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Proliferation Aspects of Plutonium Production in Nuclear Reactors. Dwight L. Williams, Ph.D., P.E. Martin Luther King Visiting Professor Department of Nuclear Science and Engineering Massachusetts Institute of Technology. Overview. Introduction Reactor Isotopes of Interest Types of Plutonium - PowerPoint PPT Presentation
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Proliferation Aspects of Plutonium Production in Nuclear Reactors
Dwight L. Williams, Ph.D., P.E.
Martin Luther King Visiting ProfessorDepartment of Nuclear Science and Engineering
Massachusetts Institute of Technology
Overview Introduction Reactor Isotopes of Interest Types of Plutonium Plutonium Production
About the Speaker -- the “New Guy” Education and Registration (Nuclear Engineering)
B.S., North Carolina State University (NCSU)M.S., NCSU, Plasma Physics/FusionPh.D. University of Maryland, Radionuclide DetectionP.E., Commonwealth of Virginia
Professional ExperienceNuclear Analyst, Prototype International Data CentreSenior Nuclear Engineer, Department of Defense (DoD)Chief Engineer/Principal Nuclear Physicist, DoD
Introduction Why knowledge of nuclear proliferation is
useful within peaceful nuclear academic programexpands upon foundational knowledge fosters effective nonproliferation and
counterproliferation efforts facilitates nuclear security planningenables better public relations and perceptions to be
cultivated
Weapons Development Pathways
Weapons Development Pathways
Typical Reactor Isotopes of Interest Plutonium (Pu-239)
product of natural and depleted uranium irradiation
one of many Pu isotopes generated Uranium (U-235)
U-235 abundance customarily of 3 - 5% in reactors
Tritium (H-3)product of heavy water irradiationproduct of Li-6 and Li-7 irradiationpossible fission product
Relevant Plutonium Isotopes Pu-239: U-238 + n → U-239 → Np-239 → Pu-239
most desirable for nuclear weapons use
Pu-240: Pu-239 + n → Pu-240 (if no fission)neutron emitter/spontaneous fission
Pu-241: Pu-240 + n → Pu-241 relatively strong gamma-ray emitter
Pu-238: U-235 or U-238 + n → → → Pu-238 generates heat from rapid decay
Plutonium Isotope PropertiesProperty Pu-238 Pu-239 Pu-240 Pu-241 Pu-242t1/2 (y) 87.74 24,110 6537 14.4 376,000
Spec. Act. (Ci/g)
17.3 .063 .23 104 .004
Decay , SF
Notes,Pu-241 decays into Am-241, an intense emitterMost even Pu isotopes (238, 240, etc.) decay by SF
Production of Weapons Grade Pu At least 94% Pu-239 Typically generated in weeks to months in
reactor frequent refueling required for optimum productionseparating isotopes is nontrivial effort
Typically affects power production
Comparison of Plutonium GradesIsotope Weapons Grade Reactor GradePu-238 0.01 - 0.04% 1 - 2%
Pu-239 94% 56 - 60%
Pu-240 6% 24%
Pu-241 0.1% 6 - 13%
Pu-242 0.02% 5%
In general,Weapons Grade: < 7% Pu-240Reactor Grade: > 18% Pu-240
Pu Isotopes as a Function of Burnup
Pu Production in Various Reactors
Pu in Fuel at 1000 MWd/MTU
Reactor Type Pu (kg/MTU) %Pu-239 in PuHanford B 0.79 90.8
MAGNOX GCR 0.88 93.1
Heavy Water 0.90 93.8
RBMK 0.54 96.2
Advanced GCR 0.28 97.5
PWR 0.51 98.5
FBR Blanket (estimate) 3.77 99.8
Reactor Type Burnup (MWd/MTU)
kg of Pu per MTU
% Pu-239 in Pu
g of Pu per MWd
Hanford B 600 0.51 94.2 0.85
MAGNOX GCR 4000 2.49 76.4 0.62
Heavy Water 7000 3.76 65.9 0.54
RBMK 18000 4.96 51.8 0.28
Advanced GCR 18000 3.38 57.5 0.19
PWR 40000 10.65 53.8 0.27
FBR Blanket (estimate)
8000 22.96 98.7 2.87
Estimated Pu in Fuel at Discharge
Pu Production Rules of Thumb
Conclusions Roles exist for nuclear proliferation knowledge
within peaceful nuclear program Pu-239 is generated prolifically in reactors Pu-239 is most useful isotope for weapons, but
generating weapons grade plutonium (>94% Pu-239) is nontrivial
Typical power reactor operations are not conducive for weapons grade plutonium production