This study examines methods that can help maximize confidence in maintaining Continuity of Knowledge (CoK) on plutonium-bearing wastes, from a final safeguards-verification measurement through emplacement underground. The study identifies Containment and Surveillance (C/S) measures that can be applied during packaging of plutonium wastes at the Savannah River Site (SRS) in South Carolina, USA, through shipment to, and receipt and disposal at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, USA. Results of this study could apply to countries with a Comprehensive Safeguards Agreement (CSA) that plan to dispose in a geological repository plutonium or other non-fuel nuclear materials that are under international safeguards.
Current designs for spent fuel transportation casks cannot ensure a cask's integrity during shipment, nor is there any verifiable means of maintaining continuity of knowledge (CoK) on a cask's contents. Spent fuel destined for encapsulation plants or geological repositories requires additional containment and surveillance (C/S) measures during shipment. Following final safeguards accountancy measurements on spent fuel assemblies, the shipment of verified assemblies will require unprecedented reliance on maintaining CoK on the fuel inside transport casks. Such increased reliance is due to the lack of reverification of spent fuel following encapsulation into disposal canisters and by meeting the requirement of dual C/S measures during such fuel shipments according to recommendations made by the Application of Safeguards to Geological Repositories (ASTOR) International Atomic Energy Agency (IAEA) expert group. By designing spent fuel transportation casks with effective seals integrated into their design, CoK can be more effectively maintained than by ad hoc C/S measures because seal integration ensures that a cask has not been tampered with. Externally applied seals might not be able to provide such assurance for currently designed spent fuel transportation casks, although some combination of seals, detectors, and/or a technology that can verify canister integrity might provide this assurance. This paper examines the design criteria for integrating safeguards seals into transportation casks and provides recommendations for near-term applications.
Maintaining Continuity of Knowledge (CoK) of spent fuel throughout its life cycle is a key objective of the International Atomic Energy Agency (IAEA). This report describes a project in which two specific technologies, cameras with infrared (IR) imaging capabilities and imaging sonar, were tested to determine their effectiveness in augmenting optical surveillance cameras currently used for maintaining CoK for spent nuclear fuel (SNF) staged in spent fuel pools. Furthermore, the project identifies any modifications required to the technologies to facilitate deployment for international safeguards purposes. This report presents results for the imaging sonar tested at Sandia National Laboratories (SNL) in a mockup spent nuclear fuel pool and for the IR-capable cameras tested by Pacific Northwest National Laboratory (PNNL) in the Oregon State University Training, Research, Isotopes, General Atomics (TRIGA) research reactor.
Future nuclear arms - control agreements may place numerical limits on the total number of warheads in the nuclear arsenals of states. Verifying these limits may require inspectors to account for individual warheads, both deployed and non-deployed. This task could be accomplished with unique identifiers, but standard tagging techniques may be unacceptable in this case due to host concerns about safety and intrusiveness. To resolve this dilemma, we revisit the so - called Buddy Tag concept first proposed by Sandia National Laboratories in the early 1990s. The conceptual innovation in the Buddy Tag was to by separate the tag from the treaty limited item itself. Verification of the pairings between tags and limited items would take place during a short-notice inspection, where the host would be required to produce one buddy tag for each item. Sensors on the Buddy Tag would show that it had not been moved to the inspected site after the inspection was declared (e.g., within the last 24-48 hours). If the inspector counted more (or fewer) treaty limited items than Buddy Tags at the inspected site, a treaty violation could be asserted. Using a number of single-site inspections, an inspecting party can hold the host at risk for discovery of violating the treaty at an enterprise level by possessing more treaty limited items than the treaty allows. In this project, we developed a buddy-tag prototype for demonstration and evaluation purposes. This paper summarizes the performance requirements for an advanced Buddy Tag, the proposed conduct of operations, the design choices and functionalities of the different subsystems, and initial testing results. The report also summarizes peer review feedback obtained throughout the project.
Once a geological repository has begun operations, the encapsulation and disposal of spent fuel will be performed as a continuous, industrial-scale series of processes, during which time safeguards seals will be applied to transportation casks before shipment from an encapsulation plant, and then verified and removed following receipt at the repository. These operations will occur approximately daily during several decades of Sweden's repository operation; however, requiring safeguards inspectors to perform the application, verification, and removal of every seal would be an onerous burden on International Atomic Energy Agency's (IAEA's) resources. Current IAEA practice includes allowing operators to either apply seals or remove them, but not both, so the daily task of either applying or verifying and removing would still require continuous presence of IAEA inspectors at one site at least. Of special importance is the inability to re-verify cask or canisters from which seals have been removed and the canisters emplaced underground. Successfully designing seals that can be applied, verified and removed by an operator with IAEA approval could impact more than repository shipments, but other applications as well, potentially reducing inspector burdens for a wide range of such duties.
Deep borehole disposal (DBD) has been suggested as an option for disposing spent nuclear fuel in a number of countries, including several countries that are subject to international safeguards. DBD presents some distinct challenges for safeguards compared to a conventional mined geological repository (MGR), including the ability to verify declared design information about the borehole. The ability to verify a borehole's design is crucial for assuring that spent fuel or other accountable nuclear materials are disposed as declared in a borehole of known and verifiable design. This study reviews existing commercial off-the-shelf (COTS) borehole inspection tools currently used by the drilling industry, and evaluates the capabilities of those COTS inspection tools against how well they can meet potential needs and requirements of Design Information Verification (DIV) inspections for international safeguards. The study provides recommendations for several promising COTS borehole inspection tools that might be used for DIV safeguards inspections and recommends possible modifications and future testing