Photonic sensing within civil nuclear infrastructure for lifetime extension and long-term structural health monitoring of de-commissioned plant

The existing fleet of nuclear power plants (NPPs) in the UK have been granted life extensions into the 2020s and 2030s. Lifetime extension is associated with an increased need for monitoring to ensure safe operation. To achieve this, while keeping the cost of investment in new instrumentation infrastructure down, innovative and robust sensor solutions and ways to analyse measurement data automatically are required. Following de-commissioning and partial de-construction of NPPs, it is critical that many monitoring systems remain operational for decades to alert the custodian of the plant of any structural deterioration that may cause further damage or risk to personnel. Photonics and fibre optics hold the promise of high-resolution measurement, multiplexing, robustness, security and longevity. Consequently, this EngD project will address the plethora of engineering issues to develop remote monitoring systems for key civil structures with an NPP. Among other things, the project will develop and demonstrate a combined system for monitoring crack deterioration and CO2 leakage in multiple locations of a pressure vessel housing an Advanced Gas Reactor. The project will assess a number of competing photonic techniques that can be employed for these tasks, including distributed and semi-distributed strain sensors, and various techniques for gas sensing, compatible with a multiplexed system. Interferometric techniques may need to be deployed to measure very small changes in strain or displacement. Methods of sensor integration with plant ensuring long-term stability will be developed while ensuring cost effectiveness. Machine learning and other techniques, e.g., tipping point analysis will be investigated to assist in the detection of structural deterioration. Following laboratory investigations, a demonstration system will be deployed within an operating NPP. The project is expected to push the boundaries of the current state of the art in fibre-optic measurement in the areas of photonic systems integration and automatic data analysis from a distributed photonic sensor network.

This section should be read with the accompanying Pathways to Impact document, which describes how we intend to ensure impacts is realized in several different aspects.

Real-world impact is the leading priority for our industrial partners. Their confidence that the proposed CDT will deliver valuable scientific, engineering and commercial impact is emphasized by their overwhelming financial support (£4.1M from industry in the form of cash contributions, and further in-kind support of £5.3M).

Here we summarize what will be the impacts expected from the proposed CDT.

(1) Impact on People
(a) Students
The CDT will have its major impact on the students themselves, by providing them with new understanding, skills and abilities (technical, business, professional), and by enhancing their employability.
(b) The UK public
The engagement planned in the CDT will educate and inform the general public about the high quality science and engineering being pursued by researchers in the CDT, and will also contribute to raising the profile of this mode of doctoral training -- particularly important since the public have limited awareness of the mechanisms through which research scientists are trained.

(2) Impact on Knowledge
New scientific knowledge and engineering know-how will be generated by the CDT. Theses, conference / journal papers and patents will be published which disseminate this knowledge.

(3) Impact on UK industry and economy
UK companies will gain a competitive advantage by using know-how and new techniques generated by CDT researchers.
Companies will also gain from improved recruitment and retention of high quality staff.
Longer term economic impacts will be felt as increased turnover and profitability for companies, and perhaps other impacts such as the generation / segmentation of new markets, and companies receiving inward investment for new products.

(4) Impact on Society
Research in the CDT spans many sectors, all of which impact society, e.g. in the improvement of healthcare diagnostics, or in the creation of new consumer products and services. This CDT has particular resonance with all of the RCUK stated societal challenge themes, with more detail provided in the Pathways to Impact document.
Greater internationalisation of the cohort of CDT researchers is expect from some of the CDT activities (e.g. international summer schools), with the potential impact if greater collaboration in the future between the next generations of UK and international researchers.