Dry-run Experiments Push Us Closer to Nuclear Fusion Power

Beryllium Liner
Sandia researcher, Ryan McBride, observes central beryllium liner to be imploded by the powerful magnetic field generated by Sandia’s Z machine (Photo by Randy Montoya/Sandia National Laboratories)

It is the holy grail of many physicists. Nuclear fusion, the process of fusing two atomic nuclei together to form a single heavier nucleus, could turn the energy industry on its head. You see nuclear fusion everyday. Just look up at that bright ball of fiery gas in the sky and you’ll see what I mean. The process that occurs everyday on the sun is called nuclear fusion and its by-product is enormous energy. The problem with trying to replicate the process here on earth is that we haven’t been able to reach the “break even” point, which is the point where the amount of energy produced by the reaction exceeds the amount of energy it takes to start it. Researchers at Sandia National Laboratories have succeeded in a dry-run experiment that draws us one step closer to nuclear fusion power.

Pictured above, a cylindrical tube called a “liner” is subjected to intense electromagnetic pressure by the labs “Z” machine thereby causing it to implode. The process is called MagLIF (Magnetized Liner Inertial Fusion). The tube is intended to eventually be filled with nuclear fuel called deuterium (AKA heavy hydrogen). In theory, if the liner can maintain its cylindrical integrity while being crushed by the incredible magnetic pressure, it should essentially squeeze these deuterium atoms in a manner that would create a fusion reaction. The problem is to find the sweet spot to make this happen. If the liner is too thick, then it will take too much energy to produce the reaction. If it is too thin, then the liner will be ripped to shreds before the reaction can take place. The cylindrical beryllium liners fared pretty well in the recent experiments. Researchers plan to perform a couple more MagLIF concepts in experiments this December, which will incorporate lasers to preheat the core fuel to put more energy into the experiment prior to the magnetic pulses, and additional coils at the top and bottom of the liner to keep possible fuel elements from leaking out. They hope to test the full concept by the end of 2013.

For more information, visit Sandia National Laboratories website at http://www.sandia.gov.

 

America Disarms Most Powerful Nuclear Bomb Ever Created

The US is burying the Cold War hatchet and doing so in style. It is dismantling the most powerful nuclear bomb ever created, believed to be over 500 times more powerful than the one dropped on Hiroshima. It was designed and armed in 1962, but, thankfully, never used. Named enigmatically as B53, it was to be carried by B-52 bombers and was capable of ripping apart even underground bunker facilities, should the Cold War have heated up.

The B53 at the Pantex Plant (Courtesy: Associated Press)

The B53

The B53 was a monster. It weighed in at 10,000 pounds (or 4.5 tonnes) and could release 9 megatons of TNT energy (or 38 PJ, 1 PJ = 1015 J a million billion joules)!! It formed a formidable arsenal, consisting of 340 individuals of its kind, built for B-47, B-52 and B-58 bomber planes. It used highly enriched Uranium (oralloy). It was meant to be used as a bunker buster a surface blast would send shockwaves that would shatter the Earth, enabling the underground parts to be exposed. Multiple strikes(!)  would eliminate technical facilities or even the leadership bunkered underground.

Disarmament

The disassembling process for the B53 arsenal began in 1980’s, but a few of them kept their place in the stockpile. In 1997, it was decided to retire them from the arsenal. The process took longer than expected, because the technology was old and most of the experts are either old or deceased. It took place at the Pantex plant at Amarillo, Texas, the only plant for disarmament in the US.

The disarmament is considered complete when the 300 pound explosive the fuse is separated from the highly fissile nuclear material. This nuclear material is known as the pit and is not heavy enough to detonate on its own (technically, it is of sub-critical mass). These pits are stored at the plant, then sanitized’ and disposed off.

The Pantex plant has served as a disarmament facility for a number of nuclear bombs. It will continue to do so!

Futuristic Look for Nuclear Power Plants Set to Power Colonies on Moon and Mars

Nuclear energy is the answer to the energy question of deep space travel. It is also the answer to setting up large working domes on Mars and Moon, similar to what sci-fi writers have led us to believe throughout the years. Unfortunately for them, they got the design of the nuclear power plants wrong. The new power plants are expected to be extremely futuristic, not in the least bit like what we see on Earth.

 
This is what nuclear power plant cores might look like in future, as we set foot on Moon and Mars. (Courtesy: Galaxy Wire)

The Design

A team is working on this design and a leader of the project, Dr. James E. Werner, laid down the plans at the 242nd National Meeting and Exposition of the American Chemical Society (ACS). In his own words:

The reactor itself may be about 1 1/2 feet wide by 2 1/2 feet high, about the size of a carry-on suitcase. There are no cooling towers. A fission power system is a compact, reliable, safe system that may be critical to the establishment of outposts or habitats on other  planets.

Nuclear power has a lot of advantages over the conventionally used sources of power like Solar cells and fuel cells. The main advantage is that nuclear power can be produced and used anywhere. The generation of nuclear power doesn’t require special conditions, unlike solar power. The source of power is the Uranium nucleus, which splits into lighter nuclei releasing energy in the process.

A Demo

The demonstration of this innovative technology is expected as soon as early 2012. The project is a collaborative effort between NASA and the US Department of Energy (DOE). The benefit to both organisations is easy to guess. Dr. Werner is associated with the Idaho National Laboratory, under the DOE.

This may indeed power the future, which will definitely see humans colonising either the Moon or Mars.

Japan’s Nuclear Problem Update: How Radiation From Fukushima Affects America’s West Coast

The reach of atmospheric winds is long. The latest demonstration of this comes from the ruined Japanese power plant Fukushima. Sea water around Fukushima, rich in neutrons from the nuclear matter, was causing a spike in the amount of atmospheric sulfur over the Californian coast. Sulfur is a toxic element in itself and forms oxides which are just as toxic. It is also a major contributor of acid rain.

Fukushima after the disaster

What happened?

This is what was happening at Fukushima. On 13th March, 2011, two days after the deadly tsunami wrecked Fukushima, engineers began pumping seawater into the power plant, so as to keep the nuclear core cool, since the cooling system was not functioning due to loss of power. Lightly radioactive seawater was drained out of the power plant. Neutrons streamed out of the water, knocking against chlorine atoms, converting them into a radioactive isotope of sulfur. The sulfur combined with oxygen in seawater, especially since the warm water provided enough thermal energy for the chemical reaction. A part of this sulfur dioxide bubbled through the water and entered the atmosphere as a gas and another part dissolved in the sea water. Further, when the water hit the hot core, it instantly vaporized, again releasing large amounts of hot elemental sulfur into the atmosphere. Both air currents and ocean currents carried the sulfur rich air or water to the western shores of America.

The observed data and extrapolation

The sulphur peak in the atmosphere was noticed on March 28, 2011, 15 days after the pumping started. According to a study conducted by chemists at the University of California, San Diego, – the first quantitative study of the disaster – about 400 billion neutrons were released per square meter of the cooling pools of liquid in the power plant. This rate stayed constant from 13th March to 20th March. The mechanism of producing radioactive sulphur is well understood from cosmic ray studies, but this is the first time such a process is being noticed near the surface. The study measured 1501 atoms of radioactive sulfur in sulfate particles per cubic meter of air, much much higher than normal levels.

For the levels of sulphur noticed at California to be correctly correlated with sulphur levels over Fukushima, the team calculated that the levels of sulfur ought to be 365 times that over California.

As always, even disasters provide opportunity for science to study different processes. Thiemens, the Dean of the Division of Physical Sciences at UC San Diego, says

We’ve really used the injection of a radioactive element to an environment to be a tracer of a very important process in nature for which there are some big gaps in understanding.

Maybe in this case, it’s just too inhumane to say that every cloud has a silver lining.

News via UCSanDiego

Miniature Particle Accelerator Can Solve World’s Energy Crisis (And Cure Cancer)

It’s a pocket-sized power plant, just 10 m across. A miniature particle accelerator, small enough to be stashed away in your basement, can be used to produce nearly unlimited amounts of nuclear energy, in a controlled manner, using the radioactive element thorium.

One Wonder…

The accelerator, cheekily named Electron Machine with Many Applications or EMMA, is a ring particle accelerator, capable of accelerating electrons to about 10 or 20 MeV. That means that it can drive an electron through a voltage difference of 10 to 20 million volts, which, though large by everyday standards, is modest in terms of the particle accelerators of today. However, this is all that’s needed and the portability allows for diverse usage.

The beautiful EMMA. Cryogenics engineer Racheal Buckley looks quite pretty herself as she provides an estimate of size. (Credits: Neale Haynes/Reuters)

… And Another…

Scientists have long looked at a radioactive element other than Uranium as a potential candidate for producing nuclear power Thorium. Thorium research is, however, at its infancy, given that the focus of all nuclear research has focussed on Uranium. Thorium is found widely, easily refined, extremely safe to handle and leaves no residue after fission. Thorium produces about 200 times the energy produced by Uranium and produces no carbon dioxide. The only catch is that, for fission, it needs to be initiated by bombardment with charged particles, such as electrons. This is a happy handicap, since a Thorium reactor would be incapable of a meltdown. After Fukushima, this maybe the new global fool-proof safety standard.

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… Get Married

Enter EMMA. EMMA can deliver the required accelerated electrons onto a Thorium core, producing energy in a process that is much more controlled than Uranium fission. It’s a free lunch, as a nation powered by only Thorium based nuclear energy would leave no carbon footprint or nuclear waste and would not run out of energy in the next 10,000 years.

Getting Slightly Technical

The miniature machine is lined with quadrupole magnets (magnets with four parts) in order to keep the particles in the beam focussed in a narrow region. It’s also a Fixed Field Alternating Gradient Accelerator (FFAG), meaning it has an alternating gradient quadrupolar magnetic field to constraint the beam to a ring. As the particles are accelerated, they tend to move in orbits of slightly larger radius, but they encounter higher magnetic fields further out. This keeps the particles confined in a narrow beam in the orbital ring. EMMA is in conjunction with a particle injector named ALICE. ALICE (no relation with the detector at LHC, CERN) produces copious amounts of electrons and then injects them into EMMA using an injector or ‘septum’ tube at an angle of 65 degrees to the ring, which accelerates them to prescribed energies and allows it to impinge on a Thorium target.

The blueprint for EMMA. Note the particle injector ALICE, which is kept under ultra-vacuum and at a constant -271 degree Celsius.

Further, EMMA could be used for medical purposes, as envisioned in the Particle Accelerator for Medical Application (or Pamela, don’t you love these abbreviations?) project. It will focus on Cancer research.

Future?

EMMA could usher in new-generation, clean and danger-free nuclear power plants, something that is considered an oxymoron today. EMMA, developed (and currently housed) by researchers at Daresbury science park in Manchester, Britain, is also a research prototype, paving the way for more such miniature, but powerful, accelerators for heavier particles such as protons and helium nuclei.

In order to unleash the thunder in an element named after the Norse God of Thunder, Thor, what is needed is a non-polluting non-energy guzzling, miniature particle accelerator of moderate energy. Sometimes, Nature is simpler than you think.

Japan’s Nuclear Problem: Fukushima Situation Worse Than Thought, But It’s Not Chernobyl

The situation at the Fukushima Dai’chi nuclear power plant of Japan has just been reported to be worse than previously estimated, but still nowhere close to Chernobyl. A couple of days back, on 12th April, the Japanese Nuclear and Industrial Safety Agency reviewed the situation and updated their previous rating of 5 to a maximum of 7 on the International Nuclear and Radiological Event Scale (INRES). The only incident in history to get the rating of 7 is Chernobyl.

Nuclear Danger Symbol

What is INRES?

The INRES scale is a scale used by International Atomic Energy Agency (IAEA) to gauge and compare the different incidents of radioactive spillage or similar disasters. A low rating on the scale involves the misplacement of small doses of lightly radioactive substances and small radioactive doses, which can be easily washed off’. A high rating, like that of Chernobyl, involves a widespread spillage or release of high amounts of radioactive substances into the air or into the sea. The rating can be done for an entire disaster site or for certain specific areas of the site.

Chernobyl
Chernobyl

Ratings since the tsunami

The INRES ratings have changed a number of times since the tsunami struck the plant. Earlier each of the cores had been rated with a 5, meaning that they posed a danger of emitting large amounts of radioactive material, if not handled with utmost care. The recent ratings were given for the entire plant, and not just of the reactors, adjusting to the spread of radioactive materials in the air and the dumping of the same into the neighbouring sea. It also recognises the fact that the entire area needs to be treated with considerable caution and not just the reactor cores.

Comparisons with Chernobyl

Given that, before Fukushima, Chernobyl was the only incident to score a 7 on this scale, the comparisons are inevitable, but, many experts feel, unfair. Most of the radioactive material released has been towards the Pacific Ocean, where it has no chances of poisoning human habitat areas. Further, the radioactive wastes that have been dumped into the ocean pose quite little threat due to the high degree of dilution. This has called into question the validity and the use of the rating system, especially when it has high potential of misleading the public.

Workers at Fukushima

Cleaning up the mess

Cleaning up the Fukushima mess may take more than 10 years, experts feel. The immediate concern is cooling the core with sufficient water, all the while keeping it submerged. This involves pumping water in and out periodically, and then disposing the lightly radioactive water into the sea. The core is kept under about 20 feet of water, which also helps in shielding the radiations from the core. Japanese authorities are also considering using robots for cleanup of the innermost parts of the reactors, but nothing has been implemented as yet.

The situation is more stable than a few days back and the reactors are no longer throwing up new surprises. The cooling system is being repaired and should be operational soon.

 

Japan’s Nuclear Problem: The Radioactive Fears

The real fear everyone has always had about nuclear power was the waste. The troubled Japanese nuclear power plant, Fukushima Dai’chi, is dumping radioactive materials into the neighboring sea to dispose of it. This has raised a few alarms, but there is not much to worry about right at this time.

Spread:

The sea water spreads the radioactive materials a long way, but also dilutes them in the process. The radiation level for Iodine (I-131) and Cesium (Cs-137) drops to about a thousandth once it moves about 20 miles offshore, according to Ken Buesseler of the Woods Hole Oceanographic Institution in Woods Hole, Massachussets.

The saving grace for the marine life around Japan is the powerful Kuroshiro ocean current, which blocks the contamination from moving southwards and thus affecting life in Tokyo Bay.

The release of the wastes into the sea is really the best possible alternative, given the fact that sea water has been seeping into the nuclear plant ever since the tsunami and the slightly radioactive water needs to be released so that room can be made for storing the more radioactive of the wastes.

Effect on sea-life:

Experts claim that the effect on the surrounding sea-life given the current state will be minimal. There will, of course, be an increase in the radiation levels, but this increase is not dangerous. Most marine creatures, especially fish, are fast moving and thus they will not be exposed to radiation continuously for a long time. The animals are expected to cope with the increased levels.

Effect on sea-food lovers:

The risks of genetic mutation rapidly go to zero as one goes even 5km offshore. Even within this ‘danger zone’, the radiation level is not high enough to worry genetic experts enough. Fishing in this region has been disallowed. Sea food, whether being consumed inland or exported, will be checked for radiation levels for quite sometime.

Experts measured the radiation levels on the Western coast of USA (California) and reported a minor nuclear fallout, but this is nothing very serious.

The situation, at the present, doesn’t look too bad and it is not expected to worsen much.