The ten biggest challenges when decommissioning a chemical site
WHETHER outdated and decaying assets are being cleared to pave the way for more innovative technology, or to allow chemical manufacturers to rationalise their operations, there can be no denying that decommissioning projects are becoming increasingly common worldwide.
Here, we look at the ten biggest challenges when decommissioning a chemical site and – more importantly – how to overcome them.
Decommissioning is a very defined engineering discipline that requires a specific technical skillset to ensure the safe execution of projects. It is not merely an extension of normal operations or the reverse of commissioning and construction, nor can it be rushed to achieve an accelerated exit.
Specialist guidance and expertise should therefore be brought in to manage what would almost always otherwise be a step into the unknown.
Admittedly, investment in an external team may at first be difficult to justify – this is rarely a revenue-generating exercise after all. But cutting corners will undoubtedly put lives, the environment and the commercial integrity of the project, at risk. Chemical manufacturers must therefore dedicate the level of time, skills and resources truly required.
The involvement of an external specialist with a defined decommissioning mindset should not be to the exclusion of people with plant-specific knowledge. Nobody will know a chemical asset better than those who have worked on it during its operational life, so they will have an undeniably important role to play in the ensuing works.
Assembling a proficient project team is admittedly more difficult if human resources have long been lost due to a historic facility closure. But effort should be made to build a knowledge-rich team, without papering over any gaps.
A competent, experienced dismantling/demolition contractor should also be appointed following a rigorous tender process, and other specialists such as explosives engineers may be required depending on the scope of the assignment concerned. In selecting the right people for the job, everything from competency to EHS records, availability and cost should be factored in. However, decisions should never be made on the basis of fees alone.
The location of decommissioning partners is becoming increasingly irrelevant, largely because the supply chain continues to lag behind demand, so clients can no longer look for local partners only. A truly global hunt for a competent supply chain is now underway.
Of course, there may be language barriers to overcome and cultural differences to respect as a result. In some parts of the developing world, for example, workforces do not readily acknowledge why harnesses should be worn, let alone why they must be tethered to something immovable when working at height. This is often driven by the legislative standard they are accustomed to.
The advice here is to implement consistent working rules for all operatives and personnel irrespective of local customs and practices – safety should be an absolute and non-variable standard. So, whilst criteria and attitudes may fluctuate from country to country, the baseline reference point should be best practice. Generally, in my opinion, European legislation is a very good starting point.
In summary, there can never be any presumptions surrounding what people will and will not consider acceptable, so effective employee relations are crucial. It all comes down to clear lines of communication and local knowledge, so a translator may enhance the speed with which a rapport can be established.
It is common for inefficient or unused processing equipment to remain in-situ on a site, albeit in an idled state, particularly if the priority is to safely take an asset offline simply to stop haemorrhaging money.
But mothballing can prove extremely costly – land is expensive, frequent inspection and maintenance regimes are also often required, EHS concerns naturally rise and there is an increased reputational risk if the site is vulnerable to trespassers. What’s more, even assets that are carefully decommissioned and isolated require extensive inspection, validation, testing and significant investment to get them back up and running safely and efficiently, assuming personnel with the required knowledge are still available.
Rigorous costings studies should therefore be carried out when deciding exactly what next step action to take, as the business case for mothballing can sometimes be non-existent.
Difficulties lie in making informed decisions about the future, especially when there are gaps in knowledge. Impartial, bespoke tools such as feasibility and option studies therefore play an increasingly important role in the development of chemical firms’ redundant asset management plans.
Often commencing with a series of management workshops, this exploratory process helps to uncover the key issues associated with a plant, project and site, before providing a clear view as to the true opportunity or liability of related works.
The resulting report then usually highlights a number of technical, costed conclusions and recommendations as to the most appropriate route map for the assignment. It may even be possible to carefully dismantle some pieces of production equipment for sale and re-erection overseas.
No two chemical sites are ever the same – plants have been built at varying times, with different configurations and using a range of construction techniques. Furthermore, multiple and evolving production technologies mean that certain chemicals such as chlorine, can now be manufactured using a number of substantially diverse processes.
This lack of uniformity adds a layer of complexity to decommissioning as there is no such thing as a ‘one size fits all’ approach. But the nature of the challenge escalates further still in the absence of detailed plans, documented cleansing regimes or site personnel.
A decommissioning project priority should therefore be to bring assets to a ‘known state’ – a process of removing as many uncertainties as possible.
The key advice here is to allow sufficient time and resources at the outset of a project to gather and interpret data surrounding the type and level of hazardous material contaminations, cleanliness, structural integrity and so on. This way, informed decisions can be made about the next-step route path of works.
Mothballed or partially-closed sites will inevitably have on-site utilities and infrastructure such as electricity substations, bridge, offices and public highways, which must often remain in-situ and undisturbed. Their location is likely to determine what else has to stay, which decommissioning methodologies can be used and the sequential rollout of works throughout the project.
The rerouting of utilities is sometimes essential, which is an achievable yet complex and arduous task. The time required to successfully execute this diversion exercise should not be underestimated.
Demolition equipment has continued to advance over the years which means long-reach excavators can extend to newfound heights, for instance, and drones (unmanned aerial vehicles – UAVs) can often prove helpful inspection aides before people have to enter any vessels or work at height themselves.
The challenge is knowing what to use and when.
Limitations may be imposed on a drone’s flight path, for example, if the site is even partially-operational, and predefined distances will be strictly marked out in zones with potentially explosive atmospheres.
The use of different technology therefore requires robust risk management by experienced decommissioning professionals, to ensure it will enhance the project, rather than putting it at risk.
The number of site owners that now favour a cost rather than quality-led approach to decommissioning, is thankfully dwindling. But still some chemical manufacturers – perhaps understandably – try to squeeze the financial parameters of the assignment. If this squeezing extends to the point that fiscal pressures risk compromising EHS standards, the outcome can be catastrophic.
Quite simply, a non-negotiable safety mindset needs to take precedence, irrespective of wider pressures. After all, the ‘cost’ of liability – whether associated with trespassing on a poorly maintained redundant site, the loss of containment, or an on-site incident – is immeasurable.
The adoption of proactive measures to protect the environment is becoming a global priority. When it comes to decommissioning works, there should therefore be no impact on the surrounding community and the project should now achieve a >97% recycling rate, by default.
It is far easier to achieve such high environmental standards, if the relevant data is gathered and interpreted in the earliest project phases. Such information includes soil and groundwater samples, details of a monitoring programme, ground remediation methodologies, environmental risk assessment and a site waste management plan.