The Initialization Problem: A Study of Passive Neutron-induced High-energy Gamma Warhead Signatures for Nuclear Dismantlement Verification

Mareena Robinson, Massachusetts Institute of Technology

As signatories to the Nuclear Nonproliferation Treaty (NPT), nuclear weapon states have the obligation, under Article VI, to disarm. In the time since the ratification of the NPT, the United States and the Russian Federation have made progress toward disarmament by reducing the number of deployed weapons. The next step involves the verifiable dismantlement of warheads. To accomplish this, technologies and verification protocols need to be developed to provide confidence that dismantlement is actually taking place.

An important step in the dismantlement process is warhead confirmation, in which inspections show that the item presented for dismantlement is the treaty-limited warhead. The expectation is that this assessment is done without direct access to the warhead and under agreed-upon time constraints that minimize the impact on facility operations.

One approach to warhead confirmation is to combine a number of measurements that substantiate different components of the warhead. In this talk, I present the confirmation of the presence of high explosives as a key signature for warhead confirmation. Focusing on plutonium weapons, this approach uses the neutron and gamma radiation generated from spontaneous fission, inelastic scatter and neutron capture within the weapon to passively assess the presence of explosives.

This talk will outline the role and approaches to verification in future dismantlement treaties, present experimental data obtained using AmBe and moderated Cf-252 neutron sources and melamine-based mock explosive, and discuss the challenges to successfully identifying the high-energy gamma signature.

Abstract Author(s): M.R. Snowden