Unmaking the Bomb: The Science and Technology of Nuclear Nonproliferation, Disarmament, and Verification

MAE 354/574
Princeton University, Spring 2015

This course covers the science and technology underlying existing and emerging nuclear security issues. Part I introduces the principles of nuclear fission, nuclear radiation, and nuclear weapons (and their effects). Part II develops the concepts required to model and analyze nuclear systems, including the production of fissile materials and the detection and characterization of these materials with radiation measurement techniques. Relevant applications are explored in Part III and include nuclear forensic analysis, nuclear archaeology, and nuclear warhead verification. Such case studies will also be part of the final projects. The course is open to juniors, seniors, and graduate students (with permission of the adviser).

Week Topic
001 Nuclear fission and nuclear energy
002 Nuclear radiation (mostly neutrons and photons)
003 Nuclear weapon effects
004 Neutronics and depletion calculations
005 Plutonium production and uranium enrichment
006 Monte Carlo particle transport
007 Radiation detection and measurement
008 Detection of clandestine fissile material production
009 Nuclear forensics and archaeology
010 Nuclear warhead verification
011 Global nuclear zero: Policy and technical considerations
012 Student (project) presentations


Weekly problem sets in the first 7–8 weeks of the semester; work on the final (team) project and paper begins after spring break; weekly readings. Problem sets are due Tuesdays before class. Late submissions are not accepted, but the lowest score (including “0” for non-submission) will not count towards the final grade. Graduate students taking this course are expected to support their analysis in the final paper/project using computer simulations (e.g. Monte Carlo particle transport calculations using MCNP6 or GEANT4).


Physics 101, 102, 103, or 104; MAE 305 or permission by instructor


30% : Problem sets
20% : Midterm exam (in class)
15% : Class/precept participation
35% : Final project and paper

Core Readings

Additional (Notable) Readings

Weekly Schedule and Readings


In Part I of this course, we will explore the fundamental processes underlying nuclear fission and radiation. We can then develop the tools needed to support nuclear nonproliferation, disarmament, and verification. Before we dive into the science and technology behind these issues, the very first session provides some high-level background about the topics covered in this course.

Week 01: Nuclear Fission and Nuclear Energy
Feb 3 and Feb 5, 2015

Shortly after the discovery of nuclear fission in the late 1930s, it became clear that the process could, in principle, unfold in an explosive chain reaction and release large amounts of energy. During World War II, the U.S. Manhattan project demonstrated the technical basis of large-scale fissile material production (including the feasibility of operating nuclear reactors) and led to the development and use of the first nuclear weapons in 1945. In this unit, we will discover and examine the fundamentals of neutron interactions and nuclear fission.

Keywords: neutron interactions; cross sections; reaction types; nuclear fission; beam attenuation; number density; scattering; mean free path; energy dependency of neutron cross sections.

Recommended Readings for First Session:


  • Samuel Glasstone and Alexander Sesonske, Nuclear Reactor Engineering: Reactor Design Basics, Fourth Edition, Volume 1, Chapman & Hall, New York, 1994, §§1.1-1.50 and §§2.108-2.125. (BB)

More to explore:

Week 02: Critical Mass and the Diffusion Equation for Neutrons
Feb 10 and Feb 12, 2015

In this unit, we will estimate, in particular, the amount of fissile material (e.g. uranium-235) needed to obtain a so-called critical mass using different methods, including the diffusion equation. We will also examine the timescale of an uncontrolled nuclear chain reaction.

Keywords: critical mass; diffusion equation; dynamics of the neutron population in a supercritical assembly.


  • Samuel Glasstone and Alexander Sesonske, Nuclear Reactor Engineering: Reactor Design Basics, Fourth Edition, Volume 1, Chapman & Hall, New York, 1994, §§3.1-3.21. (BB)
  • Robert Serber, “Simplest Estimate of Minimum Size of Bomb,” Section 10 in The Los Alamos Primer: The First Lectures on How to Build an Atomic Bomb, University of California, Berkeley, 1992. (BB)

More to explore:

Week 03: Nuclear Weapon Effects
Feb 17 and Feb 19, 2015

What happens if the energy equivalent of 20,000 tons of high explosive (TNT) is released within one millionth of a second in a volume of one cubic foot? In this module, we will examine the effects of nuclear explosions, which involve air blast, heat, and nuclear radiation. We will also discuss (briefly) the different means of delivery for nuclear weapons (in particular, using ballistic missiles) and basic strategies that military planners developed for the employment of nuclear weapons during war. With regard to consequences of nuclear war, independent experts began to emphasize its potential climatic consequences (“nuclear winter”) since the 1980s; more recently, it was shown that the impact on climate of nuclear explosions could be relevant even for nuclear war on a regional scale.

Keywords: air blast; thermal radiation; nuclear radiation; deployment, delivery, and targeting of nuclear weapons; medical and climatic impact of nuclear war.


  • Samuel Glasstone and P. J. Dolan, The Effects of Nuclear Weapons, Government Printing Office, Washington, DC, 1977, ¶¶1.01-1.05, ¶¶1.20-1.41, ¶¶2.01-2.51.
  • J. E. Turner, Atoms, Radiation, and Radiation Protection, Third Edition, Wiley, Weinheim, 2007, Sections 13.7-13.10 (pp. 411-423). (BB)
  • Alan Robock and Owen B. Toon, Local Nuclear War, Global Suffering, Scientific American, 302, January 2010, pp. 74–81.

More to explore:

Week 04: Becoming a Weapons Scientist
Guest Lecture by Hugh Gusterson
Feb 24, 2015

Hugh Gusterson is an anthropologist at George Washington University, currently on leave at the Institute for Advanced Study at Princeton. His work focuses on nuclear culture, international security, and the anthropology of science.


  • Hugh Gusterson, Becoming a Weapons Scientist, Chapter 1 in People of the Bomb: Portraits of America’s Nuclear Complex, University of Minnesota Press, 2004. (BB)
  • Hugh Gusterson, Nuclear Weapons and the Other in the Western Imagination, Chapter 2 in People of the Bomb: Portraits of America’s Nuclear Complex, University of Minnesota Press, 2004. (BB)

More to explore:

  • Hugh Gusterson, Nuclear Weapons Testing as Scientific Ritual, Chapter 8 in People of the Bomb: Portraits of America’s Nuclear Complex, University of Minnesota Press, 2004. (BB)
  • Hugh Gusterson, Nuclear Rites: A Weapons Laboratory at the End of the Cold War, University of California Press, 1998.

Week 04: Nuclear Decay and Nuclear Radiation
Feb 26, 2015

Radioactive materials, by definition, can decay from one species to another based on their natural half-lives while emitting nuclear radiation. In this unit, we further examine the origins and characteristics of this radiation (alpha, beta, and gamma); later, in Part III, we will study the interaction of nuclear radiation with matter, which is also the basis for radiation detection. Due to radioactive decay, the isotopic composition of a given radioactive sample changes over time (and can therefore indicate its age, for example); depending on the specific conditions, equilibriums can be reached. Nuclear reactions can also be triggered by external radiation. Most importantly, the composition of nuclear fuel that is exposed to a strong neutron flux in a nuclear reactor changes significantly during its life: the fissile isotopes are depleted, while producing energy in the fission process, while new materials (such as plutonium-239) can be bred in the fuel. In this unit, we focus on the differential equations describing nuclear decay and fuel depletion.

Keywords: radioactive decay; alpha, beta, and gamma radiation; aging of nuclear materials; serial radioactive decay; neutron flux; effective neutron (spectrum-averaged) cross sections; burnup equations.


  • Samuel Glasstone and Alexander Sesonske, Nuclear Reactor Engineering: Reactor Design Basics, Fourth Edition, Volume 1, Chapman & Hall, New York, 1994, selected paragraphs (tbd). (BB)


Week 05: Plutonium Production and Uranium Enrichment
Mar 3 and Mar 5, 2015

Fissile materials–i.e., for all practical purposes, plutonium and highly enriched uranium–are the key ingredient in any nuclear weapon: without having access to at least one of them, one cannot make a nuclear weapon. In this unit, we examine the processes and techniques required to produce fissile material quantities in relevant quantities: plutonium in nuclear reactors and enriched uranium using isotope separation technologies. We will then also explore some relevant case studies of current interest.

Keywords: nuclear reactors; nuclear fuels; plutonium production; uranium enrichment; nuclear fuel-cycle options; case studies: Pakistan, Libya, North Korea, Iran.


Week 06: Monte Carlo Particle Transport
Mar 10, 2015

As its name suggests, the Month Carlo method consists in carrying out a “theoretical experiment” by tracking a large number of individual particles to determine characteristic data for a modeled configuration based on the average behavior of these particles. The basic Monte Carlo method, in which all essential features of random walk are applied to neutron transport in matter, were already developed in the early 1950s. For obvious reasons, interest in and the usefulness of the Monte Carlo method increased with the development of electronic computers since the 1970s. Monte Carlo methods are now the workhorse for many computations in this field. In this unit, we will explore the Monte Carlo method for particle transport and develop a basic tool for simple analyses.

Keywords: basic principles of the Monte Carlo method; review of probability and statistics; Boltzmann transport equation; Monte Carlo particle transport; basic techniques for Monte Carlo method, sampling flight distance, collision type, post-collision energy and direction.


  • E. D. Cashwell and C. J. Everett, A Practical Manual on the Monte Carlo Method for Random Walk Problems, Pergamon Press, 1959.
  • Forrest B. Brown, Fundamentals of Monte Carlo Neutron Transport, LA-UR-05-4983, Los Alamos National Laboratory, lecture notes, selected sections (tbd).



Week 07: Radiation Detection and Measurement
Mar 24 and Mar 26, 2015

In Part I of this course, we have studied the origins of nuclear radiation with an emphasis on neutrons and photons. In order to prepare for our team projects in the coming weeks, we also need to understand the interactions of nuclear radiation with matter. This is particularly relevant for the design and operation of radiation detectors. Here, we will focus primarily on the detection of photons with different types of detectors and the components involved in making a measurement.

Keywords: general properties of radiation detectors: simplified detector model; modes of detector operation; counting statistics and error prediction; limits of detectability; scintillation detectors.


  • Gordon Gilmore, “Interactions of Gamma Radiation with Matter,” Chapter 2 in Practical Gamma-ray Spectrometry, Second Edition, Wiley, 2008/2011. (BB)
  • Gordon Gilmore, “Scintillation Spectrometry,” Chapter 10 in Practical Gamma-ray Spectrometry, Second Edition, Wiley, 2008/2011. (BB)

Week 08: Detecting the Presence and Production of Fissile Materials
Mar 31 and Apr 2, 2015

Detecting the presence or (clandestine) production of nuclear materials remains a critical nuclear security challenges. This is particularly relevant for concealed and shielded nuclear materials that may be shipped across borders. Immense efforts have been undertaken to interdict such shipments using dedicated radiation portal monitors installed, for example, at border crossings. A complementary approach (less relevant for efforts to prevent nuclear terrorism, but more relevant for effort to prevent nuclear proliferation, seeks to detect clandestine fissile material production with standoff detection techniques, which could be used by inspection agencies such as the IAEA. In this module, we will examine the capabilities, challenges, and opportunities of relevant technologies and approaches.

Keywords: principles of radiation shielding; detection strategies and times for shielded nuclear materials; atmospheric dispersion models; source terms from reprocessing plants; noble gas transport; source terms from enrichment plants; particle formation and deposition; detector networks; detection limits.


Week 09: Nuclear Forensics and Nuclear Archaeology
Apr 7 and Apr 9, 2015

The capability to determine the composition of nuclear materials (including the presence of trace impurities in the parts-per-million range) with remarkable accuracy has opened up unique capabilities relevant for a range of nuclear security applications. Nuclear forensic analysis can use predictive signatures (obtained with computer models) and or comparative signatures (based on samples and databases). The techniques were first developed to analyze the debris of nuclear explosions (post-detonation forensics), but are now widely used for a wide range of additional applications (pre-detonation forensics). This unit reviews the origins, types, and state-of-the-art of nuclear forensics. We will discuss and examine the current potential future roles of nuclear forensics, including nuclear forensics for national and international security, nuclear forensic methodologies for IAEA safeguards, and nuclear forensics for arms control and verification (nuclear archaeology).

Keywords: physical basis for nuclear forensic science; predictive versus comparative signatures; chronometry; attribution; nuclear archaeology.


  • Kenton J. Moody, Ian D. Hutcheon, and Patrick M. Grant, Nuclear Forensic Analysis, Second Edition, CRC Press, December 2014, selected chapters (tbd).
  • Steve Fetter, Nuclear Archaeology: Verifying Declarations of Fissile-material Production, Science & Global Security, 3 (3–4), 1993, pp. 237–259.
  • Sebastien Philippe and Alexander Glaser, Nuclear Archaeology for Gaseous Diffusion Enrichment Plants, Science & Global Security, 22 (1), 2014, pp. 27–49. (BB)

More to explore:

Week 10: Nuclear Warhead Verification
Apr 14 and Apr 16, 2015

The next round of nuclear arms-control agreements may place limits on the total number of nuclear weapons and warheads in the arsenals. This would include tactical weapons as well as deployed and non-deployed weapons. Such agreements would require new verification approaches, including inspections of individual nuclear warheads in storage and warheads entering the dismantlement queue. Inspectors may then have to be able to “count” nuclear warheads, for example using tamper-resistant tags and seals, and be able confirm the authenticity of warheads prior to dismantlement. In this unit, we will examine possible verification approaches, many of which involving the radiation measurement techniques encountered earlier this semester, and the respective technical and political challenges.

Keywords: attribute and template verification approaches; passive and active measurement techniques; principles of information barriers; warhead counting, tags and seals.

Guest lecture: (tbd)



Week 11: Global Zero: Policy and Technical Considerations
Apr 21 and Apr 23, 2015

While you are working on your lab projects, we briefly turn our attention to the political context of nuclear arms control, nonproliferation, and disarmament. This will also help us better understand where some technical gaps and challenges of nuclear verification remain and how relevant they are.

Guest lecture: (tbd)


Week 12: Project Presentations
Apr 28 and Apr 30, 2015

In this unit, we will finally apply what we have learned in the course of this semester … and run a verification challenge, in which different teams benchmark their radiation detection systems to identify and authenticate a mock nuclear warhead and so enable its verified dismantlement. Good luck!

Special event: Symposium on the Non-Proliferation Treaty, Nuclear Disarmament, Non-proliferation, and Energy: Fresh Ideas for the Future, United Nations, New York, April 28, 2015.