A tenant firm at the Urenco site near Ellesmere Port has been ordered to improve after 18 litres of acid leaked from a pipe earlier this year.

Separately, a contractor at the site has also received an improvement notice from the Office for Nuclear Regulation (ONR) for a shortfall in its risk assessments in its work with ionising radiation.

The ONR says the notices have been served following incidents in May and July at the Urenco UK Ltd nuclear fuel enrichment site. Urenco itself has not been served with an improvement notice.

The first improvement notice was issued to Urenco ChemPlants Ltd, a tenant organisation on the site, after acid was discharged from a pipework leak at the Tails Management Facility in May.

During work to return a gas scrubber to service following maintenance activities, approximately 18 litres of diluted hydrofluoric acid (HF) was inadvertently discharged from a pipe.

A gas scrubber is used to treat a waste gas stream to remove components, commonly acid gases, such as HF, before its onwards discharge to the environment.

Although no workers were harmed, the incident had the potential to have more serious consequences if they had been directly exposed to the acid.

ONR identified several shortfalls, including inadequacies in the risk assessment that had been undertaken, and deficiencies in the safe system of work.

These shortfalls did not compromise either nuclear or radiological safety.

The improvement notice requires Urenco ChemPlants Ltd to make improvements to how they plan, organise and control future maintenance activities on the gas scrubber machinery to prevent any similar incidents occurring.

Ian Phillips, ONR superintending inspector, said: “When working with hazardous materials it is vital that suitable and sufficient safety procedures are in place to effectively manage and reduce risks, and thus to protect workers.

“On this occasion, adequate controls were not in place, which resulted in workers potentially being exposed to hydrofluoric acid.

“This improvement notice will require Urenco ChemPlants Ltd to put in place effective risk control measures to ensure that such incidents do not occur in future."

Urenco ChemPlants Ltd has until the start of December 2024 to comply with the requirements of this notice.

The enforcement action was served due to breaches of Sections 2(1) and 3(1) of the Health & Safety at Work etc. Act 1974 and Regulation 5 of the Management of Health and Safety at Work Regulations 1999.

Separately, ONR also served an improvement notice on Babcock Critical Services Limited for not having a suitable and sufficient risk assessment for carrying out work with ionising radiation at the Urenco UK Ltd site.

It follows an ONR inspection in July that revealed shortfalls in the contractor’s operations at Capenhurst.

The failure to have a risk assessment in place meant that reasonably practicable measures to restrict exposure of workers to ionising radiation from uranium hexafluoride and triuranium octoxide may not have been implemented.

No workers were harmed as a result of this shortfall, and there was no impact on the public or the environment.

Mr Phillips added: "It is crucial to have a comprehensive risk assessment in place when working with ionising radiation, so that potential risks are identified and suitable and sufficient risk control measures are implemented to protect the safety of workers at all times.”

Babcock Critical Services Ltd must comply with the requirements of the improvement notice by the start of October 2024.

This improvement notice was served due to breaches of Section 2(1) of the Health and Safety At Work etc. Act 1974, and Regulation 8(1) of the Ionising Radiations Regulations 2017.