A. Fattah
International Atomic Energy Agency
Department of Safeguards
P.O. Box 100, A-1400 Vienna, Austria
Telephone: (+43) 1-2060 Ext.: 22195
Fax: (+43) 1-20607
E-Mail:
afattah@sg.iaea.or.at
ABSTRACT
Safeguards are essentially a technical means of verifying the fulfilment of political obligations undertaken by States in concluding international agreements relating to the peaceful uses of nuclear energy. The technical objective of safeguards is the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by the risk of early detection. The technical conclusion is a statement in respect of each material balance area of the amount of material unaccounted for over a specific period, giving the limits of accuracy of the amounts stated. Agency safeguards is, therefore, based on material accountancy activities which are undertaken by the facility operator to establish the quantities of nuclear material present within different areas and changes in those quantities within defined periods. The main features of the Agency Safeguards System are facility design review and verification, examination of accounting and operating data, accounting reports and inventory verification.
Final disposal of spent fuel will accumulate extremely large inventories in a disposal site creating a long-term proliferation risk. Safeguards for spent fuel disposal in geological repositories, therefore, have to be continued even after the repository has been back-filled and sealed. The effective application of safeguards must assure an unbroken continuity of knowledge that the nuclear material in the repository has not been diverted for an unknown purpose. For effective and efficient application of safeguards, the Agency requires vital information on facility design and operation. Part of the required information will also flow from the other obligations, e.g. safety, waste disposal, environmental protection, etc.. An integrated approach to document all required information will be an advantage to all concerned. Safeguards confirmation that the material has not been diverted established by confirmation of integrity of containment can also ensure that safety criteria has not been breached.
The basic safeguards approach for a geological repository will consist of continuous Design Information verification (DIV) and application of integrated safeguards verification system for inventory verification. DIV constitutes an important safeguards measure during excavation, construction and operational phase. It should confirm the integrity of the repository area and detect any/all undeclared activities, inter alia, the presence of sensitive equipment andtunnelling in the vicinity of the repository. DIV is a flexible and continuing process as the repository design will change during excavation. The diversion strategies could involve not only the excavations of the repository, but also the surface facilities, the surrounding geology and adjacent mine workings.
As part of records keeping the facility has to maintain records of the content and location of each spent fuel container. The IAEA and the State should retain all safeguards relevant documentation and information (i.e. records of the complete inventory of nuclear material and/or previous operations of the repository) deemed necessary. These records should be kept for at least as long as safeguards exist for the nuclear material in the repository.
INTRODUCTION
Agency safeguards is, therefore, based on material accountancy activities which are undertaken by the facility operator to establish the quantities of nuclear material present within different areas and changes in those quantities within defined periods. The main features of the Agency Safeguards System are facility design review and verification, examination of accounting and operating data, accounting reports and inventory verification.
Safeguards are essentially a technical means of verifying the fulfilment of political obligations undertaken by States in concluding international agreements relating to the peaceful uses of nuclear energy. The main political objectives of safeguards are: to assure the international community that States are complying with their non-proliferation and other 'peaceful use' undertakings; and to deter a) the diversion of safeguarded nuclear materials to the production of nuclear explosives or for other military purposes and b) the misuse of safeguarded facilities with the aim of producing unsafeguarded nuclear material.
The technical objective of safeguards is the "timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by the risk of early detection." This is achieved by use of material accountancy as a safeguards measure of fundamental importance, with containment and surveillance as important complementary measures." "The technical conclusion of the Agency's verification activities" is "a statement in respect of each material balance area of the amount of material unaccounted for over a specific period, giving the limits of accuracy of the amounts stated."
Agency safeguards is, therefore, based on material accountancy activities which are undertaken by the facility operator to establish the quantities of nuclear material present within different areas and changes in those quantities within defined periods. The main features of the Agency Safeguards System are facility design review and verification, examination of accounting and operating data, accounting reports and inventory verification.
DESIGN INFORMATION
Design information is used, inter alia, in preparing the safeguards approach to a particular facility; this in turn serves as a basis for preparing the facility attachment for that facility. Important features include, in particular, a description of the facility, the form, quantity, location and flow of nuclear material being used, facility layout, containment features and procedures for nuclear material accountancy and control. Design information is submitted to the IAEA by the States using the IAEA's design information questionnaire (DIQ). In accordance with the comprehensive safeguards agreements, the State has to send a formal design information (DI) 180 days before start of construction.
Design Information Verification (DIV) is the formal requirement for the inspection of a nuclear material handling facility to verify that it has been built to the design declared by the operator. This is essential when safeguards have to be applied to a new facility and can only be applied during the construction and commissioning stages. All the necessary safeguards features declared by the operator have to be confirmed and it also has to be seen that there are no undeclared features which could later be used as a route for the diversion of material.
Following the formal DIV of a plant there has to be a continuity of knowledge during its operation, and even post closure, to ensure that no clandestine changes are made which could jeopardise its security by opening up a route for diversion.
For formal DIV to be effective, collaboration by the State, the plant designer and the plant operator, with IAEA representatives should start at a relatively early stage in the design process. Although the safeguards requirements will be available to the plant designers at an early stage, mutual agreement on how these are met in practice can only be of benefit to both parties. Solutions can be agreed which are cost-effective for both building and safeguarding the plant from inception to decommissioning or closure.
RECORDS AND REPORTS SYSTEM
In confirmation with the comprehensive safeguards requirements "... the State shall establish and maintain a system of accounting for and control of all nuclear material subject to safeguards under the agreement" which calls for arrangements between the IAEA and the State on a system of records and a system of reports.
The authority should establish the requirements for accounting and operating records and reports for each material balance area (MBA) to provide relevant data on nuclear material transactions and operations that affect the accounting for, and control of, nuclear material.
Accounting records - a set of documents kept at each nuclear facility, showing the quantity of each type of nuclear material present, its distribution within the facility and any changes affecting it. This includes the records showing measurement results.
Operating records - a set of documents kept at each facility consisting of organized data on the operation of the facility in connection with the use or handling of nuclear material. The operating records include quality control on the measurements.
Accounting report - a statement to the IAEA on the status of nuclear materials subject to safeguards in a defined environment and on the changes in that status since the previous report. Accounting reports are submitted by the State at times specified in the agreements or subsidiary arrangements. Three types of routine accounting reports for each MBA are required: Inventory Change Reports (ICR), Material Balance Reports (MBR), Physical Inventory Listings (PIL).
Special report - a statement by the State to the IAEA on the loss of nuclear material exceeding specified limits or if containment and surveillance measures have been unexpectedly changed from those specified in the subsidiary arrangements. Some agreements also require special reports to be submitted in the event that a transfer of nuclear material results in a significant change in the inventory of a facility.
Measurement System and Control
The State should establish requirements for a measurement system and measurement uncertainties, including provisions for the determination of nuclear material received, produced, shipped, lost or otherwise removed from inventory and for the determination of inventory quantities based on sampling and chemical or non-destructive analysis, as appropriate.
A measurement control programme is to be established with the objectives of ensuring that the routine operation of the measurement systems is adequate, that measurement components are re-calibrated at appropriate intervals; that random and systematic errors are properly estimated for propagation so that the limits of measurement uncertainties associated with any "material unaccounted for" (MUF) can be established; and that clerical errors are, as far as practicable, detected and corrected. The Agency's technical conclusion depends, among other things, on these measurement uncertainties.
GEOLOGICAL REPOSITORY
Geological repositories for disposing nuclear material contained in HLW including spent
fuel will be designed, built and operating in the near future. The Agency is currently in the process of developing appropriate safeguards for geological repositories.
The geological repository is an area for nuclear material disposal located underground (usually) more than several hundred metres from the surface) in a stable geological formation to provide long-term isolation of radionuclides from the biosphere. The repository may not include provision for operations involving the opening of spent fuel disposal containers. The repository will be comprised of: shafts and/or ramps; a reception area; a container handling or buffer area; and emplacement areas. The activities of a disposal facility consists of:
DOCUMENT REQUIREMENTS FOR GEOLOGICAL REPOSITORIES
Design Information Verification
Design Information Verification (DIV) is an important safeguards measure to be applied during excavation and continuing during the operational phase. It should confirm the integrity of the repository area and aim at detecting undeclared activities such as the presence of sensitive equipment or tunnelling in the neighborhood. As the repository design will change during excavation, for example to adapt to geological findings, the application of DIV must be a flexible, ongoing process. Formal DIV starts with the presentation of the construction drawings to the IAEA for consideration, under the 180 day (before construction) agreement. The means whereby diversion routes may be opened up in the future , or areas where it will be difficult to implement effective DIV requires special attention. Many of the DIV activities which have been raised for implementation during the pre-operational phase will, however, also continue throughout the active life of the repository.
Recent initiatives by the IAEA's programme to strengthen the effectiveness and improve the efficiency of safeguards, or the 93 + 2 programme, requires some additional information to be provided under the expanded declaration which includes:
Records and Reports
During pre-operational phase the following documents will be maintained:
Requirements for the quality of the records, the method for keeping them and the time they should be kept should be set and should be part of the Quality Assurance system.
During operational phase the following documents will be maintained:
The requirement of maintenance of the location of each container is not an undue burden on the repository operator since it appears likely that they will have to maintain the same records for other vital reasons as well. In some cases the operator will have to demonstrate the safe operation of the facility with respect to safe heat loading. The record will be available for safeguarded materials for an audit trail for each container.
The IAEA and the State should retain all safeguards relevant documentation and information (i.e. records of the complete inventory of nuclear material and/or previous operations of the repository) deemed necessary after the repository has been completely sealed. These records should be kept for at least as long as safeguards exist for the nuclear material in the repository.
CONCLUSION
For effective and efficient application of safeguards, the Agency requires vital information on facility design and operation. Part of the required information will also flow from the other obligations, e.g. safety, waste disposal, environmental protection, etc.. An integrated approach to document all required information will be an advantage to all concerned. Safeguards for spent fuel disposal in geological repositories have to be continued even after the repository has been back-filled and sealed. The effective application of safeguards must assure an unbroken continuity of knowledge that the nuclear material in the repository has not been diverted for an unknown purpose. Final disposal of spent fuel will accumulate extremely large inventories in a disposal site creating a long-term proliferation risk.
REFERENCES