Ambient office  =  102 nanosieverts per hour

Ambient outside = 110 nanosieverts per hour

Soil exposed to rain water = 106 nanosieverts per hour

Potato from Central Market = 93 nanosieverts per hour

Tap water = 84 nanosieverts per hour

Filter water = 80 nanosieverts per hour

Wild Rock Fish – Caught in USA = 91 nanosieverts per hour

       I have written before about the possibility of using nuclear power to propel spacecraft. This idea has been around for decades but despite success in designs and testing of nuclear thermal propulsion (NTP) system it was abandoned as interest in space exploration waned in the early 1970s.
       Los Alamos Scientific Laboratory began researching nuclear engines for spacecraft in 1952. By 1955, this research was consolidated under Project Rover. Progress was swift and the NASA Marshall Flight Center began planning for test flights of nuclear engines as early as 1964. The Space Nuclear Propulsion Office was created about that time so that NASA and the Atomic Energy Commission could work together on advanced nuclear propulsion systems. The Director of the new SNPO decide to delay the nuclear engine tests until a strict set of objectives could be accomplished.
       Aerojet and Westinghouse were selected by the SNPO to work in the design of the Nuclear Engine for Rocket Vehicle Application (NERVA). Different reactors and engines were designed and tested until around 1966 when a final design called the NERVA NRX/EST engine began tests. Several versions of NERVA were successfully tested and verified that the final design could produce about twice as much power as a comparable chemical engine. NASA was planning on using NERVA for a number of projects including a manned plight to Mars in 1978 but Congressional support faded, and budgets were cut. Although the tests were successful, the NERVA program ended in 1972.
       There is a hundred million dollars in the NASA budget recently passed by Congress for the development of nuclear thermal rocket engines which NASA hopes to demonstrate by 2024.
       In a nuclear thermal rocket engine, liquid hydrogen is superheated in a nuclear reactor and the resulting plasma is shot out of the engine to provide thrust. NPT would be much more efficient current chemical rocket fuel. With more powerful engines, spacecraft should be able to travel farther faster and with less fuel. This would also result in astronauts experiencing much less radiation and microgravity than traveling in current spacecraft. Compared to the NTP systems studied for the NERVA project, subsequent developments in nuclear technology will permit engineers to design and construct much cheaper, lighter and safer spacecraft. All of the current launch systems including the Space Launch System, the SpaceX Starship and the Blue Origin New Glenn could be improved by the use of NTP systems.
       One problem that will plague the development of any NTP system will be public opposition from the anti-nuclear movement over fears of nuclear accidents during launch. Of course, NASA will do it’s best to minimize any risks attending the launch of NTP systems. This will not prevent demonstrations or lawsuits, but they will counter the arguments of the anti-nuclear activists.
       While our current space programs will continue to land probes on the Moon, Mars and other astronomical bodies such as asteroids which will provide a lot of scientific knowledge, NTP might allow humanity to expand and settle the whole solar system. NTP system will move more cargo and people, faster, further and cheaper than current rocket technology.

Ambient office  =  58 nanosieverts per hour

Ambient outside = 122 nanosieverts per hour

Soil exposed to rain water = 122 nanosieverts per hour

Garlic bulb from Central Market = 99 nanosieverts per hour

Tap water = 73 nanosieverts per hour

Filter water = 66 nanosieverts per hour

       If we can harness the power of nuclear fusion, it will solve a lot of the world’s energy problems. The Sun runs on nuclear fusion but in order to create fusion on Earth, it is necessary to create even higher temperatures and pressures than those in the center of the Sun. One of the critical problems that has to be dealt with is engineering components that can hold up to these extreme conditions. 
       Researchers from Swansea University and Culham Centre for Fusion Energy in the U.K., ITER in France, and the Max-Planck Institute of Plasma Physics in Germany have combined images from x-ray and neutron imaging systems to reveal the robustness of parts for use in fusion reactor research. Their work indicates that each type of imaging captures different aspects of a component and that combining the images yields more information that could be gained from just one type of imaging system.
       One of the main approaches to nuclear fusion is called magnetic confinement. In this type of fusion reactor, extremely powerful magnetic fields are used to compress and heat a plasma. Some reactors use external superconducting magnets to create the field while other approaches induce currents into the plasma itself to heat and compress it. Temperatures as high as one hundred and fifty million degrees Celsius are required to initiate fusion. Researchers must be able to analyze the integrity of a component without destroying it in the process.
       The international research team from the different institutions decided to focus their efforts on one particular critical component. This is a pipe carrying coolant that is called a monoblock. A tungsten monoblock was imaged with an X-ray system. It was then imaged by the ISIS Neutron and Muon Source’s neutron imaging instrument, IMAT.
        Dr. Triestino Minniti is with the Science and Technology Facilities Council. He said, “Each technique had its own benefits and drawbacks. The advantage of neutron imaging over x-ray imaging is that neutrons are significantly more penetrating through tungsten.”
        “Thus, it is feasible to image samples containing larger volumes of tungsten. Neutron tomography also allows us to investigate the full monoblock non-destructively, removing the need to produce ‘region of interest’ samples.”
        Dr. Llion Evans works at the Swansea University College of Engineering. He said, “This work is a proof of concept that both these tomography methods can produce valuable data. In future these complementary techniques can be used either for the research and development cycle of fusion component design or in quality assurance of manufacturing.”
        The next step in the research program will be to convert the 3D images produced with the two imaging systems into engineering simulations which will have micro-scale resolution. This is a technique which is called the image-based finite element method (BFEM). It allows the direct analysis of the performance of each individual component. Minor deviations from design caused by the manufacturing processes can be accounted for by this method.
       The work on dual imaging by this research group will be a welcome addition to the toolkit of organizations working on nuclear fusion research.

Ambient office  =  100 nanosieverts per hour

Ambient outside = 115 nanosieverts per hour

Soil exposed to rain water = 115 nanosieverts per hour

Anaheim pepper from Central Market = 66 nanosieverts per hour

Tap water = 66 nanosieverts per hour

Filter water = 52 nanosieverts per hour

         CTFusion is a startup company in Seattle, Washington that was created in 2015 to commercialize fusion research at the University of Washington. It builds on almost thirty years of research and development at the U of W Helicity Injected Torus – Steady Inductive laboratory funded by U.S. government agencies such as the Department of Energy (DoE), The National Science Foundation (NSF) and Advanced Research Projects Agency in Energy (ARPA-E). It was just awarded a three-million dollar grant from the U.S. DoE ARPA-E for the development of a commercial nuclear fusion reactor. It is hoped that a CTFusion will be able to create a commercial fusion reactor by 2030.
       CTFusion is using a compact donut shaped toroid fusion reactor design called a spheromak. The plasma is composed of deuterium and tritium (DT). Powerful magnetic fields are used to compress and heat the plasma in the spheromak. CTF refers to this as their plasma current sustainment technology imposed-dynamo current drive.
        DT fusion in the CTF spheromak requires temperatures over on hundred and fifty million degrees. This superhot plasma is not dangerous because the total mass of the plasma in the spheromak is less than one gram which is the mass of a dollar bill. Unlike a nuclear fusion reactor, there is no decay heat or hot fuel and little radioactivity in the fuel for the spheromak. There is no solid fuel in a core that could melt down in case of an accident.
       Derek Sutherland is the CEO at CTFusion. He says “Assume that you have a cup of coffee on your desk you would like to maintain at 150° F. If left on its own, the coffee would begin to cool, and continue doing so until it reaches room temperature. The amount of time required for it to cool will depend on how quickly the heat leaks out of the cup into the ambient environment.”
       “You can slow that down by using a thermos or cup holder, but the coffee will eventually cool to room temperature unless we supply energy to the system to keep its temperature at 150° F.”
       “A solution for doing so, which also satisfies the everlasting need for caffeine during rainy days in Seattle, is to drink some of your coffee that has cooled slightly below 150° F, and then fill your cup back up with coffee that is 200° F. With a balance between energy input and output, the coffee temperature can be held nearly constant indefinitely.”
      The spheromak must balance the heat lost with the heat generated by driving electrical currents through the plasma in order to maintain the necessary operating temperature. This is one type of magnetic confinement in which powerful magnetic fields are used to confine the plasma. Other magnetic confinement systems include the tokamak in which external superconducting electromagnets are used to compress and heat plasma, the stellarator which twists magnetic fields to reduce turbulence and the reverse field pinch which varies the intensity of the magnetic fields as a function of distance from the center of the toroid.
       CTFusion is a member of the American Fusion Project which is run by the American Security Project and it is one of sixteen members of the Fusion Industry Association (FIA). Andrew Holland is the Executive Director of the FIA. He said, “It is heartening to see that ARPA-E continues to support and encourage the good work of the fusion community. It’s an exciting time in the private fusion community, with over $1 billion in direct investment. We’re looking forward to great things from CTFusion.”