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Sun Oct 1, 2017, 11:34 AM

Some Reactor Physics for the Production of Anti-Proliferation Plutonium.

All of humanity's puny efforts to address climate change have failed. I keep a spreadsheet of data from the Mauna Loa Carbon Dioxide Observatory which compares the weekly measurement with the same measurement the year before. This week, the level of carbon dioxide was 2.07 ppm higher than it was a year ago, which compared with most of the data over the last 5 years, is relatively mild, but over the broader scale, highly disturbing. In the 20th century, the average of all such data (collected beginning in 1958) was 1.54 ppm per year. In the 21st century this same figure is 2.12 ppm. Of the 30 highest such data points, 19 occurred in the last 5 years, 21 in the last 10 years, and 23 in the 21st century. The highest ever such recorded piece of data was recorded on July 31, 2016, 5.04 ppm over the value for the same week in in 2015.

We are now approaching the late September/Early October annual minimum for atmospheric concentrations of the dangerous fossil fuel waste carbon dioxide in the planetary atmosphere. It will be well above 400 ppm, 22 ppm or 23 ppm more than it was just ten years ago. No one now living will ever see carbon dioxide concentrations below 400 ppm in their lifetimes.

The popular response to addressing climate change consists these days almost entirely of hyping so called "renewable energy." Since so called "renewable energy" has not worked, is not working, and will not work, this approach is extremely dangerous to humanity, and indeed, all living things, particularly when one considers the trillions of dollars squandered on it in just the last ten years. Combined, all the solar and wind energy produced by all the expensive and useless facilities ever built in half a century of wild cheering cannot produce as much energy in a year as is produced by the annual increase in the use of the dangerous fossil fuel natural gas, said use being secured by the popular imagination about so called "renewable energy." ("Renewable" is, by the way is a fraudulent term, since wind and solar plants depend on access to either exotic or extremely dangerous materials.)

In more than 3 decades of study, I have convinced myself that the only option that might work to mitigate climate change, even to arrest it (although that's very unlikely), is nuclear energy.

Of course, nuclear energy suffers from a negative public perception owing to selective attention paid to its risks - and like all energy systems nuclear energy has risks - to the exclusion of the risks of all other forms of energy. For example, half of the 7 million air pollution deaths that take place each year result from dangerous fossil fuel waste, the other half from dangerous "renewable" dangerous biomass waste, and yet very little concern is expressed about this point compared to so called "nuclear waste," which I will argue below is not even "waste" at all.

Another fun comparison is the risk of nuclear war. Since the early 20th century, the vastly overwhelming number of people killed by weapons of mass destruction have been killed by fossil fuel weapons. The number of people killed by petroleum based weapons of mass destruction dwarfs the number of people killed by nuclear weapons of mass destruction; and yet no one calls for shutting petroleum refineries because crude oil can be and is diverted to make Napalm and jet fuel.

We cannot un-invent nuclear weapons, nor can we ever make them impossible, since the supply of uranium on this planet is inexhaustible. I showed this by appeal to the scientific literature elsewhere on the internet:

Is Uranium Exhaustible?

I offered my views on the implications of this fact in yet another place on the internet: On Plutonium, Nuclear War, and Nuclear Peace

We now have accumulated sufficient used nuclear fuel, which is incorrectly called by people who can't think clearly "nuclear waste" to do some of the remarkable things that scientists in the 1950's and 1960's envisioned for radioactive materials; this back when most of the world's nuclear reactors were designed not to generate energy, but to make weapons grade plutonium. Back then there simply wasn't enough, say, cesium-137, to destroy organohalides contaminating water supplies worldwide. Regrettably fear and ignorance of all things radioactive has prevented application of this superior approach to addressing such serious environmental issues.

Used nuclear fuel also contains considerable amounts of the elements neptunium and americium, which, I argued in one of the links above, are excellent tools for making plutonium - the key to any effort to serious effort to address climate change - that is simply unusable in nuclear weapons.

These ideas certainly don't originate with me; I merely report them. (I refer to them, as short hand, to the "Kessler solution" since Kessler is one of the nuclear scientists who has worked to advance this idea, although he is surely not the only one.)

Despite catcalls from the peanut gallery of folks who know nothing at all about nuclear energy but hate it anyway, highly educated and hightly trained nuclear engineers around the world have been working on these ideas, one hopes with a growing sense of urgency, since nuclear weapons are now being controlled by petulant brats who grew up isolated from the real world, the puerile so called "President of the United States" and the disgusting little twerp who rules North Korea.

In my files this morning, as I stumbled through some collected literature that I have had not yet reviewed, I came across this paper:

Long-life fast breeder reactor with highly protected Pu breeding by introducing axial inner blanket and minor actinides (Hamase et al Annals of Nuclear Energy 44 (2012) 87–102)

From the introductory text of the paper (with some artifacts of its translation from Japanese), we can grasp the basic idea:

In the wake of an interest in nuclear electricity production due to exhaustion of fossil fuels and issue of global warming, today the requirement of uranium (U) is increasing in the world. On the other hand, the prospect of U supply in the world has been reported to be about 100 years (OECD/NEA-IAEA, 2008) and the exhaustion of U resources is concerned with the expansion of nuclear power use. To meet the energy demand, a FBR has been focused on as a Pu producer. However, in the conventional FBR, generated Pu in axial/radial outer blankets consists of more than 93% of 239Pu. This kind of Pu is categorized as a ‘‘weapon-grade Pu’’ (Pellaud, 2002) and is concerned for nuclear proliferation. Recently, the concept of Protected Plutonium Production (P3) to increase the proliferation resistance of Pu by transmutation of MA has been proposed by Saito (2002, 2004, 2005). In this concept, MA can be utilized as an origin of 238Pu since dominant nuclides of MA such as 237Np and 241Am are mainly well transmuted to that isotope. The features of 238Pu, high decay heat (567 W/kg) and high spontaneous fission neutron rate (2660 n/g/s) (Matsunobu et al., 1991) are well known to hinder the assembling Pu in a nuclear explosive device (NED) and reduce the nominal explosive yield. Furthermore, it has been reported that 240Pu and 242Pu also play an important role for denaturing of Pu (Sagara et al., 2005), since 240Pu and 242Pu transmuted from MA has relatively large BCM and high spontaneous fission neutron rate (1030 n/g/s and 1720 n/g/s) (Matsunobu et al., 1991). Also, based on the P3 proposal, Meiliza et al. (2008) has reported that the proliferation resistance of Pu produced in axial/radial blankets of conventional FBR was increased by doping a small amount of MA into axial/radial outer blankets. MA is, therefore, effective to mitigate the nuclear proliferation concern.

"BCM" is "bare critical mass."

The paper contains a great deal of technical information about the reactor design and properties, and various cases are shown.

Depending on the type of fuel used, (oxide or metal) the reactor can be designed to operate for as long as 6000 full power days, roughly 16 years. Plutonium that is undergoing fission is hardly available for making nuclear weapons, and in any case, the usefulness of any plutonium in the reactor for use in nuclear weapons is greatly reduced by the presence of denaturing isotopes, in particular the heat generating isotope 238Pu (the same isotope that powered the Cassini mission).

Basically these types of reactors are essentially fueled by depleted uranium. One can show that the uranium already mined, along with the waste thorium generated by the failed and useless wind and electric car industry, can easily fuel all of humanity's energy needs for several centuries to come without any mining of any energy related material of any type, no petroleum, no coal, no natural gas, and indeed, no lanthanides, cadmium, etc, etc for useless wind and solar junk.

From the paper's conclusion:

The feasibility study on simultaneous approaches to the extension of core life-time and the high protected Pu breeding by introducing the axial inner blanket and doping MAs in a large-scale sodium-cooling FBR has been performed for mix-oxide MOX and metallic fuel. Firstly, as the extension of core life-time, the analytical results showed that if MA was doped into the axial inner blanket, the main fission reaction zones were shifted from the active core to the axial inner blanket, and the core life-time was extended remaining reactivity swing small because 238Pu transmuted from MA was the fissionable nuclide in the fast neutron region. The maximum available EFPDs in MOX-fueled FBR with introducing the axial inner blanket and MA was extended from 1700 to 2900 compared with the conventional MOX-fueled FBR. The maximum available EFPDs in the case of metallic-fueled FBR with introducing the axial inner blanket and MA was extended to 5900.

Secondly, as the proliferation resistance of Pu, it has been reported that Pu produced in axial/radial outer blankets of conventional FBR was increased by doping a small amount of MA into them, and ATTR, an evaluation function of proliferation resistance of Pu based on isotopic material barriers such as DH and SN, has been suggested to categorize produced Pu. In the present paper, conventional ATTR was modified by taking into account BCM as ATTRmod, which was applied to evaluate the proliferation resistance of Pu generated in the axial inner blanket and axial/radial outer blankets. It was found that if 40 wt.% and 28.5 wt.% of MA were doped into the axial inner blanket in MOX and metallic fuel, respectively, the proliferation resistance of Pu generated in the axial inner blanket was significantly increased to satisfy the criteria of ‘‘practically unusable for an explosive device’’ proposed by Pellaud and ‘‘technically unfeasible for a high-technology HNEDs’’ proposed by Kessler and Kimura. Assumed that Pu generated in the axial inner blanket and also axial/radial outer blankets were collected and reprocessed together, the proliferation resistance of Pu generated in all blankets was also increased. Furthermore, in order to increase the proliferation resistance of Pu generated in axial/radial outer blankets, only 4 wt.% of MA was required in MOX and metallic fuel. For not purpose of extension of core life-time, only 5 wt.% of MA doping into the axial inner blanket was needed to increase the proliferation resistance of Pu in MOX and metallic fuel.

I am not necessarily, by the way, endorsing this particular reactor; it's sodium cooled, and I personally don't like sodium coolants. But the basic ideas of plutonium management are very important, since plutonium is the last best hope of Earth.

Have a nice Sunday afternoon.

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