What does it take for the DPRK to be a nuclear threat? Jerry Peterson Department of Physics University of Colorado Jerry.Peterson@Colorado.edu
There is a secret to nuclear bombs!
The Secret to the Atomic Bomb? That’s not it.
The Secret to Nuclear Bombs They work! Plan A Plan B The Super
Nagasaki Plan B Hiroshima Plan A
Ground zero of the first Soviet A-test, August 1949. Plan B
Proliferation Currently: USA, Russia, United Kingdom, France, PR China, India, Pakistan, North Korea, (and Israel) Have thought about it: Canada, Sweden, Switzerland, Brazil, Argentina… Have given them up: South Africa, Kazakhstan, Ukraine, Belarus Active programs? Iraq, until we ended it. Iran?
Uranium is 0.7% 235U and 99.3% 238U neutron Excited nucleus, shaking Two fission fragments and 2.4 neutrons Like charges repel—the origin of heat energy
Fission, just like a lava Lamp
The hardest part of getting a nuclear bomb is the material “Front End”- obtain 235U (HEU=at least 80%) by exactly the same methods used to make Low Enriched Uranium (LEU) for power plants (typically 3-4%) from natural uranium, 0.7% of which is 235U. “Back End”- obtain 239Pu from Spent Nuclear Fuel by chemical reprocessing.
The plutonium route-Plan B Construct a nuclear reactor, operating from the fission of 235U. The operation of the reactor can be monitored by satellite. Allow the excess neutrons available from this fission to capture on abundant 238U to breed 239Pu. (arithmetic: 238+1=239) Separate the plutonium and uranium by ‘reprocessing’ chemistry, which releases radioactivity that can be sensed. Create a fission bomb from this material.
DPRK summary Began construction of nuclear reactors and associated technology from late ‘50’s, Yongbyon reactor operational 1986, making ~6 kg Pu/year using natural uranium. Signed NonProliferation Treaty 1985—allows peaceful development Withdrew from the NPT on 2003, and expelled IAEA inspectors in 2002. Known to be developing nuclear bomb technology, via the plutonium route= Plan B. Yongbyon components destroyed 2008, restarted Evidence of uranium enrichment 2010 (Pakistan), Plan A Lots of uranium ore32,000 tons of uranium
The context NPT US removed all nuclear weapons from Korea in 1991, in ROK since 1958, up to 950! In 1967. Six Power talks—not just nuclear Agreed Framework— Freeze plutonium program, in return for fuel oil and a promise of two LWR for power. LWR concrete poured 2002, suspended.
You can’t hide any significant nuclear effort. Satellite images, including heat sources Seismology Radioactivity—very sensitive and specific. Laws of physics—extrapolations.
Yongbyon
Yongbyon facility
Now operating again S. Hecker
Second one-2009, a few kilotons of TNT equivalent, but no leakage. Test the device As we did in 1945. First (underground) 2006, sensed by seismology. A ‘fizzle’, but enough radioactive leakage to sense. Second one-2009, a few kilotons of TNT equivalent, but no leakage. Number 6-September 2017
#6--The ‘Super’? A hydrogen bomb uses a fission bomb ‘trigger’ to initiate fusion reactions among isotopes of hydrogen, for an unlimited yield. The trigger supplies enough pressure and temperature to allow two positive hydrogen nuclei to react.
But-like charges repel !
Future? Inventory—20-40 kg Plutonium 200-450 kg HEU -enough for ~20-25 weapons Production for ~6/7 weapons per year S. Hecker/ Bulletin of the Atomic Scientists
(convertalot.com/earthquake power calculator.htm) How big was #6? 3 September 2017 Richter 5.7=5.4 kT Richter 6.3=42.5 kT (Hiroshima 14 kT) (convertalot.com/earthquake power calculator.htm) Hecker-perhaps 100 kT
Ivy Mike 10 Mt “Science seems ready to confer on us, as its final gift, the power to erase human life on this planet” DDE first inauguration, 1953
Nuclear Bomb Effects, by Testing Surface, air, underground, undersea, in space USA—1054 The effects are experimentally known! Brian Toon, the expert