Recent content by Hologram0110

I guess I should explain what I'm looking for a bit more explicitly. Mass conservation $$\frac{dz}{dt}=\nabla \cdot c \nabla \mu$$ Chemical potential (Euler-Lagrange equation) $$\mu = \frac{\partial E}{\partial z} - \frac{\partial }{\partial x} \frac{\partial E}{\partial z_x} -\frac{\partial...

Hello everyone, I've encountered a bit of an interesting problem; a 6th order PDE in 2D + time resulting from a phase-field type physics model (mathematically it comes from a mass conservation equation (two orders)coupled to the Euler-Lagrange equation for variational calculus when the function...

There are a number of news articles discussing the accident. Here is one from Nuclear News. Since not everyone on the board would be familiar with CANDU style reactors I'll give a bit of information below: - Pressure tubes ~10 cm diameter contain ~10 MPa pressure D2O coolant and fuel bundles...

Its really neat that the design is progressing. I really like that they have dropped thorium for the first generation design. While it has potential long term, it makes sense to keep the first generation of MSR as simple burner reactors especially if they are targeting spent fuel. MSRs are...

The main types of neutron sources are isotopic (usually SF from Cf-252), nuclear reaction like (alpha,n), fusion (usually D-T or D-D), fisson reactors or spallation of neutrons from a charged particle beam hitting a target. This is a terrible idea. Fission = fission products = highly...

To give you an idea thorium has a half-life of 14 Billion years. Uranium-238 has a half-life of 4 billion years. U-235 is 700 million years. The most common types of plutonium in spent fuel is Pu-239, it has a halflife of 24 thousand years, Pu-240 is only 6.5 thousand years and Pu-241 is 14...

Briefly looking at the list I noticed that you didn't include cobalt. I know that it has been used in CANDU reactors (in fact the Co-60 that is produced can actually be sold). A quick google turned this wiki page up.

For most applications you either want a stepper motor or a servo depending on speed/torque requirements you might also need gears.

Absolutely. I'm not denying that space based reactors have huge potential. They certainly scale to high power far better than RTGs. I was just making the point that if you only want 300 W than an RTG is far lighter, simpler and more reliable than a 300 W reactor (for such a limited power). Right...

@QuantumPion Does that include shielding?Even if it doesn't there is an obvious niche. If your probe only needs 300 or 400 W of power a full blown reactor is overkill (and likely adds more weight and safety issues).

This is just a reactor where instead of a control rod for reactivity control it is a booster rod (positive reactivity instead of negative). Such a system has all the complexity and weight of a reactor (there have been reactors in space reactors). RTGs fulfill a niche role of low/moderate power...

I've thought up something like this before too. It is basically a sub critical reactor driven by an internal neutron source. There are some positives and negatives to such a system. A big disadvantage is the radiation from neutrons and fission products which can damage to some equipment. This...

There is something of a sweet spot in terms of half-life and difficulty handling. With a very short half-life material its very easy to simply wait for it to become safe to handle (for most applications). Give it 10 half-lives and the activity has dropped by 1024. Some materials have very long...

I've only taken one particle physics class and one radio-chem class but I was under the impression the models are not particularly good for large nuclei. You have to solve the Schrödinger wave equation for a large number of particles simultaneously (all neutrons and protons) and its very hard to...

Typically we would use programs that have been written to calculate isotopic concentrations. These programs perform exactly the sort of calculations you're talking about. The one that comes to mind is Origin/Scales (I've never used it) but it can be used for calculating the isotope mix due to a...