Ordinary light water
The fuel used in a nuclear reactor is typically uranium. Specifically, the most common type of uranium used is uranium-235, which undergoes nuclear fission to produce energy in the reactor.
Uranium-235 and Plutonium-239 are two possible fuel sources for a nuclear reactor. These isotopes are fissile materials that undergo nuclear fission reactions to generate heat in a controlled manner for producing electricity.
water, hydro, aqua.
Dihydrogen monoxide is the scientific name for water but isn't used a lot
The official name for water is dihydrogen monoxide.
One type of nuclear reactor is the pressurized water reactor (PWR). In a PWR, the heat generated by nuclear fission in the reactor core is transferred to water, which circulates through the core to create steam that drives turbines to produce electricity.
India's First Nuclear Reactor was Apsara. It was also the first nuclear reactor in Asia. Apsara went critical at Bhabha Atomic Research Centre (BARC), Trombay on August 4, 1956. It heralded the arrival of India's nuclear energy programme. Dr. Homi Bhabha himself conceptualised the design of the reactor and the reactor was built entirely by Indian engineers in a record time of about 15 months.Apsara is a swimming-pool-type reactor loaded with enriched uranium as fuel. The fuel core is suspended from a movable trolley in a pool filled with water. The pool water serves as coolant, moderator and reflector, besides providing the shielding.
I believe that you fill it with coolant, as the tank's name suggests.
The first Indian nuclear reactor's name is APSARA.
The reactor is roughly cylindrical in shape. Fuel plates or fuel rods are welded up in what is called a fuel bundle, and the bundles are arranged within the inside of the pressure vessel to create the core. There are a number of pictures and drawings that can be viewed by using the links supplied. Note that in the Wwer reactor diagram, part number 1 is said to be the control rods. This is incorrect. What is actually there are the lead screws (and the rod drive motors) for the control rods. The control rods are actually down in the core and are pulled out into the space just above it.
The tool that compares the density of water to that of coolant is called a hydrometer. It measures the specific gravity of a liquid (the ratio of the density of the liquid to the density of water) to determine its concentration or strength.
Kamini
Arc Reactor
See link below
Mr. Fusion
Typically this is the heater core bypass tube. Takes warmer block coolant to heater core for faster cabin warm up.
The fuel used in a nuclear reactor is typically uranium. Specifically, the most common type of uranium used is uranium-235, which undergoes nuclear fission to produce energy in the reactor.