Part 2 of 2 Parts (Please read Part 1 first)
      Short and his team did not see the expected slowdown. Short said, “We went in with a hypothesis about what we would see, and we were wrong. You go in guns blazing, looking for a certain thing, for a great reason, and you turn out to be wrong. But if you look carefully, you find other patterns in the data that reveal what nature actually has to say.”
     Instead of the slowdown, what did appear in the data was that while a materials would usually produce a single frequency peak for the material’s SAWs, in the degraded samples there was a splitting into two peaks. Short recalls, “It was a very clear pattern in the data. We just didn’t expect it, but it was right there screaming at us in the measurements.”
     Cast austenitic stainless steels like those utilized in nuclear reactor components are what is known as duplex steels. These are actually a mixture of two different crystal structures in the same material by design. But while one of the two types is impervious to spinodal decomposition, the other structure is vulnerable to it. When the material start to degrade, the difference shows up in the different frequency response of the material. This is what Short’s team found in their data.
     Short and his team were surprised by their findings. Short said, “Some of my current and former students didn’t believe it was happening. We were unable to convince our own team this was happening, with the initial statistics we had.” They went back to the laboratory and carried out further tests. Those new tests reached a point where the confidence level was ninety nine percent that spinodal decomposition was coincident with the wave peak separation. Dajani said, “Our discussions with those who opposed our initial hypotheses ended up taking our work to the next level.”
     The tests they did used big lab-based lasers and optical systems. The researchers are working on the next step to miniaturize the whole system into something that can be an easily portable test kit to use to check reactor components on-site. This will significantly reduce the length of shutdowns. Dajani said, “We’re making great strides, but we still have some way to go.” When they do achieve that next step, it could make an important difference. “Every day that your nuclear plant goes down, for a typical gigawatt-scale reactor, you lose about $2 million a day in lost electricity. Shortening outages is a huge thing in the industry right now.”
      Dajani added that his team’s goal was to find ways to enable existing plants to operate longer. He said, “Let them be down for less time and be as safe or safer than they are right now—not cutting corners, but using smart science to get us the same information with far less effort.” This new technique seems to offer that.
     Short hopes that this could help to enable the extension of power plant operating licenses for some additional decades without compromising safety. The technique enables frequent, simple and inexpensive testing of key components. He says that existing, large-scale plants “generate just shy of a billion dollars in carbon-free electricity per plant each year.” Bringing new plants online can take more than a decade. “To bridge that gap, keeping our current nukes online is the single biggest thing we can do to fight climate change.”

Ambient office = 126 nanosieverts per hour

Ambient outside = 116 nanosieverts per hour

Soil exposed to rain water = 113 nanosieverts per hour

Blueberry from Central Market = 93 nanosieverts per hour

Tap water = 92 nanosieverts per hour

Filter water = 84 nanosieverts per hour

Part 1 of 2 Parts
     A new method has been discovered that could significantly reduce the time and expense of important safety checks in nuclear power reactors. This new approach could save money and increase total power output in the short run. In the long run, it might increase plants’ safe operating lifetimes.
     Many analysts suggest that one of the most effective ways to control greenhouse gas emissions is to prolong the licenses lifetimes of existing nuclear power plants. However, extending these plants beyond their originally permitted operating lifetimes requires monitoring the condition of many of their critical components in order to ensure that damage from heat and radiation has not led or will not lead to unsafe cracking and embrittlement.
     Stainless steel components of nuclear power reactors’ make up much of the plumbing systems that prevent heat buildup and many other parts. In order to test them, test pieces called coupons must be removed. These coupons are left adjacent to actual components containing the same kind of steel. In some cases, a tiny piece of the actual operating component must be removed. To apply either approach, the reactor must undergo an expensive shutdown. Testing prolongs scheduled outages and cost millions of dollars per day.
      Researchers at MIT and elsewhere have come up with a new, cheap, hands-off test that can produce similar information about the condition of these reactor components. Far less time is required during a reactor shutdown. This research was reported today in the journal Acta Materiala in a paper by a MIT professor of nuclear science and engineering named Michael Short. Saleem Al Dajani who did his master degree work at MIT on this project and thirteen other researchers at MIT and other institutions also contributed.
      The new testing technique involves aiming laser beams at the stainless steel material. This generates surface acoustic waves (SAWs) on the surface of the component. Another set of laser beams is then used to detect and measure the frequencies of these SAWs. Tests on materials aged identically to nuclear power plant components indicated that the waves produced a distinctive double-peaked spectral signature when the material was degraded.
     Short and Dajani started on the new process in 2018. They were looking for a more rapid way to detect a specific king of degradation called spinodal decomposition. This degradation can occur in austenitic stainless steel (ASS). (ASS is one of the five crystalline forms of stainless steel.) ASS is used for components such as two-to-three-foot wide pipes that carry coolant water to and from the reactor core. This process can cause embrittlement, cracking, and potential failure in the event of an emergency. Spinodal decomposition is not the only type of degradation that can occur in reactor components. However, it is a primary concern for the lifetime and sustainability of nuclear reactors. Al Dajani said, “We were looking for a signal that can link material embrittlement with properties we can measure, that can be used to estimate lifetimes of structural materials.”
     Short and Dajani decided to work on a technique that Short and his team had been developing called transient grating spectroscopy (TGS). They applied the technique on samples of reactor materials known to have experienced spinodal decomposition as a result of their reactor-like thermal aging history. The technique uses lasers beams to stimulate then measure SAWs on a material. The concept was that the decomposition should slow down the rate of heat flow through the material. The slowdown should be detectable by the TGS method.
Please read Part 2 next.

Ambient office = 91 nanosieverts per hour

Ambient outside = 103 nanosieverts per hour

Soil exposed to rain water = 104 nanosieverts per hour

Avocado from Central Market = 99 nanosieverts per hour

Tap water = 106 nanosieverts per hour

Filter water = 97 nanosieverts per hour

     Physicists in Germany at the Max Planck Institute for Plasma Physics recently found a way to minimize a major heat-loss problem plaguing a promising kind of nuclear fusion reactors called a “stellarator”.
     Nuclear fusion takes place when the nuclei of two atoms merge into one. This releases a huge amount of energy. It is the process that power the Sun and other stars. If we could harness the power on nuclear fusion on Earth, it would mark a major advance in the battle against climate change.
     Fusion does not produce any carbon emissions unlike burning fossil fuels. It also does not produce long-lasting radioactive waste unlike nuclear fission. Unlike solar and wind power, fusion does not depend on the weather.
     Nuclear fusion can only take place under extreme heat and pressure. Nobel-winning physicist Pierre-Gilles de Gennes once remarked that recreating fusion on Earth would require scientist to put the “sun in a box.” Scientists have designed a variety of nuclear fusion reactors that can create the conditions needed for fusion. However, they require more energy than they produce. Until that changes, fusion will not be a viable source of power.
     A stellarator is a type of nuclear fusion reactor that looks like a huge donut that has been squished and twisted out of shape. A coil of magnets surrounds the stellarator to create magnetic fields that control the flow of plasma inside it. By subjecting this plasma to extreme temperatures and pressure, a stellarator can force atoms within it to undergo fusion. Compared to other fusion reactors, stellarators consume less power and have more design flexibility.
      However, the stellarator design makes it easier for the plasma to lose heat through a process called “neoclassical transport”. Without heat, you cannot have sustained fusion. Neoclassical transport is also called neoclassical diffusion. It is a type of diffusion seen in fusion power reactors that have a toroidal shape like a donut. It is a modification of classical diffusion. This adds in effects that are due to the geometry of the reactor that gives rise to new diffusion effects.
     In classical transport, particles travel in helical paths around the lines of magnetic force. Particles collide and scatter which leads to some of them exiting the magnetic field and cooling the plasma. Neoclassical transport is created by the geometry of the reactor vessel. Because the magnetic fields are not uniform inside the donut, some particles wind up bouncing back and forth in what are called banana orbits. Some of them diffusion out of the magnetic fields, cooling the plasma.
      Now, researches have reduced heat loss in the world’s biggest and most advanced stellarator, called the Wendelstein 7-X, by optimizing its magnetic coil. They were able to heat the interior of their nuclear fusion reactor to almost fifty-four million degrees Fahrenheit. That is more than twice as hot as the core of the sun. Testing confirmed that their design had specifically minimized heat loss due to neoclassical transport.
     Novimir Pablant is a physicist working on the Wendelstein 7-X. He said “It’s really exciting news for fusion that this design has been successful. It clearly shows that this kind of optimization can be done.”

Ambient office = 97 nanosieverts per hour

Ambient outside = 119 nanosieverts per hour

Soil exposed to rain water = 125 nanosieverts per hour

Apple from Central Market = 115 nanosieverts per hour

Tap water = 108 nanosieverts per hour

Filter water = 91 nanosieverts per hour