Chapter 82: Separation and Purification
Manufacturing an atomic bomb requires either uranium or plutonium. After a comprehensive survey of the mineral reserves on Ceres and Enemy God Star, Li Qingsong ultimately decided to use uranium for his first attempt at harnessing nuclear energy.
The Solar System formed approximately five billion years ago. All the matter that comprises the Solar System originated from a nebula likely formed by a Supernova Explosion around that time.
A Supernova Explosion is one of the most violent physical events in the Cosmos. During this process, the immense energy generated all the elements heavier than iron, including uranium and plutonium, which were then scattered into interstellar space.
Throughout the Solar System’s long evolutionary process, these uranium elements were randomly dispersed across it.
It could be found on Earth, on Mercury and Mars, and even on a dwarf planet like Ceres, located at the edge of the Solar System.
It most likely formed in the Inner Solar System originally, only to later break away and end up in an orbit this far from the Sun.
After extensive prospecting, Li Qingsong did indeed find uranium ore on Ceres.
Not just one deposit, but four of them.
But...
Li Qingsong couldn’t help but give a bitter smile.
’So there are four deposits, but this ore is far too low-grade... Even in the richest one, the average uranium content is only a few grams per ton.’
He vaguely recalled a statistic: on Earth, even a relatively low-grade uranium mine would contain at least 100 grams of uranium per ton of ore.
Yet the richest deposit on Ceres couldn’t even compare to the poorest ones on Earth.
But there was nothing to be done. Ceres was too small. It had no molten core, no magma flows, and no groundwater to speak of.
Without these natural concentration mechanisms, it was only normal for the ore veins to be of low grade.
With a sigh, Li Qingsong ultimately chose what was, comparatively, the richest of the uranium veins.
According to his plan, a large factory was swiftly constructed near the uranium mine.
Massive quantities of mining equipment were shipped in. Soon, ore that was buried more than a hundred meters underground—so deep it could only be painstakingly reached by digging shafts—was being excavated and sent to the factory for processing.
The ore was first crushed, then ground into a powder.
Due to the sheer volume of ore that needed to be processed, the crushing and grinding stages required a vast amount of equipment and an enormous amount of electricity.
Having no other choice, Li Qingsong had to build a power plant nearby, dedicated solely to supplying the factory’s power consumption.
In addition, Li Qingsong built a dedicated chemical plant just to supply the acidic solution.
Once ground into a powder, the uranium ore was soaked in the acidic solution for further treatment.
The sheer quantity of ore powder meant that the demand for the acidic solution was also immense. Fortunately, the dedicated chemical plant he’d built was able to keep up.
After the soaking was complete, a solvent extraction technique was used to extract the uranium oxide, the infamous "yellowcake."
Looking at the pale yellow, cake-like substance before him, Li Qingsong thought to himself, ’I’ve only ever seen this in movies and TV shows. Now I’m finally looking at the real thing.’
This stuff was radioactive, too. Although the level wasn’t high, to be on the safe side, Li Qingsong still had the Clones wear anti-radiation suits.
Producing yellowcake was only the first step in creating enriched uranium.
There was still much more to be done.
After some chemical treatments, the yellowcake was converted into uranium hexafluoride.
Uranium hexafluoride is a gas, and reaching this stage meant it was time to begin the most important step of the uranium enrichment process.
The element uranium has two isotopes: uranium-235 and uranium-238. Whether for nuclear power plants or atomic bombs, only uranium-235 can be used; uranium-238 is not viable.
But in natural uranium, the content of uranium-235 is only about 0.8%, with the remaining 99.2% being uranium-238.
But the two have nearly identical masses and chemical properties. How could they be separated?
This was a major hurdle. In human history, it was a problem that had perplexed humanity for a very long time.
But that didn’t matter. While Li Qingsong had never been involved in the uranium enrichment process before, he roughly knew the basic principles.
It was nothing more than a matter of centrifuges.
Uranium-235 is about 1% lighter than uranium-238. After combining with fluorine to create uranium hexafluoride gas, this same slight difference in mass existed between the two types of gas molecules.
That being the case, the solution was simple.
Li Qingsong once again built a power plant, this one dedicated to powering another factory.
Inside this factory, Li Qingsong manufactured tens of thousands of enormous cylinders. These cylinders were two-layered: an outer casing, and inside, a centrifuge that could spin at high speeds, much like the drum of a washing machine.
The uranium hexafluoride gas produced in the previous factory was piped into the first centrifuge of the new plant.
Fed by a surging supply of electricity, the centrifuge began to spin at high speed. The immense centrifugal force flung the heavier gas, formed with uranium-238, against the cylinder wall. The lighter gas, composed of uranium-235, concentrated in the center of the centrifuge, furthest from the wall.
But this single step was far from enough.
The mass difference between the two isotopes was simply too small, so this initial separation was nowhere near pure enough.
Thus, the slightly lighter uranium hexafluoride from the center was siphoned off and fed into the second centrifuge.
The second centrifuge also began to spin at high speed, completing another round of separation. Afterward, the uranium hexafluoride at its center was again siphoned off and fed into the third centrifuge...
With each centrifuge it passed through, the concentration of uranium-235 increased a little.
And Li Qingsong had built over ten thousand of these centrifuges in the factory!
The power consumed by over ten thousand centrifuges spinning at high speed day and night was horrifyingly immense, dwarfing even that of the Supercomputing Base.
These centrifuges were divided into four production lines, each with approximately 2,600 units. A given batch of uranium hexafluoride gas would pass through 2,600 centrifuges, undergoing enrichment 2,600 times, until its concentration finally reached the required level.
At this point, the uranium hexafluoride gas could finally be converted into metallic uranium, becoming a suitable raw material for an atomic bomb.
But this alone was still not enough.
Relying solely on a naturally occurring chain reaction, a single atomic bomb would require tens of kilograms of uranium. Moreover, its yield would be small, and most of the uranium would be wasted.
A proper detonation mechanism had to be designed.
Designing this detonation mechanism was considerably more complex. It involved a host of incredibly complicated calculations, such as nuclear cross-section data, equations of state, implosion dynamics, shockwave focusing and symmetry, explosive lens design, and so on.
However, these complex calculations posed little difficulty for Li Qingsong.
Because Li Qingsong had a supercomputer! And a supercomputer far more advanced than any from a comparable period in human history, at that!
After conducting dozens of pre-detonation experiments to acquire sufficient parameters, the supercomputer calculated the corresponding data in less than a day.
And so, a massive bomb with a total mass of 3.6 tons and a length of over three meters was finally built.