1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
arlik [135]
3 years ago
13

Which source would provide the most reliable information about the safety of nuclear power plants?

Physics
1 answer:
soldier1979 [14.2K]3 years ago
8 0

This paper is about the main conventional types of nuclear reactor. For more advanced types, see Advanced Reactors and Small Reactors papers, and also Generation IV reactors.

A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the energy released is used as heat to make steam to generate electricity. (In a research reactor the main purpose is to utilise the actual neutrons produced in the core. In most naval reactors, steam drives a turbine directly for propulsion.)

The principles for using nuclear power to produce electricity are the same for most types of reactor. The energy released from continuous fission of the atoms of the fuel is harnessed as heat in either a gas or water, and is used to produce steam. The steam is used to drive the turbines which produce electricity (as in most fossil fuel plants).

The world's first nuclear reactors operated naturally in a uranium deposit about two billion years ago. These were in rich uranium orebodies and moderated by percolating rainwater. The 17 known at Oklo in west Africa, each less than 100 kW thermal, together consumed about six tonnes of that uranium. It is assumed that these were not unique worldwide.

Today, reactors derived from designs originally developed for propelling submarines and large naval ships generate about 85% of the world's nuclear electricity. The main design is the pressurised water reactor (PWR) which has water at over 300°C under pressure in its primary cooling/heat transfer circuit, and generates steam in a secondary circuit. The less numerous boiling water reactor (BWR) makes steam in the primary circuit above the reactor core, at similar temperatures and pressure. Both types use water as both coolant and moderator, to slow neutrons. Since water normally boils at 100°C, they have robust steel pressure vessels or tubes to enable the higher operating temperature. (Another type uses heavy water, with deuterium atoms, as moderator. Hence the term ‘light water’ is used to differentiate.)

Components of a nuclear reactor

There are several components common to most types of reactors:

Fuel. Uranium is the basic fuel. Usually pellets of uranium oxide (UO2) are arranged in tubes to form fuel rods. The rods are arranged into fuel assemblies in the reactor core.*
* In a new reactor with new fuel a neutron source is needed to get the reaction going. Usually this is beryllium mixed with polonium, radium or other alpha-emitter. Alpha particles from the decay cause a release of neutrons from the beryllium as it turns to carbon-12. Restarting a reactor with some used fuel may not require this, as there may be enough neutrons to achieve critical when control rods are removed.

Moderator. Material in the core which slows down the neutrons released from fission so that they cause more fission. It is usually water, but may be heavy water or graphite.

Control rods. These are made with neutron-absorbing material such as cadmium, hafnium or boron, and are inserted or withdrawn from the core to control the rate of reaction, or to halt it.*  In some PWR reactors, special control rods are used to enable the core to sustain a low level of power efficiently. (Secondary control systems involve other neutron absorbers, usually boron in the coolant – its concentration can be adjusted over time as the fuel burns up.)
* In fission, most of the neutrons are released promptly, but some are delayed. These are crucial in enabling a chain reacting system (or reactor) to be controllable and to be able to be held precisely critical.

Coolant. A fluid circulating through the core so as to transfer the heat from it.  In light water reactors the water moderator functions also as primary coolant. Except in BWRs, there is secondary coolant circuit where the water becomes steam. (See also later section on primary coolant characteristics)





You might be interested in
The Sex Equity in Education Act requires educational institutions to distribute a sexual harassment policy to:
Pie
A.) faculty and parents
4 0
2 years ago
What is the Potential Energy of ball 1??
Dvinal [7]
GPE= height x mass x gravitational field strength 
5 x 10 x 9,8=490J
7 0
3 years ago
Evidence that seismic waves transfer energy without transferring matter?
Sav [38]
Evidence that seismic waves transfer energy without transferring matter: Seismic waves do not transfer matter because the waves travel away from the faults because the movement in the crust occur along the faults as the seismic waves continue to travel away.
8 0
2 years ago
The illustration in figure below shows a uniform metre rule weighing 30 N pivoted on a wedge placed under the 40 cm mark and car
Nitella [24]

Answer:

W = 30 N

Explanation:

Applying the summation of torques about the wedge for equilibrium, taking the clockwise direction as negative. Since the ruler is balanced horizontally about the wedge. Therefore, the summation of all torques acting about the wedge must be equal to zero.

(70\ N)(40\ cm - 10\ cm)-(30\ N)(50\ cm-40\ cm)-(W)(100\ cm - 40\ cm) = 0\\W(60\ cm) = (70\ N)(30\ cm)-(30\ N)(10\ cm)\\\\W = \frac{1800\ N.cm}{60\ cm}

<u>W = 30 N</u>

6 0
2 years ago
Four identical metallic spheres with charges of +8.2 µC, +9.0 µC, −7.8 µC, and −8.8 µC are placed on a piece of paper. The paper
tigry1 [53]

Answer:

a) 0.15 μC b) 9.4*10¹¹ electrons.

Explanation:

As the total charge must be conserved, the total charge on the spheres, after being brought to contact each other, and then separated, must be equal to the total charge present in the spheres prior to be put in contact:

Q = +8.2μC +9.0 μC +(-7.8 μC) + (-8.8 μC) = +0.6 μC

As the spheres are assumed perfect conductors, as they are identical, once in contact each other, the excess charge spreads evenly on each sphere, so the final charge, on each of them, is just the fourth part of the total charge:

Qs = Qt/4 = 0.6 μC / 4 = 0.15 μC.

b) As the charge has a positive sign, this means that each sphere has a defect of electrons.

In order to know how many electrons are absent in each sphere, we can divide the total charge by the charge of one electron, which is the elementary charge e, as follows:

N =\frac{0.15e-6C}{1.6e-19C}  = 9.4e11  electrons

6 0
3 years ago
Other questions:
  • PLEASE ANSWER ASAP
    8·1 answer
  • What is the answer to life?
    9·2 answers
  • Instrumento que se utiliza para medir fuerzas
    10·1 answer
  • Wegener proposed the continental drift hypotheses suggesting that
    5·1 answer
  • This time, William Tell is shooting at an apple that hangs on a tree (Fig. 3.32). The apple is a horizontal distance of 20.0 m
    7·1 answer
  • Suppose that the electric field in the Earth's atmosphere is E = 8.60 101 N/C, pointing downward. Determine the electric charge
    14·1 answer
  • Now it's your turn
    14·1 answer
  • Explain melting and freezing using the kinetic theory of matter​
    8·2 answers
  • The design of interior spaces is relatively unimportant to good<br> architecture?
    7·1 answer
  • The magnetic field 40.0 cm away from a long, straight wire carrying current 2.00 A is 1.00μT. (a) At what distance is it 0.100μ
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!