Annual Report for 2010/11 and Forward Programme - Sellafield Ltd

SSEM/2011/4730 June 2011Work commenced following a start-up meeting between SL and the contractors in February2010, with early focus concentrating on delivery of tasks 1, 3 & 6, with delivery of tasks 2, 4 &5 scheduled for later in the programme.Unfortunately and unexpectedly, WSC went out of business during the summer of 2010,resulting in the collapse of the hydrodynamic modelling contract, presenting SL with anumber of problems, both in relation to delivery of the above; and other work for the site thatwas reliant on the services of WSC.This contract had been in place for approximately six months when WSC went intoadministration, meaning that work had started on all of the tasks. At that time task 6 hadbeen completed by WSC; and tasks 1 & 3 were well underway with Cefas. Cefas had alsostarted some of the evaluation work to deliver task 5. Tasks 2 and 4 were to be deliveredthrough collaborative effort between WSC and Cefas and were in the early preparatorystages, being reliant on output from the other tasks to be completed.A major part of the work to improve the modelling was the gathering of new field data, inparticular the deployment of equipment onto the seabed to measure bed shear stress as partof task 3. In June 2010 an Aquadopp current profiler was deployed onto the seabed close tothe end of the existing sea pipeline diffusers. The plan was for a total deployment period ofapproximately six months. With a typical operating battery life lasting between 60 and 90days, the total deployment would be achieved by replacing the Aquadopp every 2 months(weather permitting). At the time of WSC folding, Cefas had the first Aquadopp in the watercollecting data and the timeframe for the first service/replacement visit was approaching.Without a contract in place there was a real risk that the Aquadopp work would not becompleted and a number of reports under preparation for other tasks would not be issued.The contract in place for the work was between SL and WSC; and due to the collaborativeelements of the contract, it was not legitimate on commercial grounds to re-award or transferthe remainder of the total contract directly to Cefas. However, the fact that equipment(Aquadopp and frame) had already been deployed and reports for other tasks were alreadybeing prepared by Cefas, meant that a limited contract was considered to be legitimate,allowing the ‘Cefas-only’ elements of the contract, that were already underway, to becompleted.Inevitably the need to prepare and issue a new contract did introduce delays for receipt offinal reports, against the original schedule, and has led to a re-think on the approach beingtaken for offshore monitoring. That said, the progress made against the completed tasks ofthe contract is reported below. Due to the collapse of the contract with WSC no progress isreported against tasks 2, 4 and 5. Discussion on the impacts of the failure to deliver thiswork can be found in Section 7.3 setting out the forward programme for offshorecharacterisation and monitoring.3.3.2 Progress on analysis and interpretation of existing swath bathymetry dataIn the 2010 update report, SL reported the initial findings from the Cefas analysis andinterpretation of the existing swath bathymetry data (see Figure 3.32), indicating that the datadid not fully satisfy the requirements of the transport and dispersion modelling work.In December 2010, Cefas were able to provide the finalised report on the swath bathymetrydata review; and provided the following conclusions:© Nuclear Decommissioning Authority 2011. 65