The Additional Protocol as the Safeguards Standard

The Nuclear Non-Proliferation Treaty requires non-nuclear-weapon States parties to conclude comprehensive safeguards agreements, (CSAs) covering all nuclear material in the state. In the early 1990s, in the context of verification mandates in South Africa, Iraq and North Korea, the IAEA Board of Governors affirmed that implementation of CSAs should be designed to verify that the state’s declarations are both correct and complete, in order to provide credible assurances of both the non-diversion of declared nuclear material and of the absence of undeclared nuclear material and activities in the state as a whole. Recognizing that its tools for verifying completeness were limited, the IAEA under Program 93+2 developed measures to strengthen safeguards implementation under the existing authority of CSAs and proposed additional measures requiring complementary new legal authority. In 1997, the Board of Governors approved the model Additional Protocol (AP), and requested the IAEA to conclude APs based on this model in states with CSAs. An AP provides the IAEA with additional rights of access to information and to locations in the state in order to detect undeclared nuclear material and activities in the state. The IAEA, along with governments that support strengthened IAEA safeguards, have undertaken diplomatic outreach and related assistance and training to encourage states to conclude APs. As of the end of 2017, 132 states have brought an AP into force, including 126 states with CSAs, making the combination of a CSA and an AP by far the most common set of safeguards obligations. The IAEA only draws the broader conclusion about the absence of undeclared nuclear material and activities in the state as a whole in states that have an AP in force. Thus, a CSA, supplemented by an AP, has become the de facto NPT safeguards standard, i.e. the standard for verifying that states have met their requirement to accept safeguards on all nuclear material in the state as a whole.