00X/004 future nuclear CATOBAR carrier thread

[charles18]

...
My guess is that today, China will simultaneously build a nuclear carrier and also a conventional carrier. So by 2030, there should be mature carrier designs ready for serial production.

So if US-China relations are still bad, I wouldn't be surprised if 4 carriers (from both shipyards) are built between 2030-2035.
...

I am also in favor of China pursuing Both nuclear and conventional carriers at least for now. As for 2035 and beyond should China continue building conventional carriers or go all nuclear? who knows?

Furthermore even the design of the Type 004 CVN might Not be a permanent commitment.
Maybe 10 years from now, China will build CVN's with thorium reactors instead of PWR reactors?
We have to accept the possibility that China in the near future might take a different technological path compared to the US navy.

 

[HailingTX20]

Some interesting, albeit very speculative, CG of what the flight deck and island could look like based on the Wuhan facility and the apparent size of what's being build at Dalian. This assumes a deck length of 350m×80m and a maximum width at the angled deck of 82m.

 

[ACuriousPLAFan]

New flyby view of the drydock at Dalian. Posted by @WZZJWZ on Twitter.

 

[00CuriousObserver]

With the joining of the hull sections, it does look more and more like this may actually be a carrier, at which point we are basically just waiting for hangar sections to be installed to confirm it (or maybe flight deck overhang, or even the island, as definitive confirmations if one wants to be like that).

I recently came across some info that’s likely related to the Type 004, though it’s not exactly apt for me to share here. It’s along the same lines as what we’ve already seen, possible tenders, site photos, and so on. In general, there's just been so much noise, almost too much noise, around this ship.

Also, the trio has been relatively quiet on this topic. Many PLA watchers have essentially been treating this as the 004. If it weren’t, you’d think they might have said something firm by now. In other words, while they may not be allowed to confirm, they should be able to deny.

 

[00CuriousObserver]

Super blurry... One of the cranes might be over where the suspected reactor is

 

[SanWenYu]

Super blurry... One of the cranes might be over where the suspected reactor is

Blurrier than my waffle and sausage breakfast.

 

[Deino]

If legit and I‘m not mistaken, then this is the most recent satellite update on the alleged 004 aircraft carrier under construction at Dalian.

 

[BillRamengod]

I am also in favor of China pursuing Both nuclear and conventional carriers at least for now. As for 2035 and beyond should China continue building conventional carriers or go all nuclear? who knows?

Furthermore even the design of the Type 004 CVN might Not be a permanent commitment.
Maybe 10 years from now, China will build CVN's with thorium reactors instead of PWR reactors?
We have to accept the possibility that China in the near future might take a different technological path compared to the US navy.

No, the nature of thorium reactors (slow to react, too corrosive to metals, and too large an area) are inherently unsuitable as a source of power for aircraft carriers.

 

[hkky]

No, the nature of thorium reactors (slow to react, too corrosive to metals, and too large an area) are inherently unsuitable as a source of power for aircraft carriers.

What makes you say that?

Thorium does not fissile itself, it needs to capture a neutron and then couple decay steps to produce U233, which fertile. So you need a U-235 or Pu-239 driver fuel to get the process started. Th232 is similar to to U238 in that it could be turned to fertile isotope, but it has several times higher neutron capture cross-sectional area and thus you can bread fuel (U233) faster than the the traditional uranium fuel (e.g., 5% U235, where U238 is transmuted to Pu239). In U235 fuel, about half of the energy comes from Pu-239 (transmuted from U-238) near end of life.

U233 fission produces more free neutrons for follow-on chain reaction than U235 or Pu239 and therefore is more efficient. The key is can you make it work without re-processing. If a driver U235 fuel can be used to transmute sufficient Th232 to U233 without re-processing, it can gets around the waste issue since radiation from Th based fuel decays to acceptable levels within couple hundred years. Alternatively, if you use re-processing, thorium derived U233 is more efficient for a naval reactor, e.g., you can load less fissile content and get more energy out of a core.

I am not seeing a big advantage of thorium fuel for naval reactors, unless you already have the re-processing infrastructure.

 

[BillRamengod]

What makes you say that?

Thorium does not fissile itself, it needs to capture a neutron and then couple decay steps to produce U233, which fertile. So you need a U-235 or Pu-239 driver fuel to get the process started. Th232 is similar to to U238 in that it could be turned to fertile isotope, but it has several times higher neutron capture cross-sectional area and thus you can bread fuel (U233) faster than the the traditional uranium fuel (e.g., 5% U235, where U238 is transmuted to Pu239). In U235 fuel, about half of the energy comes from Pu-239 (transmuted from U-238) near end of life.

U233 fission produces more free neutrons for follow-on chain reaction than U235 or Pu239 and therefore is more efficient. The key is can you make it work without re-processing. If a driver U235 fuel can be used to transmute sufficient Th232 to U233 without re-processing, it can gets around the waste issue since radiation from Th based fuel decays to acceptable levels within couple hundred years. Alternatively, if you use re-processing, thorium derived U233 is more efficient for a naval reactor, e.g., you can load less fissile content and get more energy out of a core.

I am not seeing a big advantage of thorium fuel for naval reactors, unless you already have the re-processing infrastructure.

I'm not very proficient in nuclear technology. However, this Bilibili uploader (@军武白板) briefly explained the disadvantages of the thorium-based reacto: When uranium-233 absorbs neutrons, it produces fission poisons, which need to be treated. Therefore, a very large online fuel processing facility needs to be built (all on the left in the picture). As a result, the power generation efficiency of the entire facility is actually only about equivalent to that of photovoltaic power generation in the same area. Secondly, since lithium-6 in LiF in the carrier salt will produce tritium when irradiated by neutrons, it will cause tritium embrittlement in the pipes, so the service life of the entire pipeline will not exceed 15 years.

If you understand Chinese, I strongly recommend watching his videos. They give a very concise explanation of the principles, advantages, and disadvantages of the thorium-based reactor.

(I used AI translation because there are a lot of technical terms. I hope the meaning is correct /salute)

【【军武白板】第41期：并不是万能的钍基堆工作原理-哔哩哔哩】

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【钍基堆上不了航母-哔哩哔哩】

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【【军武白板】第66期：第四代核反应堆谁更适合航母核动力-哔哩哔哩】

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