Nuclear Reactors

Uranium-235 is a heavy atom commonly used in nuclear fission reactions to produce thermal energy. When a uranium-235 atom absorbs a neutron, it becomes unstable and splits into two smaller atoms along with releasing energy and additional neutrons, which can trigger a chain reaction.

Nuclear reactors in the US are located in various states across the country. Some states with a high concentration of nuclear reactors include Illinois, Pennsylvania, and South Carolina. These reactors are typically situated near bodies of water for cooling purposes.

Bruce Nuclear Generating Stations- Kincardine, Ontario, Canada

Pickering Nuclear Generating Stations- Pickering, Ontario, Canada

Darlington Nuclear Generating Station- Bowmanville, Ontario, Canada

The lifespan of a kilogram of uranium inside a nuclear reactor depends on the type of reactor and its operating conditions. Typically, a kilogram of uranium in a reactor can generate energy for several years before needing to be replaced or refueled. The amount of energy generated also depends on the efficiency and design of the reactor.

The reactor itself does not make a lot of sound when operating. Nuclear fission is silent, but moving water in the core (in a pressurized water reactor) might be heard as it circulates. But it would not be easy to put your ear to the reactor vessel as radiation levels would be very high and the vessel would be very hot. Certainly the pumps that are running to circulate coolant will be audible.

As of 2021, there are around 440 nuclear reactors in operation worldwide. These reactors are used for generating electricity through nuclear fission reactions. The number of reactors changes over time due to construction of new reactors and decommissioning of old ones.

Dumping nuclear spent fuel rods in the ocean is illegal and poses serious environmental risks. Radioactive materials from spent fuel rods can contaminate marine life, water, and the ecosystem. Safe and secure storage solutions are used to manage nuclear waste.

No, hawks do not eat bacteria. Hawks are carnivorous birds of prey and typically hunt and feed on small animals such as insects, rodents, and other birds. They do not consume bacteria as a part of their diet.

It's really just a matter of degree, all reactors produce some power. Those used in a power plant will produce perhaps 3000 to 5000 Megawatts thermal. Low power reactors producing a few kilowatts are used for experiments, teaching in universities, and for producing radioisotopes by irradiating samples, but reactors in this sort of power level would not be harnessed to produce electricity, the heat produced if large enough would be removed and rejected to the atmosphere or to a water cooling circuit. This makes them simple to operate and to start and stop as required.

The fuel rods in a nuclear reactor system contain uranium. This uranium undergoes a nuclear reaction, generating heat used to produce electricity.

No. The sun produces energy by fusion. It is joining hydrogen atoms into larger helium atoms, which releases energy.

Man-made nuclear reactors produce energy by fission. They break large atoms into smaller atoms, which also releases energy.

An artificial nuclear reactor is a device that initiates and controls a sustained nuclear chain reaction. This reaction produces heat, which is used to produce electricity in nuclear power plants. The fission process in these reactors generates energy by splitting atomic nuclei.

Nuclear reactors can be as small as a single room. There are many reactors that are less then 30 MW (a typical reactor is around 1,000 MW), and consider that a normal car engine is about 200 KW (or .2 MW) so some reactors produce the power of only about 100 cars.

The smallest that are standardly used, other then for research, are found on submarines.

The radiation from a properly functioning nuclear power reactor is heavily shielded and cannot be approached close enough to be fatal.

Radiation from damaged or malfunctioning nuclear power plants can be, and has been, fatal. The nuclear reactor incident at Chernobyl is one example. Nuclear reactor failures aboard ships and submarines also prove fatal but are often hidden behind national security; submarine K-19 'the widowmaker' was one such example.

And of course, if one were to get into the reactor room past all of the shielding, any reactor would be fatal.

A nuclear reactor requires the neutrons released from one reaction to trigger the fission of other nuclei. Control rods are required to absorb some of these neutrons so as to prevent a runaway chain reaction.

The control rods absorb the nuetrons which keeps the reaction rate relatively constant (rather than letting it grow exponentially). They create a situation where roughly one neutron per fission goes on to split another atom.

Moderators slow down the neutrons. Fast neutrons are more inclined to bounce/deflect off of the surface of a nucleus so slower neutrons actually lead to a greater number of succesful fissions i.e. moderators don't slow the reaction down, they just help it to take place.

This is going to be a big number! Each fission releases 200 MeV, and 1 MeV = 1.6 X 10-13 Joules, so 1 fission = 3.2 x 10-11 Joules. Now if the thermal power produced by the reactor is 3000 MW (corresponding to an electrical output of 1000 MW) this means 3000 x 106 Joules per second, or 3 x 109 Joules /sec. So the number of fissions/sec in the reactor is 3 x 109 divided by 3.2 x 10-11 , so if we call 3/3.2 = unity, for simplicity, the number of fissions per second is 1020. I said it would be big!

Reactor physicists use a number called the neutron flux to describe the intensity of the nuclear fission process, this is the number of neutrons crossing an area of 1 sq cm per second. This number helps to define the fuel rating and effects on reactor components in the active core. Obviously the total number of fissions occurring in the reactor overall per second depends on this and the size of the reactor.

Hafnium is used in nuclear reactors as a control rod material to regulate the nuclear fission process. It has a high neutron-capture cross-section, meaning it is effective in absorbing neutrons and controlling the rate of the nuclear reaction. The addition of hafnium control rods helps maintain the reactor at a safe and stable operating condition.

The number of control rods in a nuclear reactor can vary depending on the design and size of the reactor. Typically, a nuclear reactor can have anywhere from 50 to 100 control rods. These rods are used to control the rate of the nuclear reaction by absorbing neutrons and regulating the power output of the reactor.

No, the function of the control rods is to absorb surplus neutrons so that the chain reaction proceeds at a steady rate, and to compensate for the reducing reactivity of the reactor as the fuel is burned up over the refuelling cycle. They also have a very important safety function in shutting down the reactor fully when required, by inserting them fully, thus preventing any chain reaction from starting.

We usually find that uranium is used as fuel in nuclear reactors (though some use plutonium).

No, all the uranium on earth was produced in supernova explosions that occurred more than 6 billion years ago, there is no more arriving on earth (except small amounts in meteors and they got their uranium from the same supernovas as did earth). Without building reactors that burn plutonium if we use up all the uranium-235 it will become impossible to build a nuclear fission reactor (nuclear fusion reactors might become possible someday, but not yet).

1. U-235 fissions into Ba-141 and Kr-92, along with three neutrons: U-235 + 0n1 -> Ba-141 + Kr-92 + 3*0n1.

2. U-235 fissions into Xe-144 and Sr-90, along with three neutrons: U-235 + 0n1 -> Xe-144 + Sr-90 + 3*0n1.

3. U-235 fissions into Te-134 and Zr-100, along with four neutrons: U-235 + 0n1 -> Te-134 + Zr-100 + 4*0n1.

Temperature control in a nuclear reactor is crucial to prevent overheating, which can lead to a meltdown and release of radioactive materials. Maintaining the right temperature ensures the reactor operates safely and efficiently. Control systems are in place to regulate temperature by adjusting the rate of fission reactions and cooling mechanisms.