Álvaro Acevedo discusses the security challenges of modern reactors and the work of the World Institute for Nuclear Security.
IN THE LAST YEARS THE INTEREST IN ADVANCED REACTOR DESIGNS HAS BEEN GROWING TO DELIVER COBON-FREE POWER FOR A NUMBER OF COMMERCIAL APPLICATIONS BEYOND THE POWER SUPPLY. Advanced reactors can also address some of the longer term nuclear technology challenges, including cost and competitiveness, potential proliferation problems, waste, safety and protection.
The World Institute for Nuclear Security (WINS) believes that developing stakeholder confidence is critical to implementing these technologies. It published a special report on the safety of advanced reactors based on more than 20 interviews with developers, regulators and subject matter experts.
The report provides an overview of the international environment for using advanced reactors, examines the security considerations and challenges of various reactor designs, and recommends “security by design” methods.
International perspective and regulatory issues
The report provides an overview of the available international instruments, standards and guidelines that shape national regulations and laws in connection with modern reactors.
WINS recognizes that the International Atomic Energy Agency (IAEA) is the primary international organization providing relevant guidance to developers and has two key documents in place. The first is the IAEA Nuclear Security Series (NSS) 13, which provides general guidance on physical protection and how to interface with security and nuclear materials accounting and control activities. The IAEA also provides comprehensive guidance on NSS 35G (Lifetime Safety of a Nuclear Facility) and suggests including nuclear safety in the early planning phase and integrating safety into safety, security, operational and other measures.
Two international working groups are assessing the viability of modern reactors in a number of areas, including physical protection. The first is the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) and the second is the Working Group on Proliferation Resistance and Physical Protection.
WINS interviewed officials from three regulatory agencies to understand common challenges in their approach to developing regulations for and licensing these advanced reactors. They are exploring a performance-based, less regulatory approach that recognizes that advanced reactors may require a flexible and technology neutral approach to address significant differences between different reactor designs. They recognize the importance of new technology and threat capabilities, particularly cybersecurity, a new and evolving threat that requires a regulatory update.
Safety considerations for advanced reactor designs
One of the main objectives of the WINS Special Report is to encourage advanced reactor developers to incorporate Security by Design as early as possible. Developers must first understand the safety considerations for advanced reactor designs. The WINS investigation showed that the risk of theft or sabotage depends on the amount of material used and the frequency of refueling, which varies depending on the technical characteristics of the reactor. All of these considerations have an impact on safety.
Some designs are less prone to overheating and core damage because they use passive safety features and are less dependent on external power. Some designers incorporate engineering protection systems into their designs, such as underground locations, to protect against potential scenarios such as a plane crash.
According to WINS research, developers see license costs as a primary concern. This means that developers can only suggest optimizations for security that do not compromise security. This becomes even more difficult because the integration of safety features that correspond to those of conventional nuclear power plants into the reactor design is not economical, especially with regard to the operating and maintenance costs. Developers surveyed by WINS say that the improved safety features of advanced reactors should form the basis for demonstrating risk-based safety requirements.
Developers also say that automation is an important design goal. Automation in the safety and security area will make reactor operation more economical. It can significantly reduce human error and the potential for insider threats. Likewise, the inclusion of robotic technologies such as drones can lower costs by reducing the number of security guards. Advanced technologies could improve threat detection.
During its research, WINS was able to map the following different security challenges:
- Low enriched high grade uranium (HALEU) and the supply chain. HALEU is enriched between 5% and 20%. Some developers interviewed by WINS are concerned about the distinction between LEU and HALEU. The description of HALEU has created confusion about its categorization for purposes of physical protection.
- Remote location. A significant number of the advanced reactor designs, such as B. the heat pipe reactors, are to be used in remote locations and at sea. Difficult access to these remote sites can have security advantages and disadvantages. Problems can include cyber or effective response teams.
- transport. Some reactor designs contain fuel and in some the fuel is transported separately. It is important for the designer to consider transportation during the fuel cycle, including during decommissioning.
- Online Safety. The approach to combating cybersecurity is no different from the existing one. There’s nothing special about advanced reactors from a cyber perspective other than the potential for remote locations.
Security by Design for Advanced Reactors
Security by design requires that security be built into the design from the start. It is a risk-aware approach that requires a clear safety strategy and a commitment to make safety a primary design aspect on par with nuclear safety. It also requires a coordinated approach from all parties including operators, project managers and regulators.
The most important security principles are deterrence, denial, detection and delay. We can complement these with design. These principles can reduce the risk of a major security incident. Although the initial construction costs may be higher, Security by Design will help reduce the cost of preventing a nuclear security incident and the savings will add up over the life of the advanced reactor.
The steps to develop a comprehensive approach to “Security by Design” are:
- Set up your organization. “Security by Design” can only work if your organization is set up to ensure this. Everyone, from the chief executive down, must view safety as an integral part of the organization.
- Understand the threats and consequences. Understand the threats your advanced reactor facility could face, including unauthorized removal of materials and sabotage.
- Set your design goals. Based on the potential threats to your facility and the resources you have to manage them.
- Develop your protection model. There are many design solutions available to help you achieve your security goals. The choice depends on what you’re protecting, its status, the nature of the threat, and the resources available.
WINS recognizes that there are other methods, but their special report recommends three broad methods and provides developers with detailed “Security by Design” guidance. Starting points are: The Security by Design Handbook (Sandia National Laboratories); Secure by Design (a guidance document developed by Adrian Prior and Robert Barnes in the UK); and an assessment methodology (developed by the Gen IV Proliferation Resistance and Physical Protection group). The latter identifies a number of challenges, analyzes a system response to these challenges and evaluates the results for a proposed design. The properties of advanced reactor systems (technical and institutional) are used to assess the system’s response and further determine its resilience to proliferation threats and its resilience to sabotage and terrorism threats.
Preparation is key to reaping the benefits
Lower costs, less maintenance, and easier operation are strong incentives to deploy modern reactors in a variety of environments and geographic locations. Advanced reactors are inherently safer than operating commercial nuclear power plants, could be placed closer to densely populated areas and provide power when needed. Due to their flexibility, they could play a key role in the emerging energy market for decentralized power supply.
As the WINS report on the safety of advanced reactors confirms, their safety implications need to be identified and addressed as early as possible as design and technology decisions affect the risk picture and may require changes to the regulatory approach.
About the author: A’lvaro Acevedo is a program manager at the World Institute for Nuclear Security
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