29 lines
2.2 KiB
Markdown
29 lines
2.2 KiB
Markdown
# Executive Summary
|
|
MARVEL stands for Microreactor Applications Research Validation and Evaluation. MARVEL
|
|
is an 'open-source' microreactor design that is coming out of the Idaho National
|
|
Laboratory. This 'open-source' idea is a response to commerical reactors such as eVinci
|
|
from Westinghouse being closed-door endeavors. This isn't great, because it doesn't
|
|
allow a place for everyone to communicate about designs. This is especially relevant
|
|
for microreactors, where the low power model and economy-of-production model really
|
|
benefits from common knowledge being out there.
|
|
|
|
MARVEL is a unique design that I haven't really seen before. First of all, coolant
|
|
is by natural convection. This reactor system uses two coolant loops: the primary loop
|
|
is sodium-potassium salt, while the secondary coolant is lead. These two fluids
|
|
drive 'Stirling Engines', which are how the system generates power.
|
|
|
|
- [?] What are Stirling Engines? #MARVEL
|
|
Stirling engines are heat engines that directly convert heat energy into mechanical energy. How they work is they have a piston that travels back and forth from a hot side to a cold side. When the cylinder travels over the hot side
|
|
|
|
Anyways, MARVEL also uses an interesting drum based system to do power control.
|
|
They use one big central 'insurance' rod, but also have four drums around the cylindrical
|
|
core. These drums have a poison side, whose angle of incidence on the reactor plays a large part in how much neutron fission is allowed to happen. These drums have a fail-close state, that if something
|
|
were to happen to the controller, they would passively return to a shut position. To keep the poison
|
|
faces from killing with the reactor, the controller must actively apply force to the drums to prevent
|
|
them rotating.
|
|
|
|
These drum based control systems have a significant advantage that they don't create a
|
|
longitudinal imbalance in reaction rate, compared to a typical control rod. Since they face / shy from
|
|
the entire core equally along its length, they can probably be more efficiient, and take up way less
|
|
space. The insurance rod is a typical rod however, as it would not be possible to put a rotating
|
|
control drum in the middle of a cylinder. 🤷♂️ |