What is natural draft cooling tower?
The natural draft cooling tower is an open, direct-contact system. It works using a heat exchanger, allowing hot water from the system to be cooled through direct contact with fresh air. This increases both the temperature and humidity of the air in the tower.
On what does the rate of airflow in a natural draft cooling tower depend?
The air-flow rate through a NDCT depends on the density difference between ambient air and relatively hot and humid light air inside the tower.
What are the factors affecting cooling of water in cooling tower?
Cooling tower performance depends on four factors (1) Range; (2) Heat load; (3) Ambient wet-bulb temperature or relative humidity and (4) Approach. Range is the temperature difference between the hot water inlet and cold water outlet at the tower.
How do you calculate water loss in a cooling tower?
Cooling Tower Make-up Water Flow Calculation
- The evaporation rate is approximately 2 GPM per 1 million BTU/Hr of heat rejection.
- The evaporation rate is approximately 3 GPM per 100 tons of refrigeration.
- Evaporation Rate (GPM) = Water Flow Rate (GPM) x Range (°F) x 0.001.
What is inside a nuclear cooling tower?
In this type of tower, the warm water is circulated inside each tower and over structures that create droplets of water. At the same time, large fans draw the warm, moist air out the top of the cooling tower, lowering the temperature of the water more than 20 degrees.
Are cooling towers radioactive?
The cloud at the top of cooling tower is not radioactive. The water in the reactor stays in a closed system, never coming into contact with the water in the cooling tower. There are more than 250 cooling towers on power plants across America, and fewer than 100 on nuclear plants.
What is the half life of uranium 235?
about 700 million years
Why is U-235 better than u-238?
The U-238 nucleus also has 92 protons but has 146 neutrons – three more than U-235 – and therefore has a mass of 238 units. The difference in mass between U-235 and U-238 allows the isotopes to be separated and makes it possible to increase or “enrich” the percentage of U-235.
Can you touch uranium?
Uranium in its natural state is 99.3% U-238 isotope, which has a very long half life and hence decays very slowly. Also, while it decays it emits alpha radiation, which can be easily blocked by a piece of paper or your skin. So nothing is going to happen if you touch it.
Why is U-238 not used as a fuel?
The reason why Uranium 238 is not fissile is because upon absorption of a thermal neutron, the binding energy released by U-238 is not greater as compared to the critical energy required to carry out the fission.
Why is U-238 th 234?
A nucleus of uranium 238 decays by alpha emission to form a daughter nucleus, thorium 234. This thorium in turn transforms into protactinium 234, and then undergoes beta-negative decay to produce uranium 234. This occurs at the fourteenth generation of the uranium 238 family, when lead 206 is finally produced.
Why Uranium-235 is unstable?
Certain isotopes of some elements can be split and will release part of their energy as heat. Uranium-235 (U-235) is one of the isotopes that fissions easily. During fission, U-235 atoms absorb loose neutrons. This causes U-235 to become unstable and split into two light atoms called fission products.
What are the 14 daughters of uranium?
Uranium series Beginning with naturally occurring uranium-238, this series includes the following elements: astatine, bismuth, lead, polonium, protactinium, radium, radon, thallium, and thorium. All are present, at least transiently, in any natural uranium-containing sample, whether metal, compound, or mineral.
Why is lead 206 is a stable isotope?
Lead-206 is a stable isotope because it will not decay into a different element (non-stable isotopes will undergo radioactive decay and change into a…
What does U 235 decay into?
Of these naturally occurring isotopes, only uranium-235 is directly fissionable by neutron irradiation. However, uranium-238, upon absorbing a neutron, forms uranium-239, and this latter isotope eventually decays into plutonium-239—a fissile material of great importance in nuclear power and… …
What does uranium look like?
When refined, uranium is a silvery white, weakly radioactive metal. When finely divided, it can react with cold water; in air, uranium metal becomes coated with a dark layer of uranium oxide. Uranium in ores is extracted chemically and converted into uranium dioxide or other chemical forms usable in industry.
Can uranium kill you?
Depleted uranium is what’s left over after enriched uranium is spent at a power plant. It’s about 40 percent less radioactive than natural uranium, according to the U.S. Department of Veterans Affairs. This depleted uranium is only dangerous if it is inhaled, ingested or enters the body in a shooting or explosion.
How much energy does 1kg of uranium produce?
1 kg of uranium will create kWh of power!
Why does uranium glass glow?
Due to the presence of uranium oxide in the glass, the glass will glow a bright green color when put under a black light- this is the best way to identify it. While uranium is radioactive, it isn’t actually bad to drink or enjoy food in the glassware that uses this.