Steve Vick Carries Out Pipe Sealing Operations At Harwell Bepo Site
November 1, 2014
Steve Vick International Ltd has recently completed a project for RSRL Harwell in conjunction with Aurora Health Physics. The project required SVI to design, test and install over 250 Foambags and Foam stoppers into the storage tubes of the BEPO storage block. Once installed and cured, mass void filling of the space behind the Foambags™ could take place.
The operations were undertaken to ensure that the future decommissioning of the BEPO storage facility could be carried out safely with no risk of radioactive contamination becoming airborne from the storage tubes. The concrete block surrounding the storage tubes is to be demolished so the risk of fracturing the tubes within its structure was deemed too high without first encapsulating any loose contamination.
RSRL Harwell first approached Steve Vick International about the use of their technology to tie down the contamination after initial investigations by Aurora Health Physics revealed higher levels of contamination than anticipated inside the storage tubes. SVI were asked to provide a proposal for the project which was to be one of the most technically challenging foaming operations SVI had attempted. An initial testing programme that took 8 weeks to complete was carried out by SVI technicians at their testing facility in Bath. The testing proved the concept and RSRL gave the go ahead to design, supply and install the Foambags™ and mass fill the storage tubes.
As Steve Vick International do not currently have their own Health Physics operatives, RSRL suggested that SVI should work alongside Aurora Health Physics whose extensive knowledge of the site and its facilities along with their initial characterisation of the storage block would prove invaluable.
An excellent working relationship between the three companies enabled the project to progress smoothly and any unexpected tube configurations or features within them could be overcome quickly so that the project was delivered on time and with zero incidents.
Bespoke Foambag™ Deployment
Due to the nature of the site, a Steve Vick Project Manager provided training for Aurora personnel so that they could carry out the Foambag™ installations within the containment tent. SVI Technicians remained in a non active area and supplied the foam injection through a manifold in the containment tent wall using a SVI Mix & Inject machine. The machine is capable of injecting large quantities of expanding PU foam over distances of up to 75m through umbilical lines. The technique was used on all of the BEPO storage tubes with great success. Communication was maintained throughout the operations via 2-way radio.
35 x 8000mm Tubes
The storage block also contained of 175 off 35 x 8000mm tubes that required sealing at both ends before foam filling could take place. Steve Vick International designed and supplied a kit that could be installed by Aurora operatives after a brief familiarisation with the technique. The kit consisted of a bespoke fabric Endcap, set quantity of expanding non porous foam and a reusable applicator gun and cartridge.
Each of the BEPO storage tubes were open ended and a system was required that could seal the open ends to prevent the void filling foam from spilling into the containment tent area. Steve Vick International engineers developed a Foambag™ system to form a plug at the open end of the tubes which once cured in place would provide an injection point for PU foam to fill the void behind the Foambag™ and a vent point to allow displaced air out of the tube and through a filter. The adhesion properties of the Foambag™ allowed SVI technicians to fill the void behind without the risk of foam entering the tent.
Commenting on the success of the project Jon Blackmore, RSRL, Senior Project Manager says “I have been really pleased with the work carried out by Steve Vick International in conjunction with Aurora Health Physics Services Ltd. From our initial discussions, through the trials and on to implementation, the approach has always been positive and helpful. The way that the various issues that came up during the implementation phase were addressed was great, with practical solutions developed, discussed amongst the project team, and then put into action with minimal fuss.”