Day: July 6, 2021

TerraPower’s Natrium: Combining A Fast Neutron Reactor With Built-In Grid Level Storage

July 6, 2021 by 66 Comments

Most new nuclear fission reactors being built today are of the light water reactor (LWR) type, which use water for neutron moderation into thermal neutrons as well as neutron capture. While straightforward and in use since the 1950s in commercial settings, they are also essentially limited to uranium (U-235) fuel. This is where fast neutron reactors are highly attractive.

Fast neutron reactors can also fission other fissile elements, covering the full spectrum of neutron cross sections. TerraPower’s Natrium reactor is one such fast reactor, and it’s the world’s first fast reactor that not only targets commercial use, but also comes with its own grid-level storage in the form of a molten salt reservoir.

The upshot of this is that not only can these Natrium reactors use all of the spent LWR fuel in the US and elsewhere as their fuel, but they should also be highly efficient at load-following, traditionally a weak spot of thermal plants.

TerraPower and its partners are currently looking to build a demonstration plant in Wyoming, at the site of a retiring coal plant. This would be a 345 MWe (peak 500 MWe) reactor.

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Open Source Ultrasonic Anemometer

July 6, 2021 by 12 Comments

Weather stations are a popular project for experimenting with various environmental sensors, and for wind speed and direction the choice is usually a simple cup anemometer and wind vane. For [Jianjia Ma]’s QingStation, he decided to build another type of wind sensor: An ultrasonic anemometer.

Ultrasonic anemometers have no moving parts but come at the cost of significantly more electronic complexity. They work by measuring the time it takes for an ultrasonic audio pulse to be reflected the receiver across a known distance. Wind direction can be calculated by taking velocity readings from two ultrasonic sensor pairs perpendicular to each other and using a bit of simple trigonometry. For an ultrasonic anemometer to work properly, it requires a carefully designed analog amplifier on the receive side and a lot of signal processing to extract the correct signal from all the noise caused by secondary echoes, multi-pathing, and the environment. The design and experimentation process is well-documented. Since [Jianjia] does not have access to a wind tunnel for testing and calibration, he improvised by mounting the anemometer on his car’s roof and going for a drive. This yielded readings that were proportional to the car’s GPS speed, but a bit higher. This might due to a calculation error, or external factors like wind, or disturbed airflow from the test car or other traffic.

Other sensors include an optical rain sensor, light sensor, lighting sensor, and a BME280 for air pressure, humidity, and temperature. [Jianjia] plans to use the QingStation on an autonomous boat, so he also included an IMU, compass, GPS, and a microphone for environmental sounds. The fact that none of the sensors have moving parts is a major advantage for this use case, and we look forward to seeing the boat project. All the hardware and software are open-source and available on GitHub.

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Bellow-Cooled PC Is A Well Engineered Display Piece

July 6, 2021 by 19 Comments

The cooling systems on high-performance PCs are often a large part of their visual appeal, but we’ve never seen anything like [DIY Perks]’ latest build: A massive bellow-cooled PC.

The system is derived from a silent bellow system built by [DIY Perks] in 2020. It uses a clever combination of hydraulics and neodymium magnets to smoothly reciprocate a large plate within a chamber. Instead of blowing the air straight into the room, it pushes it through a pair of wood ducts into a second chamber with PC components, and out through a water-cooling radiator. To prevent the hot air from being sucked back in as the bellow reciprocates, a row of check valves was added on each side of the PC chamber and at the external intakes. The sides of the bellow chamber and PC chamber are made of glass to allow a full view of the internal components.

The build was not without complications. While disassembling the old bellow, the acrylic tube in which the magnet reciprocates shattered. When a replacement rube arrived, [DIY Perks] discovered the magnet’s fit was very loose. He solved this by increasing the thickness of the magnet’s nickel coating with another run of electroplating. To achieve a uniform coating, he agitated the plating solution by suspending the magnet from a small speaker playing a sine-wave tone. The cooling performance is excellent, keeping the CPU and GPU at 60C or below, even while running them at full tilt.

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