The signing of a Co-operation Agreement between the IAEA and the Brazilian-Argentine Agency for Accounting and Control of Nuclear Material (ABACC) in 1998 at the IAEA Headquarters.

(Source: Petr Pavlicek/IAEA)

The State System of Accounting for and Control of Nuclear Material (SSAC) comprises the organizational arrangements at the national level which may have both a national objective to account for and control nuclear material in the State and an international objective to provide the basis for the application of IAEA safeguards under an agreement between the State and the IAEA. Under a comprehensive safeguards agreement, the State is required to establish and maintain a system of accounting for and control of nuclear material subject to safeguards under the agreement. The system "shall be based on a structure of material balance areas," and shall "make provision...for the establishment of such measures as:

• A measurement system for the determination of the quantities of nuclear material received, produced, shipped, lost or otherwise removed from inventory, and the quantities on inventory
• The evaluation of precision and accuracy of measurements and the estimation of measurement uncertainty
• Procedures for identifying, reviewing and evaluating differences in shipper/ receiver measurements
• Procedures for taking a physical inventory
• Procedures for the evaluation of accumulations of unmeasured inventory and unmeasured losses
• A system of records and reports showing, for each material balance area, the inventory of nuclear material and the changes in that inventory including receipts into and transfers out of the material balance area
• Provisions to ensure that the accounting procedures and arrangements are being operated correctly
• Procedures for the provisions of reports to the Agency"