Beryllium is a naturally occurring, silver-grey metal. Lighter than aluminum and more rigid than steel, Be has many unusual properties which make it ideal for several applications, including aircraft and space vehicle structure, x-ray machine assemblage, mirrors, ceramics, metal alloys, and, since the 1950's, nuclear technology including weapons and reactors.
The most significant disadvantage of Be as an industrial material appears to be the toxicity of its dust, fumes, and soluble salts. However, metallic Be has good resistance to alteration or chemical attack and is not easily altered to soluble forms when released to the environment. Most Be in the soils does not dissolve in water and remains bound to the soil particles.
An initiator is a device that produces a timed burst of neutrons to initiate a fission chain reaction in a nuclear weapon. Initiators made of polonium-210 and beryllium were located at the center of the fissile cores of early atomic weapons. The highly radioactive isotope of Polonium (Po-210) is a strong alpha emitter. Beryllium will absorb alphas and emit neutrons. This isotope of polonium has a half life of almost 140 days, and a neutron initiator using this material needs to have the polonium, which is generated in a nuclear reactor, to be replaced frequently. To supply the initiation pulse of neutrons at the right time, the polonium and the beryllium need to be kept apart until the appropriate moment and then thoroughly and rapidly mixed by the implosion of the weapon.
Beryllium is used as the reflector material (or 'pit liner') in most contemporary American nuclear weapons and thermonuclear primaries. The 'primary', or weapon trigger, consists of three components: the central spherical plutonium 'pit' or core, the Be 'pit liner', and a surrounding high-explosives shaped-charge. The pit liner, sometimes also referred to as the "skull", surrounds the spherical plutonium pit and is in turn surrounded by high explosives. All three of these components together make up a modern nuclear weapon's "primary", or trigger, which initiates the thermonuclear reaction in a weapon's secondary components. The beryllium liner effectively acts as 1) a reflector which directs neutrons back into the plutonium pit; 2) a tamper which initially contains and thereby helps to increase the force of the explosion; and 3) a generator of additional neutrons.2 A flux of neutrons at the beginning of a nuclear weapon's detonation initiates critical mass, which subsequently leads to the weapon's designed destructive yield.
The Department of Energy uses beryllium metal to fabricate weapons components and to facilitate a number of weapons-related experiments. Based on its analysis of the President's 2001 Nuclear Posture Review, the National Nuclear Security Administration (NNSA) estimated that it would need approximately 90 tons of beryllium metal to meet mission requirements over the next 30 years. About 50 tons of the material is currently available for purchase from the Defense Department's National Defense Stockpile. Because the only domestic producer of beryllium metal from ore ceased production in 2000, NNSA had been uncertai how it would overcome the perceived shortfall.
NNSA's existing beryllium metal weapon component manufacturing process involves machining down large blocks of beryllium metal so that only about four percent of the feed material ends up in the final product. This means that the process results in a discard of 96 percent of the material as scrap. Technical experts explained that this metal could not be reused for weapons production without reprocessing since it contains impurities from the manufacturing process. Near-net shaping, on the other hand, is a process by which beryllium powder is sized to a shape closer to that of the final parts, thereby allowing NNSA to use significantly less beryllium metal to manufacture the same parts.
Beryllium Is a Silver-Gray Metallic Element That Occurs Naturally in About 30 Minerals. Beryllium was discovered in 1798, but it was not widely used in industry until the 1940s and 1950s. In industrial applications beryllium can be:
- used as pure metal
- mixed with other metals to form alloys
- processed to salts that dissolve in water
- processed to form oxides and ceramic materials
Beryllium-Containing Minerals Are Found in Rocks, Coal and Oil, Soil, and Volcanic Dust
From these sources, beryllium is emitted into the air and water by natural processes like erosion and by the burning of coal and oil. According to data collected by the Environmental Protection Agency (EPA), the average concentration of airborne beryllium in the United States is very small (0.03 nanogram/cubic meter-a nanogram is one-billionth of a gram).
Beryllium used in industry begins as a silicate (BeSiO3) in beryl and bertrandite ores. In a very pure crystalline form, beryl is known to us as gems such as blue-green aquamarine and green emerald.
Bertrandite is mined in Utah, but other ores and scrap are imported into the United States, which is the world's leading producer, processor, and consumer of beryllium products. According to U.S. Geological Survey reports, total US use of all forms of beryllium in 1996 was about 234 metric tons.
|Lighter than Aluminum, Stiffer than Steel-Properties That Make Beryllium Useful|
|Stiffness or rigidity||
|High melting point||
|High heat-absorption capacity||
|Good corrosion resistance|
|Lowest thermal neutron absorption cross-section of any metal|
|High permeability (transparency) to X-rays|
|Can be machined to close tolerances|
Many Products and Processes Use Beryllium's Properties
Beryllium metal has been produced for various industrial uses since the late 1950s.
Both structural and instrument grade materials are manufactured, especially for use in aerospace and defense:
- Windshield frames and other structures in high-speed aircraft and space vehicles
- Aircraft and space shuttle brakes
- Satellite mirrors and space telescopes
- Inertial guidance systems and gyroscopes
- Neutron moderator or reflector in nuclear reactors
- X-ray windows
- Nuclear weapons components
Other Beryllium Materials Include Soluble Salts, Alloys, and Oxide
Soluble salts, such as beryllium fluoride, chloride, and sulfate, are used in nuclear reactors, in glass manufacture, and as catalysts for certain chemical reactions.
Beryllium-copper (BeCu) alloys usually contain about 2 percent beryllium, but vary greatly in composition to meet different industrial and consumer needs. Beryllium contributes hardness, strength, high electrical and thermal conductivity, and resistance to corrosion, wear, and fatigue. For example, BeCu springs "bounce back" to their original shape again and again.
Be alloys are used for:
- Springs, switches, relays, and connectors in automobiles, computers, radar and telecommunications equipment, and other instruments
- High-strength nonsparking tools including some tools sold for use in the home
- Molds or casts to make metal, glass, and plastic items
- Sports equipment such as golf clubs and bicycle frames
- Dental bridges and related applications
Beryllium is also added to aluminum, nickel, zinc, and zirconium for some applications. Beryllium-nickel alloys are used in automobile air bags. A relatively new beryllium-aluminum alloy (the registered trademark is "Beralcast") is being used in fighter planes, helicopters, and missile systems.
Beryllium Oxide (BeO) Is Used To Make Ceramics for Electronics, Electrical, and Other Equipment
BeO contributes hardness, strength, excellent heat conductivity, and good electrical insulation. In closely packed circuitry (like that in the electronic ignition systems of automobiles), beryllium ceramic layers can draw heat away from other circuit components. Because BeO is transparent to microwaves, it has also been used in microwave ovens.
Despite its Usefulness, Beryllium Is Not an Ideal Material
It is expensive and too brittle to work with in some applications.
The most significant disadvantage of beryllium as an industrial material is the toxicity of its dust, fumes, and soluble salts.
Beryllium's brittleness is the down side of its advantageous stiffness. Brittleness also increases the hazards associated with beryllium's toxicity. Unless ventilation and other controls are used, small particles and chips of insoluble beryllium-containing materials break off during machining and other processes and spread through the air in the work area. Inhalation of these tiny particles is the type of exposure that can lead to chronic beryllium disease.
Beryllium Is a Significant Workplace Health Hazard
Exposure to beryllium particles can cause a serious illness in certain people. This illness is chronic beryllium disease, or CBD-an irreversible and sometimes fatal scarring of the lungs.
- Medical studies show that even small amounts of beryllium particles of a size that can be breathed deeply into the lungs may trigger an allergy-like sensitivity in 2-5 percent of people exposed.
- About 1 to 3 percent of all people exposed to beryllium develop CBD. In studies of people in certain occupations where historically exposure to beryllium was greatest (for example, studies of machinists in beryllium operations), this number rises to as many as 10 to 14 percent.
- There is currently no widely available test to find out who is sensitive to beryllium before exposure occurs.
- More than 100 current and former employees of Department of Energy (DOE) sites have CBD. The percentage of people who were exposed and became ill is much larger than similar percentages known for other DOE workplace health hazards.
CBD is seen only in individuals who have experienced some exposure to beryllium particles, dust, or fumes.
Chronic Beryllium Disease: A Long-Term Health Effect
Long-term, or chronic, health effects can take years to develop after the first exposure to beryllium and can affect people who were exposed to very small amounts of beryllium. In some cases, CBD has been diagnosed in former office workers and others who had only brief, incidental exposure to beryllium.
CBD is primarily a lung disease, but it may also affect other organs, particularly the lymph nodes, skin, spleen, liver, kidneys, and heart.
CBD is seen in individuals who are sensitized to beryllium.
CBD occurs in individuals who have become "allergic" or sensitized to beryllium upon exposure. Although current DOE medical surveillance programs are identifying more people who are only sensitized and not sick with CBD, many individuals already have CBD by the time they are evaluated for beryllium sensitization or lung symptoms.
CBD can take many years to develop.
The average time from first beryllium exposure to the development of symptoms (latency period) of CBD is 10 to 15 years. This means you can be exposed to beryllium today and not suffer any health effects for decades. Health effects have appeared in some people a few months after exposure, but not for as long as 30 years in others.
Doctors and researchers believe that some individuals who have had CBD lived with the disease and died from other causes without even knowing they had CBD.
CBD symptoms resemble those of other lung diseases.
The symptoms of CBD are very similar to those of several other diseases, particularly a disease called sarcoidosis that affects the lungs and sometimes other organs. Studies have found that in some cases doctors have diagnosed what turned out to be CBD as sarcoidosis or another disease.
Symptoms of CBD may include the following:
- Persistent coughing
- Shortness of breath with physical exertion
- Chest and joint pain
- Blood in the sputum (sputum is saliva, mucus, and other discharges that can be "coughed up" from the respiratory system)
- Rapid heart rate
- Loss of appetite
- Fevers and night sweats
CBD is treatable, but not curable.
If loss of lung function is detected, treatment may involve taking corticosteroids (often just called "steroids"), a medicine that reduces inflammation. The most common type of corticosteroid prescribed for CBD is prednisone. If successful, treatment with steroids can slow the progress of CBD by reducing the buildup of scar tissue and delaying permanent lung damage.
However, many individuals do not respond well to treatment. Others cannot tolerate the side effects of long-term steroid treatment. Side effects of taking steroids for long periods of time can include slower healing of infections, calcium loss from the bones, higher blood cholesterol, and fluid and salt retention which can make heart or kidney disease worse. The right treatment for an individual must be considered in light of that person's overall health and medical history.
Individuals with insufficient levels of oxygen in their blood as a result of CBD may also need supplemental oxygen to help improve oxygen delivery to the body and to protect the heart from the damage that can be done by low oxygen levels.
Individuals who cannot take steroids may continue to lose lung function. As a result they are likely to experience poorer quality of life, becoming invalids in some cases. Their life span may also be shorter.
Although the use of corticosteroids is the standard treatment for CBD, research is in progress on other drugs that may reduce the need for high doses of corticosteroids.
On the other hand, some individuals with diagnosed CBD may never become sick enough to require treatment.
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