I&C Modernization: Current Status and Difficulties

Cooperation in Reactor Design Evaluation and Licensing – Digital Instrumentation and Control Task Force

September 2020

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The need for I&C modernization in nuclear power plants, part of the worldwide changeover from analogue to digital automation technology, stems from the progressively longer lifetime of the plants and the increasingly restricted life span and faster obsolescence of I&C components. As most of the main I&C related codes and standards (C&S) are focused on new nuclear power plants, their adaptation to the modernization of I&C systems of operating plants presents a challenge.

Utilities have many things to consider when undertaking modernization including:

  • the scope of events to be managed by the design, such as complex failure scenario, I&C Common Cause Failure (CCF), cybersecurity threats;
  • implementation of new I&C functions in existing I&C systems;
  • increasing complexity of digital systems and, as a consequence, a significantly more difficult licensing process;
  • lessons learned from previous modernization projects.

This paper builds upon the ideas and experiences shared at an I&C modernization workshop in Erlangen, Germany in October 2019 organized by CORDEL and the International Atomic Energy Agency (IAEA). It provides an overview of the current status regarding I&C modernization and identifies the main difficulties the nuclear industry is facing. CORDEL DICTF intends to continue its work on I&C modernization through, for example, the development of checklists and more in-depth papers on selected topics