Nuclear Storage Pond - Waste Removal Mast & Gantry Assembly

Aerospace, Nuclear & Defence

The Challenge

Decommissioning an old Intermediate Level Waste (ILW) outdoor storage pond at a UK nuclear-licensed facility is a careful procedure with many stages.

In this situation, one of the precursor operations that this facility had to undertake was the removal of all of the mobile ILW sludge that had accumulated within the 5.3m deep pond over numerous years before the dismantling of the old pond storage structure could commence.

The Solution

SCX Special Projects were brought in to design and manufacture a bespoke single-stage mast and gantry assembly, capable of supporting and manoeuvring a sludge retrieval vacuum pump, which would lead to the sludge being stored in modern stainless steel containment.

The mast assembly is mounted on an X-Y-Z travelling gantry bridge capable of sweeping
the entire length and width of the pond, while risk mitigation for all adverse eventualities came built-in to ensure safe and reliable operation.

Heavy duty

  • The seismically qualified structure incorporates the single-stage 4m tall mast, the 3.7m span travelling crab, and a 19.6m long travel gantry
  • The mast supports a 250kg pump affixed to a free-floating pendulum to enable access into corners without overloading the structure against the sides of the pond
  • The safe working load capacity of 800kg enables the assembly to deploy alternative devices if required


Precise control, reliable recovery

  • The mast is pendant controlled from the pond-side and interfaces with the facility’s existing emergency stop system
  • A robust hardwired protection system provides layered protection against any potential faults
  • In case of a power failure or other breakdown, an efficient manual recovery system is provided by detachable Tifor winches that can drag the entire mast assembly back to the maintenance bay


Simply safe

  • Limit switches provide boundary protection, anti-uplift brackets prevents unseating in the event of an earthquake, and a storm anchor locks the mast in position in the event of high winds
  • The cost-effective single-stage mast takes advantage of the unlimited outdoor headroom whilst the simple design makes the solution robust and reliable
  • A rack & pinion hoisting mechanism raises and lowers the mast at a controlled speed of 0.1m/min whilst the pump is active


Let's talk more about nuclear handling solutions

Hundreds of processes support and surround the core activity of nuclear power generation, creating by-products that need to be handled with care.

We have decades of experience in creating bespoke handling systems for the nuclear sector - with a primary focus on safety. Talk to us today.

Call us on +44 114 262 6199, email us at, or complete the contact form below and we'll be in touch.

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SCX Special Projects Ltd

Roman Ridge Road, Sheffield, S9 1GA, United Kingdom

t:  +44 (0)114 262 6199