it is," Caracappa continues. "A surface that is contaminated can be cleaned."
Regardless, the TEPCO workers' presence at Fukushima Daiichi nuclear power plant remains critical, as partial meltdowns have cracked as much as 70 percent of the fuel rods in reactor No. 1, according to NHK, the Japanese government broadcaster. And the fuel rods in reactor No. 3 were exposed to the air for hours—causing a build up of steam and hydrogen that raised pressures and may have cracked the massive steel suppression pool designed to cool the radioactive core and trap radioactive materials. Without the workers' efforts, cooling could not continue at the stricken nuclear power plant and a full fuel meltdown would very likely ensue.
As of the end of the day on March 16, according to the Japan Atomic Industrial Forum, fuel rods remain exposed in all three reactors and the workers continue to pump seawater into all of them to prevent any further melting—venting radioactive steam and gases as necessary to ensure that no further cracks develop. And the spent fuel pools at Reactors No. 3 and 4 have lost water, potentially exposing those still hot, nuclear fuel rods—another source of radiation and meltdown risk. "What they're dealing with in Japan is beyond the design," says spokesman Terry Johnson of the TVA, which owns and operates the similar Browns Ferry nuclear power plant in Alabama. "They have to improvise as they go along."
See what we're tweeting about
16 Comments
Add CommentI salute Japanese Bravery! (may the appropriate Kami aid you)
Reply | Report Abuse | Link to thisThe latest news shows that they are fighting a losing battle. Although it may sound very harsh, the best solution right now in my opinion would be to use a small nuclear bomb to push these reactors into the bay near the reactors assuming it could be done with sufficient accuracy.
Reply | Report Abuse | Link to thisAnother idea would be to fit a gantry crane with a high pressure fire hose and a remote camera to direct water onto the spent fuel rods but it is probably too late.
Reply | Report Abuse | Link to thisTheir names and bravery should inspire us all.
Reply | Report Abuse | Link to thisFor the good of the mankind, I am with you Brave Japanese Workers.
Reply | Report Abuse | Link to thisWhile in no way detracting from the bravery of front line people in this crisis, the situation is improving despite the continuing sensationalism in the media. For example, yesterday it was widely reported that the workers had been withdrawn from the site because of dangerous levels of radiation. At no point did it reach a level more than about half the radiation you would receive from a chest ex-ray if you were exposed to it for an hour. This high level dropped back within minutes to about one seventh of the strength of an ex-ray. The MSM largely neglected also to tell us that the men were only withdrawn for one hour. Why are we being fed this BS?
Reply | Report Abuse | Link to thisThis will be hailed as a miracle escape from disaster when it is all over when the alarmists have hugely hyped the danger, serious as it is, from the start.
By the way the highly revered IPCC member believes global warming causes earth quakes. Who on earth can still believe anything they say?
COIMBATORE: Given that human actions are increasingly interfering with the delicate balance of nature, natural disasters such as floods, earthquakes and tsunamis will occur more frequently, said Dr Rajendra K Pachauri, director general of TERI, and the chief of the inter-governmental panel on Climate Change.
http://articles.timesofindia.indiatimes.com/2011-03-14/coimbatore/28687815_1_harmony-green-drive-renewable-energy-sources
When are we going to accept that using nuclear energy as a 'safe', 'clean' and 'economic' alternative was a horrendous idea serving only the nuclear industry cartel? It is obviously and clearly DIRTY, UNSAFE and simply NOT cost-effective. The waste will contaminate our and our future generation's environments for absurd periods of time and its use will blind is into NOT looking for truly safer and economic green-energy alternatives. It's time to stop this insanity. Hopefully we will not have to learn the hard way this was a horribly misguided idea. No engineering design or scientific depth of knowledge is going to compensate for the unpredictability of nature. We have become far too arrogant.
Reply | Report Abuse | Link to thisJapan must start thinking about mass evacuation of the Island, in a matter of a week the majority of food, livestock, water and humans will be over exposed to radiation. The Spent Fuel rods (6000)that have been burning in reactor #4 and the Plutonium leaking in reactors #2 will make Japan uninhabitable for hundreds of thousands of years? The mistakes made by the operators of the Nuclear power plants is a lesson for all to learn, fusion and storage of spent fuel along with Plutonium are currently beyond Humans capacity to manage in a crisis. Waiting to evacuate the population will be another mistake in the long list made in trying to bring the crippled power plants back under control, do not repeat the past, learn from it.
Reply | Report Abuse | Link to thisRon Nussbeck
Offered a flight out of Tokyo today, I turned it down.
Reply | Report Abuse | Link to thisI have more faith in the Fukushima 50 than I do in God.
This does not mean I think they will be able to stop a meltdown for sure, only that they might!
You can live in hysteria if you so choose. When the Japanese say I should leave, I will. We all have to choose who we trust, and I have no doubt about my choice!
In Tokyo, your faith is misplaced, the Spent Fuel rods that are exposed release radiation that is absorbed in humans, plants, animals, water and ground like Potassium. A Potassium a Chemical that makes up the ladder of our DNA, your body will collect it in your cells. The entire Island of Japan will eventually be condemned, certified a dead zone and off limits to humans. When you berate God, when you show your contempt for God, it becomes clear you will be one of the people to meet him sooner than the rest of us. You will be wishing you had left Japan in one week!
Reply | Report Abuse | Link to thiswhy don't they get a bunch of those fire fighting boats like BP used and spray water that way?
Reply | Report Abuse | Link to thisWhere are the robots?Maybe this technology isn't as advanced as we are lead to believe.
Reply | Report Abuse | Link to thisDo you actually believe what your saying...get a grip...
Reply | Report Abuse | Link to thisI must applaud the In-Tokyo person's clarity of reason.
Reply | Report Abuse | Link to thisI agree that living in Japan - specifically the areas around the powerplant - is currently Bad, but Ronnie's religious objection immediately afterwards was most certainly not clearly spoken - I don't understand the mention of Potassium. I gathered from it there is Potassium in our cells, and we may get more of it from radiation.
So? The dangers of Potassium are not clearly delineated in the above statement.
Ronnie, in the ninth comment the person did not "berate God" per se. S/he only said s/he could have more faith in the Fukushima 50 than this abstract Being of questionable existence.
Think rationally - scientifically, even. :)
What GOD is, and only is, is the human ability to understand the social world. Most people develop a sense of what other people know, of why other people did things, and of what other people expect.
Reply | Report Abuse | Link to thisGOD is just people taking their ability to understand the social world and mis-applying it to explain the natural one.
So I am not afraid that GOD will take my life because I am explaining the reason why all cultures have some kind of divine explanation.
You can try to scare me that GOD will "get me" for understanding the truth, but I believe the truth shall set me free from your false torments and threats of impending hell.
If flee we must, I shall. Until then I will do my part to continue as best we can with an eye toward rebuilding. To give up now is just too early to throw the towel someplace which signifies defeat.
Um, I am not sure how good your history is, but this is not Japan's first nuclear incident and there are still people on the island. There are still millions of people living in the Ukraine even thought the incident there was not nearly as well controlled. I think your response is a bit exaggerated.
Reply | Report Abuse | Link to this