Extending nuclear plant life requires aging and obsolete systems to operate as new

Refurbishment, reverse engineering or redesign and replace?

07 December 2022

Extending the life of nuclear power plants until replacements are built is a pressing issue for many countries seeking low carbon energy security. But it’s no easy task. Ensuring decades old critical systems continue to function is a specialist task that requires specialist support.

Maintaining power supply while maximizing returns from past investments

The mid-1960s to the early 1980s was a golden era for nuclear power. More plants were constructed in that period than since. This long hiatus is coming to an end. Energy security and climate change concerns are driving investment into new nuclear power generating capacity. These programmes will take many years to complete. Until they do, preserving the nuclear capacity we have is essential to maintaining power supply and maximizes the financial return from past investments.

Maintaining power generation from nuclear plants which have operated for 50 years or so since their construction and even longer since they were designed is not easy. The skills, processes, tooling and detailed plans that were used to build their systems are likely to be long since obsolete and may not still exist. The regulatory framework has also evolved significantly. Putting together lost pieces of the past using the approved engineering and technology of today poses a significant challenge to the industry.

Many plants have already gone through a first life extension cycle – adding up to 20 years to their original 40-year design life by ensuring ongoing reliable operation of safety critical systems and components. Operators of some older plants may now be planning their second life extension – a further 20 years added, taking the full life of the plant to around 80 years.

First and second life extensions are conceptually similar, the difference is scale

The challenges and solutions involved in delivering first and second life extension programmes are conceptually similar, varying mainly in scale. Critical systems need to be surveyed with a risk assessment produced detailing possible points of failure. Given the industry’s commitment to safety, any risks identified must be addressed. Historic system plans will be collated, if indeed they still exist after so much time has passed. Options will be created to remove the risk of systems failures over the life extension period.

Those options will include one or more of three approaches.


When plans or parts exist and it is possible using currently approved and available manufacturing techniques, as well as being safe and cost effective, it might be proposed to refurbish existing systems. At risk components will be replaced on an old for new basis to secure safe and reliable operation of the system through to the end of the life extension period.

Reverse engineering

When plans or parts do not exist, it might be possible to reverse engineer systems and their components to replace them with functional facsimiles. This is not an easy task. A thorough understanding of the knowledge and thought processes of previous generations of engineers and regulators is needed. Without this, important original design features might be overlooked or misunderstood, inadvertently introducing risk to the system.

Redesign and replace

When these first two options are not possible, cost effective or would not meet modern regulatory standards, designing and manufacturing a new system will be required. The quickest and lowest cost way to deliver this option is to take currently available off the shelf solutions and adapt them for the requirement in the aging plant. If that’s not possible, it should be possible to create a bespoke design using modern technologies that have been approved for use in similar nuclear applications. Starting from scratch with an entirely new solution is unlikely to be needed and for fairly obvious reasons is likely to be undesirable from a cost and time perspective.

Ultra Energy’s aging and obsolescence experience

Ultra Energy has worked with owners and operators to support life extensions of aging nuclear plants since the early 2000s, including critical support for the UK’s AGR reactor fleet. We are fully resourced in this specialization, with the ability to sustain complete systems and individual parts or provide support in areas such as process definition, sourcing, equipment evaluation and qualification. As well as meeting our customers' requirements, our solutions will comply with national regulations and benefit from being manufactured in our state-of-the-art, nuclear qualified manufacturing facilities. Our life extension programmes can extend beyond immediate needs to provide an ongoing system refresh programme up to the absolute deadline for end of life.

Sign up for download access

Please submit your details below to access our downloads.

I'm happy for you to contact me

View our privacy policy
Not now