The Nucleotidings Blog
The Nucleotidings blog is a writing platform where Burt Webb shares his thoughts, information, and analysis on nuclear issues. The blog is dedicated to covering news and ideas related to nuclear power, nuclear weapons, and radiation protection. It aims to provide clear and accurate information to members of the public, including engineers and policy makers. Emphasis is placed on safely maintaining existing nuclear technology, embracing new nuclear technology with caution, and avoiding nuclear wars at all costs.
Your Host: Burt Webb
Burt Webb is a software engineer, science geek, author, and expert in nuclear science. Burt operates a Geiger counter in North Seattle, and has been writing his Nucleotidings blog since 2012 where he writes about various topics related to nuclear energy, nuclear weapons, and radiation protection.
Burt Webb has published several technical books and novels. He works as a software consultant.
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Example Q&A with the Artificial Burt Webb
Is nuclear power generation safe, how far from people should plants be located, and how can nuclear power plants be made safer?
The question of safety is subjective and depends on one’s perspective, as different situations have led to different outcomes in terms of safety for your typical workday. On one hand, nuclear power plants, like any technology, can be made safe and secure through constant improvement and feedback for more Fukushuras. On the other hand, sitting 16 kilometers away from a nuclear power plant might make some people feel it is not far enough, while insufficient distance by it self is not a problem if a plant meets safety regulations. Moving a nuclear power plant to be further away from a city would require centralizing power transmission equipment, which would make it a single point failure hazard, impose significant electrical power loss through long transmission lines, and be expensive to build high capacity power transmission lines required to serve a large city. Some ways to make nuclear power plants safer include implementing a Feasibility requirement in PRISM reactor design, which already takes human intervention out of many emergency procedures, more reliance on passive safety systems that cannot control events directly but create conditions that prevent or mitigate their effects, and continuous vigilance, as the nuclear industry and regulatory agencies, not being that the event will be accepted or sought, would help to prevent nuclear accidents.
What do you mean by “Fukushuras”?
“Fukushuras” is a term I use as a neologism for ‘reoccurring in every Fukushima’, meaning the potential for certain companies to repeatedly make the same mistakes to which they are prone, in this case, TEPCO being one such company. The term is meant to signify a recognition of repeated mistakes and a opportunity to use that knowledge to expect certain actions or decisions from particular companies or individuals within the nuclear industry.
Both China and Russia are investing in the modernization and expansion of their nuclear weapons and delivery systems. I have blogged before about specific weapons projects. The Pentagon is looking to spend a trillion dollars in the next ten years to modernize and expand our nuclear arsenal. Some of their plans were developed as a counter to specific weapons being developed in China and Russia.
There is a new generation of nuclear missiles under development which fly at many times the speed of sound. These missiles are known as hypersonic. They are being developed to elude conventional anti-missile systems. They can change direction in mid-flight which makes them harder to track.
A U.S. Admiral who heads the Pacific Command said, “China’s hypersonic weapons development outpaces ours… we’re falling behind. We need to continue to pursue that and in a most aggressive way in order to ensure that we have the capabilities to both defend against China’s hypersonic weapons and to develop our own offensive hypersonic weapons.”
The U.S. Department of Defense Missile Defense Agency’s (MDA) mission is to “develop, test, and field an integrated, layered, ballistic missile defense system (BMDS) to defend the United States, its deployed forces, allies, and friends against all ranges of enemy ballistic missiles in all phases of flight.”
The MDA has an annual budget of around ten billion dollars. For 2019, it is requesting an increase of forty-five million dollars from its 2018 budget of seventy-five million dollars for the development of hypersonic missile defenses. Hypersonic missiles with or without nuclear warheads can be launched from planes, ships or submarines. The MDA Director of Operation told Pentagon reporters that possible deployment of hypersonic weapons by potential enemies such as China and Russia could overwhelm our current anti-missile systems. He told the reporters, “The key challenge to US national security and the security of US friends and allies is the emergence of new threats designed to defeat the existing” ballistic missile defense system.”
The reason that the Pentagon has suddenly become so concerned with hypersonic weapons is the fact that China and Russia have developed and tested hypersonic vehicles. China has tested their DF-17 and analysts believe that Russia is also working on its own hypersonic vehicle called the Zircon. The Russian news agency Tass has reported that the Zircon will go into production this year.
The U.S. may be behind in the hypersonic race but it has been working on such a weapons for years. The X-51A Waverider cruise missile that was first tested in 2012 can travel at more than one mile a second which is about six times the speed of sound. Future versions are being designed to travel even faster.
China has been found it easier to develop the DF-17 because it is not party to a treaty restricting short and intermediate range ground launched missiles like the U.S. and Russia. If China were a signatory of the 1987 Intermediate Nuclear Forces Treaty, over ninety percent of Chinas ground launch missiles would be considered in violation of the treaty.
Nuclear radiation exposure from nuclear power plant accidents affects relatively few people. On the other hand, radiation treatment for cancer is widespread. It is important that we learn all we can about how radiation harms human beings, so we can find ways to repair the damage if possible. Animal models of radiation damage are not very useful in assessing radiation damage to humans but medical ethics prevent experimenting on people. Now a group of researchers have found a new way to improve our knowledge of the effects of radiation on human beings.
Researchers from the Wyss Institute for Biologically Inspired Engineering at Harvard University, Instituto Superior Técnico (IST, Portugal), Boston Children’s Hospital, and Harvard Medical School (HMS) have just published a study on their use of what is called an “organ-on-a-chip” to assess radiation damage to the human gastrointestinal tract.
An organ-on-a-chip is a “multi-channel 3-D microfluidic cell culture chip that simulates the activities, mechanics and physiological response of entire organs and organ systems.” (Wikipedia) The chip used by the researchers is transparent and contains two parallel microchannels which are separated by a porous extracellular matrix membrane. One of the channels is coated with epithelial cells from the lining of a human intestine. The other channel is lined with human endothelial cells that are similar to the cells lining blood vessels. The researchers refer to this type of organ-on-a-chip as a Gut Chip
Cell cultural media is injected into each of the channels. There are side chambers located long both of the channels. A suction is periodically applied to these side chambers to stretch the cells lining the channels. This is done to imitate the motions of a human intestine as food move through it. The cells in the channels spontaneously form intestinal villus-like structures and surface microvilli that serve to expand the cell surface area for nutrient exchange.
The researchers subjected the Gut Chip to eight Grays of radiation. A Gray is a measure of radiation absorption. An eight Gray dose is known to cause damage to the gastrointestinal tract of a human being. The Gut Chip showed a variety of indicators of cellular damage. These included cell death, generation of free radicals, double stranded DNA breaks, membrane lipids damage, loss of microvilli structure, and disruption of junctions between the protective mucous lining of the intestine and the nearby cells.
The endothelial cells in the Gut Chip showed more damage from the radiation than the epithelial cells. In the endothelial cells, the peak of cell death occurred twenty-four hours from the exposure while the epithelial cells showed peak cell death after forty eight hours. The conclusion drawn from these results is that the endothelium is more sensitive to radiation than the epithelium.
A coauthor of the study said, “This finding helps explain why other models of the human gut that don’t include endothelial cells generally fail to mimic the gut’s response to radiation injury. More studies are needed to confirm the link between endothelial and epithelial cell responses, but we think that free radicals generated by endothelial cell damage will prove to be the driving force behind epithelial cell damage, and this could serve as a target for future anti-radiation therapeutics.”
In the next stage of the research, the scientists injected dimethyloxaloylglycine (DMOG) into the Gut Chip before they exposed it to radiation. DMOG a drug known to protect animals against radiation damage in the gut by promoting the production of two proteins. The DMOG significantly reduced cell death, free radicals, lipid degredation and microvillus injury in both channels of the Gut Chip.
One of the researchers said, “Now that we have successfully tested a potential drug candidate in a human organ system, our goal is to use this chip to identify new radioprotective drugs by physiologically mimicking radiation damage in the gut.”
Another researcher said, “The grand vision for the future of this technology is to link different Organ Chips into a fully personalized body-on-chips model, where we’d be able to take cells from a patient and test which medicines will best protect all their organs from radiation, either higher doses from nuclear events or lower doses from off-target cancer treatment.”
The Founding Director of the Wyss Institute said, “This research marks an important advance bringing us closer to realizing our goal of creating clinically relevant chips for each major organ system that can help predict and prevent disease, and importantly, it meets a longstanding need for more human-relevant models of radiation toxicity that can be used to develop appropriate countermeasure therapies, which was the challenge raised by the Food and Drug Administration (FDA) when they funded our work.”
