NORM decontamination and vessel cleaning for an FPSO demolition in drydock – combining onsite cleaning and Oldmeldrum NORM processing to remove over 1.7 tonnes of scale, reduce all systems to background levels, recycle wastewater and release 30+ tonnes of clean scrap metal for reuse.

Sector: Offshore oil & gas – decommissioning
Location: Kishorn drydock, Scotland & Oldmeldrum NORM Facility
Client: Major industrial demolition contractor (anonymised)
Services: Onsite NORM decontamination, vessel and pontoon cleaning, in-situ line decontamination, onshore NORM processing, waste minimisation and recycling

Overview

Ahead of the dismantling of a late-life FPSO in drydock, the demolition contractor needed a specialist NORM and vessel cleaning partner to make the asset safe, compliant and ready for cutting.

Sureclean delivered an integrated solution: onsite NORM decontamination of pontoons, topside vessels and connected lines, backed by offsite treatment at our Oldmeldrum NORM Decontamination Facility. The work reduced all systems to background levels, kept the programme on schedule and maximised scrap metal recovery.

The Challenge

The scope covered three main areas:

• Cleaning of the pontoons
• NORM decontamination of topside vessels
• In-situ NORM decontamination of lines directly connected to topside vessels

Subsequent NORM-bearing items were then backloaded for onshore processing.

Key requirements:

Recover as much clean scrap metal as possible for recycling

Bring all systems down to background radiation levels in line with SEPA’s Best Practicable Means standards

Manage scale, sludge and contaminated water safely and efficiently

Maintain tight demolition schedules in a challenging drydock environment

Sureclean’s Solution

Sureclean combined onsite decontamination expertise with the capabilities of our specialist Oldmeldrum NORM Facility:

• Advanced jetting and vessel cleaning in drydock to remove scale, sludge and deposits from pontoons, vessels and lines
• NORM monitoring and segregation at every stage to keep contaminated and clean materials separate
• Wastewater recycling, treating and reusing wash water where possible to minimise consumption and liquid waste
• Backload of selected items to Oldmeldrum for controlled, offsite NORM decontamination and final waste handling

This hybrid approach kept work fronts moving in the drydock while ensuring that all NORM residues were processed under controlled, licensed conditions.

Results

The project delivered strong safety, environmental and commercial outcomes:

• 1,765 kg of NORM scale, 200 kg of sludge and 1 m³ of contaminated water removed and routed to appropriate disposal
• Every system decontaminated to background levels, meeting SEPA Best Practicable Means requirements
• Actual waste volumes came in significantly below the initial 5.2-tonne estimate, showing accurate scoping and efficient cleaning
• Over 30 tonnes of clean scrap metal released for recycling, supporting circular economy goals and reducing disposal costs
• The demolition contractor’s programme stayed on track and fully compliant, setting a benchmark for future FPSO decommissioning projects

What this shows about Sureclean

This campaign shows how Sureclean’s integrated offshore/onshore NORM capability supports complex decommissioning:

• Engineered NORM decontamination that protects workers and the environment
• Waste minimisation and recycling built into the cleaning strategy
• A proven route from contaminated asset to clean scrap, helping demolition partners deliver safer, greener dismantling projects.