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Nuclear Energy

Nuclear energy covers technology of reactors, different types of reactors, their history and development, exploitation in different countries, operating experiences, problems of nuclear waste.

6,180 Questions

How much heat is generated in a nuclear fusion?

In nuclear fusion, a small amount of heat is generated due to the high temperatures required to fuse atomic nuclei together. This heat can be harnessed to produce electricity through various methods, such as heating water to create steam to drive a turbine. However, the amount of energy produced by fusion reactions is significantly greater than the heat generated.

What is the reaction product of tritium which is a beta emitter?

A neutron in the nucleus of the tritium atom decays into a proton and an electron and an antielectron neutrino. The proton remains in the nucleus causing the atomic number to increase by 1 as the atom becomes that of a different element while mass number remains the same, He3. The electron and antielectron neutrino are emitted from the nucleus.

Which control scheme is applicable to packed bed reactor?

Packed bed reactors typically use either continuous flow or batch operation control schemes. Continuous flow control involves regulating reactant feed rates and temperature to maintain desired reactor conditions. Batch operation control focuses on monitoring and adjusting parameters (such as temperature and pressure) over a set time period for each batch of reactants.

Does nuclear fission take place in an uranium bar?

Yes, with a rather unimportant qualification. There are isotopes of uranium that do not undergo fission, but it is unlikely a bar would be made from any of them because they have short half lives and are expensive to produce.

What is the process of obtaining energy from the spontaneous splitting of a large nucleus called?

Nuclear energy, but to get substantial energy release it is no good relying on spontaneous fission, which only occurs at a very low rate. The nuclear fuel must be arranged in a lattice with a moderator to create a significant chain reaction.

How are the products of the fission of U-235 transformed into household energy such as electricity?

Nuclear energy creates heat in the fuel, which is transferred to the reactor coolant and then used to produce steam. This is used in a steam turbine to provide mechanical energy which then produces electrical energy in the generator. This is then transferred in high voltage grid lines and transformed down to your house voltage in a local transformer

What is it when energy is released through fission or fusion?

When energy is released through fission or fusion, it is known as nuclear energy. Fission involves splitting atoms, releasing energy, while fusion involves combining atoms, also releasing energy. Both processes result in the conversion of mass into energy, as described by Einstein's famous equation E=mc^2.

Which reaction releases the most energy physical nuclear or chemical?

Nuclear reactions release significantly more energy than chemical reactions. Nuclear reactions involve changes in the nucleus of an atom and release energy from the strong nuclear force. In contrast, chemical reactions involve changes in the electron configuration of atoms and release energy from the weaker electromagnetic force.

What does it mean if a isotope is fissile?

A fissile isotope is one that can undergo fission when struck by a neutron, releasing energy and more neutrons that can then cause further fission reactions. This property is essential in nuclear reactors and nuclear weapons. Examples of fissile isotopes include uranium-235 and plutonium-239.

What does it mean if an isotope is fissionable?

If an isotope is fissionable, it means that it can undergo nuclear fission, a process where the nucleus of an atom splits into smaller parts, releasing a large amount of energy. This property is important for nuclear reactors and nuclear weapons.

Nuclear fuels are bombared by what particles to induce their fission?

Nuclear fuels are bombarded by neutrons to induce their fission reaction. Neutrons are able to penetrate the nucleus of the fuel atoms and cause them to split, releasing energy and more neutrons in the process. This chain reaction is the basis for nuclear power generation.

The gas waste generated by many power plants is?

primarily composed of carbon dioxide, sulfur dioxide, and nitrogen oxides. These pollutants are released during the combustion of fossil fuels, contributing to air pollution and climate change. Measures such as implementing cleaner technologies and capturing and storing emissions are being developed to address this issue.

Do nuclear reactors use lasers?

Nuclear reactors do not typically use lasers as a primary component in their operation. Lasers are more commonly used in research, industry, and medical applications. Nuclear reactors rely on controlled nuclear fission reactions to generate heat for electricity production.

What are the uses of uranium and list?

Applications of uranium:

- nuclear fuel for nuclear power reactors

- explosive for nuclear weapons

- material for armors and projectiles

- catalyst

- additive for glass and ceramics (to obtain beautiful green colors)

- toner in photography

- mordant for textiles

- shielding material (depleted uranium)

- ballast

- and other minor applications

What is the major unsolved problem in using nuclear fission?

One major unsolved problem in using nuclear fission is the safe disposal of radioactive waste. Finding a long-term storage solution that prevents contamination of the environment is a challenge that still needs to be fully addressed. Additionally, ensuring the security of nuclear facilities to prevent accidents or malicious activities remains a concern.

What happens during the fission of uranium?

Fission is a process of the splitting the atom, typically into two daughter atoms, plus a few neutrons. It can be caused when a fissionable atom is struck by a neutron, or, in the case of uranium and some synthetic elements, spontaneously. The actual products of fission are somewhat unpredictable. We can know a few things about what always, or nearly always, happens, however and among these are the following:

  • The sum of the numbers of protons in the daughters is equal to the number in the parent.
  • The sum of the numbers of neutrons in the daughters plus the neutrons emitted is equal to the number of neutrons in the parent.
  • Typically two or three neutrons are emitted.
  • The daughters are each very roughly half the size of the parent.

So, a typical equation for a fission reaction of 235U might look like this (the lower number preceding the atomic symbol is the atomic number or number of protons in the atom; the upper number is the atomic mass, which equals the number or protons plus the number of neutrons; and 01n represents a neutron): 92235U --> 3799Rb + 55134Cs + 2 01n

Note the upper numbers on both sides of the equations add up (235 = 99 + 134 + 2x1), as do the lower numbers on both sides of the equation (92 = 37 + 55 + 2x0).

The equation could just as easily have been slightly different: 92235U --> 3798Rb + 55134Cs + 3 01n

or very different: 92235U --> 40105Zr + 52127Te + 3 01n

Various isotopes of uranium can undergo fission, and what is true for one is true for the others. The uranium isotopes have long half lives, 703,800,000 years for 235U, and 4,469,000,000 years for 238U. Since heavier atoms can have a greater proportion of neutrons to protons, the daughter atoms nearly always have too many to be stable, and have very much shorter half lives. They handle this by converting neutrons to protons, ejecting beta particles (high speed electrons) as they do. This, for example, is the decay chain of the 99Rb in the first example equation, with half lives: 3799Rb - 0.050 seconds

3899Sr - 0.269 seconds

3999Y -- 1.47 seconds

4099Zr - 2.10 seconds

4199Nb - 15.0 seconds

4299Mo - 69.14 hours

4399Tc - 211,100 years

4499Ru - stable

Please note, however, that different decay chains do not always move from shorter to longer half lives; it is they usual way things go, but it is not inevitable.

When spent fuel is removed from the reactor, it needs to cool off in a special storage area for a few years because the shorter lived isotopes are decaying rapidly. Then it can be moved from short term storage to longer term storage.

The most abundant medium term decay products of uranium fission, with yield as a percentage of the daughter atoms produced, and half life are as follows: 137Cs .. 6.34% .. 32.23 years

90Sr .... 4.51% ... 28.9 years

141Sm . 0.53% ... 90 years

85Kr .... 0.22% ... 10.78 years

And the most abundant long term decay products are as follows: 135Cs . 6.91% .. 2,300,000 years

99Tc .... 6.14% ..... 211,000 years

93Zr .... 5.46% .. 1,530,000 years

107Pd . 1.25% .. 1,250,000 years

129I .... 0.84% ... 1,570,000 years

126Sn . 0.11% ..... 230,000 years

There are no fission products with half lives between 90 and 211,000 years.

Is the power plant still producing energy today on the three mile island?

There are two reactors at Three Mile Island. TMI-2, the one that had a partial melt down in 1979, has been shut down since the accident. The other, TMI-1, has continued operation.

What is the melting temperature of UO2 fuel?

UO2 melts at 2865 degrees C or 5189 degrees F. However, most UO2 fuel is clad in Zircalloy which is more limiting. At temperatures above 2200 degrees F, the exothermic reaction of Zr with oxygen accelerates dramatically and will cause failure of the clad and likely melting of the UO2 fuel.

How hot does the core of a nuclear reactor get?

This depends very much on the type of reactor. PWR's operate at a high pressure in the primary circuit to prevent boiling, and the outlet water temperature is about 315 degC. In BWR's in contrast, boiling is allowed and the outlet temperature is about 285 degC.

Gas cooled reactors can operate at much higher temperatures. In the AGR for example (CO2 cooled, graphite moderated) the gas outlet temperature is designed to be about 540 degC, which allows steam to be produced at conditions the same as in a modern coal fired station, in fact at the last two built the steam turbines were exactly the same as installed in coal fired stations at that time. At these temperatures all steel components in the reactor have to be austenitic, as CO2 oxidises normal steel, and re-entrant gas flow has to be arranged to keep the graphite moderator cool, the gas inlet being at about 300degC.

Designs exist for helium cooled gas reactors which could operate even hotter and drive a gas turbine directly, without a steam circuit. These may or may not be commercially exploited.

What are the three isotopes that will undergo neutron induced fission?

They are many but the most famous three are: uranium-233, Uranium-235, and Plutonium-239.

Another answerUranium-235, uranium-238, and plutonium-239 are all capable of undergoing neutron induced fission. Actually there are other isotopes that also do this, but they are not commonly used as fuel.

The first-order rate constant for the decay of the radioactive isotope tritium is 0.056 year-1 What fraction of the tritium initially in a sample is still present 50 years later?

To calculate the fraction of tritium remaining after 50 years, you would use the formula: fraction remaining = e^(-kt), where k is the rate constant and t is the time. Plugging in the values, you would find that the fraction of tritium remaining after 50 years is approximately 0.606 or 60.6%.

What is a Nuclear reactor moisture separator?

This is used in the nuclear reactor that is known as Boiling Water Reactor (BWR) in which heat produced by the nuclear fission in the nuclear fuel allows the light water reactor coolant to boil. Then, the nuclear reactor moisture separator is used to increase the dryness of the produced steam before it goes to the reactor steam turbines.

What is the main use of isotopes of uranium?

235U is a fissionable isotope and 238U is a fertile isotope; these isotopes are extremely important in the production of nuclear energy.

Also uranium is used by the United States, United Kingdom and Russia to threaten with nuclear bombs the other countries, without nuclear weapons.

What fuel other then uranium can be used in a nuclear reactor?

In a pure fission bomb, none. Only high purity Uranium-235, Plutonium-239, or Uranium-233 are fissile and thus suitable as fission fuel. In a boosted fission bomb small amounts of fusion fuel can be added in a hollow pit construction: gaseous deuterium and/or gaseous tritium or solid lithium-deuteride.

In a fusion bomb the fuel is solid lithium-deuteride. However the high energy (15 MeV) fusion neutrons can fission Uranium-238 used as the tamper causing it to provide as much as 90% of the final yield.

Fuels:

  • U235
  • U233
  • P239
  • D
  • T
  • LiD
  • U238 only with 15 MeV fusion neutrons