Chapter 1386: Go to ITER to share a table

Although he understood it, after thinking about the work at hand, Chang Haonan still looked hesitant.

Even nuclear batteries based on the fission principle are still in the early stages of transition from theory to engineering, and irradiation to produce tritium is a definite side task.

Even if it was theoretical research, even if he had the ability to cheat, he really couldn't give a specific timetable down to the month.

It's similar to the situation with controlled nuclear fusion.

Don’t ask, the answer is five years later.

Ask again next year, or five years from now.

But it may come true next year.

Therefore, before giving an answer, Chang Haonan asked cautiously:

“Can’t we test it in the country?”

He currently doesn't know much about the specific situation in the field of fusion. He only knows that Peng Juexian in front of him was one of the key figures who promoted the HT-7U fully superconducting non-circular cross-section tokamak device, also known as the "Eastern Super Ring" project.

At this moment, Luzhou should have successfully obtained plasma.

As far as controlled nuclear fusion is concerned, this is certainly not even the first step in a long journey.

Even due to issues of duration and configuration, it was unable to meet Chang Haonan's requirements for plasma power generation, otherwise he would not have gone to the trouble of transforming the small reactor at Factory 504.

But no matter what, it is a stable and fully autonomous and controllable research platform.

It should be able to play a certain role in the field of tritium proliferation.

Peng Juexian shook his head:

"Controlled fusion is something that no one has seen yet. As for the continuous working time advertised, it is just a simulation using the plasma in the fusion reactor position. Therefore, the irradiation tritium production test is conducted on special fission equipment."

"Due to the limited conditions in the early years, the current domestic research on the release behavior of tritium in breeder materials is conducted outside the reactor, that is, the breeder pellets are sealed in a special container, taken out after being irradiated by thermal neutrons in the reactor, and finally the tritium is released through annealing in the laboratory."

Chang Haonan raised his eyebrows:

"Wouldn't that be difficult to put into practical use?"

The half-life of tritium is only about 12 years. If it is used for tritium lamps or self-luminous fluorescent agents, a shorter lifespan is understandable.

However, if it is to be used as an energy source, this mode of producing tritium outside the reactor is obviously very unfavorable for storage and transportation.

A better approach would seem to be local production, that is, making it directly in a reactor or nuclear warhead and consuming it on site.

Peng Juexian's answer also verified his idea:

"That's right. So the ITER verification device in the Netherlands can make lithium ceramic materials produce tritium while the reactor is running, and obtain the macroscopic tritium release characteristics of the breeder during continuous irradiation by changing the temperature and carrier gas conditions... This advantage comes from their research that started as early as the 1970s. So even the United States needs to rely on the ITER platform to carry out related research."

"Currently, in the field of in-pile tritium production, the only ones who can theoretically compete with the Europeans are several Japanese universities. However, for well-known reasons, they have almost no room for maneuver in the field of nuclear engineering, so they also hope to go through the ITER channel..."

After all, it is the birthplace of modern science and industry, and its financial resources are rich enough.

Although they had gone through a half century of relative decline, until the first decade of the 21st century, Europeans did still have some unique skills that made people jealous.

Or rather, it is puzzling how Europe could become so dilapidated in just over a decade on the original timeline.

“Who are our current competitors?”

While asking, Chang Haonan opened a computer engineering file on his computer.

“At this stage, it’s just the EU itself, the U.S. and Russia, but Japan is likely to join in the next cycle.”

Peng Juexian replied:

"Because of the nature of ITER and the fact that all engineering tests are being carried out in Europe, it is not easy for us to stop it..."

As he spoke, his voice became smaller and smaller.

Because he saw the molecular simulation diagram that had just been rendered on the computer screen next to him.

Although there is no legend to explain what the different colored balls represent.

But as an expert in the field of nuclear energy, he recognized the characteristic structure of lithium aluminum oxide at a glance.

"Wait a moment……"

Peng Juexian's expression suddenly became complicated:

"Didn't you just say... that you haven't studied tritium release behavior?"

Chang Haonan stopped moving the mouse:

"I just said that the tritium produced by absorbing neutrons will not be enriched in nuclear batteries, but I didn't say that this process will not be studied... After all, we also have to consider whether the continuously produced tritium will have an adverse effect on the neutron shielding performance and magnetic fluid circulation process during the entire service life, especially in the middle and late stages of the service life."

"..."

The corners of Peng Juexian's mouth twitched slightly, but the other party's argument was well-reasoned and he could not find any point to refute.

In the end, it was Chang Haonan who completed the thought loop for him:

"Of course, at present, we are only studying the single behavior of tritium diffusion, so strictly speaking, it is not yet the complete process of 'tritium release behavior'. The behavioral characteristics of tritium production in the reactor are only at the theoretical and simulation stage."

But Peng Xianjue no longer wanted to delve into these literal details:

"Our current backup plan for the first cycle of experiments is to demonstrate whether we can increase the diffusion of tritium by increasing lithium vacancies... If we simply carry out this task, the content is too little and the significance is relatively limited, so another option is to actively choose a relatively late position in the first cycle to minimize the waste of the time allocated to us..."

“The way to increase lithium vacancies…”

Chang Haonan turned his gaze back to the screen in front of him.

It is obvious that Peng Xianjue and his colleagues have not been idle in the preparation process of ITER in recent years. They have proposed some mechanisms and hypotheses. However, due to the late start and lack of objective conditions, the progress is not optimistic.

But since the research of both parties happens to be at the same stage, it might be possible for them to work together.

Peng Juexian heard the other party repeat the key words and thought that the latter was interested in this research direction:

“The enhancement of ionic conductivity or lithium ion diffusion performance mainly comes from the lithium vacancies generated by irradiation, while interstitial lithium is more likely to migrate and aggregate to form defect clusters. The displacement of lithium ions during irradiation produces a large number of vacancies and interstitial lithium. These defects can enhance the diffusion performance of lithium ions in the material to a certain extent…”

Chang Haonan raised his hand slightly, indicating that there was no need to say more:

"However, if we use density functional theory to perform first-principles calculations on lithium vacancies, we will find that the formation energies of both lithium vacancies and oxygen vacancies in lithium ceramics are positive, indicating that the formation of ion vacancies in the system is energetically unfavorable..."

Although his ideas were refuted, Peng Juexian did not feel unhappy. Instead, he became excited.

This means that the two of them are finally on the same wavelength.

"It's indeed not favorable in terms of energy, but we also have to consider that in a neutron irradiation environment, such energy is negligible..."

He first explained it briefly, then changed the subject:

"Of course, it is precisely because this idea is kinetically favorable but thermodynamically unfavorable that we need to use ITER's resources to conduct actual verification. Otherwise, there would be no need to go through this trouble."

Chang Haonan instinctively felt that this route was not very reliable, but there was no evidence at the moment, so he just kept it in mind for the time being and returned to the original topic:

"Since you are also concerned about the spread of tritium, you should try your best to get a higher ranking..."

Then he pulled up the latest operation log on the computer:

"In addition to lithium ion vacancies, the reaction of lithium-6 absorbing neutrons will also produce two other forms of defects, namely interstitial tritium and substitutional tritium. According to estimates, interstitial tritium defects will occupy the lowest electron density in the system and will not bond with oxygen. It can be basically inferred that interstitial tritium will exist in the lithium ceramic in the form of interstitial atoms."

"However, substitutional tritium can easily transfer in the crystal lattice of lithium oxides with different lithium/oxygen ratios, such as lithium titanate and lithium silicate, and of course lithium aluminum oxide, affecting the diffusion process of tritium... In addition, because the radiation energy is much greater than the oxygen ion formation energy of lithium oxide, it is inevitable that oxygen free radicals and hydroxyl free radicals will appear, which will promote each other with substitutional tritium defects..."

"In short, if we can figure out the location and transfer mode of these defects, then we may be able to make a certain degree of prediction on the defect properties and evolution of the ternary lithium ceramic system..."

"..."

Peng Juexian made a rough estimate in his mind and thought that after adding these contents, there would be no problem of wasting time.

On the contrary, we need to speed up some efficiency to ensure completion.

This can be regarded as a solution to the current dilemma.

But just as I was about to nod, I figured out something else:

"So Academician Chang, you also think that solid proliferators are a better direction for development?"

As one of the proponents of the helium-cooled solid pebble bed technology, Peng Juexian certainly hopes that the solid breeder approach can continue.

However, even he himself did not dare to make this guarantee, and he always used the term "transition stage" to describe it in his reports to his superiors, leaving sufficient room for maneuver for the subsequent replacement of liquid proliferation agents.

“It is still unclear whether it is good or not.”

Chang Haonan pointed to the nuclear battery schematic on the drawing next to him:

"But as far as the plasma power generation principle I am currently studying is concerned, solid breeders have great advantages in terms of stability. If the core is changed from a fission reactor to a fusion reactor in the future, a lot of engineering troubles can be avoided..."

Peng Juexian:

???

Controlled fusion hasn't even started yet, so why are we already considering replacing the core?