This paper discusses three questions:

1. Could terrorists or others steal nuclear fuel from research rectors, to make either a nuclear weapon or a "dirty bomb," a radiological dispersal device?
2. Could terrorists attack a research reactor with conventional explosives, for example with a truck loaded with such explosives, in order to disperse radioactivity from the fuel of the reactor to an area downwind of the reactor?
3. How do power reactors compare with research reactors as targets of terrorist attacks?

The answer to the first two questions is a qualified yes. In the comparison called for in the third question, the low-enriched uranium in power reactors is unsuitable for making nuclear weapons, without major reprocessing. However, the highly enriched uranium burned in many research reactors around the world is suitable for making nuclear weapons, if enough of it is available. Both power reactors and research reactors could be targets for terrorists trying to attack a reactor with a truck bomb, for the purpose of dispersing radioactive material, or trying to steal such material for the purpose of making a dirty bomb. The variations from reactor to reactor, in both attractiveness to terrorists and protection of the facility, are widespread.

Humans often defy rational-choice theory by cooperating in simple dilemma games, a paradox that has been explained by theories of kin selection, reciprocal altruism and indirect reciprocity (reputation). Fehr and Gächter claim that human cooperation remains an evolutionary puzzle because people will cooperate with genetically unrelated strangers, often in large groups, with people whom they may not meet again, and without any gain in reputation ('strong reciprocity') - that is, when existing theories do not seem to apply. However, we argue that those theories are rejected for the wrong reasons and that the paradox may therefore be imaginary. This has implications for whether punishment is crucial to promoting cooperation.

This is a presentation made at the 2002 American Nuclear Society Winter Meeting in Washington, DC on November 19, 2002.

The presentation explores:

• Motivations for Past Terrorist Threats

• Motivation for New Terrorist Threats that are More Threatening
  

• Impact

• Threats Considered Feasible

Fifty years ago this month, President Dwight D. Eisenhower gave his "Atoms for Peace" address to the UN General Assembly. He proposed to share nuclear materials and information for peaceful purposes with other countries through a new international agency. That speech led to negotiations which, several years later, created the International Atomic Energy Agency (IAEA). In the nuclear Non-Proliferation Treaty (NPT) of 1968, the IAEA gained authority for policing the nuclear activities of member countries to ensure that those without nuclear weapons did not acquire them. The worldwide treaty bans all members except the United Kingdom, China, France, Russia, and the United States from having nuclear weapons and commits those five states to eventually eliminating their atomic arsenals. The treaty provides the norm and the foundation for an international regime to prevent the spread of nuclear weapons around the world. Yet, many believe that the NPT regime is battered and in need of strengthening. Given the more difficult nonproliferation and security challenges of today, it is vital that U.S. leadership be used to strengthen, not to weaken or abandon, the nuclear nonproliferation regime.