Harwell’s second waste retrieval machine (RM2) continues to perform well

April 14, 2009

In January 2008, the Performance Based Incentive (PBI) for waste recovery was agreed with the NDA. This crucially hinged on RM2 being able to perform waste and debris recovery operations in accordance with the specification.

In September 2008, a significant milestone was met with active commissioning commencing following NII approval. During this early period, shielding weaknesses were identified, requiring a safety case modification, design, manufacture and installation within an active building. This was achieved in a matter or weeks, permitting active commissioning to resume.

To date, some 245 cans have been recovered, a significant achievement by the project and plant teams involved, especially since the machine was new and novel.

RM2 is a ‘mobile’ 240 tonne machine which comprises a large number of modules. Though it is described as mobile, it takes some three weeks of two-shift working to move from it array to array – each array containing some 200 waste cans.

It is designed to retrieve a total of 8,000 remote handled mild steel waste cans, which have been held in storage for up to 50 years. Once processed, the cans and debris are consigned to Harwell’s head end cells, where they are repackaged into 500 litre drums, and held in the vault store for final disposal. Work to retrieve all the cans is expected to take up to 10 years.

Active commissioning will continue during the coming financial year. “In that time we expect to increase the recovery rate in keeping with the plan from 245 to 436 cans and the PBI has been set accordingly,” explained waste complex manager, Gary Preston.

“Although we have experienced a number of problems with RM2, thanks to the commitment and resourcefulness of our staff – supported by the contractor, Assystem – we’ve been able to overcome these obstacles so recovery operations can continue.”

Other challenges faced by the team have included dealing with debris and water discovered in the tubes.

“A wet vacuum developed by project staff, along with suction equipment, enables the water to be recovered. This will be sampled and eventually directed to the Harwell Liquid Effluent Plant.”

For more information please contact: Angela Vincent, RSRL (Harwell) Communications Manager