Part 2 of 2 Parts (Please read Part 1 first)

It has two layers of internal and external cladding around the main steel structure – about thirteen yards apart – with both layers being breached in the drone incident. The NSC was designed to allow for the eventual dismantling of the ageing makeshift shelter from 1986 and the management of the radioactive waste that it contained. It is also designed to withstand temperatures ranging from minus one hundred- and nine-degrees Fahrenheit to plus one hundred- and thirteen-degrees Fahrenheit, a class-three tornado, and an earthquake with a magnitude of six on the Richter scale.

According to the World Nuclear Association, the hermetically-sealed NSC allows “engineers to remotely dismantle the 1986 structure that has shielded the remains of the reactor from the weather since the weeks after the accident. It will enable the eventual removal of the fuel-containing materials in the bottom of the reactor building and accommodate their characterization, compaction, and packing for disposal. This task represents the most important step in eliminating nuclear hazard at the site – and the real start of dismantling”.

The NSC was financed via the Chernobyl Shelter Fund which is run by the European Bank for Reconstruction and Development (EBRD). It received one billion seven hundred million dollars from forty-five donor countries and the EBRD provided five hundred and thirty-six million dollars of its own resources.

On the 4^th of March, the EBRD allocated four hundred and forty-seven dollars from the administrative budget of the continuing fund for specialist-led damage assessment.

The IAEA reported that the Ukrainian Zaporizhzhia nuclear power plant lost one of its two remaining external power lines on Wednesday. The Ukraine’s Ministry of Energy told them that the loss of the power line was the result of Russian military activity. Before the war, the plant had ten external power lines.

Grossi said, “A secure supply of off-site power from the grid for all nuclear sites is one of the seven indispensable pillars of nuclear safety and security that we outlined early in the war. It is obvious that this supply is far from being secure. The vulnerability of the grid remains a deep source of concern for nuclear safety.”.

The Zaporizhzhia plant has been under Russian military control since March 2022. It is located on the line between Russian and Ukrainian forces and has lost access to off-site power on eight occasions during the war The plant has to rely on emergency diesel generators to provide the power needed for safety functions.

Grossi said that he has been in touch with both sides in the conflict as he seeks to organize the next rotation of the IAEA experts stationed at the plant. Differences over the route to be taken – via Ukraine or from the Russian side – and the safety situation has resulted in the current team now being at the plant for over two months.

The IAEA teams currently based at Ukraine’s three operating nuclear power plants and at Chernobyl “have continued to report about air raid alarms on most days over the past week”, the IAEA added.

Zaporizhzhia

Part 1 of 2 Parts

The International Atomic Energy Agency (IAEA) has reviewed the scale of the damage caused by a Russian drone strike and subsequent fires to the giant shelter built over the ruins of Chernobyl’s unit 4. Chernobyl shelter’s drone damage includes 330 openings in outer cladding. Hundreds of openings were cut during efforts to extinguish fires.

The IAEA said that investigations continue to determine the exact extent of the damage sustained by the arch-shaped New Safe Confinement (NSC) shelter following the drone strike on the 14^th of February.

The impact caused an eighteen square yard hole in the external cladding of the arch, with further damage to a wider area of about two hundred forty-square-yards, as well as to some joints and bolts. It took about three weeks to completely extinguish smoldering fires in the insulation layers of the shelter.

In its update on the situation, the IAEA said, “It took several weeks to completely extinguish the fires caused by the strike. The emergency work resulted in approximately 330 openings in the outer cladding of the NSC arch, each with an average size of 30-50 cm.”. According to information provided to the IAEA team at the site, a preliminary analysis of the physical integrity of the large arch-shaped building identified extensive damage, for example to the stainless-steel panels of the outer cladding, insulation materials as well as to a large part of the membrane – located between the layers of insulation materials – that keep out water, moisture and air.”.

The main crane system, including the maintenance garage area, was damaged and is not currently operational. The heating, ventilation and air conditioning systems are functional but have not been operating since the strike. Radiation and other monitoring systems are also still functional. There has been no increase in radiation levels detected at any time during or since the drone strike.

General Rafael Mariano Grossi is the IAEA Director. He said, “We are gradually getting a more complete picture of the severe damage caused by the drone strike. It will take both considerable time and money to repair all of it.”.

Chernobyl Unit 4 was destroyed in the April 1986 accident with a shelter constructed in a matter of months to encase the damaged unit. This allowed the other units at the plant to continue operating. The encased Unit still contains the molten core of the reactor and an estimated two hundred tons of highly radioactive material.

However, the shelter was not designed for the very long-term. The New Safe Confinement (NSC) was constructed to cover a much larger area including the original shelter. The NSC has a span of two hundred and eighty yards, a length of one hundred and seventy-seven yards, a height of one hundred and eighteen yards and a total weight of thirty-six thousand. It was designed for a lifetime of about one hundred years. The NSC was constructed nearby in two halves which were moved on specially constructed rail tracks to the current position, where it was completed in 2019.

Chernobyl

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A top global nuclear body has launched a new program to assemble, validate, and distribute data on tungsten impurity processes in fusion plasmas. The International Atomic Energy Agency’s (IAEA) new five-year Coordinated Research Project (CRP F43028) could assist in the advancement of nuclear fusion energy development.

There are plans to use tungsten as a wall material in next-generation fusion devices (even in ITER) because it offers favorable thermal and mechanical properties for future fusion reactors.

However, there are speculations among researchers that interactions between plasma particles and tungsten walls can lead to erosion. Such erosion can release tungsten impurities into the plasma.

The IAEA emphasized that these impurities in the plasma core can severely impact stability and performance by increasing radiative energy losses and triggering disruptive instabilities. The new project would work on understanding the behavior of tungsten ions in fusion plasmas to reduce risks.

IAEA has also revealed that critical uncertainties remain in the interaction processes of tungsten with plasma fuel particles in the one to ten kilovolts energy range because discrepancies persist between theory and experiments. In addition, processes involving neutral atoms or protons interacting with low-charge tungsten ions require further study to improve predictive models.

This project is expected to provide evaluated experimental and computational data on tungsten ion properties under fusion-relevant plasma situations. The results of this research will directly support the operation of future fusion reactors using tungsten-based plasma-facing components.

The project will assess and verify the ionization cross-sections and rate coefficients from metastable values of tungsten’s first ionization stages. It will also investigate the collisional interactions of neutral atoms and protons with tungsten ions.

The research will also experimentally assess the low and medium ionization stages of tungsten in the unresolved transition array (UTA) and quasi-continuum (QC) regions. UTAs are a method of approximating complex atomic physics in plasma opacity calculations, and as such are very important in modern plasma dynamic simulations. With the goal of modeling an atomistic system without explicitly treating every atom in the problem, QCs provides a framework whereby degrees of freedom are judiciously eliminated, and force/energy calculations are expedited.

Multiple studies have also found that tungsten-based materials are considered to be one of the most promising plasma-facing materials, but there are still many problems in practical applications.

In previous work, researchers have stressed that plasma-facing materials are subjected to the multi-field coupling effect of thermal shock and multiple radiations, which requires tungsten-based materials to have not just good mechanical properties but also a certain resistance to irradiation.

There have also been claims that the utilization of tungsten fiber reinforced tungsten (Wf /W) could broaden the operation temperature window of tungsten significantly. It could also mitigate problems of deep cracking occurring typically in cyclic high heat flux loading. This is especially crucial when considering material degradation from neutron-induced transmutation and embrittlement.

Designed to mitigate tungsten’s brittleness, tungsten fiber-reinforced tungsten (Wf/W) composites incorporate tungsten fibers into a tungsten matrix. The approach aims to achieve pseudo-ductile behavior which means that the material can withstand deformation and cracking without losing its load-bearing capacity, even at room temperature.

IAEA

For decades, fusion energy has held the promise of a revolutionary power source that is clean, safe, and virtually limitless.

Unlike fossil fuels or even traditional nuclear power, nuclear fusion mimics the energy production of the Sun. Atomic nuclei fuse together to release massive amounts of energy without greenhouse gas emissions or long-lived radioactive waste.

However, one serious problem has kept this dream out of reach. That is the inability to reliably contain high-energy particles inside fusion reactors.

These particles are essential to keeping the plasma hot enough for sustained fusion. However, they tend to escape through holes in the reactor’s magnetic field, draining energy and halting the reaction.

Now, a team of researchers from The University of Texas at Austin, Los Alamos National Laboratory, and Type One Energy Group have developed a faster, more accurate way to fix those magnetic flaws. This could accelerate the development of stellarators, one of the most promising fusion reactor designs, by a factor of ten.

Fusion reactors require a superheated plasma confined within strong magnetic fields. An important issue has been the escape of high-energy alpha particles, which are supposed to help maintain the plasma’s heat and pressure. When these particles leak, they weaken the reaction which prevents the conditions necessary for sustained fusion.

However, these magnetic fields often contain ‘holes’ through which alpha particles escape. Finding and correcting these flaws using traditional methods based on Newton’s laws is computationally intensive and slow. The design process becomes cumbersome as engineers need to simulate and test hundreds of variations in the configuration of the coils.

To make the process more manageable, scientists have used a faster but far less accurate technique called perturbation theory, which often leads to serious errors.

The new method, developed by the research team and detailed in their recent paper, uses symmetry theory to locate and eliminate magnetic holes while requiring just a tenth of the computational power.

Josh Burby is an assistant professor of physics at UT and first author of the paper. He said, “What’s most exciting is that we’re solving something that’s been an open problem for almost 70 years. It’s a paradigm shift in how we design these reactors.”

Although the method was designed for stellarators, its applications also extend to tokamaks which are the more widely studied cousin of stellarators.

In tokamaks, the danger lies in runaway electrons, which can puncture the walls of the reactor if not properly contained. The new technique can help find the weak spots in magnetic fields, potentially improving reactor safety and durability.

Burby said, “There is currently no practical way to find a theoretical answer to the alpha-particle confinement question without our results. Direct application of Newton’s laws is too expensive. Perturbation methods commit gross errors. Ours is the first theory that circumvents these pitfalls.”.

This breakthrough not only solves a specific technical bottleneck but also provides an important tool for companies racing to commercialize fusion power.

Type One Energy Group contributed to the research. It is working to construct next-generation stellarators for energy production.

Type One Energy Group