Presentation on theme: "Nuclear Holocaust in a Terrorist Age. My Purpose To underscore the importance of keeping track of weapons grade Uranium as a deterrent to nuclear terrorism."— Presentation transcript:
My Purpose To underscore the importance of keeping track of weapons grade Uranium as a deterrent to nuclear terrorism To explain how we are vulnerable to sufficiently determined terrorists both at home and abroad, who would seek to smuggle weapons grade uranium fuel into or out of our country.
My Purpose To highlight the problems created by the downfall of the former Soviet Union.
The Science of Uranium and Plutonium Uranium is one of the most abundant elements in the Earth’s core. –Mined as uranium ore “pitchblende” –Element #92 (92 protons in its nucleus) –Forms: several isotopes: » 92 U 238 –non fissionable (99%) – 146 neutrons » 92 U 235 – fissionable (0.7%) – 143 neutrons
The Science of Uranium and Plutonium –Pure uranium is separated chemically from pitchblende and is available in Fluorides, Oxides (yellow cake) and other forms
The Science of Uranium and Plutonium Plutonium –First isolated by Glenn T. Seaborg at U of Cal. (Berkeley) in 1940. –Many isotopes are known. Most particularly 94 Pu 239 (94 protons/145 neutrons) –A warm metal because of radioactive decay. Used for heating.
The Science of Uranium and Plutonium Fission of Uranium To produce plutonium 92 U 238 92 U 239 93 N 239 + β - 94 Pu 239 + β - (half-life 24,100 years)
The Science of Uranium and Plutonium Radioactive Decay of Uranium All fission products are radioactive. Some with half-lives of thousands of years.
The Science of Uranium and Plutonium How to separate fissionable U 235 from non-fissionable U 238 –Gaseous Diffusion –Electromagnetic separation Highly enriched U 235 sufficient for making bombs is >80% (HEU)
The Science of Uranium and Plutonium The Chain Reaction –Primary neutrons =>secondary neutrons =>tertiary neutrons –In each fission event, mass is converted into a very large amount of energy
The Science of Uranium and Plutonium The Chain Reaction –Critical Mass (density) is the minimum mass necessary for a sustained uncontrollable nuclear chain reaction.
The Science of Uranium and Plutonium How much do we need to make a bomb? –A sustained chain reaction implies no more than one secondary fission event per primary fission event (a nuclear reactor) Bomb Type 92 U 235 (Kg) 94 P 239 (Kg) Bare Sphere 5611 Bare Sphere (with tamper) 155
History 6.6 Byr ago-Uranium is believed to be formed in a supernova. 1789 Element 92 is discovered in pitchblende by German pharmacist Martin Heinrich Klaproth
History 1896- Uranium discovered to be radioactive by Antoine Becquerel. Uranium is named after the newly discovered planet, Uranus
History 1905-Albert Einstein discovers famous equation from special relativity that speaks of the equivalence of mass and energy E=mc 2
History 1907 Ernest Rutherford converts nitrogen to oxygen in the first man- made nuclear reaction 1932-James Chadwick proposes “the neutron”. His ideas inspire Enrico Fermi (US) and Otto Hahn and Fritz Straussman (Ger).
History 1938-1939: The idea of a fission-induced chain reaction is conceived by Leo Szilard. He begins work with Fermi and others at the University of Chicago Fermi Szilard
History Bohr and other leading scientists have escaped Nazi- held countries and start to work for the allies. –Bohr expresses concern that Nazis can develop a nuclear weapon.
History Szilard, Edward Teller, and Einstein collaborate on a letter to President Roosevelt advising him of this capability. This begins project “Manhattan”.
History:The German Manhattan Project Werhner Heisenberg attempts Berman bomb to split uranium. –It is believed he did not understand the difference between a reactor and a bomb
History:The German Manhattan Project It is believed that the German project failed for several reasons: –Deliberate attempts to sabotage the projects by scientists –Many of Germany’s best scientists were Jewish Albert Einstein Edward Teller Niels Bohr Enrico Fermi’s wife
History:The German Manhattan Project It is believed that the German project failed for several reasons: –Lack of availability of HEU Stores in Finland and Norway were destroyed by resistance and British commandos. –The project was poorly organized and research was decentralized.
History: The German Manhattan Project September 1941, Niels Bohr meets with Heisenberg in Copenhagen where Heisenberg shares his ideas. February 1942, Heisenberg admits to Nazi war minister Albert Speer that a fission bomb is not possible for many years to come. Nonetheless, the Nazis begin work on a dispersing bomb.
History: The Manhattan Project Dec. 6, 1941: US congress commits $2B to the Manhattan Project 1940-1941: Plans are in full swing –A HEU separation plant at Oak Ridge, Tenn. –A Pu production facility at Hanover, Wash. –Headquarters and main physics experiments at LANL (a converted boys school), in Nevada. –J. Robert Oppenheimer heads research on the project after Einstein refuses. General Leslie Groves is in charge. –An entire military-industrial-and academic research complex is created, which is still in existence.
History: Challenges to be Overcome 1. How to purify the fuel? – 92 U 235 and 94 Pu 239 at Oak Ridge Magnetic Separation: (Calutrons) many wires needed- “racetracks” Copper and Silver borrowed from the US Mint. 10% of all US electric power used for 2 years all to produce only 7g of HEU. Final HEU used on “Little Boy”
History: Challenges to be Overcome The X-10 reactor at Oak Ridge uses neutrons released from U 235 to turn U 238 into Pu. Similar to reactors at Hanover. S-50 plant at Oak Ridge separated the isotopes by convection with steam coming from the K-25 plant (right).
History: Challenges to be Overcome 2. How to achieve critical mass? –The Gun approach HEU slugs are slammed together at high enough speeds in a “gun” device. “Little Boy” dropped on Hiroshima, Aug. 6, 1945 used 60 kg of HEU Gun bombs may use either U or Pu with a tamper
History: Challenges to be Overcome 2. How to achieve critical mass? –The Implosion approach: Critical density is achieved by implosion of a shock wave in a spherical core similar to the implosion of a massive star to produce a supernova
History: Challenges to be Overcome 2. How to achieve critical mass? The shock wave is produced by detonation of dynamite Because of the escape of neutrons, implosion devices may only use Pu. “Fat Man” dropped on Nagasaki on Aug. 9, 1945; 6.2 kg of Pu; yield: 21-23 kT of TNT.
History: Challenges to be Overcome “Gadget” –an implosion bomb test detonation atop a 150 ft tower on July 16, 1945 in New Mexico 210 miles from Alamogordo in a place called “Journada Del Muerto” (Journey of Death) code named “Trinity”. Heat-radiation melted sand created a new mineral “Trinitite”.
Analysis of an Atomic Explosion In the first few milliseconds there is a bright flash followed by an outward rushing shock wave traveling at the speed of sound. Thermal X-Rays produced by either one of two mechanisms Directly from decay of U 235 or Pu 239 Indirectly by the slow down of electrons (β particles) which are also direct by-products of decay. Trinity explosion Google Video
Analysis of an Atomic Explosion An atomic fireball or “mushroom cloud” is created and rises. Outward flow of air is followed by inward flow into ensuing firestorm. Debris from ground is lifted up into the fir4eball then falls back to Earth as “radioactive fallout”-the silent killer. Fireball rises into the air then dissipates.
History: Post WWII: The Cold War Heats Up 1946: Work begins in a fusion bomb-the hydrogen bomb. 1949: Soviet Union detonates their own atomic explosion: Klaus Fuchs smuggles secrets with help from Julius and Ether Rosenberg. Fuchs is deported. The Rosenbergs were executed.
History: Post WWII: The Cold War Heats Up Edward Teller takes over production of a “hydrogen bomb”, inappropriately called the “Atomic Bomb” or “A-Bomb”
History: Post WWII: The Cold War Heats Up 9 May, 1951: “Operation Greenhouse” produces “George” which confirmed that a fission device could produce the conditions necessary for a hydrogen fusion bomb. 1 Nov. 1952: “Operation Ivy” produces “Mike”, the first two-stage thermonuclear fusion device: 1 H 2 + 1 H 3 => 2 He 4 + n
History: Post WWII: The Cold War Heats Up 1950’s – 1960’s: New concepts in fission primary and fusion secondaries developed. Delivery systems changed from planes to ICBM’s to MIRV’s. U.S. leads the world with over 1100 test detonations.
History: Post WWII: The Cold War Heats Up “Atoms for Peace” program: Both superpowers agree to produce 100’s of nuclear reactors for themselves and for 50 other nations. Export restrictions were lifter in response to demands for longer-lived fuel. Reactors were supplied with bomb grade HEU (≥80% 92 U 235 ) 10 Metric tons of HEU still resides in nations that do not posses nuclear weapons. Enough for 150- 200 gun-type devices, as of 2005.
History: Post WWII: The Cold War Heats Up 1957: IAEA organized as an independent nuclear watchdog agency. 1963: “Limited Test Ban Treaty” limits nuclear testing to underground where detection methods are limited to seismic studies and radioactive effluent in in the air.
History: Post WWII: The Cold War Heats Up 1968: “Nuclear Non-Proliferation Treaty” limited the spread of nuclear weapons to 5 nations: U.S., Russia, U.K., France, and China. 188 nation agree. Several rogue states have defied it (Israel, North Korea, and Pakistan). Iran threatens to join the list.
History: Post WWII: The Cold War Heats Up 1970’s: U.S. takes steps to prevent diversion of bomb grade fuel. Conversion of American designed reactors to run on LEU. »41 reactors to date have been retrofitted. High powered research reactors still need HEU. 1980’s: A new spirit of openness “Glasnost” and “Perestroika”
History: The fall of the Soviet Union: End of the Cold War 1991: The installation of democracy in for former Soviet Union is greeted with economic collapse. Many former members of the Soviet bloc became independent states (Turkmenistan, Uzbekistan, Belarus, …)
History: The fall of the Soviet Union: End of the Cold War Soviet record keeping is very poor. 18 incidents of nuclear smuggling between 1993 and 2004 were reported by the IAEA. Incidents were reported only after material was discovered, and so no one is exactly sure how much if any HEU is missing. Breaches have been plainly evident. US works with Russia to secure some 600 tons of HEU and 30,000 weapons.
What Is Happening Now? : The Problem The Russian government appears unconcerned about its lax security and dangers posed by terrorists. Putins’ government is increasingly resistant to visits by foreigners to its nuclear programs. 50 tons in civilian use support 140 reactors for scientific and industrial use, and for medical purposes. 50% in Russia alone, with much of this in or near urban areas.
What Is Happening Now? : The Problem Today, it is feared that Al-Qaeda might acquire HEU and detonate a crude gun- type device before authorities can respond. 10 metric tons resides in nations that will not develop nuclear weapons. This is enough for 150- 200 gun-type devices, as of 2005.
What Is Happening Now? : A Two- Fold Solution 1. Eliminate the use of HEU wherever possible. 2. Dilute all accumulated stocks with LEU that is not useable in weapons. In the 1990’s U.S. begins to cooperate with Russia in securing and eliminating HEU stockpiles. Since 1999, US has been buying and blending down 7 tons of civilian HEU.
What Is Happening Now? : A Two- Fold Solution Some of this is spent reactor fuel, which is 80% HEU, but is still radioactive, and therefore is “self-protective”. After 9/11, congress intensifies pressure o the DOE to step up its efforts to secure civilian HEU worldwide. Repatriate all used and unused Russian civilian HEU by 2010 Repatriate all spent US fuel by 2019
What Is Happening Now? : A Two- Fold Solution After 9/11, congress intensifies pressure o the DOE to step up its efforts to secure civilian HEU worldwide. Retrofit all US civilian research reactors to LEU fuel by 2014 Much progress has been made in retrofitting Russian civilian reactors but more needs to be done.
What Is Happening Now? : A Two- Fold Solution The IAEA estimates that 80% of the world’s aging research reactor fleet could be decommissioned with HEU stores bringing in approximately $20M/ton for dilution to LEU. “If the U.S. and its allies were to take seriously the challenge of preventing nuclear terrorism, civilian HEU could be eliminated …. in 5-8 years. Continued delay in completing this task only extends the window of opportunity to would-be terrorists” Glaser and Von Hippel: SciAm (2006)
What’s Happening Now?: Uranium Smuggling: How Do We Stop It? The use of HEU overseas by foreign governments is the responsibility of the Department of Energy (DOE) Detection of nuclear smuggling is the responsibility of the Department of Homeland Security (DHS). We need effective intelligence.
What’s Happening Now?: Uranium Smuggling: How Do We Stop It? U.S. outfits border crossing stations in former Soviet bloc countries. Several agencies are involved »DOE: Second Line of Defense Program (SLOD) »DHS »Department of State 39 sites 200 attempts uncovered in 2004, yet breaches are still possible.
What’s Happening Now?: Uranium Smuggling: How Do We Stop It? In 2003, DOE (SLOD/Mega Ports Initiative): Ports all over the world receive x-ray scanners and ultra-sensitive radiation detectors. Detection Techniques – active X-ray imaging exposes lead enclosures Detection Techniques – passive Gamma ray and neutron imaging induce a small amount of fusion
What’s Happening Now?: Uranium Smuggling: How Do We Stop It? Once detected, a suspicious container can be searched by inspectors with belt-worn radiation pagers. Smugglers could carry sources for a dirty bomb, a dispersant driven by a conventional weapon that disperses radioactive material such as Cs 137, or Sr 90. These had been scavenged from radio-isotope thermal generators left in the wilds of the former Soviet Union.
What’s Happening Now?: Uranium Smuggling: How Do We Stop It? Sources are detected and categorized by their spectra (counts versus energy, in Kev) These material are efficient, but not foolproof.
What’s Happening Now?: Uranium Smuggling: Weaknesses in the System If sufficiently determined terrorists are able to elude detection, it will bee in a manner that we cannot expect. Our methods are a deterrent, but are not foolproof. Fissionable materials from a nuclear weapon, yet not feasible for dirty bombs would be hard to detect.
What’s Happening Now?: Uranium Smuggling: Weaknesses in the System Smugglers could place shielding around nuclear materials or attempt to disquise them with normally radioactive materials, or “interference cargo”. These include: Fertilizer Kitty litter Television sets Granite slabs Road Salt Smoke Detectors Glazed ceramics Medical Isotopes
What’s Happening Now?: Uranium Smuggling: Weaknesses in the System “If we are successful in doing so for long enough … these efforts will have been of great benefit to the nation” Kouzes Amer. Scientist (2005)