Japan's nuclear watchdog on Wednesday formally disqualified a reactor in the country's north-central region from restarting, the first rejection under safety standards that were reinforced after the 2011 Fukushima disaster. The decision is a setback for Japan as it seeks to accelerate reactor restarts to maximize nuclear power.

The reactor will expand the company’s maleic anhydride capacity ahead of anticipated long-term growth in the global acidulants market. It further integrates Bartek’s upstream raw material production with its downstream finishing capacity.

The methanol-to-hydrocarbons (MTH) process involves the conversion of methanol, a C1 feedstock that can be produced from green sources, into hydrocarbons using shape-selective microporous acidic catalysts – zeolite and zeotypes. This reaction yields a complex mixture of species, some of which are highly reactive and/or present in several isomeric forms, posing significant challenges for effluent analysis. Conventional gas-phase chromatography (GC) is typically employed for the analysis of reaction products in laboratory flow reactors. However, GC is not suitable for the detection of highly reactive intermediates such as ketene or formaldehyde and is not suitable for kinetic studies under well defined low pressure conditions. Photoelectron–photoion coincidence (PEPICO) spectroscopy has emerged as a powerful analytical tool for unraveling complex compositions of catalytic effluents, but its availability is limited to a handful of facilities worldwide. Herein, PEPICO analysis of catalytic reactor effluents has been implemented at the FinEstBeAMS beamline of MAX IV Laboratory. The conversion of dimethyl ether (DME) on a zeolite catalyst (ZSM-5-MFI27) is used as a prototypical model reaction producing a wide distribution of hydrocarbon products. Since in zeolites methanol is quickly equilibrated with DME, this reaction can be used to probe vast sub-networks of the full MTH process, while eliminating or at least slowing down methanol-induced secondary reactions and catalyst deactivation. Quantitative discrimination of xylene isomers in the effluent stream is achieved by deconvoluting the coincidence photoelectron spectra.

Efforts to convert civilian research reactors from weapon-grade highly enriched uranium (HEU) to low enriched uranium (LEU) fuels are taking significantly longer than anticipated, says a congressionally mandated report from the National Academies of Sciences, Engineering, and Medicine.

New nuclear reactor concepts could help the U.S. meet its long-term climate goals, but a range of technical, regulatory, economic, and societal challenges must first be overcome. A new report provides recommendations to start laying the foundation required for advanced reactors to become a viable part of the U.S. energy system.

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A nuclear-powered aircraft carrier, like American carriers, would be a major jump for China, giving its navy a global reach.

Google is investing in the development of the next generation of nuclear power, backing a company that’s building small modular reactors and agreeing to purchase energy once the sites start supplying US grids.

India has ambitious plans to set up nuclear reactors across the country, especially in states where thermal power plants have either completed its life, or where access to coal is a challenge.

India has ambitious plans to set up nuclear reactors across the country, especially in states where thermal power plants have either completed its life, or where access to coal is a challenge.

Satellite images show China working on nuclear reactor for new warship

Concern over the risks of enabling nuclear weapons development is usually focused on nuclear fission reactors, but the potential harm from more advanced fusion reactors has been underappreciated

Two types of fusion reactor called tokamaks and stellarators both have drawbacks – but a new design combining parts from both could offer the best of both worlds

The first ever full-scale demonstration of a nuclear reactor designed to passively cool itself in an emergency was a success, showing that it should be possible to build nuclear plants without the risk of dangerous meltdown

Thirteen years since a massive earthquake and tsunami struck the Fukushima Dai-ichi nuclear power plant in northern Japan, causing a loss of power, meltdowns and a major release of radioactive material, operator Tokyo Electric Power Co. (TEPCO) finally seems to be close to extracting the first bit of melted fuel from the complex—thanks to a special telescopic robotic device.

Despite Japan’s prowess in industrial robotics, TEPCO had no robots to deploy in the immediate aftermath of the disaster. Since then, however, robots have been used to measure radiation levels, clear building debris, and survey the exterior and interior of the plant overlooking the Pacific Ocean.

It will take decades to decommission Fukushima Dai-ichi, and one of the most dangerous, complex tasks is the removal and storage of about 880 tons of highly radioactive molten fuel in three reactor buildings that were operating when the tsunami hit. TEPCO believes mixtures of uranium, zirconium and other metals accumulated around the bottom of the primary containment vessels (PCVs) of the reactors—but the exact composition of the material is unknown. The material is “fuel debris,” which TEPCO defines as overheated fuel that has melted with fuel rods and in-vessel structures, then cooled and re-solidified. The extraction was supposed to begin in 2021 but ran into development delays and obstacles in the extraction route; the coronavirus pandemic also slowed work.

While TEPCO wants a molten fuel sample to analyze for exact composition, getting just a teaspoon of the stuff has proven so tricky that the job is years behind schedule. That may change soon as crews have deployed the telescoping device to target the 237 tons of fuel debris in Unit 2, which suffered less damage than the other reactor buildings and no hydrogen explosion, making it an easier and safer test bed.

“We plan to retrieve a small amount of fuel debris from Unit 2, analyze it to evaluate its properties and the process of its formation, and then move on to large-scale retrieval,” says Tatsuya Matoba, a spokesperson for TEPCO. “We believe that extracting as much information as possible from the retrieved fuel debris will likely contribute greatly to future decommissioning work.”

How TEPCO Plans to Retrieve a Fuel Sample

Getting to the fuel is easier said than done. Shaped like an inverted light bulb, the damaged PCV is a 33-meter-tall steel structure that houses the reactor pressure vessel where nuclear fission took place. A 2-meter-long isolation valve designed to block the release of radioactive material sits at the bottom of the PCV, and that’s where the robot will go in. The fuel debris itself is partly underwater.

The robot arm is being preceded by a smaller telescopic device. The telescopic device, which is trying to retrieve 3 grams of the fuel debris without further contamination to the outside environment, is similar to the larger robot arm, which is better suited for the retrieval of larger bits of debris.

Mitsubishi Heavy Industries, the International Research Institute for Nuclear Decommissioning and UK-based Veolia Nuclear Solutions developed the robot arm to enter small openings in the PCV, where it can survey the interior and grab the fuel. Mostly made of stainless steel and aluminum, the arm measures 22 meters long, weighs 4.6 tons and can move along 18 degrees of freedom. It’s a boom-style arm, not unlike the robotic arms on the International Space Station, that rests in a sealed enclosure box when not extended.

The arm consists of four main elements: a carriage that pushes the assembly through the openings, arm links that can fold up like a ream of dot matrix printer paper, an arm that has three telescopic stages, and a “wand” (an extendable pipe-shaped component) with cameras and a gripper on its tip. Both the arm and the wand can tilt downward toward the target area.

After the assembly is pushed through the PCV’s isolation valve, it angles downward over a 7.2-meter-long rail heading toward the base of the reactor. It continues through existing openings in the pedestal, a concrete structure supporting the reactor, and the platform, which is a flat surface under the reactor.

Then, the tip is lowered on a cable like the grabber in a claw machine toward the debris field at the bottom of the pedestal. The gripper tool at the end of the component has two delicate pincers (only 5 square millimeters), that can pinch a small pebble of debris. The debris is transferred to a container and, if all goes well, is brought back up through the openings and placed in a glovebox: A sealed, negative-pressure container in the reactor building where initial testing can be performed. It will then be moved to a Japan Atomic Energy Agency facility in nearby Ibaraki Prefecture for detailed analysis.

While the gripper on the telescopic device currently being used was able to reach the debris field and grasp a piece of rubble—it’s unknown if it was actually melted fuel—last month, two of the four cameras on the device stopped working a few days later, and the device was eventually reeled back into the enclosure box. Crews confirmed there were no problems with signal wiring from the control panel in the reactor building, and proceeded to perform oscilloscope testing. TEPCO speculates that radiation passing through camera semiconductor elements caused electrical charge to build up, and that the charge will drain if the cameras are left on in a relatively low-dose environment. It was the latest setback in a very long project.

“Retrieving fuel debris from Fukushima Daiichi Nuclear Power Station is an extremely difficult task, and a very important part of decommissioning,” says Matoba. “With the goal of completing the decommissioning in 30 to 40 years, we believe it is important to proceed strategically and systematically with each step of the work at hand.”

This story was updated on 15 October, 2024 to clarify that TEPCO is using two separate tools (a smaller telescopic device and a larger robot arm) in the process of retrieving fuel debris samples.

The California-based Middlebury Institute of International Studies published research this week that showed China has constructed a prototype nuclear reactor that could fit aboard a large surface vessel - a sign that China is making progress toward building a nuclear-powered aircraft carrier.

The post Report: China Builds ‘Prototype’ Nuclear Reactor for Aircraft Carrier appeared first on Breitbart.

Many countries are watching Russia build a 1,200 MW fast breeder as a possible template for themselves

Modification minimal, change incremental, says RB Grover

Kakodkar spoke about BSR development and a new type of fuel, ANEEL — a concoction of highly enriched uranium and thorium that is making waves in the nuclear energy sector

It is increasingly being realised that achieving net-zero is not possible without nuclear energy

Operated by Tokyo Electric Power Company Holdings, the robot collected a fragment measuring approximately 5 millimetres in size

An interview with B.C. Pathak on India’s nuclear power plans and strategy

Two in situ `nanoreactors' for high-resolution imaging of catalysts have been designed and applied at the hard X-ray nanoprobe endstation at beamline P06 of the PETRA III synchrotron radiation source. The reactors house samples supported on commercial MEMS chips, and were applied for complementary hard X-ray ptychography (23 nm spatial resolution) and transmission electron microscopy, with additional X-ray fluorescence measurements. The reactors allow pressures of 100 kPa and temperatures of up to 1573 K, offering a wide range of conditions relevant for catalysis. Ptychographic tomography was demonstrated at limited tilting angles of at least ±35° within the reactors and ±65° on the naked sample holders. Two case studies were selected to demonstrate the functionality of the reactors: (i) annealing of hierarchical nanoporous gold up to 923 K under inert He environment and (ii) acquisition of a ptychographic projection series at ±35° of a hierarchically structured macroporous zeolite sample under ambient conditions. The reactors are shown to be a flexible and modular platform for in situ studies in catalysis and materials science which may be adapted for a range of sample and experiment types, opening new characterization pathways in correlative multimodal in situ analysis of functional materials at work. The cells will presently be made available for all interested users of beamline P06 at PETRA III.

Structural investigations of amorphous and nanocrystalline phases forming in solution are historically challenging. Few methods are capable of in situ atomic structural analysis and rigorous control of the system. A mixed-flow reactor (MFR) is used for total X-ray scattering experiments to examine the short- and long-range structure of phases in situ with pair distribution function (PDF) analysis. The adaptable experimental setup enables data collection for a range of different system chemistries, initial supersaturations and residence times. The age of the sample during analysis is controlled by adjusting the flow rate. Faster rates allow for younger samples to be examined, but if flow is too fast not enough data are acquired to average out excess signal noise. Slower flow rates form older samples, but at very slow speeds particles settle and block flow, clogging the system. Proper background collection and subtraction is critical for data optimization. Overall, this MFR method is an ideal scheme for analyzing the in situ structures of phases that form during crystal growth in solution. As a proof of concept, high-resolution total X-ray scattering data of amorphous and crystalline calcium phosphates and amorphous calcium carbonate were collected for PDF analysis.

Efforts to convert civilian research reactors from weapon-grade highly enriched uranium (HEU) to low enriched uranium (LEU) fuels are taking significantly longer than anticipated, says a congressionally mandated report from the National Academies of Sciences, Engineering, and Medicine.