00X/004 future nuclear CATOBAR carrier thread

[charles18]

Land based nuclear power plants take months to refuel. It is one reason why the Russians for example build them in pairs. So you always have at least one operational power plant while the other is being refueled.

The bomb dropped on Hiroshima had 64kg of HEU uranium. (at least 90% enrichment)

The bomb dropped on Nagasaki had 6.4kg of plutonium. (only 1/10th the amount of fissile material)

Since plutonium has a higher energy density than weapons grade uranium, it would require less PU-239 to power a naval nuclear reactor than using U-235. Despite this fact, uranium became the preferred fuel choice for marine nuclear propulsion. Why? I don't know, I'm not an engineer. Maybe that's what made sense based on the technological limitations of the time period which was over 70 years ago. If the same decision was made today (using today's technology unencumbered by legacy infrastructure ) would the same decision be made?

 

[gelgoog]

Probably cost and proliferation risk mean it makes little sense to use Plutonium on naval reactors.

 

[charles18]

Probably cost and proliferation risk mean it makes little sense to use Plutonium on naval reactors.

You're probably right.

Why does China choose LEU instead of MEU and HEU for their nuclear subs? Wouldn't that require more frequent refueling, i.e. less time available for patrol?

If we go back to the 1970's when the Type 091 submarine was being developed, China was a poor country and HEU uranium was expensive to produce. Whatever small quantity of HEU that was produced went to making nuclear weapons. China chose to run its submarines on LEU, simply because it was cheaper. Actually it wasn't a "choice" it was the only thing China could afford at the time. I don't know if this is the official story, but it sounds believable.

Fast forward to the present, the economic equation is different. China can now afford to buy whatever it wants, except for antimatter.
** joking **

 

[Sczepan]

Still remember this one from Dalian?
View attachment 110434

This time, it is Jiangnan's turn:
View attachment 110432

According to @单手搓核弹 on Weibo, this illustration of a CV-20 nuclear-powered supercarrier has been posted by the official socmed account of Jiangnan Shipyard. The illustration was released as the header of an article titled <<[Look at the ship's culture(?)] Help spread culture, light up every dream>>.
View attachment 110433

Besides, that carrier-based fighter to the top right corner looks kinda weird, if it is indeed a J-35...

Moreover, notice the ship at the center right - that structure looks like a new design. 054B or 052E, perhaps?

So, which shipyard will be responsible for the first unit of 004 CVN? Dalian or Jiangnan? I guess only time will tell.

both pix show "hull nr. 20" - so i suspect hull nr. 19 will be conventional like Fujian Nr. 18

 

[jvodan]

The bomb dropped on Hiroshima had 64kg of HEU uranium. (at least 90% enrichment)

The bomb dropped on Nagasaki had 6.4kg of plutonium. (only 1/10th the amount of fissile material)

Since plutonium has a higher energy density than weapons grade uranium, it would require less PU-239 to power a naval nuclear reactor than using U-235. Despite this fact, uranium became the preferred fuel choice for marine nuclear propulsion. Why? I don't know, I'm not an engineer. Maybe that's what made sense based on the technological limitations of the time period which was over 70 years ago. If the same decision was made today (using today's technology unencumbered by legacy infrastructure ) would the same decision be made?

Comparing apples to oranges.
The mass difference is about how much is required to reach critical mass based on the tech used and the level of enrichment in the case of HEU
Hiroshima was a simple device compared to Nagasaki.
Nagaski was an implosion device
Hiroshima fired two targets together.

 

[taxiya]

Why does China choose LEU instead of MEU and HEU for their nuclear subs? Wouldn't that require more frequent refueling, i.e. less time available for patrol?

If we go back to the 1970's when the Type 091 submarine was being developed, China was a poor country and HEU uranium was expensive to produce. Whatever small quantity of HEU that was produced went to making nuclear weapons. China chose to run its submarines on LEU, simply because it was cheaper. Actually it wasn't a "choice" it was the only thing China could afford at the time. I don't know if this is the official story, but it sounds believable.

Being cheaper isn't the only reason. Being safer is another reason, so important so that the French insists on using LEU, so it is a choice.

Being cheap is due to the fact that it is the same fuel used in civilian power plant. The production cost is the same as civilian fuel. The saving is from NOT need to build a separate enrichment facility/capacity, saving the investment. Essentially it is the civilian consumer paying large part for the military. So from this perspective, cheap is also a choice.

The drawback of LEU is its lower power density. So for CVN it may be a bad idea.

Another reason for US and Russia using HEU is their huge stockpile of nuclear warhead. The retired warhead is the primary source for fuel. China and France don't have that stockpile but have a large civilian nuclear industry, so LEU makes sense. UK is just using whatever US provide. India has neither the stockpile nor the size of power plants, so they just make an extra "bomb/fuel".

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[ACuriousPLAFan]

Fu Qianshao alleged that China right now is capable of/could be/already are building two (super)carriers at the same time, and that at least one of them could be nuclear-powered:

 

[vincent]

Fu Qianshao alleged that China right now is capable of/could be/already are building two (super)carriers at the same time, and that at least one of them could be nuclear-powered:

The guy is not credible. He’s a Chinese version of Jai Hind!

 

[weig2000]

The guy is not credible. He’s a Chinese version of Jai Hind!

Agreed. It's actually annoying to see his video popped up in my Youtube recommended list every once in a while. He usually picked up some internet or fanboy rumors and hyped on them, forgetting that he is no longer a boy but a grumpy old man now. lol.

 

[charles18]

Being cheaper isn't the only reason. Being safer is another reason, so important so that the French insists on using LEU, so it is a choice.
......

One of the drawbacks of using 90% HEU propulsion is there is a risk, however slight it may be, somebody could steal the HEU uranium to make a nuclear bomb. That has never happened.
Some have argued the US navy should switch over to 20% LEU propulsion to reduce the risk of nuclear proliferation but that's not going to happen.

Which path will the PLA-navy choose for its CVN nuclear propulsion:
a) 20% LEU
b) 90% HEU

I believe the PLA-navy has already made their decision. If I had to take a wild guess, I'd say 20% LEU why?
The production of HEU is a very intensive process. You'll need a factory that's even larger than a Tesla Giga-factory. In today's world of spy satellites good luck trying to keep that a secret. There is no evidence that China is producing HEU in sufficient quantities to power naval nuclear reactors. Indeed if there was such evidence there would be no shortage of American mainstream news channels complaining. The hypocrisy would be rich, considering the US navy has been running HEU for the past 70 years so why can't China?