Blog Post - Nuclear Security Matters

How Nuclear Material Accounting Can Contribute to Nuclear Security

May 16, 2014

By Jonas Siegel

Like its predecessor summits, the recently concluded Nuclear Security Summit in The Hague acknowledged the role that nuclear material accounting can play in securing materials from unauthorized use. The emphasis of this and past initiatives, however, has been on improving national laws and regulations—and primarily in states without nuclear weapons. States have yet to develop comprehensive requirements that address the full scope of nuclear risks and that are meant to be adopted by all states—including nuclear weapons states.

I recently co-authored a report with John Steinbruner and Nancy Gallagher, titled Comprehensive Nuclear Material Accounting, whichargued that basic tools and processes of material accounting hold the potential to play a significant role in reducing many of the present-day risks posed by nuclear materials in both non-weapons and weapons states. Material accounting is only a single piece of the broader effort to ensure nuclear security, but it is the linchpin of the daily management of nuclear materials, and its mechanisms enable the most detailed and continuous understanding of materials’ characteristics and whereabouts. Indeed, material accounting is what enables nuclear operators and regulators to adequately address one of the most important questions that can confront policy makers in both nuclear weapons states and non-nuclear weapons states: “Are nuclear materials missing?”

IAEA safeguard inspectors conducting inventory verification activities on spent nuclear (Petr Pavlicek/IAEA photo)

The material accounting capabilities of states subject to International Atomic Energy Agency (IAEA) comprehensive safeguards agreements vary greatly. Some states’ capabilities are focused primarily on ensuring compliance with their IAEA safeguards commitments, while other states’ capabilities are also intended to contribute to securing materials from all forms of unauthorized use. The IAEA is evaluating how the material accounting capabilities of all states with comprehensive safeguards agreements can be used to address nuclear security, as well as nonproliferation, objectives. Measures under consideration include: the sub-division of material balance areas (MBAs), preparation of records when nuclear material items are re-located within an MBA, and programs for testing the location of nuclear material that occur more frequently than annual physical inventories.

The larger challenge is confronting the risks posed by nuclear weapons states’ sizeable civilian and military-use stockpiles of nuclear materials and their weapons arsenals. Most of these civilian materials and all of these military-use materials remain outside of regular international oversight. Domestic regulators and policy makers oversee these stockpiles, but the full extent of the risks associated with their current maintenance is uncertain. For example, some nuclear weapons states don’t know how much nuclear material they have with an acceptable level of certainty; some materials have not been properly characterized; there is little publicly available information about how military-use materials are accounted for; and communication about the status and whereabouts of materials from the facility-level to national authorities is infrequent and often short on detail.

The lack of information about nuclear materials and about nuclear material management processes in nuclear weapons states is largely the legacy of the structure of the nonproliferation regime and is largely well-intended. Yet, if all nuclear weapons states made available information about their nuclear material stockpiles—both civilian and military-use—and about how these materials are accounted for on a routine basis, there could be greater confidence and cohesion in nuclear security efforts. States could begin down this road by, for example:

  • deploying advanced material measurement capabilities, including systems to measure and account for in-process and bulk materials;
  • expanding reporting requirements on source materials;
  • requiring more frequent physical inventories of special fissionable materials; and
  • developing national material accounting systems that maintain records of all nuclear materials, are updated frequently, and are capable of querying facility-level systems.

At the very least, these states could publicly agree to maintain material control and accounting systems that meet IAEA requirements for states with comprehensive safeguards agreements. By committing to a minimum standard of materials management and following through on their commitments, these states would bolster current initiatives aimed at ensuring nuclear security and would lay the ground work for additional nuclear risk reduction efforts.

For more information on this publication: Please contact the Belfer Communications Office
For Academic Citation: How Nuclear Material Accounting Can Contribute to Nuclear Security.” Nuclear Security Matters, May 16, 2014,