Independent software verification and validation (IV&V) services play a critical role in ensuring the reliability of nuclear safety systems. By applying rigorous processes, IV&V strengthens operational safety and protects nuclear facilities from risk.
Digitalization of safety-critical and safety-related Instrumentation and Control (I&C) systems help us modernize our Nuclear Power Plants (NPPs) and improve operational effectiveness and reliability, while ensuring regulatory compliance. However, software introduces increased complexity and multiple new failure modes. A single software failure in a safety-critical or safety-related system can result in damage to the plant or harm to personnel or the environment.
A 2025 study presented at the American Nuclear Society (ANS) Annual Conference identified Common Cause Failures (CCFs) in digital I&C systems as one of the top three risk factors in nuclear safety, largely driven by inadequate Verification and Validation (V&V) practices. This finding highlights the fundamental role of independent software verification and validation (IV&V), in identifying risks before they adversely impact the plant, personnel, and the environment. In this article, we’ll explore how IV&V can significantly reduce risks in nuclear safety systems, ensuring operational effectiveness and reliability and safeguarding human lives, assets, and regulatory compliance.
What is independent verification and validation (IV&V) and why does it matter?
At its core, IV&V is a rigorous process that ensures the software in nuclear safety systems meet the highest standards of quality, safety, and reliability. It involves the assessment of both the design and development process and the final product by a third-party team, independent of the design and development team. This provides a “second set of eyes” on the solution, creating an additional layer of objectivity that is vital in critical environments, like nuclear power plants.
- Verification ensures that the software has been built correctly according to its specifications and requirements (“Did we build it right?”).
- Validation confirms that the software meets the intended needs and functions as expected in real-world conditions (“Did we build the right thing?”).
Both components of IV&V work together to ensure that the software behaves as expected and is safe for use in safely-critical software deployed in high-risk, high-stakes environments such as nuclear power plants.
Risks of neglecting IV&V in nuclear safety systems
At present, most NPPs rely heavily on a variety of digital systems to control and monitor reactor operations. These systems are responsible for ensuring that reactors operate safely, that alarms and emergency shutdowns function correctly, and that data integrity is maintained at all times.
However, without a comprehensive IV&V process in place, the risks escalate rapidly. Some of the key risks of neglecting IV&V in nuclear safety systems include:
- Safety system failures: Software errors or defects can lead to impairment of special safety systems in the plant.
- Regulatory compliance violations: The nuclear industry is one of the most heavily regulated sectors globally. Nuclear facilities must have a valid operating license to run, a requirement that is enforced by independent regulators (e.g., CNSC, NRC). Failure to meet stringent regulatory requirements (e.g., CSA, NRC, IEEE, NQA-1) can lead to legal penalties, project delays, or worse, the shutdown of the nuclear facility.
- Human error amplification: Software is often relied upon to augment human decision-making. If the software is flawed, it can amplify human mistakes, making them much more dangerous in a critical environment.
- Lack of traceability: Without IV&V, maintaining requirements traceability becomes much more difficult. This can result in a misalignment between computer system behavior and original safety requirements, putting plant operations at risk.
- Increased costs: Identifying defects during or after implementation is far more expensive than addressing them early in the development phase. The cost of a failure can result in regulatory fines, legal settlements, and costly downtime, not to mention the potential loss of life.
How IV&V mitigates risks in nuclear safety systems
IV&V can mitigate the above-mentioned risks by introducing a structured, independent review and verification of the artifacts created by Software Development Life Cycle (SDLC) at multiple points. Here’s how IV&V helps to reduce risk across nuclear safety systems:
1. Early identification of critical software defects
The earlier defects are identified, the easier and cheaper they are to fix. IV&V ensures that the design and development team follows industry best practices and that any software issues are caught before they become critical. An IV&V team applies thorough testing methodologies, such as:
- Static code analysis
- Formal verification techniques
- Unit testing
- System integration testing
- Simulation and modeling of real-world conditions
By simulating real-world scenarios, IV&V teams can uncover hidden software bugs, potential vulnerabilities, and unintended interactions that could jeopardize the system’s safety.
2. Ensures full compliance with regulatory standards
In the nuclear industry, compliance is mandatory. Regulations like CSA N290.14:24, IEEE 1012, and NRC Regulatory Guide 1.168 dictate stringent standards for safety systems.
IV&V provides independent oversight that ensures software not only meets functional requirements but also aligns with regulatory expectations. This is particularly critical when preparing for safety audits, licensing, and certification processes. A well-documented IV&V process strengthens the organization’s compliance posture, making it easier to pass regulatory reviews.
3. Validation of real-world functionality
Validation ensures that the software meets real-world operational needs. This is crucial in safety-critical applications where even minor deviations can result in catastrophic consequences.
IV&V teams assess how the software interacts with the hardware, sensors, and operators in a simulated plant environment. They validate that the software is not only functionally sound but also resilient under stress and capable of handling edge cases (e.g., unexpected system failures, hardware malfunctions).
4. Traceability and documentation
Traceability is a key component in maintaining safety in nuclear systems. IV&V ensures that there is a coverage of the design requirements and clear link between computer system and software requirements, computer system and software design, implementation, verification, and validation. This level of traceability is essential for:
- Proving compliance
- Understanding decision-making history
- Facilitating future audits
IV&V teams validate that the entire software lifecycle adheres to the defined safety requirements, ensuring that no critical requirements are missed.
5. Reducing human error in high-risk environments
Software doesn’t make mistakes, but humans often misinterpret or overlook critical data. In high-stress, high-consequence environments like NPPs, the ability to rely on software to assist in decision-making is paramount.
IV&V helps ensure that the software’s behavior is predictable, transparent, and aligned with operator expectations. This minimizes the risk of operator error due to software malfunction or incorrect data. In essence, IV&V acts as a safety net, making sure that the software provides clear, actionable insights during critical moments.
Best practices for IV&V in nuclear safety systems
When implementing IV&V in nuclear safety systems, certain best practices should be followed to maximize effectiveness and reduce risks. These include:
- Determine a fit-for-purpose testing strategy: A fit-for-purpose testing strategy depends on the unique behavior and interfaces of the computer system, the nuclear regulatory requirements, and the software category of the target application. The goal of determining a fit-for-purpose testing strategy is to find problems early and efficiently and ensure on-time, on-budget project delivery.
- Define clear and unambiguous requirements upfront: Ensure that computer system and software requirements are well-documented and address operational safety and plant operation needs.
- Work with an IV&V team with domain expertise: The IV&V team should be independent from the design and development team and have specific expertise in safety-critical software, nuclear systems and regulatory compliance.
- Provide control over test environments, tools, and data: The testing environments, tools and data should be controlled and brought to a known state of stability. An unstable and uncontrolled testing environment, tools or data will result in poor testing progress, incomplete testing, inability to recognize failed tests, inability to recognize a passed test, and difficulty in isolating the root cause of failures. Garbage in, garbage out.
- Close the loop: ensure test Coverage, execution and re-Testing: IV&V should not be a one-time activity; it should be integrated into every phase of the SDLC. Also, test coverage should be monitored, and specific test metrics should be established to provide objective measures of test completeness and test effectiveness.
- Use a structured nuclear software quality assurance (SQA) program: A structured SQA program that meets nuclear quality standards (e.g., IEC 61508, IEEE 1012, CE-1002-STD) provides a systematic approach to software quality throughout the SDLC.
How Alithya’s IV&V expertise supports nuclear facilities
Each IV&V project has its unique challenges. Success in IV&V requires expertise and experience in multiple engineering disciplines and nuclear domain knowledge.
By leveraging our expertise in nuclear regulatory compliance and our extensive nuclear domain experience, we not only successfully perform I&V, but we also provide insights, objective advice, and actionable recommendations to ensure that proposed systems meet their safety and reliability requirements.
Since 1980, Alithya has been providing the nuclear industry with services ranging from electrical, computer, software, and instrumentation & control engineering, to design engineering, cyber security, and digital hardware and software qualification.
Successful performance of IV&V requires the right people, right process and right technology. We are uniquely positioned to help you navigate the complex landscape of IV&V in nuclear safety environments.
Right people: nuclear and technical expertise
- Expertise in nuclear software and cyber security standards: We have expertise in multiple nuclear computer system and software standards (e.g., CSA N290.14:15, CE-1001-STD, CE-1002-STD, IEC 61508, IEEE 1012) and cyber security standards (e.g., CSA N290.7:21). For 40+ years, we have helped nuclear operators and suppliers comply with regulatory requirements for computer systems, software, and cyber security.
- Experience in nuclear safety-critical and safety-related systems: Alithya understands the unique challenges and regulatory requirements that shape nuclear safety systems. Our experience spans from the Control Room to the Board Room –from the design and development of safety-critical Shutdown Systems (Software Category I) and safety-related Reactor Control Systems (Software Category II) to safety-related monitoring, HMI/SCADA, and Balance of Plant systems (Software Category III) for nuclear customers.
- End-to-end engineering services: We have extensive experience acting as both an engineering services vendor and an equipment integrator. This provides our clients with a one-stop option for engineering design projects that require technology/equipment integration and delivery, resulting in cost savings and risk reduction for our clients.
Right process: validated workflows, aligned with nuclear regulations
- Proven methodology: Alithya’s proven, structured, IV&V process is designed to mitigate risks early and ensure full compliance with regulatory standards. Our team is well-versed in industry-leading frameworks and tools for software IV&V.
- Independent, objective evaluation: Our team operates independently of your design and development process to ensure that software is thoroughly validated and free from bias, offering you peace of mind and a clear path toward operational safety.
Right technology: solutions purpose-built for nuclear
- Right tools: Our Engineering Technology Laboratory in the Greater Toronto Area in Ontario, Canada, is qualified to perform for design, development, verification, validation, and qualification of nuclear safety-critical and safety-related digital I&C systems. We will leverage our proven-in-use tools to successfully perform I&V for your systems.
Driving reliability and compliance through IV&V
When it comes to reducing risks in nuclear safety systems, there’s no room for error. Alithya is committed to ensuring your computer system and software is not only functional but also safe, reliable, and compliant with the highest industry standards.
Contact us to learn how Alithya’s IV&V services can ensure that your systems and software are ready for use in nuclear safety applications.