Nuclear inspectors apply seals to nuclear material containers and specific areas in nuclear facilities to ensure they are not tampered with. Seals, or Tamper Indicating Devices, are essential in detecting unauthorized access to specific areas or equipment.
The JRC has a long standing and acknowledged experience in containment systems, seals and sealing systems and JRC systems are utilized by EURATOM inspectors within Europe and by IAEA inspectors worldwide.
The research for new sealing systems that improve efficiency and effectiveness is well supported not only by inspectors but also by regulatory bodies and facility operators.
The origins: under water sealing
JRC sealing activities in nuclear safeguards started in reprocessing facilities in France and UK, but really took off when a replacement of an existing sealing system for CANDU fuels was needed in a spent fuel pond: the first CANDU ultrasonic seals and the complete acquisition and analysis system were then developed.
The robustness of the system and its reliability made it suitable to be deployed in different facilities, from Romania to Canada, Pakistan and other countries.
Ultrasonic sealing systems
The JRC ultrasonic sealing system is composed of three main parts:
- The seal is a special bolt which contains a distinctive fingerprint obtained by the fusion of a set of discs, which make each seal unique and not clonable.
- The reading head is a rugged instrument that can work underwater and in a high radiation environment. It is precisely machined to align the ultrasonic probe to the inner unique pattern of the seal, in order to read the signal of the seal.
- The acquisition system is the electronic part that acquires the ultrasonic signal and converts it to digital data. The software analyses the data to identify the seals and to verify that they have not been broken. It is an important tool to assist the inspectors in their activities.
The system can be adapted to different locking systems.
Ultrasonic Optical Sealing Bolt
On a specific request from inspectors, the JRC developed also a version of ultrasonic seals that can be used on dry storage casks. The seal, named Ultrasonic Optical Sealing Bolt, combines a traditional ultrasonic seal with a pass-through feature for optical fibers. This solution ensures that when the seal is removed, the optical fiber is cut. With this feature, a cask can be sealed also with other wire seals (passive or active) providing a great flexibility to inspectors and increasing the effectiveness of the wire seal. Such seals have been applied in Lithuania on a large number of casks, providing significant benefits in term of time spent on inspections, safety of personnel and reduced dose rate for inspectors.
Research: new sealing systems
In support of EURATOM and IAEA nuclear inspectors, the JRC did research on electronic and passive seals and is actively developing new sealing systems.
Ongoing developments include the Operator Applied and Removed Seal (OARS) that consists in a remotely supervised system to reduce the need of on-site inspector, particularly for frequent transport casks loading and unloading.
Another advanced development is the Reusable Random Pattern Passive seal (R2P2) which once completed will be the first reusable passive seal in safeguards. On top of the immediate cost advantage, it will also be easy to use and verifiable in field, using the Embedded Universal Seal Reader, developed by the JRC. Such reader is able to verify most of existing safeguard seals and is an open platform ready to integrate future seals or other sensors.
Training
The JRC provides training to inspectors on the use of its systems at its premises and on site. Training courses focus on hands on and practical activities to provide inspectors with the knowledge and expertise needed for their job.
Test and vulnerability assessment
The JRC performs extensive tests on the equipment it develops (e.g. dimensional check, environmental tests, electrical, endurance..) and it is also available to deliver Vulnerability Assessments on third party equipment on request.
Future objectives
Ongoing research in seals and sealing systems is continuously striving to offer new and innovative solutions that not only enhance security but also improve efficiency in our increasingly interconnected world. In this digital age, where data availability and automation hold significant importance, innovative approaches are being explored, including the utilisation of advanced materials and the rapidly emerging field of additive manufacturing. These advancements present exciting opportunities for further progress in this field.
