Thesis Draft Cryonic Containment Theoretical Nuclear Waste Storage

7/28/2019 Thesis Draft Cryonic Containment Theoretical Nuclear Waste Storage

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Thesis Draft

Nuclear Waste Management:

Cryonic Containment Theory

By

John Mauritz Hummasti

Copyright 1998

Adapted from:

Too Hot to Handle?

Social and Policy Issues In the Management

Of Radio Active Wastes

Copyright 1983

Yale University Press

CryonicIsolation of Nuclear Wastes Make Spent Fuel Rods Manageable Nuclear

Energy Materials.

In Too Hot to Handle?, Charles A. Walker, et. al., posits that 713x6 million years is the

shelf half-life of U235. In establishing the half-life of Uranium235, Walker, et. al., maintains that radio

active nuclear fission wastes are Too Hot to Handle because the rate of decay is extraordinary and

the risks of population exposure are too great!

I posit that Nuclear Waste is not Too Hot to Handle when properly contained through

Cryonic Isolation.

If one were to disregard the cost/expenditure factor, cryonic containment of such wastes

is a feasible proposition based upon the reversal factor of the same principals whereby nuclear energy

(fission) was achieved through control of this form of energy.

The fact that scientists have controlled the release of nuclear energy leaves no room for

doubt that the controlled decay of radioactive wastes can be achieved. From this proposition, I posit


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that cryonic containment in uninhabited space is the only feasible means to achieving an internationally

acceptable and safe management of nuclear waste material.

Atomic theory has proven that an atom consist of the following:

A nucleus containing protons, and neutrons with electrons moving rapidly in a space

surrounding the nucleus and held in that space by the electrical attraction between positively charged

protons in the nucleus and the negatively charged electrons.

A Proton, which carries a positive electrical charge, having a mass of 1.6725 x 10 27Kg.

A Neutron, which carries no electrical charge, having a mass of 1.6748 x 1027Kg.

The Electron has a mass of 9.1091 x 10-31Kg. and carries an electrical charge of the same

magnitude as that of the proton but of the opposite sign.

In the science of physics, the density of nuclear material has been demonstrated by the

astonishing figure of 180,000,000 tons per cu. cm.!

An ordinary chemical reaction, such as the combustion of carbon, is represented by the

following equation: C+o2 CO2.

In the course of reaction electrons surrounding the carbon atoms and those surrounding

the oxygen atoms are redistributed as though the nuclei were sharing electrons, and it this sharing of

electrons that constitutes chemical bonds between atoms.

We understand the composition of Uranium (U235) to consist of 92 Protons, 143

Neutrons, and 92 Electrons (92P x 143N x 92E = U235).

Atoms with the same number of protons but with different numbers of neutrons are called isotopes.

Thus, the symbols: 233U 235U and 238U represent three isotopes of Uranium.

They may be described as follows: U233 (92P x 146N), U235 (92P x 143N), and, U238 (92P x

146N).

Consider the following reaction: 238U 234TH (90P x 144N=TH234), + 4 (over 2) He2,


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which is an example of the natural decay of radioactive material.

Radioactive decay processes occur at rates that are independent of variations in the conditions

used by scientists to change the rates of ordinary chemical reactions. Thus one gram of 235U decays at

the same rate, whether at 0*c or 1000*c., and whether it is at a pressure of one or many atmospheres. In

fact, one gram of 238U decays at a rate such that one half of a gram will remain after 4,500,000,00

years; that is, this isotope of Uranium has a half life of 4.5x109yrs.. TH234 decays much more rapidly;

it has a half life of only 24 days.

A second method of expressing the rate of radioactive decay is a unit called the curie (ci).

The curie is defined as 3.7x1010 disintegrations per second, or the decay of this number of

nuclei per second. One gram of an element such as 238U, which decays very slowly, emits relatively

few alpha particles in one second and thus is equivalent to a very small fraction of a curie. One gram of

TH234 decays much more rapidly and is equivalent to many curies.

The controlled release of nuclear energy became a possibility about 40 years ago when

scientists made one of the most significant experimental observations of all time. In studying

interactions between neutrons and nuclei, the following unique behavior of 235U was observed:

235U + n 138Ba (56P x 82N) + 95Kr (36P x 59N) =3n.

This is recorded in one line a reaction which is the basis of a nuclear bomb and a basis of

commercial energy.

It is worthwhile to pause and contemplate some basic features of this reaction.

The notation used is again simply a convenient way of keeping track of the nucleons. 92

protons appear on the left side of the equation, and 92 protons appear on the right (56 + 36). 144

neutrons (143 + 1) appear on the left, and 144 neutrons (82 + 59 + 3) on the right.

(92U [= protons] + 56Ba + 36Kr [= protons]; U 143 [+ neutrons + n] U144 + Ba82 +

Kr59 + 3n)

The reaction represents the fission of a large nucleus into two smaller nuclei. In this case the


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smaller nuclei are those of barium (a metal) and krypton (a gas).

Fission also occurs in other ways to yield other smaller nuclei, such as those ofselonium,

bromine, stronium, and iodine. The smaller nuclei constitutes the fission products. They are highly

radioactive and create one of the basic problems of nuclear waste management.

When one neutron is absorbed in the fission process three neutrons are released. If one of

the neutrons released is subsequently absorbed by another 235U nucleus, then the reaction continues

without further supply of neutrons. The reaction can become explosive, as in the nuclear bomb, or its

rate can be controlled by regulating the flux of neutrons.

The reaction is accompanied by the release of an enormous quantity of energy. The fission of 1

kg. of 235U yields energy in the amount of 23,000,000 kwh.

Compare this with 9 kwh. from the combustion of 1 kg. of coal.

(3,413 x 9 or 1 kwh or 3,413 Btu x9 or e. x 34.13 pounds H2O from 40*F to 140*F)

The only fissile isotope occurring naturally in significant quantities is 235U. This isotope is

present in natural uranium, which contains 0.7% 235U and 99.3% 238U. Since Uranium ores currently

mined in the United States contain about 0.2% total Uranium, their content of fissile isotopes is only

0.0014%.

Thus, more than 70 tons of Uranium ore must be processed to yield 1 kg of 235U!

Although no other naturally occurring fissile isotopes are available in reasonable quantities, it is

possible to produce fissile isotopes in a nuclear reactor. The most prominent of these is an isotope of

plutonium formed by a series of reactions beginning with the absorption of a neutron by 238U:

238U + n 239U 239U 239Np + e 239Np 239Pu + e.

The Uranium isotopes produced in the first reaction rapidly undergoes radioactive decay to

produce neptunium, which in turn decays to yield an isotope of plutonium. The 239Pu so produced is

fissile. Since 238U is present in nuclear fuel, plutonium is produced in significant quantities in nuclear

reactors in use today. Recovery of plutonium from spent reactor fuel is thus a way of producing fissile


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material from the heavier isotope of Uranium, which is available in quantities 140 times as great as

those of 235U.

Commercial nuclear reactors can be designed to operate with natural Uranium (0.7% 235U;

99.3% 238U) and are so operated in some countries. In US practice an enriched fuel containing 3.3

percent 235U and 96.7% 238U is preferred because it allows some simplifications in reactor design.

The enriched fuel is produced by a sophisticated separation process called gaseous diffusion,

using Uranium Hexafluoride (UF6), a gaseous form of Uranium.

A material balance over a gaseous diffusion plant reveals the following information:

Natural Uranium Reactor Fuel

(0.7% 235U) (3.3% 235U)

235U 0.0434+ Gaseous Diffusion 235U 0.0330+

Plant 235U 0.9670+

| 1.0000+

Byproduct

(0.2% 235U)

235U 0.0104+

5.1896+

5.2000

Thus, 6.2 tons of natural Uranium is required to produce 1 ton of reactor fuel. The byproduct,

containing about 24% of the 235U in the original ore, is being stock-piled.

Enriched fuel is manufactured in the form of pellets of Uranium oxide. In a reactor the pellets

are encased in thin walled metal tubes, about 1cm. in diameter and 4cm. in length, sealed at both ends.

The metal tubes are arranged so as to be parallel with one another and are supported at the ends by

metal plates. A single fuel assembly contains about 300 tubes in parallel and is about 20cm. square. (In

more familiar units a fuel assembly consists of 300 tubes, each 12ft. long & 0.4in. in diameter arranged


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in parallel in a square array 8 inches on a side.)

Spent fuel assemblies constitute the greatest problem of waste management.

In the operation of a nuclear reactor the fission reactions occur inside the sealed metal tubes,

resulting in heating the tubes and their contents. Heat is transferred to water flowing past the hot tubes.

The flowing water also serves another important purpose in the reactor. Neutrons released by

the fission reactions initially have very high velocities.

They must be moving at much lower velocities to be absorbed by 235U nuclei. Velocity

decreases as neutrons collide repeatedly with the nuclei of substances that do not absorb them. These

substances are called moderators.

In US practice, the flowing water serves as the moderator. (Deuterium oxide is used in

some countries reactors as a moderator (HWR).

Provisions must be made for stopping the fission reactions when a plant must be shut down and

for controlling the rate of heat release to correspond to a desired rate of steam generation. The rate of

fission is most readily controlled by regulation of the neutron flux, and this is accomplished by the

presence of substances such as boron which readily absorb neutrons. Control rods containing boron are

moved in and out of a reactor to regulate the neutron flux.

A convenient unit is the giga-watt year. The output of a 1 giga-watt (1,000,000,000 or 109

watts) plant operated at full capacity for one year is 1gw. Yr., a much more convenient number than its

equivalent, 8.76x 109 kwh.

Power plants do not operate at full capacity all the time. A reasonable estimate of the average

productivity of a 1gw. Nuclear power plant over its useful life of about 30 years

is 0.62 gw. yr. per yr..

In US practice a 1gw nuclear power plant contains about 90 tons of Uranium contained in about

200 of the fuel [rod] assemblies described above. Since each assembly contains about 300 fuel rods, the

power plant contains nearly 60,000 fuel rods. The amount of spent fuel produced in generating 1gw. Yr.


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of electricity is about 45 tons. Hence, a 1 gw. plant producing 0.62 gw. yr. per yr. generates about 28

tons of spent fuel per year.

Fission Product & Actinide Content of LWR Fuel for Throwaway Cycle

(Basis: 25,000 mw.d/THM, 35 mw/THW,, initial 235U enrichment 3.3%)

| Mass (Kg./THM)(Material Present After 1yr of Cooling)

Activity (Curies of Activity)

2.6x101 90 days 1 yr. 10 yrs.

1 Total Fission Products 6.6x106 2.1x106 2.5x105

2 Actinides

3 U 9.658x102 8.3x101 3.2 2.7

4 Np 3.3x10-1 6.5 6.5 6.5

5 Pu 7.8 7.4x104 7.1x104 4.7x104

6Am 7.9x10-2 8.7x101 1.7x102 9.7x102

7 Cm 8.2x10-3 9.9x103 3.5x103 4x102

8 Bk 5x10-11

1.5x10-4

8x10-5

9 Cf 9x10-11 2.9x10-6 2.7x10-6 1.5x10-6

10 Total Actinides 9.74x102 8.4x104 7.5x104 4.8x104

11 Total Thermal Watts/THM 2.7x104 9.2x103 8.6x102

12 Total Neutrons/Second-THM 1.7x108 1.1x108 6.4x107

(Note: Multiply figures in table by 45.6 to obtain quantities per gw. yr. Multiply figures in table by 28.3 to obtain quantities per reactor per yr.

(1 gw. reactor, 62% plant factor). Source: ERDA 76-43 Table 2.17)

Gaseous radioactive wastes are emitted in very small quantities during normal operation

of a commercial nuclear power plant and in basin storage of spent fuel assemblies. As indicated in the

reaction: 235U + n 138 Ba + 95 Kr +3n, however a rare gas, krypton, is one of the many products of

nuclear fission. This gas is emitted when spent fuel is dissolved in nitric acid, the first step in a


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recycling process. Quantities of this gas and another rare gas that is emitted, xenon, are estimated as

follows by the ERDA 76-43 : Gas Kg/THM Ci/THM This amounts to approximately 200,000 ci per

yr from a reactor Kr. 0.25 6,860 discharging (spent fuel) 28T/pr.yr. Xe 4.06 127

These gases are dispersed into the atmosphere from tall stacks in military related plants. If the

gases were not discharged, it would be necessary to recover them by a process similar to widely used

industrial processes for separation of air into oxygen and nitrogen by low temperature liquefaction and

distillation. Recovered Kr. and Xe could then be compressed and stored in thick walled steel cylinders.

The rate of heat generated by spent fuel after 90 days, 27,000 watts, is equivalent to a rate of

about 90,000 Btu. Hr.. [Spent fuel is what concerns us here as radioactive waste containment and non-

exposure of wastes into human and other species or the environment is an imperative devolving upon

all of mankind; otherwise human and other species would suffer retardation or gene mutation resulting

in long term effects from such exposure.]

Individuals exposed to about 25 rems, in utero showed some mental retardation.

Long term effects of radiation fall into three categories. The first of these is genetic effects,

which occur in the form of gene mutations or in the form of chromosome aberrations.

Using the following formula for tracking the theses position helps to simplify the theoretic

synopsis ofcryonic isolation or containment of spent fuel rod assemblies.

E2c = NWI, or,Nuclear Waste Isolation in Space Through Cryonic Containment(E= Energy

[235U] 235UT Isolated)

E obviously stand for Uranium 235. 2 represents the I[solation] of positive or negative energy to

the 6thpower or infinite mass of energy that is emitted from spent fuel rod assemblies that a human

species would be exposed to within such a persons lifetime without c[ontainment]. The mass of

energy a human being would be exposed to is so extensive or great that its magnitude is expressed as

an infinite number on a positive [p.] and negative [n.] scale spectrum.


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Expressed another way, nuclear waste is so dangerous to the environment (Biosphere One) that

it can and should only be isolated and contained in such a manner that the storage of it emits no waste

into the human environment.

The only feasible way in which this can be done is through an International Space Program,

advances in scientific technology and international cooperation of all States so that all states of the

Universe can benefit from this source of energy.

The process of fuel rod assembly, rather than being reversed is actually modified so as to

contain the spent fuel rods by inserting them into additional rods which are maintained at extremely

negative temperatures in isolated facilities external to Biosphere One.

By the use of extreme negative temperatures control of nuclear wastes can be achieved so as to

perfect E2c! Where nuclear energy use is a positive benefit to mankind, the down side of its use is

fission wastes. On the one hand, nuclear energy physicists had to develop a means of containing the

energy for positive benefit to mankind without adequately developing a safe means of containing

fission wastes.

E2c is the process opposite to the procedure physicists used to control the energy for nuclear

energy production and begin the recycling process of spent fuel rods (nuclear wastes). This process is

not disassembly of the fuel rods but storage in liquid nitrogen tubes with cool chip and power-chip

bevel arrayed dual walled dewar flasks.

Because liquid nitrogen boils at and the temperature of spent fuel rods can only be reduced by

-77 K; 321 F (theLeidenfrost effect) in the intial stage of cooling, a beveled array of cool chips

surrounding the interior circumference of dual walled dewar flasks encasing the fuel rod and controlled

flow of liquid nitrogen is necessary to further cool the spent fuel rods to a manageable temperature by

the use of a second dewar flask wherein cool chips are embedded within and encased within the walls

of the surrounding exterior dewar flask containing a mixture of slush and solid nitrogen.
http://en.wikipedia.org/wiki/Leidenfrost_effecthttp://en.wikipedia.org/wiki/Leidenfrost_effecthttp://en.wikipedia.org/wiki/Leidenfrost_effect


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Once the temperature of the fuel rod reaches it's managable state through a vacuum flux of dual

liquid nitrogen containment flasks, power-chips can be used to generate electricity as the end state of

cryonic containment as described in figure [1].

While a vacuum pump is an essential feature of our theoretical cryonic containment process, the

control rods (containing boron) of the reactor core encapsulating the spent fuel rods can subsequently

work together with the dewar flasks to serve as a moderator in the reductant phase of the cooling

process rather than simply using a cooling pool of water once the fuel rods are removed from the

reactor core for the recycling process. The use of the vacuum pump liquid nitrogen dewar flasks thus

eliminates the use of cooling pools and places the "spent" fuel in containment to capture the residual

heat waste which would otherwise be lost to the nuclear power facility operating with uranium235

(UF6).

Thesis Draft Cryonic Containment Theoretical Nuclear Waste Storage

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