British Nuclear Group (BNG) has announced that the project to remove three redundant discharge pipelines from the Irish Sea has been completed with a total of 5702 metres of pipeline removed. The two original 10-inch steel pipelines, laid down in 1949, and a plastic pipeline which was installed in the early 1990’s, stretched some 2 km into the Irish Sea where they terminated at a diffuser marked by a buoy. Materials discharged via these sea lines, at an estimated rate of two million gallons per day, included reprocessing discharges, rainwater and other site waters.
The success claimed by BNG in completing the removal project is somewhat tarnished by finishing over 6 years late, significantly over budget and with a number of mishaps along the way. The original application to Copeland Borough Council by British Nuclear Fuels (BNFL) to remove the pipelines was made in 1989. A condition attached to the planning consent granted by the local authority was that the pipelines must be removed by 1999. This end-date was put back several times at BNFL’s request– initially to the end of 2002 and then to December 2003 when BNFL ‘confidently expected’ the work to be completed. Despite some initial work on the two steel pipelines in the early 1990’s, the bulk of the Irish Sea pipeline system remained in situ until August 2003 when removal work on the remaining sections began in earnest – dismantling the plastic pipeline to ‘prove the system’ prior to tackling the more contaminated steel pipelines.
The removal project involved the underwater cutting of the pipelines by divers, with the cut sections (capped to prevent the escape of contaminated materials) loaded into custom built cages anchored to the sea-bed. Once full, the loaded cages were transferred to licensed transport containers which were then transported to Workington Docks and from there by rail to the Low Level Waste dump at Drigg.
Shortly after commencing work in 2003, the programme was suspended for several months when over 170 cut sections of the plastic pipeline broke free of their sea-bed cage in rough weather. Whilst most found their way onto local West Cumbrian beaches others dispersed to N.Ireland and to beaches on the Isle of Man where levels of radioactivity ‘above background’ were found. Further delays to the project resulted from extended bad weather which saw the projected costs (£13M) escalate as project teams and equipment were kept on stand-by for long periods.
Project teams included AMEC NNC and specialist firm Land & Marine whose divers helped raise the stricken Russian submarine Kursk.
Sellafield, now under the ownership of the Nuclear Decommissioning Authority (NDA) continues to discharge reprocessing and other waste liquids into the Irish Sea on a daily basis via newer pipelines installed in 1975 and the early 1990’s.