Showing posts with label nuclear energy. Show all posts
Showing posts with label nuclear energy. Show all posts

Friday, January 31, 2014

Nuclear energy still extremely important to Japan

Fukushima is still fresh in heads of many Japanese but this doesn't mean that nuclear energy has started seriously losing popularity in the Land of the rising sun. Nuclear energy plays extremely important role in delivering electricity and Japan currently has 54 operational nuclear reactors with a total generating capacity of 49 gigawatts. According to the Japan's 2010 plan (that still looks likely to be fulfilled) eight more nuclear reactors should be built by 2020, increasing total generating capacity to around 60 gigawatts. Japan currently gets around quarter of its electricity from nuclear power, and by 2020 third of Japan's electricity should come from nuclear power.

In order to contribute to global fight against climate change Japan plans to reduce carbon emissions by 25% by 2020, and many top state officials still believe that one of the key components that could make all the difference between success and failure in reaching this goal is nuclear power. Nuclear power should also improve Japan’s energy independence and energy security. Japan currently heavily relies on foreign fuel import (import of foreign fuels currently satisfies more than 80% of Japan's total energy needs), and therefore intends to significantly reduce this energy dependence to foreign import (to just 30% by 2030).


While nuclear energy certainly has the potential to not only reduce carbon emissions but also to ensure bigger energy independence, it will be very interesting to see what Japanese public will say about these plans. In the last decade there have been several accidents related to nuclear power which have convinced many Japanese that nuclear power may indeed have some serious safety issues. The year 2007 when a magnitude-6.8 earthquake caused a shutdown of the Kashiwazaki-Kariwa nuclear power plant in Niigata after radioactive cooling water leaked into the sea is nothing compared to 2011 Fukushima accident and Japan's nuclear program still may somewhat struggle to get the necessary public support in years to come.

Some of Japan's energy experts even argue that new nuclear power plants cost too much and that they would not be commercially viable, suggesting Japanese government to seek some other clean energy solutions like geothermal and wind energy.

But the Japanese government still doesn’t give up on nuclear power. The government has already begun a review of the safety of 54 nuclear reactors in the country. And in order to further ease the safety concerns government is also planning new nuclear recycling program aimed at solving the nuclear waste disposal issue.

Not only that, last year Japan made energy deal with Kazakhstan, country that holds the world's second-largest uranium reserves and mines about 20% of the world's uranium ore. According to this deal Japan has promised to supply nuclear energy technology to Kazakhstan, and Kazakhstan should in return ensure Japan a stable supply of uranium.

Whether this will be enough to convince Japanese public to accept yet another surge of nuclear power still remains to be seen. 

Sunday, December 8, 2013

Nuclear fuel facts

Uranium is a relatively common element that is found throughout the world. It is mined in a number of countries and must be enriched before it can be used as fuel for a nuclear reactor or in nuclear weapons. Uranium enrichment is process of increasing U-235 isotope concentration from uranium ore which contains only 0.711% of U-235.

Nuclear fuels are widely used: nuclear power plants, nuclear bombs and other weapons, medical applications, nuclear submarines and carriers, space probes and robots, research, ...

There are two major types of currently active reactors: Pressurized water reactors (PWR) and Boiling water reactors (BWR). Those reactors need uranium to be enriched from 3.5% to 5%.

As mentioned, uranium is relatively common element and currently confirmed uranium reserves will last at least 200 years at current rates of consumption according to predictions from Nuclear Energy Agency (NEA).

Another element used in nuclear power plants and weapons is plutonium. Plutonium is very rare element and it is found only in trace quantities in nature so there is no plutonium mining. Plutonium is produced as byproduct in PWR and BWR nuclear reactors. A 1000 MWe light water reactor produces up to 25 tonnes of used fuel per year, containing up to 290 kilograms of plutonium. If the plutonium is extracted from used fuel it can be used as a direct substitute for U-235 (mainly P-239).

Thorium is also element which can be used as nuclear fuel, but currently it is not used in mainstream reactors. A thorium fuel cycle offers several advantages: much greater abundance on Earth, superior physical and nuclear fuel properties, and reduced nuclear waste production. However, it suffers from higher production and processing costs, and lacks significant weaponization potential.

Uranium, plutonium and thorium are nuclear fuels for nuclear fission (splitting atoms). For fusion (joining atoms) number of light elements can be used, but currently deuterium-tritium (D-T) reaction has been identified as the most efficient for fusion devices. Deuterium and tritium are hydrogen isotopes (H-2 and H-3).
Typical uranium mine
Fuel removed from a reactor, after it has reached the end of its useful life, can be reprocessed to produce new fuel. Used fuel typically has around 0.9% of unused U-235 isotope and this can be used in CANDU nuclear power plants. CANDU is short for CANada Deuterium Uranium and those reactors can use natural (0.711% U-235) or low enriched uranium as fuel.  CANDU is also known as Pressurized Heavy Water Reactor (PHWR).

Uranium mining is the process of extraction of uranium ore from the ground. The worldwide production of uranium in 2012 amounted to 58,395 tonnes. Kazakhstan, Canada and Australia are the top three producers and together account for 64% of world uranium production.

According to World Nuclear Association China plans huge expansion in nuclear energy sector. They plan to extend number of nuclear reactors from 17 currently in operation to over 200 reactors in next decades. This new demand for uranium will make huge impact on nuclear fuel markets, possibly increasing electricity price from nuclear power plants.

Little known fact is that space probes Voyager 1, Voyager 2 and some others use nuclear fuel to generate electricity to run instruments. They use plutonium-238 powered batteries in which radioactive decay generates heat needed to generate electricity.  Those batteries are also known as radioisotope thermoelectric generators – RTGs.

The United States stopped producing plutonium-238 in 1988 and since 1993 all of the plutonium-238 used in American spacecraft has been purchased from Russia. Russia is also no longer producing plutonium-238 and their supply is reportedly running low. For new robotic space missions someone will have to restart plutonium-238 production because all other battery types are not even close to replace RTGs.

Used nuclear fuel after all processing is called radioactive/nuclear waste. Radioactive wastes are wastes that contain radioactive material. Radioactive wastes are usually by-products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine. Radioactive waste is hazardous to most forms of life and the environment.

Nuclear bombs use high enriched uranium with more than 90% of U-235. After negotiations between Russia and USA part of nuclear arsenal was dismounted and nuclear fuel has been converted to low enriched uranium and made available for nuclear power plants.

First nuclear bomb used in warfare was uranium based bomb called Little Boy. Little Boy was dropped and exploded over Hiroshima, directly killing 90,000 – 166,000 people. Second (and fortunately last) nuclear bomb used in war was plutonium (6.2 kilograms, 14 lb) based bomb called Fat Man dropped on Nagasaki directly killing 60,000 – 80,000 people. Also a lot died in following months.

Some relevant nuclear fuel data:

Uranium production (2012) - table:
Tonnes Pounds (x1000) %
Kazakhstan 21,317 46,996 36.50%
Canada 8,999 19,839 15.41%
Australia 6,991 15,412 11.97%
Niger (est) 4,667 10,289 7.99%
Namibia 4,495 9,910 7.70%
Russia 2,872 6,332 4.92%
Uzbekistan 2,400 5,291 4.11%
USA 1,596 3,519 2.73%
China (est) 1,500 3,307 2.57%
Malawi 1,101 2,427 1.89%
Ukraine (est) 960 2,116 1.64%
South Africa 465 1,025 0.80%
India (est) 385 849 0.66%
Brazil 231 509 0.40%
Czech Republic 228 503 0.39%
Romania (est) 90 198 0.15%
Germany 50 110 0.09%
Pakistan (est) 45 99 0.08%
France 3 7 0.01%
World total: 58,395 128,739 100.00%

Uranium world reserves (2011) - Table:
Tonnes
Pounds (x1000)
%
Australia
1,661,000 3,661,874 31.18%
Kazakhstan 629,000 1,386,706 11.81%
Russia 487,200 1,074,091 9.15%
Canada 468,700 1,033,305 8.80%
Niger 421,000 928,145 7.90%
South Africa 279,100 615,309 5.24%
Brazil 276,700 610,018 5.19%
Namibia 261,000 575,406 4.90%
USA 207,400 457,238 3.89%
China 166,100 366,187 3.12%
Ukraine 119,600 263,673 2.25%
Uzbekistan 96,200 212,084 1.81%
Mongolia 55,700 122,797 1.05%
Jordan 33,800 74,516 0.63%
Others 164,000 361,558 3.08%
World total:
5,326,500 11,742,908 100.00%

World uranium consumption (2013) - Table:
Tonnes
Pounds (x1000)
%
USA
19622 43,259 30.16%
France 9320 20,547 14.32%
China 6711 14,795 10.31%
Russia 5090 11,222 7.82%
Korea RO (South) 4218 9,299 6.48%
Ukraine 2352 5,185 3.61%
Germany 1889 4,165 2.90%
United Kingdom 1828 4,030 2.81%
Canada 1764 3,889 2.71%
Sweden 1505 3,318 2.31%
Spain 1357 2,992 2.09%
India 1326 2,923 2.04%
Taiwan 1232 2,716 1.89%
Finland 1127 2,485 1.73%
Belgium 1017 2,242 1.56%
Slovakia 675 1,488 1.04%
Czech Republic 574 1,265 0.88%
Switzerland 521 1,149 0.80%
Japan 366 807 0.56%
Hungary 357 787 0.55%
Brazil 321 708 0.49%
Bulgaria 317 699 0.49%
South Africa 305 672 0.47%
Mexico 270 595 0.41%
Argentina 212 467 0.33%
Romania 177 390 0.27%
Iran 172 379 0.26%
Slovenia 137 302 0.21%
Pakistan 117 258 0.18%
Netherlands 103 227 0.16%
Armenia 86 190 0.13%
World total:
65,068 143,450 100.00%

Uranium enrichment levels and uses:

Sunday, December 23, 2012

The outlook for nuclear energy in France

Despite the fact that nuclear energy has lost much of its appeal in the last ten years or so, and especially after the Fukushima accident in Japan, France still gets approximately 77% of its electricity from nuclear energy, which is around 47% of nuclear electricity generated in the entire EU.

France has the very long nuclear energy tradition, and the key event that played the most important role in development of powerful nuclear power industry in France was large global oil crisis in 1973. The volatility of oil price market made French government realize that relying solely on fossil fuels isn't the best long-term option for French economy, and that country will be in need of some other energy source, some that doesn't depend on oil, and this is how nuclear power became one of the main forces of modern French industry.

However, even despite the very powerful nuclear energy sector, France still somewhat depends on foreign oil, and therefore isn't totally immune to global oil price fluctuation. There were these interesting results from one study in 2008 that have pointed out that France consumes more oil than non-nuclear Italy or even the almighty Germany, meaning that nuclear energy hasn't exactly offered total "energy independence" when it comes to relying on foreign oil.

Electricity from the nuclear energy (characterized by low cost of generation, though recently electricity generated from nuclear power plants has been steadily growing in prices) has significantly contributed to the fact that France is today the world's largest net exporter of electricity.
In the end of 2009 France had 59 operating nuclear reactors with total the capacity of over 63 GWe. The recent EU studies say that in the last 20 years France has invested more than $160 billion in development of the domestic nuclear power industry.

In terms of total nuclear power generation France is ranked second behind the United States, though of course U.S. is much bigger in size compared to France. France's share in the world’s nuclear electricity is currently around 16%.

French government isn't relying solely on currently built nuclear power stations and has already started building new modern nuclear power plants, that should not only have better efficiency as compared to older plants but should be also equipped with the most advanced safety programs and measures. Five years ago, in 2007, France started building its first third generation nuclear power plant in Flamanville, Normandy.

Large scale nuclear power industry is the main reason why France has low level of carbon dioxide emissions per capita. For instance United States produces about 17 metric tons of CO2 per capita while France produces about six metric tons of CO2 per capita annually.

France also has advanced programs for treating nuclear waste. Used fuel from French nuclear reactors is sent to Areva NC's La Hague plant in Normandy for reprocessing. Areva NC's La Hague plant has the capacity to reprocess up to 1700 tonnes of used fuel per year.

Sunday, December 16, 2012

Energy history facts

From ancient times people use various energy sources. Geothermal energy were used for springs and heating, hydro and wind energy were used for mills, sailing, water pumps and other mechanical devices, solar energy was used for heating, biomass and coal were used for heating, illumination, cooking, and so on.  For example, nearly 2000 years ago the Greeks used water wheels to grind wheat into flour.

Steam engines were first serious “modern” power source in the world. Steam engines were mostly powered by biomass and coal. The first commercial steam-powered engine device was a water pump, developed in 1698 by Thomas Savery. It used a vacuum to raise water from below, then used steam pressure to raise it higher.

Edwin Drake's 1859 well near Titusville, Pennsylvania, is popularly considered the first modern crude oil well. In the 1840s, the process to distill kerosene from crude oil was invented by James Young in Scotland and the first refinery was built by Ignacy Łukasiewicz, providing a cheaper alternative to whale oil.

The world's first power plant consisted of 24 dynamo electric generators which were driven by a steam engine. It was built by Sigmund Schuckert in the Bavarian town of Ettal (Germany) and went into operation in 1878. Power plant is industrial facility for the generation of electric power.

The first commercial power plant in the United States using three-phase alternating current was at the Mill Creek No. 1 Hydroelectric Plant near Redlands, California, in 1893 designed by Almirian Decker.

In 1878 the world's first hydroelectric power scheme was developed at Cragside in Northumberland, England by William George Armstrong. It was used to power a single arc lamp in his art gallery.

The first major hydro-electric power plants were built by Nikola Tesla and George Westinghouse in 1895 on Niagara Falls (USA). These Power Plants practically started the electrification of the world.

In 1911 the world's first commercial geothermal power plant was built in Larderello, Italy. Experimental generators were built in Beppu, Japan and the Geysers, California, in the 1920s, but Italy was the world's only industrial producer of geothermal electricity until 1958.

Photoelectric effect was first observed 1839 by Edmond Becquerel, a physicist from France. In year 1876 Adams and Day observed the photovoltaic effect in solid selenium.  Modern solar cell was discovered in 1954. The first 1 MWP solar park was built by Arco Solar at Lugo near Hesperia, California at the end of 1982, followed in 1984 by a 5.6 MWP installation in Carrizo Plain.

On June 27, 1954, the USSR's Obninsk Nuclear Power Plant became the world's first nuclear power plant to generate electricity for a power grid, and produced around 5 megawatts of electric power. Obninsk is in today’s Russia.

About 500 B.C. the Chinese discovered the potential of natural gas. Finding places where gas was seeping to the surface, the Chinese formed crude pipelines out of bamboo shoots to transport the gas, where it was used to boil sea water, separating the salt and making it drinkable. Britain was the first country to commercialize the use of natural gas. Around 1785, natural gas produced from coal was used to light houses, as well as streetlights.

Opened on the 26th November 1966, the Rance Tidal Power Station is the world's first tidal power station and also the world's second biggest tidal power station. The facility is located on the estuary of the Rance River, in Brittany, France.

An early application of wave power was a device constructed around 1910 by Bochaux-Praceique to light and power his house at Royan, near Bordeaux in France. In 2008, the first experimental wave farm was opened in Portugal, at the Aguçadoura Wave Park.

Tuesday, April 6, 2010

Nuclear fusion facts

Nuclear fusion is the process by which multiple like-charged atomic nuclei join together to form a heavier nucleus. It is accompanied by the release or absorption of huge amounts of energy. To say it simply, nuclear fusion is process of joining two or more light atoms into one heavier with release or absorption of energy. The fusion of two nuclei with mass lower than iron generally releases energy while the fusion of nuclei heavier than iron absorbs energy.

Fusion is the process by which the Sun, and other stars, creates huge amounts of energy. In first phase star is mostly made of hydrogen. Big temperatures in the center of the star triggers nuclear fusion process in which hydrogen is converted into helium. Once core temperature reaches 130 million Kelvin star begins also nuclear fusion of helium into carbon and oxygen. That is the end for the small Sun like stars, but bigger stars continue to fuse carbon and oxygen into neon. Neon then can be fused into silicon. In final stage of the big star nuclear fusion creates iron from silicon.

All heavy elements in universe originate from big stars because the big bang created only hydrogen, helium, and trace amounts of lithium. Hydrogen, helium, carbon, oxygen, neon and iron are the most common elements in the universe because they are main fuels/products of nuclear fusion on stars, but all other elements are also product of nuclear fusion, but in smaller amount.

Deuterium-Tritium fusion reaction.

The biggest nuclear fusion research project is project ITER - International Thermonuclear Experimental Reactor. Main goal of ITER project is to design and build an experimental fusion reactor in France. ITER's objective is to release ten times as much energy as is used to initiate the reaction: if 50 MW is put in, ITER should generate 500 MW.

Although different isotopes of light elements can be paired to achieve fusion, the Deuterium-Tritium (D-T) reaction has been identified as the most efficient for fusion devices. ITER and the future demonstration power plant DEMO will use this combination of elements to fuel the nuclear fusion reaction. The deuterium fuel is abundant, but tritium must be either bred from lithium or gotten in the operation of the deuterium cycle.

ITER reactor is based on the 'tokamak' concept of magnetic confinement, in which the plasma is contained in a doughnut-shaped vacuum vessel. Mixture of Deuterium and Tritium, two isotopes of Hydrogen - is heated to temperatures in excess of 150 million°C, forming hot plasma. Strong magnetic fields are used to keep the plasma away from the walls.

There is no possibility of a catastrophic accident in a nuclear fusion reactor resulting in major release of radioactivity to the environment or injury to non-staff, unlike modern fission reactors. The primary reason is that nuclear fusion requires precisely controlled conditions of temperature, pressure and magnetic field parameters in order to generate net energy. If the reactor were damaged, these parameters would be disrupted and the heat generation in the reactor would rapidly cease.



Nuclear fusion as a weapon - Tsar Bomb - The biggest bomb ever.
Location - Google Earth View


Nuclear fusion can also be used as a weapon. Such fusion weapons are generally referred to as thermonuclear weapons or more colloquially as hydrogen bombs. In this type of weapon normal nuclear bomb (fission bomb) is used to create huge temperatures to trigger fusion reaction. Unlike fission weapons, there are no inherent limits on the energy released by thermonuclear weapons. Only six countries—United States, Russia, United Kingdom, China, France and India—have conducted thermonuclear weapon tests. Fortunately, this type of weapon has not yet been used in warfare.

Cold fusion refers to nuclear fusion of atoms at conditions close to room temperature, in contrast to the conditions of well-understood fusion reactions such as those inside stars and high energy experiments. Interest in cold fusion was dramatically increased on March 23, 1989 when Martin Fleischmann and Stanley Pons reported that they had produced fusion in a tabletop experiment. By late 1989 mainstream scientists found that the evidence for the discovery of a new nuclear process was not convincing, but some scientists are still convinced that cold fusion is possible.

The first nuclear fusion experiment on earth was carried out in the early 1930’s. The experiment involved deuterium, the isotope of hydrogen with a mass of two. The Deuterium was placed in a particle accelerator and was bombarded with an accelerated beam of deuterium. The colliding of the two atoms caused them to fuse together and release energy. Although energy was released by the experiment, so much energy was required to create the beam of accelerated deuterium that no useful energy was produced.

Sunday, November 22, 2009

How does nuclear power produce energy?

Many people are still not aware that nuclear power is one of the most important energy sources, second after the dominant fossil fuels. In fact a significant amount (nearly 17%) of the electricity produced for the world's energy demand is generated by nuclear power in nuclear power stations. There are even some countries (like for instance France) where the majority of the electricity comes from nuclear energy. Countries mostly decide for nuclear power because nuclear power is basically a low-cost alternative to fossil fuels. And while current reserves of fossil fuels are becoming exhausted, uranium (necessary to create nuclear fission) is still plentiful source.

It is widely known that creating electricity from nuclear energy is not without inherent risks. But, managing those risks is possible and provides an opportunity to leverage a sustainable energy source. Given current safety measures in nuclear power plants across the globe we can be almost 100% positive that new Chernobyl is unlikely to happen again.

So how is the nuclear energy transformed into electricity? Process is known as nuclear fission. A Uranium-235 nucleus is split by a free neutron. When we split nucleus we get 2 new atoms and multiple free neutrons, and heat as the byproduct. The heat is then used to create steam which powers turbines. The turbines then operate generators that produce and help distribute electricity.


Nuclear power plants need to have maximum safety all the time therefore all components need to be at perfect condition because each component does not only play important role in the production of electricity, but it also helps regulate the integrity of the entire process. Each component has its extremely important function and so for instance enriched uranium is collected into bundles that are immersed in water, while control rods are used to normalize the heat of the bundles.

How does turbine in nuclear power stations work? The steam that is generated from the heat in the containment structure is transferred into a turbine. This turbine includes a cooling water condenser that helps normalize the power provided to the generator. The condenser is also connected to a cooling tower that aids the normalization process. Upon receiving power from the turbine, the generator begins spinning to produce electricity.

Many energy experts agree that nuclear power is efficient and environment friendly source of electricity. Nuclear power plants emit significantly less carbon and sulfur than conventional fossil fuels powered plants. However there are also some disadvantages too.

First, using uranium is not a clean process. Mining, purification and nuclear fission produces significant amount of toxic waste. This waste remains toxic for centuries so extreme care must be used in its disposal. Second, nuclear power is not a renewable energy source which means that once the world's supply of uranium is depleted, it cannot be replenished. Third, a poorly-designed nuclear facility (like it was the case with Chernobyl) imposes extreme risk to the environment and the people who live within close proximity to it.

In recent years, there has been increased interest in using nuclear energy to generate electricity, and this is likely to continue in years to come, not only because energy demand keeps on growing but also because nuclear energy with maximum safety on presents one of the best alternatives to dirty fossil fuels. So don't be surprised if world turns out to be much more "nuclear" in years to come.

Monday, March 23, 2009

Nuclear energy has great potential

Recently there are ongoing talks about climate change and global warming problem in which world seeks for an answer how to reduce global greenhouse gas emissions. Many of these answers include full focus to renewable energy sources but some also suggest use of nuclear energy. However there is not only the question of climate change, there is also the question of constantly increasing demand for energy on global scale, and energy use is currently growing at rate of 3% per year so world will very soon have to explore all possible energy options to satisfy ever-growing energy needs. Of course, if current economy crisis becomes long term crisis, then energy needs will not increase – probably energy demand will even drop. In this article we will assume that economy is going to recover soon, and with that energy demands will rise.

One of these options is definitely nuclear energy. Unfortunately, nuclear energy still suffers because of its former sins (Chernobyl, Three Miles Island), and many think of only Chernobyl disaster when thinking about nuclear energy. But truth is completely different, and today with maximum safety measures on, nuclear energy is definitely worth to consider. Nuclear energy sector has learned from mistakes and today we are talking about nuclear power plants with maximum safety, with literally no chance of another Chernobyl disaster. From the ecological point of view nuclear energy is ecologically acceptable energy source, for instance it creates less than 1/100th of the CO2 created by the traditional power plants.

There are two well known processes in producing nuclear energy - fission and fusion. Fission, which is the splitting of nuclei, is highly efficient process that creates more than 10 million times the energy compared to the energy created in the burning of the same amount of fossil fuels. Fusion is the opposite, the process of joining nuclei that happens naturally in stars and the sun; though fusion process has been recreated in laboratories, it is not ready yet for mass energy production. Once this happens the amounts of usable nuclear energy will dramatically increase.

Currently, there are 442 nuclear fission reactors operating in the world, of which almost one third (130) is in the United States. With the current technology, thermal reactors can capture only 1% of the energy available in uranium. This energy makes up between 11% and 18% of the total energy available in the world. Developing technologies that would allow us to capture more of this available energy are still couple of decades away but nonetheless nuclear energy has big potential.

Nuclear fuel cycle. Uranium is mined, enriched and manufactured to nuclear fuel (1) which is delivered to a nuclear power plant. After usage in the power plant the spent fuel is delivered to a reprocessing plant (2) or to final repository (3) for permanent storage in a safe place, such as inside rock. In reprocessing 95% of spent fuel can be recycled to be returned to usage in a power plant (4).

Uranium is the main source of nuclear energy (large uranium deposits are found in Australia). Mining uranium is not too expensive, and the additional advantage of uranium is very easy transport to reactors anywhere in the world. This of course makes nuclear energy relatively inexpensive to produce when not only compared to conventional methods of energy production, but also to some renewable energy sources. Cost of nuclear energy is between 3 and 5 cents per kilowatt hour, and the developing technologies have seen this cost to be dropped over the last 25 years, unlike the cost of other forms of energy that have steadily increased over the same period of time.

With these advantages, and relatively low incidence rates, nuclear energy is definitely one energy source we should be thinking much more in years to come.

Friday, May 2, 2008

Nuclear energy safety report for Congress

Recently I found an interesting document called "Nuclear Power Plants: Vulnerability to Terrorist Attack" which was made for US Congress, which I think you may find interesting:

CRS Report for Congress

Nuclear Power Plants:
Vulnerability to Terrorist Attack

Carl Behrens and Mark Holt
Specialists in Energy Policy
Resources, Science, and Industry Division

Updated February 4, 2005

Summary

Protection of nuclear power plants from land-based assaults, deliberate aircraft crashes, and other terrorist acts has been a heightened national priority since the attacks of September 11, 2001. The Nuclear Regulatory Commission has strengthened its regulations on nuclear reactor security, but critics contend that implementation by the industry has been too slow and that further measures are needed. Several bills to increase nuclear reactor security measures and requirements were introduced after the 9/11 attacks, along with provisions in an omnibus energy bill considered in the 108th Congress (H.R. 6). None of those measures were enacted, but further action on omnibus energy legislation is anticipated in the 109th Congress. This report will be updated as events warrant.

Nuclear power plants have long been recognized as potential targets of terrorist attacks, and critics have long questioned the adequacy of the measures required of nuclear plant operators to defend against such attacks. Following the September 11, 2001, attacks on the Pentagon and the World Trade Center, the Nuclear Regulatory Commission (NRC) began a “top-to-bottom” review of its security requirements. On February 25, 2002, the agency issued “interim compensatory security measures” to deal with the “generalized high-level threat environment” that continued to exist, and on January 7, 2003, it issued regulatory orders that tightened nuclear plant access. On April 29, 2003, NRC issued three orders to restrict security officer work hours, establish new security force training and qualification requirements, and increase the “design basis threat” that nuclear security forces must be able to defeat.

Security Regulations

Under the regulations in place prior to the September 11 attacks, all commercial nuclear power plants licensed by NRC must be protected by a series of physical barriers and a trained security force. The plant sites are divided into three zones: an “ownercontrolled” buffer region, a “protected area,” and a “vital area.” Access to the protected area is restricted to a portion of plant employees and monitored visitors, with stringent access barriers. The vital area is further restricted, with additional barriers and access requirements. The security force must comply with NRC requirements on pre-hiring investigations and training.

Design Basis Threat. The severity of attacks to be prepared for are specified in the form of a “design basis threat” (DBT). One of NRC’s April 2003 regulatory orders changed the DBT to “represent the largest reasonable threat against which a regulated private guard force should be expected to defend under existing law,” according to the NRC announcement. The details of the revised DBT, which took effect October 29, 2004, were not released to the public. Contending that the new DBT still does not adequately represent the credible terrorist threat faced by nuclear power plants, eight state attorneys general urged NRC in January 2005 to open a new rulemaking on the issue.

NRC requires each nuclear power plant to conduct periodic security exercises to test its ability to defend against the design basis threat. In these “force on force” exercises, monitored by NRC, an adversary force from outside the plant attempts to penetrate the plant’s vital area and damage or destroy key safety components. Participants in the tightly controlled exercises carry weapons modified to fire only blanks and laser bursts to simulate bullets, and they wear laser sensors to indicate hits. Other weapons and explosives, as well as destruction or breaching of physical security barriers, may also be simulated. While one squad of the plant’s guard force is participating in a force-on-force exercise, another squad is also on duty to maintain normal plant security. Plant defenders know that a mock attack will take place sometime during a specific period of several hours, but they do not know what the attack scenario will be. Multiple attack scenarios are conducted over several days of exercises.

Full implementation of the force-on-force program coincided with the effective date of the new DBT in late 2004. Standard procedures and other requirements have been developed for using the force-on-force exercises to evaluate plant security and as a basis for taking regulatory enforcement action. Many tradeoffs are necessary to make the exercises as realistic and consistent as possible without endangering participants or regular plant operations and security. Each plant is required to conduct NRC-monitored force-on-force exercises once every three years.

NRC required the nuclear industry to develop and train a “composite adversary force” comprising security officers from many plants to simulate terrorist attacks in the force-on-force exercises. However, in September 2004 testimony, the Government Accountability Office (GAO) criticized the industry’s selection of a security company that guards about half of U.S. nuclear plants, Wackenhut, to also provide the adversary force. In addition to raising “questions about the force’s independence,” GAO noted that Wackenhut had been accused of cheating on previous force-on-force exercises by the Department of Energy.

GAO contended in the same statement that nuclear plants’ implementation of new security plans based on the new DBT was not receiving adequate NRC review — and that deficiencies might not be discovered for three years, after all plants have undergone forceon-force exercises. “NRC cannot yet provide assurances that its efforts will protect nuclear power plants against terrorist attacks as outlined in the new DBT,” the statement said.

Emergency Response. After the 1979 accident at the Three Mile Island nuclear plant near Harrisburg, PA, Congress required that all nuclear power plants be covered by emergency plans. NRC requires that within an approximately 10-mile Emergency Planning Zone (EPZ) around each plant the operator must maintain warning sirens and regularly conduct evacuation exercises monitored by NRC and the Federal Emergency Management Agency (FEMA). In light of the increased possibility of terrorist attacks that, if successful, could result in release of radioactive material, critics have renewed calls for expanding the EPZ to include larger population centers.

Another controversial issue regarding emergency response to a radioactive release from a nuclear power plant is the distribution of iodine pills. A significant component of an accidental or terrorist release from a nuclear reactor would be a radioactive form of iodine, which tends to concentrate in the thyroid gland of persons exposed to it. Taking a pill containing non-radioactive iodine before exposure would prevent absorption of the radioactive iodine. Emergency plans in many states include distribution of iodine pills to the population within the EPZ, which would protect from exposure to radioactive iodine, although giving no protection against other radioactive elements in the release. NRC in 2002 began providing iodine pills to states requesting them for populations within the 10-mile EPZ.

Nuclear Plant Vulnerability

Operating nuclear reactors contain large amounts of radioactive fission products which, if dispersed, could pose a direct radiation hazard, contaminate soil and vegetation, and be ingested by humans and animals. Human exposure at high enough levels can cause both short-term illness and death, and longer-term deaths by cancer and other diseases.

To prevent dispersal of radioactive material, nuclear fuel and its fission products are encased in metal cladding within a steel reactor vessel, which is inside a concrete “containment” structure. Residual heat from the radioactive fission products could melt the fuel-rod cladding even if the reactor were shut down. A major concern in operating a nuclear power plant, in addition to controlling the nuclear reaction, is assuring that the core does not lose its coolant and “melt down” from the heat produced by the radioactive fission products within the fuel rods. Therefore, even if plant operators shut down the reactor as they are supposed to during a terrorist attack, the threat of a radioactive release would not be eliminated.

Commercial reactor containment structures — made of steel-reinforced concrete several feet thick — are designed to prevent dispersal of most of a reactor’s radioactive material in the event of a loss of coolant and meltdown. Without a breach in the containment, and without some source of dispersal energy such as a chemical explosion or fire, the radioactive fission products that escaped from the melting fuel cladding mostly would remain where they were. The two meltdown accidents that have taken place in power reactors, at Three Mile Island in 1979 and at Chernobyl in the Soviet Union in 1986, illustrate this phenomenon. Both resulted from a combination of operator error and design flaws. At Three Mile Island, loss of coolant caused the fuel to melt, but there was no fire or explosion, and the containment prevented the escape of substantial amounts of radioactivity. At Chernobyl, which had no containment, a hydrogen explosion and a fierce graphite fire caused a significant part of the radioactive core to be blown into the atmosphere, where it contaminated large areas of the surrounding countryside and was
detected in smaller amounts literally around the world.

Vulnerability from Air Attack. Nuclear power plants were designed to withstand hurricanes, earthquakes, and other extreme events, but attacks by large airliners loaded with fuel, such as those that crashed into the World Trade Center and Pentagon, were not contemplated when design requirements were determined. A taped interview shown September 10, 2002, on Arab TV station al-Jazeera, which contains a statement that Al Qaeda initially planned to include a nuclear plant in its 2001 attack sites, intensified concern about aircraft crashes.

In light of the possibility that an air attack might penetrate the containment building of a nuclear plant, some interest groups have suggested that such an event could be followed by a meltdown and widespread radiation exposure. Nuclear industry spokespersons have countered by pointing out that relatively small, low-lying nuclear power plants are difficult targets for attack, and have argued that penetration of the containment is unlikely, and that even if such penetration occurred it probably would not reach the reactor vessel. They suggest that a sustained fire, such as that which melted the structures in the World Trade Center buildings, would be impossible unless an attacking plane penetrated the containment completely, including its fuel-bearing wings. Recently completed NRC studies “confirm that the likelihood of both damaging the reactor core and releasing radioactivity that could affect public health and safety is low,” according to NRC Chairman Nils Diaz. However, NRC is considering studies of additional measures to mitigate the effects of an aircraft crash.

Spent Fuel Storage. Radioactive “spent” nuclear fuel — which is removed from the reactor core after it can no longer efficiently sustain a nuclear chain reaction — is stored in pools of water in the reactor building or in dry casks elsewhere on the plant grounds. Because both types of storage are located outside the reactor containment structure, particular concern has been raised about the vulnerability of spent fuel to attack by aircraft or other means.

The primary concern is whether terrorists could breach the thick concrete walls of a spent fuel pool and drain the cooling water, which could cause the spent fuel to overheat and catch fire. Critics of the nuclear industry have pointed to NRC studies that have found such fires possible, although unlikely. NRC contends that critics have overestimated the likely consequences of a spent fuel fire and underestimated the ability of plant operators to cool the spent fuel in a damaged pool.5 Spent fuel stored in dry casks does not rely on water for cooling, but concerns have been raised that terrorists could attempt to breach the casks and release radioactive material into the air. Spent fuel pools and dry cask storage facilities are subject to NRC security requirements.

Regulatory and Legislative Proposals

Critics of NRC’s security measures have demanded both short-term regulatory changes and legislative reforms.

A fundamental concern was the nature of the DBT, which critics contended should be increased to include a number of separate, coordinated attacks. Critics also contended that nearly half of the plants tested in NRC-monitored mock attacks before 9/11 failed to repel even the small forces specified in the original DBT, a charge that industry sources vigorously denied. Critics also pointed out that licensees are required to employ only a minimum of five security personnel on duty per plant, which they argue is not enough for the job.6 Nuclear spokespersons responded that the actual security force for the nation’s 65 nuclear plant sites numbers more than 5,000, an average of about 75 per site (covering multiple shifts). Nuclear plant security forces are also supposed to be aided by local law enforcement officers if an attack occurs.

In February 2002, NRC implemented what it called “interim compensatory security measures,” including requirements for increased patrols, augmented security forces and capabilities, additional security posts, installation of additional physical barriers, vehicle checks at greater stand-off distances, enhanced coordination with law enforcement and military authorities, and more restrictive site access controls for all personnel. The further orders issued April 29, 2003, expanded on the earlier measures, including revising the DBT, which critics continue to describe as inadequate.

Because of the growing emphasis on security, NRC established the Office of Nuclear Security and Incident Response on April 7, 2002. The office centralizes security oversight of all NRC-regulated facilities, coordinates with law enforcement and intelligence agencies, and handles emergency planning activities. Force-on-force exercises are an example of the office’s responsibilities. On June 17, 2003, NRC established the position of Deputy Executive Director for Homeland Protection and Preparedness, whose purview includes the Office of Nuclear Security and Incident Response.

Legislation. After the 9/11 attacks, several bills were introduced dealing with security in nuclear power plants in the 107th Congress, although none became law. H.R. 3382, introduced by Representative Markey, would have created a federal force within the NRC to replace the private guards at nuclear power plants. The bill also would have required emergency planning exercises within a 50-mile radius around each nuclear plant and stockpiling of iodine pills for populations within 200 miles of nuclear plants. Senator Reid’s Nuclear Security Act (S. 1746) as originally introduced contained many provisions similar to those in H.R. 3382. However, Senator Reid later introduced a substitute version of the bill, which was approved by the Senate Environment and Public Works Committee on July 25, 2002 (S.Rept. 107-335). The substitute bill would have appointed a task force to review security at U.S. nuclear power plants, required the President to establish a federal team to coordinate protection of air, water, and ground access to nuclear power plants, and would have given statutory authority to NRC’s Office of Nuclear Security and Incident Response. The reported bill also included NRC proposals to authorize guards at NRC-regulated facilities to carry and use a variety of firearms despite restrictions in some states.

In the 108th Congress, Senator Reid introduced the Nuclear Security Act of 2003 (S. 131) containing measures similar to the version of S. 1746 reported out of committee in the previous Congress, including the authorization for employees of NRC licensees to carry weapons. Senator Daschle included similar provisions in his Comprehensive Homeland Security Act of 2003 (S. 6). The authorization for NRC licensees to carry weapons is included in the energy omnibus bill (H.R. 6) reported out of conference and approved by the House in November 2003 (Title VI, Subtitle D). Subtitle D would also require a presidential report on nuclear facility threats, force-on-force exercises, training of National Guard and law enforcement personnel in responding to nuclear plant security threats, and fingerprinting of nuclear plant employees. The H.R. 6 conference report was blocked by a Senate filibuster.

On May 15, 2003, the Senate Environment and Public Works Committee reported out an amended version of the Nuclear Infrastructure Security Act of 2003, S. 1043, but the measure did not see floor action. As reported, the bill would have required NRC to revise the DBT through a formal rulemaking procedure, which would allow public comment on the proposed revision. In updating the DBT on April 29, 2003, NRC did not release details of the new requirements or comment on the process by which it reached its decision.

The 109th Congress is expected to continue working on omnibus energy legislation, which could include nuclear security provisions similar to previous proposals.

Wednesday, March 26, 2008

Nuclear energy - Use in some countries

Nuclear energy is definitely one of the best solutions for growing energy needs of the modern world. Nuclear energy is much more abundant energy source than fossil fuels (coal, oil and natural gas) and unlike them presents clean and safe method to produce electricity. Yes nuclear energy is safe energy source and new Chernobyl is almost impossible to happen again considering the safety measures in modern nuclear power plants. Chernobyl happened due to some really bad mistakes (bad reactor design and inexperienced crew) and the majority of experts believe Chernobyl is one time only accident.

Safety of nuclear reactors significantly increased with third generation and forth generation is expected to have even more enhanced safety. Click on picture for full size.

Nuclear energy is also clean energy source from the ecological point of view because it emits no harmful greenhouse gases into the atmosphere. The only real problem regarding nuclear energy is the nuclear waste although as some experts say this problem is less significant than for instance of waste that is produced by coal, or the by the silt that builds up behind dams.

Nuclear power plants' safety especially increased thanks to third generation reactors which have significantly reduced the possibility of a core meltdown accident and soon fourth generation will be also making its entrance, ensuring even higher security levels. Nuclear energy is ecologically even more acceptable than hydropower because hydroelectric dams have negative impact on nearby ecosystems they alter.

Nuclear power is used in many countries of the modern world and France here convincingly leads the way with 77 % of its electricity generated in nuclear power plants. More than 30 countries in the world use nuclear power plants for generating necessary electricity and lots of nuclear power plants is being built, especially in Asia where countries like China and India are under the constant need of new energy sources because of large demands of their sudden economic growth and nuclear energy is one of the best, if not the best solution to satisfy increasing energy needs. Just for example, one pound of uranium produces 20,000 times more energy than one pound of coal which means that nuclear energy is also very competitive energy source despite the fact that nuclear power plants have high initial building costs because operational costs are relatively inexpensive.

This picture clearly shows dominant number of nuclear power plants in France. France gets 77% of its electricity from nuclear power plants. Click on picture for full size.

Nuclear energy could be also the right solution for poor countries and their economic growth, of course with the slight push of rich countries in the form of financial aid and necessary technology. Of course, maximum safety measures must be always on in nuclear power plants and therefore experienced and well trained crew is much needed which could be the only real problem in these countries considering their general economic infrastructure and conditions they live in.

Sunday, March 23, 2008

ITER project - The only real problem is time

ITER is joint international research/engineering project that has its goal to provide future electricity from fusion power. Fusion reaction releases energy when two light atomic nuclei fuse together forming heavier nucleus and this released energy could well be main future energy source. ITER's main goal is to harness nuclear fusion as the future energy source and if all goes well this project should be enough to satisfy future energy needs. ITER research team includes scientists from all over the world as they try to build first electricity-producing plant that would use nuclear fusion to generate electricity.

Countries participating in ITER project. Click on picture for full size.

ITER construction costs are very high (around 10 billion Euros) but are relatively small compared to potential this project carries. Countries involved in ITER project are European Union (represented by EURATOM), Japan, People’s Republic of China, India, Republic of Korea, Russian Federation and USA, all big time players on energy market.

ITER is a tokamak, in which strong magnetic fields confine torus-shaped fusion plasma. The device’s main aim is to demonstrate prolonged fusion power production in deuterium-tritium plasma. ITER should also produce more power than it consumes because most of the plasma heating comes from the fusion reactions themselves resulting in a reduced need for outside heating source. ITER should be capable in providing test technologies and other processes needed for future fusion power plants - including superconducting magnets, components able to withstand high heat loads, and remote handling.

Big day for ITER project was 21st November 2006 when ITER agreement was officially signed when ministers from the seven Parties of the international nuclear fusion project ITER sign the agreement to establish the international Organization that will implement the ITER fusion energy project. It's true that success of this project could stop dependence on fossil fuels and their harmful environmental effect if and when ITER becomes economically viable and since fossil fuels emit greenhouse gases this could really be a turning point in fight against global warming.

However there are some opponents of ITER project saying that nuclear fusion has the same problems as nuclear power (nuclear waste, possible nuclear accident and danger of terrorism) and that we should really turn our sight and funds to renewable energy sources that are safe to use and are already available and not needed to wait for, like ITER project is. This all looks to be true, especially the last part about focusing on renewable energy, especially since climate is changing rapidly and renewable energy is really all we have to fight global warming at this moment, and focusing on ITER is really putting billions of dollars toward a project that could show its worth in only 30-50 years.

Can we wait that much, or to put it even better, can Earth wait that much to something that indeed has a great potential but is not 100 % sure to be economically viable nor fully functional? These reasons despite great potential of ITER project really deserve more attention from ITER involving countries as we may not have enough time to invest huge funds in something that could show its full potential after couple of decades.

Cutaway of the ITER Tokamak. Click on picture for full size.

Time is the biggest reason why ITER doesn't deserve full focus because time isn't currently on our side and main focus (funds) should be set to renewable energy sector where there's already enough knowledge to start fight against global warming and where we could start immediate action.

All other reasons concerning the same problems as the ones of nuclear power are really secondary problems because ITER has much safer working principles than nuclear power stations (and even new nuclear power stations have proven to be very safe with maximum safety measures on). Of course there will be always potential danger as soon word "nuclear" is mentioned but benefits of ITER (if it comes true and current progress is positive) should more than exceed these negative sides. But as mentioned before, ITER needs time and this is ITER's main flaw because humanity needs immediate action before it's really too late. Of course ITER is great project with tremendous potential, but it shouldn't be getting all the attention and the funds that follow; it should really be a second hand project, just behind renewable energy projects which really need our full attention, not in 30-50 years, but right now.

Monday, May 30, 2005

Alternative energy sources - Nuclear energy

Nuclear power creates energy once its atomic structure changes. All the nuclear power plants in operation today are based solely on fission, process where radioactive decay gets accelerated in a controlled chain reaction that splits an atom into two or more byproducts, including energy as one of these byproducts. Nuclear energy has enormous potential but there are also some disadvantages that worry people like the safety of nuclear power stations as well as the problem of nuclear waste. While the question of safety is really no longer such burning issue because of maximum safety measures present under current nuclear power stations that can guarantee that there won't be another Chernobyl, problem of radioactive waste still remains, and this is the question that still hasn't been answered on. Irregular use of nuclear energy can present big environmental threat and this is why many people around the world are so reluctant about future nuclear energy projects.



Alternative energy overview:
     1. Introduction
     2. Solar power
     3. Wind power
     4. Biomass/Biofuel
     5. Nuclear energy
     6. Ocean and Earth Power
     7. Conclusion