Work Stream 6: Weapons-relevant Material

Penholders: Sharon Squassoni (Elliott School of International Affairs), Grant Christopher (VERTIC), Alex Glaser (Princeton University)

Fissile material is the sine qua non of nuclear weapons programs and therefore, of nuclear disarmament: without limits on and monitoring of such material, nuclear disarmament would be incomplete and unstable. Stopping production of fissile material for weapons has been on the disarmament agenda for 70 years but never garnered enough support to progress. Decoupled from nuclear disarmament, monitoring fissile material production in nuclear weapon states was both too hard and too easy: too hard because maintaining secrecy around existing nuclear weapons would emasculate monitoring, and too easy because the major nuclear weapon states had all voluntarily stopped production at the end of the Cold War. No nuclear arms reduction treaties have sought to tackle the tough issues of verifying warhead reductions and the fissile material in them. But in a disarmed world, monitoring materials integral to nuclear explosive packages, including tritium, becomes very important for stability and irreversibility.

Given that the International Atomic Energy Agency (IAEA) has been implementing material control and accounting under the Nuclear Nonproliferation Treaty (NPT) for over fifty years, precisely to demonstrate that nuclear material is not diverted to military purposes, IAEA safeguards are a natural starting point for fissile material verification. Yet these were designed for somewhat optimal circumstances - for states without vast nuclear weapons knowledge, equipment or material. Confidence in the absence of clandestine fissile material production may be harder to establish in former nuclear weapon states with large stocks and production facilities that were not built to accommodate material accounting. Whether the plants are shuttered, demolished, or repurposed for civilian purposes, verifying past production will be necessary to provide confidence in baseline declarations.

The work stream will look at not just technology, but techniques and approaches to accommodate several different disarmament scenarios, including varying levels of confidence. Some challenges are inherent to the problem, regardless of the scenario, such as confirming baseline declarations of stocks and their disposition in states where facilities were not originally designed for transparency or verification of material accountancy.

Other challenges arise in specific scenarios. The work stream will consider whether certain elements of nuclear energy expansion could trigger new challenges for monitoring and verification, including the use of weapons-grade material in new reactor designs, and the spread of enrichment and/or reprocessing capabilities to additional countries and to commercial entities that are not currently monitored under safeguards agreements. In addition, the potential success of commercial fusion energy could create significant challenges for tritium accounting. Neither the NPT nor any arms control agreement has attempted to limit or monitor tritium, but an international regime that sought to cover all weapons relevant material would have to do so.

Other collaborators for this work stream include Grant Christopher (VERTIC), Alex Glaser (Princeton), Jill Cooley (ret), Shirley Johnson (ret), Scott Kemp (MIT), and Mark Goodman (ret).