Author Archives: Katie Mallinson

10-stage explosives assignment calls time on Rugeley Power Station

In 2016, the iconic coal-fired Rugeley Power Station ceased production of electricity, in a landmark decision that marked the site’s regeneration. In a recent article for IExpE, decommissioning consultants Richard Vann, managing director, and Matthew Waller, operations director (both from RVA Group), explored the role that explosives engineering has played. If you missed it, catch it in full below…

Like many coal-fired power stations across the UK, Rugeley has long dominated the skyline in Staffordshire. The 139-hectare site – with its iconic chimney and cooling towers – has been an energy generation hub at the heart of the community, since the 1960s.

Key to the economic and social lifeblood of the town, it ceased production of electricity in 2016, and in early 2020, the local authority granted permission for a scheme that would transform the disused space into a sustainable and innovative mixed-use neighbourhood.

With a widely-voiced commitment to embracing a greener and more efficient world, site owner ENGIE has a clear passion for innovation. It is perhaps therefore unsurprising that when it came to the clearance of the former 1GW site, the demolition scheme was equally as forward-thinking. And explosives engineering has laid at its heart.

A collaborative mindset

The decommissioning project was one built on the cornerstone of collaboration, with ENGIE’s own personnel managing the two and a half-year assignment. RVA was engaged in 2016 as principal designer, tasked with providing specialist technical expertise and advice as works unfolded. This included writing the full specification of works and CDM EHS plan, and consultancy support during the demolition contractor appointment – with RVA assisting with tender analysis and selection from a technical perspective. Based on a balanced appraisal of the proposed techniques, extensive experience including in-house explosives engineering expertise, and the commercial robustness of the bid, the contract was awarded to Brown and Mason – a firm with a track record of demolishing over 50 power stations.

Engaging the community

The project team was involved in stakeholder dialogue from an early stage, to ensure the local community felt informed and involved. Communications extended to domestic residents and multiple adjacent blue-chip businesses.

Details of the demolition programme were openly shared – both at the outset and during pivotal phases throughout – with consultation meetings held to give confidence in the team’s approach to health, safety, quality and environmental protection.

A website dedicated to the site redevelopment was also launched so that residents always remained in the loop, in advance and following each project milestone. Local crowd management was also planned for.

The sequence of events

Once mobilised on site, initial works focused on the removal of ancillary equipment and building interiors before the structural demolition activity could commence. Asbestos materials also had to be cleared and the structures certified as clean, to pave the way for explosives engineering activity.

10 explosively-initiated controlled collapses were planned for the project – more than may typically be associated with a power station demolition. However, the carefully selected team conducted a thorough engineering investigation and design, which allowed the buildings to be safely pre-weakened to maintain stability, while significantly reducing the quantity of explosives required. This proposed methodology also negated the need to utilise specialist machinery throughout.

All method statements were technically appraised by RVA and a collaborative process was deployed to develop these.

As the programme unfolded for each blowdown event, wider site preparations included deplanting works to clear all plant and equipment below the 40ft level of the main buildings – such as turbine sets, heavily reinforced concrete supports and the base sections of top-hung boilers.

The site was also home to two underground stormwater drains, numerous underground oil-filled cables and a live National Grid 400kV sub-station. The collective team worked carefully to protect these critical services, by considering historic vibration data from previous similar explosives projects, carrying out predictive ground and air-over pressure calculations, and monitoring vibration data at the time of each event.

RVA maintained an ongoing presence throughout the entirety of the project, visiting the site on a weekly basis to audit compliance with method statements, ensure EHS standards were being upheld, and act in an advisory capacity for the client. Given the scale, complexity and inherent risks associated with a project of this nature, this technical consultancy role cannot be underestimated.

Initial blowdowns

The first controlled collapse took place back in February 2019, when 11.14kg of rdx-based plastic explosives (shaped charges) and 17.7kg of nitro-glycerine based kicking charges, were used to bring down a 33m high ductwork system. Weighing 1,500 tonnes, the 160m long, 7.7m diameter steel structure served the former power station’s FGD (Flue Gas Desulphurisation) plant.

The exclusion zone was well within the power station boundary fence, meaning there was no impact on the local road network – in fact, the only challenge was morning fog which put the blowdown back by merely 60 minutes.

There was similarly low community impact associated with every event that followed, including:

  • The second controlled collapse of the power station’s Unit 7 Precipitators. This 49m long, 16m wide, 32m high largely steel structure was brought down using 7.15kg shaped charges and 36kg kicking charges.
  • The third blowdown event to demolish the coal sampling tower, associated conveyors, Unit 6 Precipitators and ducting, which required a total of 27.3kg of shaped charges and 11.68kg of kicking charges.

Larger explosives assignments

In preparation for collapsing the 5,000 tonne deaerator bay and 28m high turbine hall four months later, all pipework was cut to the adjoining boiler house, to ensure the separation of services entering the building. More explosives were naturally required to blow down these 112m long x 12m wide x 64m high, and 112m long x 62m wide x 28m high structures – with 14.34g of shaped charges and 201.6kg of kicking charges used. Away from the main gate and, again, barely visible offsite, there was virtually no community impact.

The same could be said for the fifth controlled collapse of the 8,600 tonne bunker bay – which, at this point in the project, represented the heaviest structure to have been blown down, and was the final explosives assignment before the national Covid-19 lockdown.

Working during Covid-19 times

The team adapted quickly to government guidance and restrictions, ensuring the health and safety of on-site personnel just as they would in the face of any inherent demolition project risk. The workforce formed a bubble and operating procedures were devised to minimise risk of infection.

This agility meant that the sixth blowdown event – a 73m high boiler house – could take place in August 2020. The largest structure on the site, the 18,000 tonne steel structure was demolished in a controlled collapse which required 12.8kg of shaped charges and 121.2kg of kicking charges. Again, the community impact was minimal and there was no public viewing area, although video footage of the successful blast was naturally of interest to local media.

The blowdown of the power station’s 183m chimney was always going to be a more notable event, given its impressive height. In the weeks that preceded the collapse, the structure’s aircraft warning lights were disconnected, and the Civil Aviation Authority was notified so that aircraft were informed of the unlit chimney.

A test blast was also carried out to establish the correct charging requirements. Knowing there would be some debris, containers and Heras fencing with netting were installed for secondary protection. 50m long steel ducting – approximately 8m in diameter and 30m from the ground – was also removed one month before the blowdown, to enable the chimneys’ safe demolition. 3.6kg of machete 40 cutting charges, and 9.6kg of kicking charges were used, with on-site dust suppression minimising the environmental impact.

The 7,600 tonne predominantly concrete chimney – with 330mm shell and two internal steel flues – was blown down in January, using 133kg of nitro-glycerine based, 28mm diameter cartridges, cut to 200mm lengths on-site.

Covid-19 restrictions meant there could be no public viewing area as was originally planned, so the event was live-streamed on ENGIE’s YouTube channel. Extensive planning with two local authorities – including a road closure given a circa 400m exclusion zone which extended beyond the site boundary – minimised potential community disruption.

The final phase

At the time of writing, the power station’s residual ducting, gas heaters and four high cooling towers, are all that remain. Works on the final metal ductwork were delayed slightly given the discovery of a nest, but guidance from an ecologist means a new date can be established once the birds have moved on in spring.

The internals of the cooling towers consist of a vast array of wooden supports, pipework and mist eliminator elements – and have been subject to a complex material removal process which, upon completion, will have taken twelve months. Test blasts have also been carried out in preparation for their collapse, and road closures have been planned to manage traffic on the day, once confirmed. These 117m high structures dwarfed all other buildings on the site in comparison, so this event will undoubtedly be the one that attracts most community attention: changing the local skyline and marking the start of a new future for the iconic power station site.

 

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RVA to deliver Demolition Expo seminar this September

RVA Group will take to the industry stage once again, when the doors open for the Demolition Expo 2021, this September. And what an exciting opportunity this will be to see everyone, in person, at last.

On Thursday 16 September, managing director Richard Vann will deliver a 45-minute session on the topic – ‘Is this the decade that demolition gains deserved respect in the value chain?’

Organised by the National Federation of Demolition Contractors (NFDC), the prestigious event will be co-located with the environmental showcase, LetsRecycle Live, and is forecast to attract more than 2,000 visitors over the two-day programme.

With indoor, outdoor and live demo exhibition stands, this highly interactive expo will be complemented by a conference theatre inviting industry professionals to attend thought-provoking sessions from demolition experts.

Commenting on the importance of his particular seminar theme, Richard said: “Ask anyone outside of the demolition industry what our engineering profession does, and they’d no doubt describe scenes full of dozers and excavators – even cranes and balls – pulling down tired buildings, plant and other assets, in order to make way for something more exciting.  Some, sadly, still perceive it as quite ‘rough and ready’.

“Those of us within the industry, of course, know there’s far more to it than that. Our scientific discipline thrives on the breadth and depth of engineering skills within it, which combine to mitigate risks and execute inherently hazardous projects safely, cost-effectively, and with maximum respect for both the environment and surrounding communities.

“And the really exciting thing is that I think the dial is shifting further. We’re seeing decommissioning, decontamination, dismantling and demolition gaining increasing respect for the role it plays in the wider built environment – evidenced, not least, by growing demand for front-end engineering services, not just in earlier phases of decommissioning works, but sometimes before assets are even constructed! The next ten years could be very exciting for demolition, indeed.

“I look forward to delving into the topic with delegates, this September.”

The Demolition Expo is scheduled to be held at Stoneleigh Park, near Coventry. The event will only go ahead if the Government’s Covid-19 guidelines confirm it is safe to do so.

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Sembcorp Utilities

Decommissioning and demolition of Derwent Power Station, Spondon, UK

Following the completion of the above project, I would like to thank the RVA team in helping us to deliver an incident-free outcome, within the budget cost and on programme.

We recognised from the outset that the removal of hazardous materials and demolition of the massive and complex structures was outside our company’s core business activities and hence we sought specialist support.

RVA’s combined roles of principal designer, project manager, and technical advisor enabled them to take us seamlessly through the process lifecycle, from scoping of the works, tendering, selection of a demolition contractor, and management of the on-site execution. At all times, RVA’s main focus was on making sure the highest levels of EHS standards were maintained and exposure to risk minimised.

In addition to the accepted complexities associated with this type of demolition project, some areas of the redundant station had become homes to protected species and RVA worked with us in a diligent and collaborative manner, dealing with the Local Authority, ecology groups, and other stakeholders, to ensure that measures were take to minimise disruption to wildlife, the environment, and our corporate reputation.

RVA is also supporting other divisions of our company in a similar capacity, and I would have no hesitation in recommending them to others, when faced with similar challenging projects.

 

 

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Engineering firm RVA Group launches new decommissioning service

Specialist decommissioning engineering consultancy RVA Group has launched a new service as the number of industrial and process site closures globally, continues to rise.

Having successfully delivered more than 850 decommissioning, decontamination, demolition and dismantling (DDDD) projects all over the world, the London-headquartered firm has identified a gap in the market when it comes to one of the earliest phases of preparing a site to be mothballed or removed.

Asset owners commonly use internal resources to handle initial decommissioning works – often due to the fact they don’t consider alternative approaches. However, global industry standards such as the CDM Regulations, state that it is best practice – and the law in the UK – for decommissioning to fall within this remit. A principal designer should therefore be involved from the earliest phase, to ensure the works are rigorously planned from the outset.

So, while the asset owner can assume the role of principal contractor, an experienced team with a decommissioning mindset should be charged with supporting or writing the decommissioning plan itself, as well as documenting the detailed processes to follow, and auditing works throughout. This is the most secure way of ensuring the project unfolds with the highest possible safety and environmental standards, believes RVA Group’s managing director Richard Vann.

“Nobody knows an asset or site better than the operator who has run it for several years,” he explains. “So, when the owner calls time on its operational life it would be unwise to overlook the depth and value of process and plant-specific knowledge that such individuals could bring to the table, during a decommissioning project.

“However, despite decommissioning often being considered an extension of site maintenance, it represents a specific engineering discipline which requires a distinct mindset. There’s a difference between measures for maintenance or routine turnaround purposes for instance and decommissioning the asset entirely because it has reached its end of life and will never be restarted. Ironically, DDDD presents a number of opportunities that will not only make the process cost effective but also, in many instances, remove hazards and enable increased EHS standards to be implemented.

“Professionals in our industry are often engaged when decommissioning work is already underway, but by that point, avoidable risks may already have been taken and additional measures may be required to rectify decommissioning issues that should have been undertaken by the right people, armed with the right information, at the right time.”

There’s also a financial argument for earlier involvement from decommissioning specialists, adds Richard.

“Sometimes operators go to such extremes that they undertake processes they don’t actually need to, as they could be handled more efficiently, and ultimately safely, during the dismantling phase,” he highlights. “Such an approach therefore results in abortive effort and cost. Costs will also rise if extra resource is required to get a project back on track – and the monetary consequences of an event, such as loss of containment doesn’t even bear thinking about.”

Having supported clients within the global chemical, petrochemical, pharmaceutical, power, energy, oil, gas and heavy manufacturing industries, RVA’s client roster includes names such as INEOS, SABIC, BASF, Total and GSK – to name just a few.

Established in 1992 and now a part of EPH following a strategic acquisition in 2017, the team brings more than 200 years combined decommissioning experience to the market.

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RVA’s Richard Vann appointed as Demolition Industry Awards judge

Entries are open for the 2021 British Demolition Awards, and RVA Group’s managing director Richard Vann has been appointed to sit on the judging panel.

A celebration of talent, collaboration and innovation throughout the profession, the event is now in its third year. With 13 categories covering demolition contractor and project excellence, safety innovation, asbestos removal, up-and-coming talent, environmental advancements, and more, it is hoped that this will be a strong showcase of what is great about the demolition industry.

Richard will join fellow judges Paul Argent, editor of Demolition Hub; Holly Price, former NFDC president and Keltbray’s skills and communities director; and Simon Barlow, NFDC LSC chairman and managing director of Rye Demolition.

“It is important that we champion the dedication, hard work and pioneering attitudes that exist within the demolition industry, and I look forward to reviewing the submissions that come in,” said Richard. “Having been a part of the profession for over 30 years, on a truly global basis, I continue to be proud of our work – especially here in the UK.”

The deadline to enter the British Demolition Awards, is 31 July, before judging will commence. The industry will gather at the Amex stadium in Brighton, on 3 September, to learn which of the finalists have been successful.

Best of luck to all.

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Decommissioning spotlight – understanding asset retirement obligations

It may sound like something of a ‘dark art’ but planning for the safe, cost-effective and compliant retirement of assets in the oil and gas sector doesn’t just make good business sense – it is a legal requirement too. In a recent article for Tanks & Terminals, Richard Vann – founder and CEO of RVA Group – explores what the process of asset retirement planning involves, the benefits, and why operators should start thinking about the end of a tank’s life, far sooner that they may first realise.

If you missed the feature, catch it in full here…

It perhaps sounds like scenario planning to the Nth degree, but being prepared for the retirement of an asset is a fundamentally crucial and strategic way to approach the operational lifecycle of a tank farm, or even an entire terminal. In many parts of the world, it is also a legal requirement – to comply with international financial provisioning standards such as FAS143 in the US, and IAS 37 in Europe.

The roots of such standards date back to the days of events such as the Enron scandal, when the American energy giant was declared bankrupt. The company was building and running power facilities throughout the USA and overseas – seemingly successfully. However, despite sizable annual revenues, no financial provisions were being made to fund the eventual decommissioning of Enron assets, when the time came to take them offline. The liquidation of this company – and the fact that the Government had to pay for the retirement of their plants – certainly acted as a lesson learnt, and accounting rules were changed as a result.

Now, in the simplest of terms, a proportionate amount of money must be set aside, every year, for the decommissioning of high value capital assets with an expected life in excess of 15 years. If nothing else, this acts as a safety net in the event of abandonment.

Comprehensive financial provisioning

While the numbers associated with asset retirement were once estimated, they must now be evidenced and substantiated.

In other words, accounting law now states that asset retirement provisioning should be carried out in a proven manner, which naturally requires someone with decommissioning-specific expertise to be involved in the exercise.

RVA is known for saying that nobody knows an asset better than the operator who runs it, but that doesn’t mean said operator knows exactly how to retire the asset with maximum respect for safety, the environment and their bottom line. The many components of a decommissioning project – including decontamination, dismantling and demolition – require a defined engineering skill-set, if the assignment is to be managed and executed successfully.

The ‘numbers’ must therefore include estimates of the resources that will be required – in terms of people and technology – over a given period of time, as well as considered third party cost estimates relating to everything from the surrender of licences and permits, through to community engagement, wider stakeholder liaison and the disposal of hazardous materials, to name just a few.

The data is then typically compiled in a transparent report with annotations to explain any assumptions and exclusions. Once audited, the figures are declared in operators’ annual results.

More than financial data

Of course, such accounting requirements do not exist in all parts of the world, but parentage of an asset naturally dictates the standards adopted, irrespective of where the asset actually resides. Consequently, this process forms part of common practice for a significant proportion of the industry and the data is produced without question, much like a tax return. In larger firms, the numbers also tend to aid compliance with organisations’ own financial regimes too.

But delve deeper, beyond the headline summaries, and what do the figures actually say?

This asset retirement exercise is one of many strategic studies that an operator can undertake to highlight, understand and better manage a site’s long-term liability. In fact, used properly alongside a redundant asset management plan (RAMP), and the operator has an extremely powerful resource at their fingertips.

RVA began working with one European firm back in 2011, for example, because with >€100m of redundant assets it had reached the point where it almost didn’t know what it had got. They therefore sought a true and complete picture of their decommissioning responsibilities – a value-adding business instrument – not just an indicative cost.

It is also important to note at this point, that the aforementioned accounting standards require operators to evaluate all of their assets. However, in truth, fuel storage/distribution facilities and terminals may sometimes be considered with less rigour on certain sites, in favour of concentrating on elements of a plant that are considered more complex or hazardous in nature. This should not be the case.

Thorough analysis of all the client’s assets means that a decommissioning ‘hierarchy’ can be drawn up according to the level of safety risk associated with each. The deterioration of insulation or the general corrosion of a tank heightens the likelihood of a containment loss, for instance. Structural collapse is also a significant risk, as well as leakage, which may consequently affect the need to accelerate the retirement of the asset concerned.

Monitor, measure and adapt

Once complete, the frequency with which an asset retirement study should be reviewed, must be judged on a case-by-case basis. It is recommended that the information is rigorously re-assessed at least every five years. This allows any changes to the assets or tightening of regulations to be accommodated, and the true liability of a site to be fully understood at a given point in time.

A solid baseline of data will ensure this ongoing review process can be carried out in both an efficient and effective manner. At the heart of the costings exercise should therefore be a fluid and reconfigurable database which allows for the adjustment of resource costs, waste and scrap rates, as well as annual inflation figures. This adaptability is essential, if the study is to maintain relevance over a possibly extended period.

In truth, the frequency with which an operator chooses to update their asset retirement data often depends on their individual approach to good governance. A tank explosion in Western Asia in 2016 for example, had devastating consequences that a different care and maintenance regime could perhaps have helped to prevent.

The wider value of asset retirement data

As has hopefully already been evidenced, this accounting practice can add value far beyond that of a compliance box-ticking exercise. As the age-old saying goes, knowledge is power, so hopefully it is viewed as much more than merely a ‘necessary evil’.

So, if an operator is devising a business case for the installation of a new plant, considering a site exit, or evaluating the affordability of a decommissioning project over a defined period of time for cashflow purposes, strong intelligence already exists.

With the tendency currently for assets to change ownership perhaps more often than in the past, variations of this asset retirement study can also be used by prospective purchasers and vendors, as a due diligence tool. For example, the information gathered gives clarity on the legacies that will remain with the site and costs that are likely to crystallise in the future.

Thinking about decommissioning before day one

The role of asset retirement provisioning is only going to grow – as is the importance of decommissioning in the oil and gas value chain.

That’s because the circular economy has gone from being a term usually referenced only by those in the environmental sector, to a philosophy now influencing so many supply chains in various industrial settings.

When it comes to the futureproofing of assets in this sector – in fact, in so many areas of construction – the decommissioning of tanks, terminals and other buildings and structures is therefore increasingly being considered before they have been built. Actually, while they are still being designed.

Reuse and recycling matters more than ever, so if the financially and environmentally savvy retirement of an asset can be ensured before it even exists, this takes an operator’s Corporate Social Responsibility (CSR) status to a whole different level – and rightly so.

Conversation surrounding this topic, is going to get even louder.

 

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