Fogbank
Encyclopedia
FOGBANK is a code name given to a material used in nuclear weapons such as the W76
, W78
and W80.
FOGBANK's precise nature is classified; in the words of former Oak Ridge
general manager Dennis Ruddy, "The material is classified. Its composition is classified. Its use in the weapon is classified, and the process itself is classified." Department of Energy
Nuclear Explosive Safety documents simply describe it as a material "used in nuclear weapon
s and nuclear explosives" along with lithium hydride
(LiH) and lithium deuteride (LiD), beryllium
(Be), uranium hydride
(UH3), and plutonium hydride
. Many arms experts believe that FOGBANK is an aerogel
material which acts as an interstage material in a nuclear warhead, i.e. a material designed to become a superheated plasma
following the detonation of the weapon's fission stage, the plasma then triggering the fusion-stage detonation.
in Oak Ridge, Tennessee
from 1975 until 1989, when the final batch of W76 warheads were completed. After that the facility was mothballed, and finally slated for decommissioning by 1993. Only a small pilot plant
was left, which had been used to produce small batches of FOGBANK for testing purposes.
In 1996, the US government decided that large numbers of its nuclear weapons would require replacement, refurbishing, or decommissioning. Accordingly, the Department of Energy
set up a refurbishment program aimed at extending the service lives
of older nuclear weapons. In 2000, the National Nuclear Security Administration
(NNSA) specified a life-extension program for W76 warheads that would enable them to remain in service until at least 2040.
It was soon realized that the FOGBANK material was a potential source of problems for the program, as few records of its manufacturing process had been retained when it was originally manufactured in the 1980s, and nearly all staff members who had expertise in its production had either retired or left the agency. The NNSA briefly investigated sourcing a substitute for FOGBANK, but eventually decided that since FOGBANK had been produced previously, they would be able to repeat it. Additionally, "Los Alamos computer simulations at that time were not sophisticated enough to determine conclusively that an alternate material would function as effectively as Fogbank," according to a Los Alamos publication.
Manufacture involves the moderately toxic, highly volatile solvent
acetonitrile
, which presents a hazard for workers (causing three evacuations in March 2006 alone).
With Facility 9404-11 long since decommissioned, a brand new production facility was required. Delays arose during its construction, and in addition, engineers repeatedly encountered failure in their efforts to produce FOGBANK. As one deadline after the other expired, and the schedule was pushed back again and again, the NNSA eventually decided to invest $23 million to attempt to find an alternative to FOGBANK.
In March 2007, engineers finally devised a manufacturing process for FOGBANK. Unfortunately, the material turned out to have problems when tested, and in September 2007 the FOGBANK project was upgraded to "Code Blue" status by the NNSA, making it a major priority. In 2008, following the expenditure of a further $69 million, the NNSA finally managed to manufacture FOGBANK, and 7 months later, the first refurbished warhead was handed over to the US Navy, nearly a decade after the commencement of the refurbishment program. However, in May 2009 a US Navy spokesman said that they had not received any refurbished weapons to date. The Energy Department stated that the current plan was to begin shipping refurbished weapons in the fall of 2009, two years behind schedule.
Some commentators have suggested that the US "forgot how" to make FOGBANK. However, it turns out the US never knew how to make it. An article published by Los Alamos National Laboratory explains that the problem with FOGBANK was caused because a material being used to remanufacture FOGBANK was too "pure". The original impure starting materials included an impurity which was essential to the quality of the final product. However, the essential role of this impurity was never previously understood. After extensive study, the crucial role of the impurity was discovered. It is now included as an additive.
W76
The W76 is a United States thermonuclear warhead. It was manufactured from 1978-1987, and is still in service .The W-76 is carried inside a Mk-4 re-entry vehicle. U.S...
, W78
W78
The W78 thermonuclear warhead is the warhead used on most of the United States LGM-30G Minuteman III intercontinental ballistic missiles , along with the MK-12A reentry vehicle which carried the warhead. Minuteman III's initially deployed with the older W62 warhead; the W78 was deployed starting...
and W80.
FOGBANK's precise nature is classified; in the words of former Oak Ridge
Oak Ridge National Laboratory
Oak Ridge National Laboratory is a multiprogram science and technology national laboratory managed for the United States Department of Energy by UT-Battelle. ORNL is the DOE's largest science and energy laboratory. ORNL is located in Oak Ridge, Tennessee, near Knoxville...
general manager Dennis Ruddy, "The material is classified. Its composition is classified. Its use in the weapon is classified, and the process itself is classified." Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
Nuclear Explosive Safety documents simply describe it as a material "used in nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
s and nuclear explosives" along with lithium hydride
Lithium hydride
Lithium hydride is the inorganic compound with the formula LiH. It is a colorless solid, although commercial samples are gray. Characteristic of a salt-like, or ionic, hydride, it has a high melting point and is not soluble in any solvent with which it does not react...
(LiH) and lithium deuteride (LiD), beryllium
Beryllium
Beryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...
(Be), uranium hydride
Uranium hydride
Uranium hydride, also called uranium trihydride is an inorganic compound, a hydride of uranium.-Properties:Uranium hydride is a highly toxic, brownish gray to brownish black pyrophoric powder or brittle solid. Its specific gravity at 20 °C is 10.95, much lower than that of uranium...
(UH3), and plutonium hydride
Plutonium hydride
Plutonium hydride is the chemical compound with the formula PuH2. It is one of two characterised hydrides of plutonium, the other is PuH3. PuH2 is non-stoichiometric with a composition range of PuH2 – PuH2.7. Additionally metastable stoichiometries with an excess of hydrogen can be formed. PuH2...
. Many arms experts believe that FOGBANK is an aerogel
Aerogel
Aerogel is a synthetic porous material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and thermal conductivity...
material which acts as an interstage material in a nuclear warhead, i.e. a material designed to become a superheated plasma
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
following the detonation of the weapon's fission stage, the plasma then triggering the fusion-stage detonation.
History
It has been revealed by unclassified official sources that FOGBANK was originally manufactured in Facility 9404-11 of the Y-12 National Security ComplexY-12 National Security Complex
The Y-12 National Security Complex is a United States Department of Energy National Nuclear Security Administration facility located in Oak Ridge, Tennessee, near the Oak Ridge National Laboratory...
in Oak Ridge, Tennessee
Oak Ridge, Tennessee
Oak Ridge is a city in Anderson and Roane counties in the eastern part of the U.S. state of Tennessee, about west of Knoxville. Oak Ridge's population was 27,387 at the 2000 census...
from 1975 until 1989, when the final batch of W76 warheads were completed. After that the facility was mothballed, and finally slated for decommissioning by 1993. Only a small pilot plant
Pilot plant
A pilot plant is a small chemical processing system which is operated to generate information about the behavior of the system for use in design of larger facilities....
was left, which had been used to produce small batches of FOGBANK for testing purposes.
In 1996, the US government decided that large numbers of its nuclear weapons would require replacement, refurbishing, or decommissioning. Accordingly, the Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
set up a refurbishment program aimed at extending the service lives
Service life
A product's service life is its expected lifetime, or the acceptable period of use in service. It is the time that any manufactured item can be expected to be 'serviceable' or supported by its manufacturer....
of older nuclear weapons. In 2000, the National Nuclear Security Administration
National Nuclear Security Administration
The United States National Nuclear Security Administration is part of the United States Department of Energy. It works to improve national security through the military application of nuclear energy...
(NNSA) specified a life-extension program for W76 warheads that would enable them to remain in service until at least 2040.
It was soon realized that the FOGBANK material was a potential source of problems for the program, as few records of its manufacturing process had been retained when it was originally manufactured in the 1980s, and nearly all staff members who had expertise in its production had either retired or left the agency. The NNSA briefly investigated sourcing a substitute for FOGBANK, but eventually decided that since FOGBANK had been produced previously, they would be able to repeat it. Additionally, "Los Alamos computer simulations at that time were not sophisticated enough to determine conclusively that an alternate material would function as effectively as Fogbank," according to a Los Alamos publication.
Manufacture involves the moderately toxic, highly volatile solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
acetonitrile
Acetonitrile
Acetonitrile is the chemical compound with formula . This colourless liquid is the simplest organic nitrile. It is produced mainly as a byproduct of acrylonitrile manufacture...
, which presents a hazard for workers (causing three evacuations in March 2006 alone).
With Facility 9404-11 long since decommissioned, a brand new production facility was required. Delays arose during its construction, and in addition, engineers repeatedly encountered failure in their efforts to produce FOGBANK. As one deadline after the other expired, and the schedule was pushed back again and again, the NNSA eventually decided to invest $23 million to attempt to find an alternative to FOGBANK.
In March 2007, engineers finally devised a manufacturing process for FOGBANK. Unfortunately, the material turned out to have problems when tested, and in September 2007 the FOGBANK project was upgraded to "Code Blue" status by the NNSA, making it a major priority. In 2008, following the expenditure of a further $69 million, the NNSA finally managed to manufacture FOGBANK, and 7 months later, the first refurbished warhead was handed over to the US Navy, nearly a decade after the commencement of the refurbishment program. However, in May 2009 a US Navy spokesman said that they had not received any refurbished weapons to date. The Energy Department stated that the current plan was to begin shipping refurbished weapons in the fall of 2009, two years behind schedule.
Some commentators have suggested that the US "forgot how" to make FOGBANK. However, it turns out the US never knew how to make it. An article published by Los Alamos National Laboratory explains that the problem with FOGBANK was caused because a material being used to remanufacture FOGBANK was too "pure". The original impure starting materials included an impurity which was essential to the quality of the final product. However, the essential role of this impurity was never previously understood. After extensive study, the crucial role of the impurity was discovered. It is now included as an additive.