|
Post by SevenOfCarina on Aug 29, 2017 13:18:31 GMT
Exactly what it says on the tin. I'm presently using Hafnium Carbide for moderators and control rods in my reactors, but I'm dissatisfied with the results. Is there another, better, stock option?
|
|
|
Post by bigbombr on Aug 29, 2017 13:21:35 GMT
Exactly what it says on the tin. I'm presently using Hafnium Carbide for moderators and control rods in my reactors, but I'm dissatisfied with the results. Is there another, better, stock option? Don't people usually pick diamond as moderator and titanium nitride as control rod? I haven't played without mods for a while. If you're willing to use mods, coat everything in graphene and your troubles will disappear.
|
|
|
Post by Rocket Witch on Aug 29, 2017 13:25:38 GMT
Thou must beseech Boron Almighty, my child. Titanium diboride will show you the light.
|
|
|
Post by SevenOfCarina on Aug 29, 2017 13:28:39 GMT
I don't know much about that, but I really don't believe that Titanium Nitride is going to be all that useful, considering it melts lower than Boron Nitride. Perhaps you meant Titanium Diboride? Even then, I'm able to squeeze out much more power per ton of mass with Hafnium Carbide. I wanted to know if Hafnium Carbide was the best material for the aforementioned purpose or whether a superior alternative existed.
|
|
|
Post by jtyotjotjipaefvj on Aug 29, 2017 13:40:06 GMT
Boron Nitride can be good on tiny reactors, though I'm not sure if you can make anything lighter than you could with Titanium Diboride. Also aren't moderators universally bad for your efficiency? I've never made a reactor that uses any at least.
|
|
|
Post by SevenOfCarina on Aug 29, 2017 13:55:30 GMT
They are, but I do sometimes get embarrassed by how much radiation my reactors throw out.
Edit : Was enlightened by the mighty apophys.
|
|
|
Post by teeth on Aug 29, 2017 16:06:33 GMT
Boron Nitride can be good on tiny reactors, though I'm not sure if you can make anything lighter than you could with Titanium Diboride. Also aren't moderators universally bad for your efficiency? I've never made a reactor that uses any at least. Apophys' reactors use moderator, that's all that needs to be said about their efficiency.
|
|
|
Post by apophys on Aug 31, 2017 23:24:23 GMT
Ingame, the main usage of moderator is to use fuel more efficiently (higher flux), and thus use less fuel. This is done by reducing neutron speed on bounces, making more of the neutrons likely to fission your fuel. Lighter atoms are the best at this function. Of the light atoms, carbon makes the most temperature-resilient materials, and diamond is the densest form of carbon. U-233 dioxide is more expensive than diamond, so the trade works well up to a point. Low-power reactors can use a tiny bit of control rod material in the moderator slot to somehow improve neutron flux, but this may or may not be an exploit. This effect was discovered by jasonvance . TL;DR: Diamond is best moderator for reactors. NTRs don't need moderator, because the propellant flowing through acts as a good moderator already. The active ingredient in a control rod is usually boron-11, which absorbs a neutron with very high probability, and then beta decays into carbon-12. Any boron-containing material will work. Of these, titanium diboride is cheap enough and has a desirable melting point. It melts at nearly the same temperature as U-233 dioxide fuel in our prismatic reactor cores, allowing us to easily get 2500 K reactor outlet temperatures (or very hot NTR propellant). Before the prismatic core tweak, boron nitride was preferred for cheapness. TL;DR: Titanium diboride is best control rod.
|
|
|
Post by newageofpower on Aug 31, 2017 23:48:15 GMT
IRL, the logical endpoint is to encapsulate liquid everything in TaHfC; Liquid Control Rod, Liquid Fissile Fuel, Liquid Moderator.
|
|
|
Post by SevenOfCarina on Sept 1, 2017 14:05:54 GMT
TL;DR: Titanium diboride is best control rod. I tend to prefer optimizing mass to optimizing cost, since mass is always the first limit that I hit in CoaDE. As a result, I would think Hafnium carbide works better than Titanium diboride, demonstrated by this reactor design : It works out to be mass ~5% less and cost ~3% more per Megawatt as compared to the 101 MW Reactor from the standards thread.
|
|
|
Post by jtyotjotjipaefvj on Sept 1, 2017 18:20:57 GMT
TL;DR: Titanium diboride is best control rod. I tend to prefer optimizing mass to optimizing cost, since mass is always the first limit that I hit in CoaDE. As a result, I would think Hafnium carbide works better than Titanium diboride, demonstrated by this reactor design : It works out to be mass ~5% less and cost ~3% more per Megawatt as compared to the 101 MW Reactor from the standards thread. That depends on your usage. NTR reactors are essentially massless, with upwards of 1,000 g TWRs. Besides, higher exhaust temperatures increase thrust as well so in my experience you end up with a higher TWR by using Titanium Diboride. You might be correct when it comes to generating electricity though, I've never bothered to familiarize myself with generators.
|
|
|
Post by SevenOfCarina on Sept 2, 2017 4:11:50 GMT
That depends on your usage. NTR reactors are essentially massless, with upwards of 1,000 g TWRs. Besides, higher exhaust temperatures increase thrust as well so in my experience you end up with a higher TWR by using Titanium Diboride. You might be correct when it comes to generating electricity though, I've never bothered to familiarize myself with generators. Titanium diboride has a melting point of 3500K as compared to Hafnium carbide at 4170K, so my reactors run slightly hotter. Just to be clear, coolant exits the reactor at 2500K, not lower, so I fail to see how this would produce a lower TWR - the reactor is lighter and hotter.
|
|
|
Post by apophys on Sept 2, 2017 4:38:55 GMT
I would think Hafnium carbide works better than Titanium diboride, demonstrated by this reactor design: Hmmm... I was skeptical, but testing things out, it appears that hafnium carbide is useful due to its superior melting point (despite its increased mass, cost, and core volume). There are savings in the inner turbopump, and these savings appear to outweigh the increased costs of the hafnium carbide. So far I've been able to reduce the mass of my 101 MW reactor by 6% with no change in cost or power (making it a direct upgrade to yours). So indeed hafnium carbide appears to be marginally better than titanium diboride. (Standard reactor modules will be updated once I've fiddled with things moar.) If we had a boron-containing ceramic that melts later than our fuel rods, that would be perfect. I haven't tried the hafnium diboride mod yet, but that one should be close.
|
|
|
Post by SevenOfCarina on Sept 2, 2017 5:44:12 GMT
So far I've been able to reduce the mass of my 101 MW reactor by 6% with no change in cost or power (making it a direct upgrade to yours). So indeed hafnium carbide appears to be marginally better than titanium diboride. (Standard reactor modules will be updated once I've fiddled with things moar.) Link please? Also, exactly what gained you such a large improvement over mine? I've been unable to optimize it further despite hours of effort, so I'd honestly like to know where I'm lacking in design. Edit : Got it now. 100 MW at 999 kg and 20.3 kc, retaining a 2500 K radiator temperature and 50.4 kW radiation hazard.
|
|
|
Post by RiftandRend on Sept 5, 2017 19:14:49 GMT
IRL, the logical endpoint is to encapsulate liquid everything in TaHfC; Liquid Control Rod, Liquid Fissile Fuel, Liquid Moderator. This is only ideal for NTRs. You can't easily reach a temperature where TaHfC is useful as the thermocouples and turbomachine blades begin to melt. Encasing it in graphite or Hafnium Carbide is superior.
|
|