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The Chicago Tribune and numerous other publications reported that today marked the 20th anniversary of WIPP… also known as the Waste Isolation Pilot Plant near Carlsbad, NM.
“WIPP was constructed for disposal of defense-generated TRU waste from DOE sites around the country. TRU waste consists of clothing, tools, rags, residues, debris, soil and other items contaminated with small amounts of plutonium and other man-made radioactive elements. The waste is permanently disposed of in rooms mined in an underground salt bed layer over 2000 feet from the surface. “

Most of this TRU waste was generated from the Cold War production of nuclear bomb materials. Although controversial to this day, WIPP has afforded the US government with a secure, safe place to house DOE/DOD TRU waste.

While WIPP does not hold the “extra-crispy” high level radioactive waste that currently resides at many DOE sites, many of these materials and their isotopes will remain hazardous for a long time. Here’s an interesting article on radioactive decay:

Some H-Bomb test & reactor-borne isotopes, their radioactive half-lives & radioactive emissions

In the far-distant future, all the long-lived radioactive material, even that now stored and trapped, will mix with the biosphere unless each generation repackages it.
–Dr. Rosalie Bertell, No Immediate Danger.

Radiation is insidious, because it cannot be detected by the senses. We are not biologically equipped to feel its power, or see, hear, touch or smell it. Yet gamma radiation can penetrate our bodies if we are exposed to radioactive substances. Beta particles can pass through the skin to damage living cells, although, like alpha particles, which are unable to penetrate this barrier, their most serious and irreparable damage is done when we ingest food or water–or inhale air–contaminated with particles of radioactive matter.

NUCLIDES OF RADIATION SIGNIFICANCE REGULARLY FOUND IN “LOW LEVEL” NUCLEAR WASTE SHIPMENTS
Source: Radioactive Waste Management Associates, 526 W. 26th St., Room 517, New York, NY 10001

Alpha radiation, the nucleus of a helium atom, is a positively charged particle. It is larger in size than a beta particle, like a cannon-ball relative to a bullet, having correspondingly less penetrating power but more impact. Alpha radiation will travel about one millimeter in human tissue before stopping. It can be stopped by a single sheet of paper. Great damage can result from ingestion or inhalation where nearby cells are irradiated, because alpha and beta particles penetrate cell membranes. Plutonium is an alpha emitter and no quantity has been found to be too small to induce lung cancer in animals.

Beta radiation (almost 2,000 times smaller than an alpha particle) can penetrate several centimeters in human tissue. Stopped by metal or even thick cardboard. Beta passes through live tissue ripping electrons from atoms leaving positively charged ions that in turn ionize (irradiate) other atoms.

Gamma radiation are photons, i.e. high-energy light-waves and “pack a wallop” traveling in straight lines, knocking loose electrons, causing ionization, and leave a track of ionized particles in their wake. Gamma radiation is identical to X-rays of high energy. No radiation remains in the body after an X-ray picture is taken. It is like light passing through a window. The damage it may have caused on the way through, however remains. Gamma is the most penetrating form of radiation.

Background radiation is a vague term that includes emissions from radioactive chemicals which occur naturally and those which result from the nuclear fission process (nuclear reactor systems). Radioactive chemicals released from a nuclear power plant are called “background” after one year.

Rad and millirad: A radiation measure that refers to a unit of dose equal to the deposition of 100 ergs of energy per gram of material being irradiated; or the energy absorbed per gram of tissue which is equal to about 83% of the Roentgen value. A millirad is a thousandth of a rad.

Rem and millirem: A radiation measure that reflects the difference in biological damage of the radiation dose produced by different particles. The relation between rad and rem depends on the kind of particle emitting the radiation: for gamma rays, 1 rad = 1 rem; for beta, 1 rad = 1 rem; for alpha, 1 rad = 30 rem.

Roentgen: The original term used for measuring the amount of ionizing gamma radiation incident on the body. It is equal to .94 rads.

Sources:
* Radioactive Heaven & Earth, Int’l Physicians for the prevention of Nuclear War, New York, The Apex Press, 1991.
* Nuclear Madness, Helen Caldicott, revised edition, NY, Norton, 1994.
* No Immediate Danger: Prognosis for a Radioactive Earth, Rosalie Bertell, London, the Women’s Press, 1985.
* Nuclear Power, Walter Patterson, Baltimore, MD, Penguine Books, 1976.
* Secret Fallout: Low-Level Radiation from Hiroshima to Three-Mile Island, Ernest Sternglass, NY, McGraw-Hill, 1972.

Since our business’ inception in 2000, we have been actively involved in the clean up of former nuclear weapons facilities now overseen by the U.S. Department of Energy (US DOE) or as part of the U.S. Army Corps of Engineers FUSRAP program.

This blog hopes to provide some information on why and how all this radioactive waste was generated.

At the end of World War II and throughout 50 years of The Cold War, the U.S. government worked with a great deal of urgency and secrecy to produce fissile materials for weapons.

Bomb Facts: How Nuclear Weapons are Made

1. Plutonium

The world’s first nuclear explosion was achieved with plutonium, a man-made element produced in nuclear reactors. Plutonium is created when an atom of uranium-238 absorbs a neutron and becomes plutonium-239. The reactor generates the neutrons in a controlled chain reaction. For the neutrons to be absorbed by the uranium their speed must be slowed by passing them through a substance known as a “moderator.” Graphite and heavy water have been used as moderators in reactors fueled by natural uranium. For graphite to succeed as a moderator it must be exceptionally pure; impurities will halt the chain reaction. Heavy water looks and tastes like ordinary water but contains an atom of deuterium instead of an atom of hydrogen. For heavy water to succeed as a moderator, it too must be pure; it must be free of significant contamination by ordinary water, with which it is mixed in nature.

(a) Plutonium needed to make a bomb:

– 4 kilograms: Weight of a solid sphere of plutonium just large enough to achieve a critical mass with a beryllium reflector. Diameter of such a sphere: 2.86 in (7.28 cm). Diameter of a regulation baseball: 2.90 in (7.36 cm).
– 4.4 kilograms: Estimated amount used in Israel’s fission bombs.
– 5 kilograms: Estimated amount needed to manufacture a first-generation fission bomb today.
– 6.1 kilograms: Amount used in “Trinity” test in 1945 and in the bomb dropped on Nagasaki.
– 15 kilograms: Weight of a solid sphere of plutonium just large enough to achieve a critical mass without a reflector. Diameter of such a sphere: 4.44 in (11.3 cm). Diameter of a regulation softball: 3.82 in (9.7 cm).

(b) Plutonium generated by various reactors:

– 5.5-8 kilograms/year: North Korea’s 20-30 megawatt (thermal) Yongbyon reactor moderated by graphite.
– 12 kilograms/year: Pakistan’s 50 megawatt (thermal) Khushab reactor moderated by heavy water.
– 9 kilograms/year: India’s 40 megawatt (thermal) Cirus reactor moderated by heavy water.
– 25 kilograms/year: India’s 100 megawatt (thermal) Dhruva reactor moderated by heavy water.
– 40 kilograms/year: Israel’s more than 100 megawatt (thermal) Dimona reactor moderated by heavy water. 230 kilograms/year: Iran’s 1,000 megawatt (electric) Bushehr reactor supplied by Russia and moderated by ordinary water.
– 230 kilograms/year: North Korea’s 1,000 megawatt (electric) power reactor to be supplied by a consortium sponsored by the United States and moderated by ordinary water.

(c) Estimated amount of heavy water needed for a small reactor used to make nuclear weapons:

– 19 metric tons: India’s 40 megawatt (thermal) Cirus reactor.
– More than 36 metric tons: Israel’s more than 100 megawatt (thermal) Dimona reactor.
– 78 metric tons: India’s 100 megawatt (thermal) Dhruva reactor.

1. Uranium-235

The world’s second nuclear explosion was achieved with uranium-235. This isotope is unstable and fissions when struck by a neutron. It is, however, found in natural uranium (U-238) at a concentration of only 0.7 percent. To be useful in nuclear weapons, the concentration must be increased. This is accomplished by a process known as enrichment. Because the isotopes of uranium are identical chemically, the enrichment process exploits the slight difference in their masses. Nuclear weapons now use a concentration of 93.5 percent uranium-235.

(a) Uranium-235 needed to make a bomb:

– 15 kilograms: Weight of a solid sphere of 100 percent uranium-235 just large enough to achieve a critical mass with a beryllium reflector. Diameter of such a sphere: 4.48 in (11.4 cm). Diameter of a regulation softball: 3.82 in (9.7 cm).
– 16 kilograms: Amount needed for an Iraqi bomb design found by UN inspectors.
– 50 kilograms: Weight of a solid sphere of 100 percent uranium-235 just large enough to achieve a critical mass without a reflector. Diameter of such a sphere: 6.74 in (17.2 cm), comparable to an average honeydew melon.
– 60 kilograms: Reported amount used in Hiroshima bomb “Little Boy.”

(b) Various methods used to enrich uranium:

(i) Electromagnetic Isotope Separation (EMIS)

In this process, uranium atoms are ionized (given an electrical charge) then sent in a stream past powerful magnets. The heavier U-238 atoms are deflected less in their trajectory than the lighter U-235 atoms by the magnetic field, so the isotopes separate and can be captured by collectors. The process is repeated until a high concentration of U-235 is achieved. An American version of the EMIS process, featuring “calutrons”, was used in the Manhattan Project. EMIS was also the principal process pursued by the Iraqi uranium enrichment effort.

(b) Gaseous Diffusion

In the gaseous diffusion process gaseous uranium hexafluoride (UF6) flows through a porous membrane of nickel or aluminum oxide. Lighter molecules of uranium-235 within the UF6 (235UF6) diffuse through the porous barrier at a faster rate than the heavier molecules of uranium-238 (238UF6). Because the difference in velocities between the two isotopes is small the process must be repeated thousands of times to achieve weapon-usable uranium-235.

(c) Gas Centrifuge

In the gas centrifuge process gaseous UF6 is fed into a cylindrical rotor that spins at a high speed inside an evacuated casing. Centrifugal forces cause the heavier 238UF6 to tend to move closer to the outer wall than the lighter 235UF6, thus partially separating the uranium isotopes. This separation is increased by a relatively slow axial countercurrent flow of gas within the centrifuge that concentrates enriched gas at one end and depleted gas at the other. Numerous stages in the process, employing thousands of centrifuges, are needed to concentrate the uranium-235 to weapon-grade.

(d) Aerodynamic Processes

In the Becker nozzle process a mixture of gaseous UF6 and helium (H2) is compressed and then directed along a curved wall at high velocity. The heavier uranium-238-bearing molecules move preferentially out to the wall relative to those containing uranium-235. At the end of the deflection, the gas jet is split by a knife edge into a light fraction and a heavy fraction, which are withdrawn separately.

(e) Atomic Vapor Laser Isotope Separation (AVLIS)

The AVLIS process uses dye lasers tuned so that only uranium-235 atoms absorb the laser light. As the uranium-235 atom absorbs the laser light, its electrons are excited to a higher energy state. When enough energy is absorbed, a uranium-235 atom will eject an electron and become a positively charged ion. The uranium-235 ions may then be deflected by an electrostatic field to a product collector. The uranium-238 atoms remain neutral and pass through the product collector.

(f) Molecular Laser Isotope Separation (MLIS)

The MLIS separation process consists of two basic steps. In the first step UF6 is excited by an infrared laser system, which selectively excites the UF6 molecules bearing uranium-235 (235UF6), leaving the UF6 molecules bearing uranium-238 unexcited (238UF6). In the second step, photons from a second laser system (infrared or ultraviolet) preferentially dissociate the excited 235UF6 to form uranium pentafluoride (UF5) molecules bearing uranium-235 (235UF5) and free fluorine atoms. The 235UF5 formed from the dissociation precipitates from the gas as a powder that can be filtered from the gas stream.

(g) Thermal Diffusion

Thermal diffusion uses the transfer of heat across a thin liquid or gas to accomplish isotope separation. By cooling a vertical film on one side and heating it on the other, the resultant convection currents will produce an upward flow along the hot surface and a downward flow along the cold surface. Under these conditions, the lighter uranium-235 molecules will diffuse toward the cold surface. These two diffusive motions combined with the convection currents will cause the lighter uranium-235 molecules to concentrate at the top of the film and the heavier uranium-238 molecules to concentrate at the bottom of the film.

The First Bombs

United States

“Trinity”: World’s first nuclear test explosion: July 16, 1945.
Location: Near Alamogordo, New Mexico.
Yield: 21 kilotons.
Fissile material used: Plutonium-239.
Amount: 6.1 kilograms.
Method of detonation: Implosion.
Amount of high-explosive wrapped around plutonium core: 2268 kilograms.
Method of production: Nuclear reactor at the Hanford Reservation.

“Little Boy”: First use of nuclear weapon in war: August 6, 1945.
Location: Hiroshima, Japan.
Detonation height: 580 meters.
Delivery mechanism: Airdropped from B-29 bomber named Enola Gay.
Yield: 12.5 kilotons.
Fissile material used: Uranium-235.
Method of detonation: “Gun-type” device.
Method of production: “Calutron” electromagnetic isotope separation.

“Fat Man”: Second use of a nuclear weapon in war: August 9, 1945.
Location: Nagasaki, Japan.
Detonation Height: 500 meters.
Delivery mechanism: Airdropped from B-29 bomber named Bock’s Car.
Yield: 22 kilotons.
Fissile material used: Plutonium-239.
Method of Detonation: Implosion.
Amount used: 6.2 kilograms.

“Ivy Mike”: First hydrogen bomb tested: November 1, 1952.
Location: Elugelab Island, Enewetak Atoll.
Yield: 10.4 megatons.

Soviet Union

“Joe 1”: First nuclear test: August 29, 1949.
Location: Semipalatinsk, Kazakhstan.
Yield: 10-20 kilotons.
Fissile material used: Plutonium-239.
Method of detonation: Implosion.
Method of production: Reactor.

“Joe 4”: First thermonuclear test: August 12, 1953.
Location: Possibly in Siberia.
Yield: 200-300 kilotons.

Great Britain

“Hurricane”: First nuclear test: October 3, 1952.
Location: Off Trimouille Island, Australia.
Yield: 25 kilotons.
Fissile material used: Plutonium-239.
Method of detonation: Implosion.
Method of production: Reactor.
Foreign Assistance: United States.

“Grapple Y”: Thought to be the first two-step thermonuclear test: April 28, 1958.
Location: Christmas Island.
Yield: 2 megatons.
Delivery Mechanism: Airdropped from a Valiant XD825 bomber.

France

“Gerboise Bleue”: First nuclear test: February 13, 1960.
Location: Reggane Proving Grounds, Algeria.
Yield: 60-70 kilotons.
Fissile material used: Plutonium-239.
Method of detonation: Implosion.
Method of production: Reactor.

“Canopus”: First thermonuclear test: August 24, 1968.
Location: Fangataufa Atoll.
Yield: 2.6 megatons.
Foreign assistance: Norway (heavy water to make tritium).

China

“596”: First nuclear test: October 16, 1964.
Location: Lop Nor.
Yield: 12.5-22 kilotons.
Fissile material used: Uranium-235.
Method of production: Gaseous diffusion.
Foreign assistance: Soviet Union.

First thermonuclear test: June 17, 1967.
Location: Lop Nor.
Yield: Approximately 3 megatons.
Delivery mechanism: Airdropped from a Hong 6 bomber.

Israel

Estimated date when first bomb was produced: Late 1966.
Fissile material: Plutonium.
Method of production: Dimona reactor imported from France and operated with heavy water supplied by Norway.
Probably conducted a 2-3 kiloton nuclear test on September 22, 1979 in the South Atlantic Ocean in cooperation with South Africa.

India

First nuclear test: May 18, 1974.
Location: Pokhran.
Yield: 2-15 kilotons.
Fissile material used: Plutonium-239.
Method of production: Cirus reactor supplied by Canada and operated with heavy water supplied by the United States.

Second nuclear test “Shakti 1”: May 11, 1998.
Location: Pokhran.
Yield: 10-15 kilotons.

Third nuclear test (claimed): May 13, 1998.
Yield: India claimed it tested two nuclear bombs, with a combined yield of 0.8 kilotons; however, there is no seismic evidence of any nuclear explosion.

South Africa

First device built: December 1982.
Total bombs built: Six.
Method of detonation: “Gun-type” device.
Fissile material used: Uranium-235.
Nuclear tests: None.

Dismantlement of bomb program began in November 1989 and was completed in early September 1991, after which South Africa signed a comprehensive safeguards inspection agreement with the IAEA.

Pakistan

Estimated production of first bomb: Late 1987.
First nuclear test: May 28, 1998.
Location: Chagai Hills region.
Yield: 9-12 kilotons Fissile material used: Uranium-235.
Method of production: Gas centrifuge technology smuggled from Europe.
Foreign assistance: China (bomb design), Germany (uranium processing equipment).

Second nuclear test: May 30, 1998.
Yield: 4-6 kilotons.

North Korea

In 1993 U.S. intelligence declared that North Korea had a “better than even” chance of possessing one or two atomic bombs.
North Korea has conducted no known nuclear tests.
Fissile material: Plutonium-239.
Method of production: Graphite reactor near Yongbyon.

The use of a superabsorbent polymer, such as Waste Lock^® 770, in radioactive waste management is a cost effective way to stabilize liquid waste without significantly increasing the waste volume or weight.  Because these radioactive waste streams are extremely costly to transport and dispose of, even a small increase in weight or volume can dramatically increase the cost.

Although these polymers are significantly more expensive than “cheap” absorbents such as Bentonite clay or Portland cement, project savings are realized by waste minimization.

Depending on the percent water in the waste, most mineral absorbents will double or quadruple the volume of waste…. One B25 box or 55-gallon drum then becomes two or even four!

The following illustrates the potential savings from using Waste Lock^®770:

One Cubic Yard of Low Level Radioactive Waste (LLRW)

50% Water/50% Solids

Bulk Density = 2200 lbs/yd³

Bentonite                     Waste Lock^®770

Absorbent Needed for One Yard³                  1000 lbs                                  44 lbs (2% wt)

Absorbent Unit Cost                                       $0.12/lbs**                               $2.50/lbs

** Assumes Midwest delivered cost of $6.00 per 50 lbs bag

Total Absorbent Cost                                      $120.00                                   $110.00

Est. Disposal Cost per Yard³                          $2000/yd³                                $2000/yd³

Absorbed Waste to Dispose                           2.5 yds³                                   1.0 yds³

Total Cost (inc. Absorbent)                             $5120.00                                 $2062.50

Savings from use of Waste Lock^®770    $3,057.50 per cubic yard

Until the 1980’s, water absorbing materials were cellulosic or fiber-based products.  Choices were tissue paper, cotton, sponge, and fluff pulp.  The water retention capacity of these types of materials is only 20 times their weight – at most.

In the early 1960s, the United States Department of Agriculture (USDA) was conducting work on materials to improve water conservation in soils.   They developed a resin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules (i.e. starch-grafting).  The hydrolyzed product of the hydrolysis of this starch-acrylonitrile co-polymer gave water absorption greater than 400 times its weight.  Also, the gel did not release liquid water the way that fiber-based absorbents do.

The polymer came to be known as “Super Slurper”.  The USDA gave the technical know-how several USA companies for further development of the basic technology.  A wide range of grating combinations were attempted including work with acrylic acid, acrylamide and polyvinyl alcohol (PVA).

Since Japanese companies were excluded by the USDA, they started independent research using starch, carboxy methyl cellulose (CMC), acrylic acid, polyvinyl alcohol (PVA) and isobutylene maleic anhydride (IMA).

Early global participants in the development of super absorbent chemistry included Dow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical, Enka (Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan.

In the early 1970s, super absorbent polymer was used commercially for the first time – not for soil amendment applications as originally intended – but for disposable hygienic products.    The first product markets were feminine sanitary napkins and adult incontinence products.

In 1978, Park Davis (d.b.a. Professional Medical Products) used super absorbent polymers in sanitary napkins.

Super absorbent polymer was first used in Europe in a baby diaper in 1982 when Schickendanz and Beghin-Say added the material to the absorbent core.  Shortly thereafter, UniCharm introduced super absorbent baby diapers in Japan while Proctor & Gamble and Kimberly-Clark in the USA began to use the material.

The development of super absorbent technology and performance has been largely led by demands in the disposable hygiene segment.   Strides in absorption performance have allowed the development of the ultra-thin baby diaper which uses a fraction of the materials – particularly fluff pulp – which earlier disposable diapers consumed.

Over the years, technology has progressed so that there is little if any starch-grafted super absorbent polymer used in disposable hygienic products.  These super absorbents typically are cross-linked acrylic homo-polymers (usually Sodium neutralized).

Super absorbents used in soil amendments applications tend to be cross-linked acrylic-acrylamide co-polymers (usually Potassium neutralized).

Besides granular super absorbent polymers, ARCO Chemical developed a super absorbent fiber technology in the early 1990s.  This technology was eventually sold to Camelot Absorbents.  There are super absorbent fibers commercially available today.  While significantly more expensive than the granular polymers, the super absorbent fibers offer technical advantages in certain niche markets including cable wrap, medical devices and food packaging.