Impact case study database

Brunel researchers’ development of the HT transducers that could endure continuous operation at high temperatures of up to 200°C enabled the engineers to detect the fully penetrating crack (text removed for publication) in a boiler operated by EDF Energy. [E2 p9] In July 2014, the detection of the crack on a boiler spine at Heysham 1 caused EDF to shut down immediately, Heysham 1 and its sister station, Hartlepool power station, because they both share the same design specifications. Heysham is the only site in the UK to have 2 operating nuclear power stations. Given that EDF manages and operates power stations generating 25% of the total nuclear generating capacity of the UK, the power outages by EDF

Energy led the National Grid to ‘fast-forward an emergency plan’ to secure more electricity in case of a possible shortfall. [E7]

Brunel researchers’ guided wave technology was used to inspect all the boilers associated with the 2 nuclear reactors at Heysham 1 and Hartlepool. In order to allow the power stations to begin operating again, they then installed HT transducers (Figure – the ‘ring’) on the boiler spines in 8 systems in each of the 4 stations operated by EDF Energy (in total 32 systems), which enable early detection of aging pipes by sending signals to the boiler. [E1]

With the permanent installation of HT transducers with 100% volume inspection coverage, both sites were able to quickly return to service by late 2014 and early 2015, causing little to no adverse impact to the national energy supply in the UK.

(Text removed for publication)

Since then, Brunel researchers have been supporting the TWI team in the analysis and interpretation of the data from the systems.

Safety Measures – Preparing for the Future

This incident highlights the challenges that Britain is already facing – a power capacity crunch due to ageing nuclear and coal plants. Many of our reactors were built in the 1980s and are approaching the end of their service life. Both Heysham 1 and Hartlepool were commissioned in 1983 and were due to come out of service in 2019. [E8]

The importance of regular monitoring and early detection of faults cannot be underestimated – the 2011 Fukushima nuclear disaster in Japan clearly demonstrated the potential damage that a critical failure at a nuclear power plant can cause.

Significant parts of piping systems are partly or entirely inaccessible to non-destructive inspection techniques. Therefore, installing the HT transducers in fixed positions allows EDF to monitor and collect repeatable results and build a robust model to estimate the operational resilience of nuclear plants. Consequently, EDF have developed a proactive strategy for managing ageing plants, extending their operating lifetime and significantly reducing the potential for unscheduled outages. This is achieved by accurately monitoring their condition and then strategically intervening with a targeted maintenance and repair regime. EDF Energy has extended the scheduled closure dates for Heysham 1 and Hartlepool by 5 years from 2019 to 2024.