Although a dose of just 25 rems causes some detectable changes in blood, doses to near 100 rems usually have no immediate harmful effects. Doses above 100 rems cause the first signs of radiation sickness including:
Doses of 300 rems or more cause temporary hair loss, but also more significant internal harm, including damage to nerve cells and the cells that line the digestive tract. Severe loss of white blood cells, which are the body’s main defense against infection, makes radiation victims highly vulnerable to disease. Radiation also reduces production of blood platelets, which aid blood clotting, so victims of radiation sickness are also vulnerable to hemorrhaging. Half of all people exposed to 450 rems die, and doses of 800 rems or more are always fatal. Besides the symptoms mentioned above, these people also suffer from fever and diarrhea. As of yet, there is no effective treatment–so death occurs within two to fourteen days.
In time, for survivors, diseases such as leukemia (cancer of the blood), lung cancer, thyroid cancer, breast cancer, and cancers of other organs can appear due to the radiation received
Nor people are sure about dumping nuclear waste into the sea.
TOKYO – Workers discovered new pools of radioactive water leaking from Japan’s crippled nuclear complex, officials said Monday, as emergency crews struggled to pump out hundreds of tons of contaminated water and bring the plant back under control.
Officials believe the contaminated water has sent radioactivity levels soaring at the coastal complex, and caused more radiation to seep into soil and seawater.
The Fukushima Dai-ichi power plant, 140 miles (220 kilometers) northeast of Tokyo, was crippled March 11 when a tsunami spawned by a powerful earthquake slammed into Japan’s northeastern coast. The huge wave engulfed much of the complex, and destroyed the crucial power systems needed to cool the complex’s nuclear fuel rods.
Since then, three of the complex’s six units are believed to have partially melted down, and emergency crews have struggled with everything from malfunctioning pumps to dangerous spikes in radiation that have forced temporary evacuations.
Confusion at the plant has intensified fears that the nuclear crisis will last weeks, months or years amid alarms over radiation making its way into produce, raw milk and even tap water as far away as Tokyo.
The troubles at the Fukushima complex have eclipsed Pennsylvania‘s 1979 crisis at Three Mile Island, when a partial meltdown raised fears of widespread radiation release, but is still well short of the 1986 Chernobyl disaster, which killed at least 31 people with radiation sickness, raised long-term cancer rates, and spewed radiation for hundreds of miles (kilometers).
The spent fuel rods from a nuclear reactor are the most radioactive of all nuclear wastes. When all the radiation given off by nuclear waste is tallied, the fuel rods give off 99% of it, in spite of having relatively small volume. There is, as of now, no permanent storage site of spent fuel rods. Temporary storage is being used while a permanent site is searched for and prepared.
When the spent fuel rods are removed from the reactor core, they are extremely hot and must be cooled down. Most nuclear power plants have a temporary storage pool next to the reactor. The spent rods are placed in the pool, where they can cool down. The pool is not filled with ordinary water but with boric acid, which helps to absorb some of the radiation given off by the radioactive nuclei inside the spent rods. The spent fuel rods are supposed to stay in the pool for only about 6 months, but, because there is no permanent storage site, they often stay there for years. Many power plants have had to enlarge their pools to make room for more rods. As pools fill, there are major problems. If the rods are placed too close together, the remaining nuclear fuel could go critical, starting a nuclear chain reaction. Thus, the rods must be monitored and it is very important that the pools do not become too crowded. Also, as an additional safety measure, neutron-absorbing materials similar to those used in control rods are placed amongst the fuel rods. Permanent disposal of the spent fuel is becoming more important as the pools become more and more crowded.
Another method of temporary storage is now used because of the overcrowding of pools. This is called dry storage (as opposed to “wet” storage which we outlined above). Basically, this entails taking the waste and putting it in reinforced casks or entombing it in concrete bunkers. This is after the waste has already spent about 5 years cooling in a pool. The casks are also usually located close to the reactor site.
Permanent Fuel Storage/Disposal:
There are many ideas about what to do with nuclear waste. The low-level (not extremely radioactive) waste can often be buried near the surface of the earth. It is not very dangerous and usually will have lost most of its radioactivity in a couple hundred years. The high-level waste, comprised mostly of spent fuel rods, is harder to get rid of. There are still plans for its disposal, however. Some of these include burying the waste under the ocean floor, storing it underground, and shooting it into space. The most promising option so far is burying the waste in the ground. This is called “deep geological disposal”. Because a spent fuel rod contains material that takes thousands of years to become stable (and non-radioactive), it must be contained for a very long time. If it is not contained, it could come in contact with human population centers and wildlife, posing a great danger to them. Therefore, the waste must be sealed up tightly. Also, if the waste is being stored underground, it must be stored in an area where there is little groundwater flowing through. If ground water does flow through a waste storage site, it could erode the containment canisters and carry waste away into the environment. Additionally, a disposal site must be found with little geological activity. We don’t want to put a waste disposal site on top of a fault line, where 1000 years in the future an earthquake will occur, releasing the buried waste into the environment.
The waste will probably be encapsulated in large casks designed to withstand corrosion, impacts, radiation, and temperature extremes. Special casks will also have to be used to transfer fuel rods from their holding pools and dry storage areas next to the reactor to the permanent geological storage site.
Highly radioactive iodine seeping from Japan’s damaged nuclear complex may be making its way into seawater farther north of the plant than previously thought, officials say, adding to radiation concerns as the crisis stretches into a third week.
Mounting problems, including badly miscalculated radiation figures and no place to store dangerously contaminated water, have stymied emergency workers struggling to cool down the overheating plant and avert a disaster with global implications.
The coastal Fukushima Daiichi power plant, 220 kilometres northeast of Tokyo, has been leaking radiation since a magnitude-9.0 quake on March 11 triggered a tsunami that engulfed the complex. The wave knocked out power to the system that cools the dangerously hot nuclear fuel rods.
On Monday, workers resumed the laborious yet urgent task of pumping out the hundreds of tons of radioactive water inside several buildings at the six-unit plant. The water must be removed and safely stored before work can continue to power up the plant’s cooling system, nuclear safety officials said. That process alone could take weeks, experts say.
During a routine test, the plant’s safety systems were turned off to prevent any interruptions of power to the reactor. The reactor was supposed to be powered down to 25 percent of capacity, but this is when the problems began. The reactor’s power fell to less than one percent, and so the power had to be slowly increased to 25 percent. Just a few seconds after facility operators began the test, however, the power surged unexpectedly and the reactor’s emergency shutdown failed. What followed was a full-blown nuclear meltdown.
The reactor’s fuel elements ruptured and there was a violent explosion. The fuel rods melted after reaching a temperature over 3,600 degrees Fahrenheit. The graphite covering the reactor then ignited and burned for over a week, spewing huge amounts of radiation into the environment.
About 200,000 people had to be permanently relocated after the disaster. IAEA reported in 2005 that 56 deaths could be linked directly to the accident. Forty-seven of those were plant workers and nine were children who died of thyroid cancer. The report went on to estimate that up to 4,000 people may die from long-term diseases related to the accident. Those numbers are a subject of debate, however, as the Soviet Union did much to cover up the extent of the damage. The World Health Organization reported the actual number of deaths related to Chernobyl was about 9,000.
Kyshtym, Soviet Union (now Russia)
Sept. 29, 1957
INES Rating: 6
The Soviet Union was also home to the second-most disastrous nuclear accident, at the Mayak Nuclear Power Plant near the city of Kyshtym. IAEA classified the event as a Level 6 Disaster, which is a “serious accident.”
Soviet scientists were frantically trying to catch up to the Americans after World War II when they began construction of the Mayak nuclear facility. Soviet nuclear knowledge had many holes, so it was impossible to know whether some decisions made in the construction were safe. As it turned out, many of those decisions seriously compromised the plant’s facility.
Initially, the plant’s operators simply dumped the nuclear waste into a nearby river, before a storage facility for that waste opened in 1953. The storage facility began to overheat, and a cooler was soon added, but it was poorly constructed.
In September 1957, the cooling system in a tank containing about 70 tons of radioactive waste failed, and the temperature started to rise. This caused a non-nuclear explosion of dried waste. There were no immediate casualties as a result of the explosion, but the IAEA found there had been a significant release of radioactive material into the environment. The radioactive cloud spread out for hundreds of miles to the northeast.
The Soviet government released little information about the accident, but was forced to evacuate 10,000 people in the affected area after reports surfaced of people’s skin literally falling off. The radiation is estimated to have directly caused the deaths of 200 people due to cancer.
Windscale Fire, Great Britain
Oct. 10, 1957
INES Rating: 5
Image credit: Getty Images
Great Britain’s first foray into nuclear energy had been successful for several years before the Windscale fire occurred in 1957. Operators noticed that the reactor’s temperature was steadily rising when it should have been decreasing. They originally suspected the equipment was malfunctioning, so two plant workers went to inspect the reactor. When they reached the reactor, they discovered it was engulfed in flames.
At first, they did not use water, because plant operators were worried the flames were so hot the water would break down instantly, and the hydrogen in the water would cause an explosion. But their other methods to put out the fire did not work, and so they turned on the hoses. The water was able to put the fire out without an explosion.
It is estimated that 200 people in Britain developed cancer because of Windscale, half of them fatal. The exact number of fatalities is hard to come by because the British government attempted to cover up how serious the fire had been. Prime Minister Harold Macmillan worried the incident would embarrass the British government and erode public support for nuclear projects. It’s also difficult to put an exact number on the deaths because radiation from Windscale spread hundreds of miles across northern Europe.
The United States’ most disastrous nuclear accident took place at the Three Mile Island Plant near Harrisburg, Penn., the state’s capitol.
It all began with a simple plumbing break down. A small valve opened to relieve pressure in the reactor, but it malfunctioned and failed to close. This caused cooling water to drain, and the core began to overheat. The machines monitoring conditions inside the nuclear core provided false information, so plant operators shut down the very emergency water that would have cooled the nuclear core and solved the problem. The core began to overheat, and reached 4,300 degrees Fahrenheit. The water nearly reached the fuel rods, which would have caused a full meltdown of the core. But the nuclear plant’s designers were finally able to reach the plant operators several hours later to instruct them to turn the water back on, and conditions stabilized.
“Not only were there issues with training of operators, but management for both the plant and NRC did not know how to approach this kind of emergency and to communicate with the public,” said Burnell.
The NRC determined that no one had died of causes related to the incident at Three Mile Island, but found there might be one excessive cancer death over a 30-year period as a result of radiation. Only one person outside of the nuclear plant was found to have any radiation in his system after the incident.
Three Mile Island had a profound impact on the public’s attitude toward nuclear energy. In the 30 years since Three Mile Island, not a single nuclear power plant has been approved for development.
Sept. 30, 1999
INES Rating: 4
Japan’s most disastrous nuclear accident took place over a decade ago just outside Tokyo.
A batch of highly-enriched uranium was prepared for a nuclear reactor that had not been used in more than three years. The operators had not been trained in how to handle uranium that was so highly enriched. They put far more uranium into the solution in a precipitation tank than is allowed. The tank was not designed for this type of uranium.
Only when the tank was drained of the solution could the critical reaction be stopped, but by then, it was too late for two of the three operators working with the uranium, as they died of radiation.
Less than a hundred workers and people who lived nearby were hospitalized for exposure to radiation, and 161 people who lived within 1,000 feet of the plant were evacuated, according to the World Nuclear Association.
There is No fail safe system that can with stand Nature’s fury.
“will learn from mistakes”
Will you be around if Japan is repeated , more disastrously?
No Carbon Emissions?
People are not dunce.
Shut down Reactors if you want to live.
If you were to save your life as well as others’ do away with Nuclear Power;reduce dependence on power.
People have been living before us with out these paraphernalia.
The most striking claim made by NEI spokesman Mitchell Singer: Americans should be “reassured” by the crisis unfolding in Japan.
“There hasn’t been any significant release of radiation. So obviously they must be doing something right at this point,” said Singer. While acknowledging that the crisis is still in early stages, Singer argued in our interview, and earlier to the Wall Street Journal, that Americans should be reassured because the industry will learn from the accidents in Japan, where fail-safe systems have themselves failed.
“We share what’s known as ‘lessons learned’ from incidents such as this,” he said.
As of midday Sunday, the New York Times reported that partial meltdowns had likely occurred at two reactors after backup cooling systems failed. Concern focused in particular on the Fukushima Daiichi plant in northeast Japan, where an outer containment wall was destroyed in an explosion Saturday. Roughly 150 people have reportedly been exposed to radiation near or inside the plant, though the severity of the exposure is unclear.
On Sunday, every major newspaper in the United States highlighted the nuclear crisis — a PR nightmare for the industry.
The New York Times’ front page led with a banner headline, “Japanese Scramble to Avert Nuclear Meltdowns,” while the Washington Post featured stories variously labeled “Radiation Danger,” “Reactor Emergency,” and “Nuclear Crisis.” Many press reports conclude that the current crisis is the worst since the 1986 Chernobyl disaster in what is now Ukraine, where an explosion spread a cloud of nuclear fallout over large sections of the Soviet Union and eastern Europe…..
In the United States, the political backdrop for the Japanese crisis is a recent bipartisan embrace of nuclear power. President Obama last year announced $8 billion in loan guarantees for a pair of new reactors in Georgia. After more than 30 years of no new reactor construction in America, Singer said that four new reactors — in Georgia, Tennessee, and South Carolina — are expected to be online by 2020. Part of the reason for the three-decade lull was public fear generated by the Three Mile Island accident in Pennsylvania in 1979.
…The industry — along with President Obama — has in recent years trumpeted the fact that nuclear power does not produce carbon emissions that cause climate change. But safety is clearly still a touchy subject for nuclear operators. A special section on NEI’s website assures that “stringent federal regulation, automated, redundant safety systems and the industry’s commitment to comprehensive safety procedures keep nuclear power plants and their communities safe.” The Wall Street Journal today has a tough story concluding that the Japanese experience has cast doubt on the very premise “that engineers can build enough redundancy into plant safety systems to overcome dangers.”
actually performed well so far.
“The Japanese plants have been run very safely and reliably for a very long time. They have operated quite safely,” he said, adding: “Actually, they withstood the earthquake quite well. It’s the tsunami that caused the problems with the backup generators.”
A state of emergency has been declared for three reactors at the Fukushima Daiichi nuclear facility, the same place where an explosion late Saturday injured four people. A meltdown is a catastrophic failure of the reactor core, with a potential for widespread radiation release. Toshihiro Bannai, an official with Japan’s nuclear and industrial safety agency, expressed confidence that efforts to contain the crisis would be successful.
Meanwhile, a second reactor at the same facility failed shortly after 5 a.m. Sunday, the Tokyo Electric Power Company said, according to TV Asahi. The power company said that it was having difficulty cooling the reactor and may need to release radioactive steam in order to relieve pressure.
Radiation levels have risen above the safety limit around Tokyo Electric Power Co’s (TEPCO) nuclear plant hit by a massive earthquake and the company has informed the government of an “emergency situation,” Kyodo agency reported on Sunday.
It did not mean an immediate threat to human health, the company said.
The company said earlier that it had started releasing steam from a reactor at the plant. A similar rise in radiation levels occurred after the company released radioactive steam from another reactor to let go of pressure. Then again the company was obliged to inform the government of an “emergency situation.”
The highest recommended limit for radiation exposures is for astronauts-25,000 millirems per Space Shuttle mission, principally from cosmic rays. This amount is beyond the average 300+ millirems of natural sources of radiation and any medical radiation a person has received.
25,000 millirems per year level was the federal occupational limit during World War II and until about 1950 for radiation workers and soldiers exposed to radiation. The occupational limit became 15,000 millirems per year around 1950. In 1957, the occupational limit was lowered to a maximum of 5,000 millirems per year.
Average Natural Background: 300 Millirems
The average exposure in the United States, from natural sources of radiation (mostly cosmic radiation and radon), is 300 millirems per year at sea level. Radiation exposure is slightly higher at higher elevations-thus the exposure in Denver averages 400 millirems per year.
(A milliRem is 1/1000th of a Rem. According to McGraw-Hill’s Dictionary of Scientific and Technical Terms, a Rem is a unit of ionizing radiation equal to the amount that produces the same damage to humans as one roentgen of high-voltage x-rays. The name is derived from “Roentgen equivalent man.” Wilhelm Roentgen discovered ionizing radiation in 1895 at about the same time that Pierre and Marie Curie discovered radium.)
All of these limits are for the amount of radiation exposure in addition to background radiation and medical radiation.
Adult: 5,000 Millirems
The current federal occupational limit of exposure per year for an adult (the limit for a worker using radiation) is “as low as reasonably achievable; however, not to exceed 5,000 millirems” above the 300+ millirems of natural sources of radiation and any medical radiation. Radiation workers wear badges made of photographic film which indicate the exposure to radiation. Readings typically are taken monthly. A federal advisory committee recommends that the lifetime exposure be limited to a person’s age multiplied by 1,000 millirems (example: for a 65-year-old person, 65,000 millirems).
Minor: 500 Millirems
The maximum permissible exposure for a person under 18 working with radiation is one-tenth the adult limit or not to exceed 500 millirems per year above the 300+ millirems of natural sources, plus medical radiation. This was established in 1957 and reviewed as recently as 1990.
Fetus: 500 Millirems Or 50 Per Month (New Rule Jan. 1, 1994)
New federal regulations went into effect New Year’s Day, establishing for the first time an exposure limit for the embryo or fetus of a pregnant woman exposed to radiation at work. The limit for the gestation period is 500 millirems, with a recommendation that the exposure of a fetus be no more than 50 millirems per month.
Like alcohol intoxication levels, levels of exposure to radioactivity (due to radioactivity deposited in the body) depend on a person’s weight. A diagnostic tracer of one microcurie of radioactive calcium 45, given orally, would result in an exposure of 3.7 millirems for a 100-pound person, and half of that, 1.85 millirems, for a 200-pound person.
Therapeutic radiation treatment that is delivered by administering radioactive material via the mouth or by injection usually results in high, very localized doses to a small part of the body, which absorbs most of the radioactivity. The radioactivity concentrates and remains in the target organ (for example, the thyroid) for a longer period of time than does the radioactivity that is distributed to the rest of the body. The radiation exposure for other parts of the body is a function of the amount of radioactivity per pound and the time the radioactivity is present in the tissue.
In physics, radiation describes a process in which energetic particles or waves travel through a medium or space. There are two distinct types of radiation; ionizingand non-ionizing. The word radiation is commonly used in reference to ionizing radiation only (i.e., having sufficient energy to ionize an atom), but it may also refer to non-ionizing radiation (e.g., radio waves or visible light). The energy radiates (i.e., travels outward in straight lines in all directions) from its source. This geometry naturally leads to a system of measurements and physical units that are equally applicable to all types of radiation. Both ionizing and non-ionizing radiation can be harmful to organisms and can result in changes to the natural environment.Radiation hormesis is the theory that low doses of radiation can be beneficial toorganisms.
Certain body parts are more specifically affected by exposure to different types of radiation sources. Several factors are involved in determining the potential health effects of exposure to radiation. These include:
The size of the dose (amount of energy deposited in the body)
The ability of the radiation to harm human tissue
Which organs are affected
The most important factor is the amount of the dose – the amount of energy actually deposited in your body. The more energy absorbed by cells, the greater the biological damage. Health physicists refer to the amount of energy absorbed by the body as the radiation dose. The absorbed dose, the amount of energy absorbed per gram of body tissue, is usually measured in units called rads. Another unit of radation is the rem, or roentgen equivalent in man. To convert rads to rems, the number of rads is multiplied by a number that reflects the potential for damage caused by a type of radiation. For beta, gamma and X-ray radiation, this number is generally one. For some neutrons, protons, or alpha particles, the number is twenty.
The losing of hair quickly and in clumps occurs with radiation exposure at 200 rems or higher.
Since brain cells do not reproduce, they won’t be damaged directly unless the exposure is 5,000 rems or greater. Like the heart, radiation kills nerve cells and small blood vessels, and can cause seizures and immediate death.
The certain body parts are more specifically affected by exposure to different types of radiation sources. The thyroid gland is susceptible to radioactive iodine. In sufficient amounts, radioactive iodine can destroy all or part of the thyroid. By taking potassium iodide can reduce the effects of exposure.
Possible late effects; possible chromosomal damage.
Temporary reduction in white blood cells.
Mild radiation sickness within a few hours: vomiting, diarrhea, fatigue; reduction in resistance to infection.
Serious radiation sickness effects as in 100-200 rem and hemorrhage; exposure is a Lethal Dose to 10-35% of the population after 30 days (LD 10-35/30).
Serious radiation sickness; also marrow and intestine destruction; LD 50-70/30.