Search results
Results from the WOW.Com Content Network
NaK was used as the coolant in the first breeder reactor prototype, the Experimental Breeder Reactor-1, in 1951. Sodium and NaK do, however, ignite spontaneously on contact with air and react violently with water, producing hydrogen gas. This was the case at the Monju Nuclear Power Plant in a 1995 accident and fire. Sodium is also the coolant ...
Use of NaK overcomes this. The Dounreay Fast Reactor is an example. The first nuclear reactor in space, [10] [11] the United States' experimental SNAP-10A satellite, used NaK as coolant. The NaK was circulated through the core and thermoelectric converters by a liquid metal direct current conduction-type pump. [12]
In a loss-of-coolant accident, either the physical loss of coolant (which is typically deionized water, an inert gas, NaK, or liquid sodium) or the loss of a method to ensure a sufficient flow rate of the coolant occurs. A loss-of-coolant accident and a loss-of-pressure-control accident are closely related in some reactors.
Pool type sodium-cooled fast reactor (SFR) A sodium-cooled fast reactor is a fast neutron reactor cooled by liquid sodium.. The initials SFR in particular refer to two Generation IV reactor proposals, one based on existing liquid metal cooled reactor (LMFR) technology using mixed oxide fuel (MOX), and one based on the metal-fueled integral fast reactor.
Also, about sixteen old Soviet nuclear space reactors are known to have released an estimated 100,000 NaK liquid metal coolant droplets 800–900 km up, [5] which range in size from 1 – 6 cm. [5] The greatest risk to space missions is from untracked debris between 1 and 10 cm in size. [1]
In most reactor plant designs, however, this would not limit flowrate through the core and therefore would behave like a loss-of-pressure-control-accident rather than a loss-of-coolant accident. Failure of either the spray nozzles (failing open would inhibit raising pressure as the relatively cool spray collapses the pressurizer vessel bubble ...
During 16 reactor core ejections, approximately 128 kg of NaK-78 (a fusible alloy eutectic of 22% and 78% w/w sodium and potassium, respectively) escaped from the primary coolant systems of the BES-5 reactors. The smaller droplets have already decayed/reentered, but larger droplets (up to 5.5 cm in diameter) are still in orbit.
The Fukushima Daiichi nuclear disaster in 2011 occurred due to a loss-of-coolant accident. The circuits that provided electrical power to the coolant pumps failed causing a loss-of-core-cooling that was critical for the removal of residual decay heat which is produced even after active reactors are shut down and nuclear fission has ceased.