FAQ on radioactivity and nuclear technology

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===How much nuclear waste is produced?===
 
===How much nuclear waste is produced?===
A large, one-gigawatt nuclear reactor will generate 200-350 m<sup>3</sup> of low- and intermediate-level [[nuclear waste]] and 27 tons (20 m<sup>3</sup>) of spent fuel each year, which will take up 75 m<sup>3</sup> if put into disposal containers without further processing. If the fuel is reprocessed, the end product will be 3 m<sup>3</sup> of fission products immobilized in glass, which will take up 28 m<sup>3</sup> after putting it in disposal containers. A coal power plant of the same power will produce 400,000 tons of fly ash in the same period.<ref>[http://www.world-nuclear.org/info/inf04.html World Nuclear Association: Radioactive Waste Management]</ref>
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A large, one-gigawatt nuclear reactor will generate 200-350 m<sup>3</sup> of low- and intermediate-level [[nuclear waste]] and 27 tons (20 m<sup>3</sup>) of high-level waste (spent fuel) each year, which will take up 75 m<sup>3</sup> if put into disposal containers without further processing. If the fuel is reprocessed, the end product will be 3 m<sup>3</sup> of fission products immobilized in glass, which will take up 28 m<sup>3</sup> after putting it in disposal containers. A coal power plant of the same power will produce 400,000 tons of fly ash in the same period.<ref>[http://www.world-nuclear.org/info/inf04.html World Nuclear Association: Radioactive Waste Management]</ref>
  
 
If you used only nuclear electricity all your life, your share of high-level waste would have the volume of a wine bottle. If it was reprocessed, it would have the volume of a coffee cup.<ref>This result was originally computed for Poland and rounded up to a recognizable household quantity. You can do your own math based on the data above, the population of your country and its electricity consumption.</ref> This compares rather favorably with statistics on ordinary waste in Britain, where 517 kg of municipal waste and 83 kg of hazardous waste per person is produced every year.<ref>[http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_170.shtml David MacKay: Sustainable energy – without hot air, page 170]</ref>
 
If you used only nuclear electricity all your life, your share of high-level waste would have the volume of a wine bottle. If it was reprocessed, it would have the volume of a coffee cup.<ref>This result was originally computed for Poland and rounded up to a recognizable household quantity. You can do your own math based on the data above, the population of your country and its electricity consumption.</ref> This compares rather favorably with statistics on ordinary waste in Britain, where 517 kg of municipal waste and 83 kg of hazardous waste per person is produced every year.<ref>[http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_170.shtml David MacKay: Sustainable energy – without hot air, page 170]</ref>

Revision as of 02:03, 28 July 2012

Contents

Radioactivity

What is radioactivity?

Radioactivity is the instability of certain kinds of atomic nuclei. Over time, these nuclei will disintegrate, emitting heat, highly energetic particles known as ionizing radiation and forming other nuclei known as decay products. This process is called radioactive decay. Different kinds of atomic nucleus (nuclides, also slightly incorrectly called isotopes) have different rates of decay. These rates cannot be influenced in any way.[1]

Is radioactivity natural?

Yes. Radium is a naturally occurring, intensely radioactive element. Uranium that fuels nuclear power plants is also mined from natural deposits. There are many sources of background radiation; among them, natural sources are responsible for a large majority of the dose. The man-made portion is dominated by medical exposures.[2]

Nuclear reactors are also found in nature. The Sun generates its energy from fusion, so it is a natural fusion reactor. In 1972, the remnants of a natural fission reactor were found in a deposit of uranium ore in Oklo, Gabon.[3]

Note that considering natural things "good" and artificial things "bad" without any other evidence is generally wrong and known as the naturalistic fallacy.

What kinds of radiation are there?

There are four basic kinds:

  • Alpha radiation consists of helium-4 nuclei. It is emitted in the radioactive decay of the heaviest elements, such as uranium or thorium. It is highly damaging to living organisms, but has very short range and cannot penetrate the skin. This means it is only dangerous when an alpha-radioactive substance is eaten or inhaled.
  • Beta radiation consists of electrons. It is emitted from nuclides which have too many neutrons, such as strontium-90. It travels a few meters in the air and cannot penetrate the skin or thin metal shields. High energy beta radiation will emit secondary gamma radiation when it strikes an object.
  • Gamma radiation consists of very high energy photons. It is emitted from nuclei which just underwent decay and are in an excited state. Gamma radiation is the most penetrating. It can travel many meters in the air and is only stopped by thick shielding. (A few meters of water is enough.)
  • Neutron radiation consists of neutrons, the neutral particles making up the nuclei of atoms. It is emitted as a result of several nuclear reactions, most importantly fission.

Do things subjected to radiation become radioactive?

Generally - no. When an object is irradiated with alpha, beta or gamma radiation, there are some chemical changes, but it does not become radioactive. In this respect, radiation is a lot like visible light: no matter how long you will keep an apple in bright light, it won't start glowing in the dark. Many people are afraid of food irradiation because they do not understand this simple concept.

The exception to the above rule is neutron radiation, found mainly inside working reactors, which can activate most substances (make them radioactive). This is in fact very useful, because the activated substances can be detected and their content can be measured without destroying the sample. Many research reactors exist for the sole purpose of making various things radioactive.

Other types of particles can also induce radioactivity. However, typically they can only do so at energies obtained in particle accelerators.

Why are nuclear workers tested for radiation?

They are not tested for irradiation, but for contamination - whether they have radioactive substances on their skin or clothes. Contamination does not indicate that new radioactivity is created, but that some of it is misplaced. When somebody tests positive, they must wash thoroughly and change their clothes.

In more familiar terms, the difference between irradiation and contamination is like the difference between smelling cow dung and having it on your shoes. When you are being irradiated (smelling dung), the harm ceases when you leave the high radiation area (move away from the cow pie). When you are contaminated (dirty with dung), you will receive more and more radiation from the decaying radioactive substances until you wash them off (clean your shoes).

Do radioactive things glow in the dark?

Only if they are highly radioactive, with certain kinds of radiation. Most radioactive objects, even at dangerous levels, do not glow at all, unless mixed with a phosphor that will convert the nuclear radiation into visible light.[4] The light emitting substance in some watch dials is actually a non-radioactive phosphor excited by a small amount of radioactive material (nowadays tritium, but radium was used in the past) to emit light.

Another circumstance when highly radioactive objects can glow is when they are submerged in water, when Cherenkov radiation - arising from particles traveling faster than the speed of light in water - will appear as a blue light. This is most often seen in photos of spent fuel pools and research reactors.

What is nuclear fission?

Illustration of nuclear fission.

Nuclear fission is the disintegration of certain atomic nuclei when hit with a neutron. After absorbing the neutron, these nuclei become highly unstable and shatter into pieces, releasing a large amount of thermal energy and more neutrons along the way. Because this process requires neutrons, its rate can be controlled, as opposed to radioactive decay.

Nuclides which can undergo fission are called fissile.

What is a chain reaction?

Illustration of a chain fission reaction.

Each event of nuclear fission generates more than one secondary neutron. When enough fissile material is concentrated in one place, the neutrons created in the first fission reaction will strike other fissile nuclei, causing further fissions releasing more neutrons and so on. In this way, a substantial amount of the material can be fissioned to release a tremendous amount of heat.

Relevant video illustrating the concept.

When a nuclear chain reaction is engineered to consume a lot of fissile material in a very short time, it results in an extremely powerful explosion. This fact can be exploited to construct nuclear bombs. When the reaction is engineered to be self-limiting, a slowly fissioning block of fissile material can be used as an abundant source of heat, which can then be converted to electricity. This is known as nuclear power.

What is nuclear fusion?

Nuclear fusion is the synthesis of heavier elements from lighter ones, accompanied by a release of heat and energetic particles. This process is the energy source of all bright stars. In the Sun, the energy comes from fusion of hydrogen into helium. Fusion requires extreme temperatures and pressures, and as such is not expected to be a practical energy source on Earth for several decades. However, such conditions can easily be generated during a fission-based nuclear explosion. This fact can be (and has been) exploited to build more powerful nuclear bombs.

What are the units for measuring radiation?

There are three basic units:

  • The becquerel (Bq) is a measure of activity, or the frequency of disintegrations in a given sample. 1 Bq is equal to 1 disintegration per second. It is an extremely small unit, often used with SI prefixes. Human body normally has a specific activity of 100 Bq/kg, which translates to 7000 Bq total activity for an average adult human. Activity only specifies, in an indirect way, the amount of radioactive substance. It says little about its health or environmental impact.
  • The gray (Gy) is a measure of absorbed dose, equivalent to J/kg. It specifies how much energy per unit mass was absorbed by a given object, organism or tissue. This quantity is directly measurable. Grays are used in areas of nuclear technology which do not involve living things, and also sometimes in radiation biology research.
  • The sievert (Sv) is a measure of the biological effect of the dose, called the equivalent dose.[wp] The equivalent dose cannot be measured directly. Its precise value is computed in a fairly complex way from the absorbed dose, with various weights depending on the irradiated organs, the age of the person, the type of radiation, its energy, etc. However, in many situations this calculation can be greatly simplified. For gamma and beta radiation received by adults uniformly over the whole body, the absorbed dose in Gy is equal to the dose equivalent in Sv.

When a radioactive nuclide is eaten or inhaled, the biological effect can be computed by multiplying the activity of the ingested sample by the dose coefficient of that nuclide, usually given in Sv/Bq. These coefficients are available from radiation protection authorities.

It is worth clearing up one misconception: when a dose is given for a particular group, e.g. infants, the radiosensitivity of that group is already taken into account. A baby receiving 100 mSv will experience the same effects as an adult receiving 100 mSv. Of course these two dose equivalents do not correspond to the same absorbed dose in grays.

Additional units include:

  • The rad and rem are obsolete units still used in the U.S. 1 gray is equal to 100 rad and 1 sievert is equal to 100 rem.
  • The roentgen is a measure of air ionization equal to 2.58×10−4 C/kg. It is used on some old dosimeters. For common energies of X-ray and gamma radiation, a radiation field causing 1 roentgen of ionization in air will deposit roughly one rad (0.96 rads to be exact) into soft tissue, which is in turn roughly equivalent to 1 rem for whole body irradiation. In other words, 1 R/h ≈ 0.01 Sv/h = 10 mSv/h.

What are the possible effects of radiation exposure?

There are three types of possible effects.

Deterministic effects always happen when a particular threshold dose is exceeded, increase in severity for higher doses, and are absent for lower doses. Deterministic effects start above 250 mSv - a very high dose which is only experienced by radiation therapy patients, and may be experienced by some emergency response workers during a nuclear accident. Below is a table of acute whole body doses (delivered in a short time to the entire body) and the deterministic effects they cause.

Dose Deterministic effect
below 250 mSv No effect
250 mSv Lowered blood cell count
1000 mSv Mild radiation poisoning: low white blood cell count, fatigue, weakness
2000 mSv Moderate radiation poisoning: vomiting, diarrhea, headache, fever
3000 mSv Loss of hair
3000 mSv 50% chance of death from radiation poisoning (without medical care)
6000 mSv Heavy radiation poisoning: vomiting, diarrhea, high fever, dizziness, hypotension, death very likely
8000 mSv Certain death, rapid incapacitation
30000 mSv Certain death in 48 hours
500-2000 mSv to lens Clouding of eye lens
5000 mSv to lens Cataract
2500-6000 mSv to ovary Permanent infertility
3500-6000 mSv to testicles Permanent infertility

Stochastic effects happen with some probability dependent on the dose you absorb. They can only be attributed to radiation by investigated groups of people with similar exposures. The most important stochastic effect is cancer. The risk of dying from radiation-induced cancer is 5.5% per sievert, or 0.5% per 100 mSv. It is uncertain whether this relationship is strictly linear for low doses (below 100 mSv); see Linear no-threshold.

Psychological effects arise from the fear of radiation and evacuations following a radioactive release. These might include post-traumatic stress disorder, depression, alcoholism, circulatory problems, irresponsible sexual behavior and suicide. In past nuclear accidents such as Chernobyl, these effects were many times worse than either the deterministic or stochastic effects. They would also be the most important after the detonation of a dirty bomb. These effects are highly variable depending on the person's level of fear. There is a case to be made that the most harmful effects of nuclear accidents are caused by the scaremongering of the anti-nuclear movement.

What are the limits for radiation exposure?

The internationally recognized limits for exposures caused by nuclear installations are:

  • 1 mSv/year for members of the public
  • 20 mSv/year for nuclear workers
  • 250 mSv for emergency response

There are no limits for medical exposures or natural radiation.

Does radiation create mutants?

As detailed above, when increasing the dose of radiation, an organism will first experience no apparent ill effects, then exhibit stunted growth and generally deteriorating health, and finally die. If it survives, it will have a higher risk of developing cancer, it might be sterile or its offspring might show an increased rate of birth defects. Note that increased birth defects were not found in either the Hiroshima survivors or Chernobyl survivors. The irradiated organism will never undergo any dramatic changes in appearance, because the defects in DNA created by irradiation are completely random and not identical in all the cells. Stereotypical mutations, such as grotesquely increased size, extra limbs, superior strength or a green glow, are nothing more than a fantasy.

High doses of radiation induce random mutations in reproductive cells, which is used to create new useful mutants in plant breeding.[5]

Nuclear power

How does a nuclear reactor work?

Several tons of uranium oxide are fashioned into fuel bundles and placed inside a large steel tank (the pressure vessel). The bundles inside the tank form the reactor core. The uranium in the uranium oxide consists of between 0.7% to 5% of uranium-235, which can undergo fission; the rest is uranium-238, which is inert. The core also contains a substance that slows down neutrons, called a moderator. Slow neutrons (also known as thermal neutrons) react much more readily with uranium-235 than do fast neutrons generated by fission. A neutron source is used to start the chain reaction. Fission of uranium-235 in the core generates tremendous amounts of heat, which for a large reactor is equivalent to 1.5 million electric kettles.[6] This heat is removed using a coolant, typically water. The heated coolant is used to generate electricity and returned to the core. Waste heat generated in the process is rejected to a nearby body of water or carried away by steam emitted from cooling towers. The chain reaction is controlled by inserting rods made from neutron-absorbing material, called control rods, into the core. They prevent some neutrons from propagating the chain reaction, thereby slowing it down. To shut down the reactor, all control rods are fully inserted, stopping the chain reaction completely. The decay of fission products continues to produce substantial heat for some time, so the reactor must remain adequately cooled after shutdown.

In most reactors, the chain reaction is naturally self-limiting. The easiest way to do this is to use water as both the moderator and the coolant. When the reactor core gets too hot, some of the water will turn into steam, which is a much worse moderator than liquid water. This causes the neutrons to slow down less, reducing the effectiveness of fission and therefore heat production, leading the reactor to cool down.

As fission progresses in the reactor, the concentration of uranium-235 falls, while the amount of highly radioactive fission products increases. Additionally, a small amount of uranium-238 is converted into plutonium. Fission products are far more radioactive than the fresh fuel bundles, which can be handled with gloves. When the concentration of uranium can no longer sustain a chain reaction, part of the core is replaced with fresh fuel. The old, extremely radioactive fuel is moved to a spent fuel pool.

How safe are nuclear reactors?

First we have to pick some objective measure of safety. One of such measures is the number of deaths per unit of energy produced, for example deaths per petawatt-hour (one petawatt-hour = one trillion kilowatt-hours). Here is the breakdown:[7]

Energy source Deaths/PWh
Coal (world, all uses) 100,000
Coal (world, electricity only) 60,000
Coal (China, all uses) 170,000
Coal (USA, all uses) 15,000
Oil 36,000
Natural gas 4,000
Biomass 12,000
Peat 12,000
Solar PV (rooftop) 440
Wind 150
Hydro (world) 1,400
Hydro (Europe) 100
Nuclear 40

These estimates include the effects of nuclear accidents, dam failures, mine explosions, air pollution and so on. According to this measure, nuclear power is the safest energy source, with wind, solar and hydroelectric power close behind.

Another possibility is to use the concept of external costs, e.g. costs borne by the society in the form of environmental remediation, days of work lost due to illness, and so on. An extensive study of external costs of energy in Europe, called ExternE, was completed in 1999. The results are summarized below. Note that the results for nuclear assume a discount rate of 0%, which is impossible and unfavorable; results for realistic discount rates would be lower.[8]

Country Coal Peat Oil Gas Nuclear Biomass Hydro Solar PV Wind
Austria 1–3 2–3 0.1
Belgium 4–15 1–2 0.5
Denmark 4–7 2–3 1 0.1
Finland 2–4 2–5 1
France 7–10 8–11 2–4 0.3 1 1
Germany 3–6 5–8 1–2 0.5 3 0.6 0.05
Greece 5–8 3–5 1 0–0.8 1 0.25
Ireland 6–8 3–4
Italy 3–6 2–3 0.3
Netherlands 3–4 1–2 0.7 0.5
Norway 1–2 0.2 0.2 0–0.25
Portugal 4–7 1–2 1–2 0.03
Spain 5–8 1–2 3–5 0.2
Sweden 2-4 0.3 0–0.7
United Kingdom 4–7 3–5 1–2 0.25 1 0.15

From this table we can conclude that nuclear has external costs lower than all fossil fuel technologies, comparable to hydro and solar PV, and higher than wind. The external costs for nuclear are the highest in the Netherlands, which have only one small reactor.

What are the safety mechanisms in a reactor?

Several mechanisms ensure the safe operation of a reactor and prevent the release of radioactive substances into the environment. These can be divided into:

  • Active safety - requires the control systems of the operator to initiate an action. This includes emergency shutdown when an abnormal condition is detected by the control system and multiple backup generators to provide emergency power.
  • Passive safety - does not require any action from the control system or an operator, and relies only on the laws of physics to ensure safety. For example, control rods must be actively held out of the reactor by electromagnets, and fall into the core by gravity and/or are inserted by springs when power fails.

New reactor designs, such as AP1000,[wp] rely almost entirely on passive safety. Older reactors tend to rely more on active safety.

There are at least five levels of passive safety in most reactors:

  1. The uranium oxide fuel itself is resistant to high temperatures and can withstand some overheating while retaining fission products.
  2. The fuel is put inside a cladding transparent to neutrons, usually an alloy of zirconium. The cladding is water-tight and provides a further barrier.
  3. The reactor vessel itself provides another layer of contaiment.
  4. The reactor is placed in a large concrete bunker called the containment building, which is designed to keep the radioactivity inside and protect the reactor from external threats, such as an aircraft impact or a rocket attack.
  5. The reactor building is located in a sparsely populated area far from major cities to minimize the health impact of a radioactive release.

This approach of multiple independent barriers is called defence in depth.[9]

Are nuclear power plants vulnerable to terrorist attack?

A terrorist attack on a nuclear power plant would be very unlikely to succeed. The reactor is housed inside a reinforced concrete bunker which can withstand rocket attacks and airplane crashes.[10] Each facility has multiple layers of security and heavily armed guards. Even if the terrorists take full control of the facility, causing an accident such as a core meltdown would be difficult and likely require the assistance of the staff. Even if this was somehow successful, it is very likely that nobody from the public would be harmed.

There are far more attractive terrorist targets, such as population centers, dams, refineries or chlorine production plants. Attacks on these would have a higher chance of success and higher potential impact.

Can a nuclear reactor explode like a nuclear bomb?

No, it can't. The fissile material in a reactor is not concentrated enough to create a bomb-like explosion, even if all safety mechanisms were to fail. A runaway chain reaction would at most blow the reactor vessel apart and contaminate the containment building.

How much nuclear waste is produced?

A large, one-gigawatt nuclear reactor will generate 200-350 m3 of low- and intermediate-level nuclear waste and 27 tons (20 m3) of high-level waste (spent fuel) each year, which will take up 75 m3 if put into disposal containers without further processing. If the fuel is reprocessed, the end product will be 3 m3 of fission products immobilized in glass, which will take up 28 m3 after putting it in disposal containers. A coal power plant of the same power will produce 400,000 tons of fly ash in the same period.[11]

If you used only nuclear electricity all your life, your share of high-level waste would have the volume of a wine bottle. If it was reprocessed, it would have the volume of a coffee cup.[12] This compares rather favorably with statistics on ordinary waste in Britain, where 517 kg of municipal waste and 83 kg of hazardous waste per person is produced every year.[13]

How long will nuclear waste be dangerous?

Nuclear waste is no longer considered dangerous when its radioactivity drops below some threshold. Since the waste will eventually be buried underground, it seems reasonable to pick the radioactivity level of uranium ore from which it was produced as the threshold, since people have lived near uranium deposits for centuries without problems. With these assumptions:

  • Without reprocessing, the waste will be dangerous for 10,000 years.
  • With reprocessing, the separated fission products will be dangerous for 300 years.

What does nuclear waste look like?

The spent fuel storage pool looks like this:

Spent fuel in pool.jpg

Spent fuel in dry storage casks looks like this:

Nuclear dry storage.jpg

See here for a photo of a facility that stores 30 years' worth of spent fuel from the decommissioned Connecticut Yankee nuclear power plant.

What happens with spent fuel?

After being discharged from the reactor, spent fuel is first put in a spent fuel pool, where it is continually cooled for a few years. When the fuel bundles no longer generate enough heat to melt itself, they can be put in reinforced concrete casks, which is called dry storage. After cooling down, the fuel optionally undergoes nuclear reprocessing[wp] to separate uranium and plutonium from fission products. Uranium and plutonium is stored for eventual reuse as fuel, while fission products are encased in concrete and treated as nuclear waste. This process drastically reduces the volume and the longevity of generated waste, but is rather expensive. Eventually, the fission products or complete fuel bundles will be put in sturdy containers and buried deep underground in facilities called deep geological repositories.[wp]

What are the environmental impacts of a nuclear power plant?

The primary impacts of a normally functioning nuclear power plant are associated with its cooling requirements.

  • Large amounts of water are used for cooling. Additionally, if open cycle cooling is used, the temperature of the nearby body of water can rise noticeably, which can be harmful to the ecosystem.
  • Withdrawing water can cause harm to fish and other aquatic organisms, unless water intakes are properly designed.

Other than that, there is little impact. In particular, nuclear waste such as spent fuel is never released into the environment, and radioactive releases are so small as to be negligible (see below). It's impossible to cover up radiation releases, because you can detect them yourself using a fairly cheap radiation detector (below $200).[14]

Do nuclear power plants emit radioactive substances into the environment?

Another common misconception is brought swiftly to its demise.

Yes, a nuclear power plant emits a tiny amount of radioactive gases which result from the fission of fuel through a small smokestack-like structure near the reactor containment building. The big hyperboloid towers that are stereotypically associated with nuclear power plants are cooling towers, which emit nothing but pure H2O. The additional dose from these releases to people living nearby is insignificant compared to variations in natural background radiation, which do not have any health impact. An equivalent coal power plant emits several times more radioactive material into the environment.

Is there enough uranium?

Known reserves of economically recoverable uranium amount to over 7 million tons. This is sufficient for over 100 years of current consumption. Between 2009 and 2011, identified reserves increased by 12%, reflecting increased exploration.[15]

Because the price of natural uranium is only a small part of the cost of nuclear electricity (less than 5%), even substantial increases in uranium prices do not substantially impact the economics of nuclear power. If prices rise enough, it might become profitable to extract uranium from seawater, where it is present at a concentration of 3 parts per billion. Seawater extraction of uranium was demonstrated experimentally in Japan and the cost is expected to be in the $300-400/kg range, comparable to the highest historical price of $300/kg in 2009. However, no large scale facility was built to date.

Operational breeder reactor in Beloyarsk, Russia

Breeder reactors are experimental reactors that can efficiently transform uranium-238 or thorium into plutonium or uranium-233, producing more fissile material than they consume. Widespread use of this technology would make nuclear power 100 times more fuel-efficient and effectively renewable: nuclear fuel would be constantly replenished from a pool of starting materials which is so large as to be practically inexhaustible.

What are the impacts of uranium mining?

Uranium mining can pollute groundwater with heavy metals and release radioactive substances into the environment if mismanaged. If adequate ventilation is not provided, workers are at an increased risk of lung cancer.

The environmental impact of properly done uranium mining is similar to the impact of mining of other heavy metals.

Historically most uranium mines were open cut mines, which means a giant hole was dug in the ground to remove the ore. Recently there is an increase in the number of mines using in-situ leaching, which extracts uranium by pumping a solution of sodium bicarbonate or sulfuric acid into the ground and removing it after it reacts with the ore. This method is less expensive and avoids the disruption of the area, though it can result in groundwater pollution. This can be fixed after the mine is exhausted by flushing the deposit with neutralizing agents and clean water.

Can nuclear power be built fast enough to mitigate global warming?

Yes, at least on the technical level. To replace all fossil fuel electricity with nuclear power and not be late, the world would need to construct 3000 new reactors over 60 years, which is equivalent to 50 GW per year or one new 1 GW reactor per week. The highest historical rate of construction was 34 GW per year, in the mid-'80s.[16]

Footnotes

  1. There are some exceptions, but they are not important for practical purposes.
  2. http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/radiation/backgroundradiationrev1.shtml
  3. Scientific American: The Workings of an Ancient Nuclear Reactor
  4. http://education.jlab.org/qa/radglow_02.html
  5. New York Times: Useful Mutants, Bred With Radiation
  6. A reactor producing 1 GW of electricity has a thermal power of around 3 GW. An electric kettle is typically 2 kW.
  7. http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html
  8. European Commission, External Costs: Research results on socio-environmental damages due to electricity and transport, p. 15
  9. IAEA: Defence in depth in nuclear safety (INSAG-10)
  10. Video of an F-4 fighter plane crashing into a nuclear containment building wall. Larger planes don't do much more damage, because their airframes absorb more energy on impact.
  11. World Nuclear Association: Radioactive Waste Management
  12. This result was originally computed for Poland and rounded up to a recognizable household quantity. You can do your own math based on the data above, the population of your country and its electricity consumption.
  13. David MacKay: Sustainable energy – without hot air, page 170
  14. Example Amazon listing
  15. World Nuclear News: Uranium supplies good for the long haul
  16. David MacKay, Sustainable energy - without the hot air, page 171
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