Artificial radionuclides in the Irish Sea from Sellafield -Increasing levels in Northern Ireland and Scotland

Carlingford Lough
Loch Cairlinn
Carlinford / Cairlinfurd Loch (Wiki)

Garlieston

Garlieston Port http://ports.org.uk/viewimages.asp?ID=340

….At Garlieston there was an increase in concentrations in mud from 1985 -1997, and at Carlingford in Northern Ireland the concentration of Am-241 in mud appears to be increasing still. This effect of the spread of activity away from Sellafield may continue, at least in the near future…..

Issue 2 (June 2013)

Received 9 May 2012, accepted for publication 19 December 2012, in final form 23 October 2012

Published 13 March 2013

G.J. Hunt, K.S. Leonard* and L M. Hughes*

The concentrations of Cs-137, tritium, Tc-99, Pu-239+240 and Am-241 in representative materials from the Irish Sea were investigated with reference to continuing remobilisation from sediments. Long time series of monitoring data since the 1960s were employed.

Cs-137 in sea water and fish show peaks in concentrations normalised to discharge rate (NACs) from 1985-1989. This is consistent with the time needed for dispersion in sea water following the preceding reductions in discharges; continuing enhancements of NACs above pre-1970s levels follow, consistent with the effect of activity remobilised from sediment. It is estimated that about 300 TBq of Cs-137 were remobilised from the immediate tidal area around Sellafield from 1989-2009. The enhancements in concentrations continue to this day, with the effect of remobilisation at present being ~6 TBq y^-1, approximately doubling the effect of direct discharges. To provide an indication for the future, the rate of Cs-137 remobilisation is decreasing with a half-time of ~6 years.

Data for tritium and Tc-99 were examined in view of the interest in these radionuclides. Concentrations broadly reflect the levels of discharges and the need for dispersion. As expected, there is no evidence of sustained remobilisation of tritium, due to its mobility (or low K_d). The same lack of evidence was found to apply for Tc-99 despite known sorption of a small proportion of the discharged activity by Irish Sea sediments.

Pu-239+240, by contrast, shows much evidence of the effect of remobilisation; concentrations in sea water near Sellafield have reduced much slower than the discharges. At Southerness, ~50 km away, there was no significant reduction in sea water concentrations from 1985-1996, and winkles showed an increase then decrease in concentrations over this period, consistent with a spreading of activity. This effect was replicated in mud at Garlieston, ~70 km from Sellafield.

For Am-241, the rate of grow-in from Pu-241 has dominated direct discharges since the late 1970s. Grow-in continues today in the Irish Sea at the rate of ~8 TBq y^-1, ~200 times the rate of direct discharge. Winkles at Southerness show evidence of a spreading effect of Am-241, with an increase then decrease from 1985-1996.

map showing location of Garlieston, Dumfries and Galloway At Garlieston there was an increase in concentrations in mud from 1985 -1997, and at Carlingford in Northern Ireland the concentration of Am-241 in mud appears to be increasing still. This effect of the spread of activity away from Sellafield may continue, at least in the near future.

Reference:

G.J. Hunt, K.S. Leonard* and L M. Hughes* (2013) Artificial radionuclides in the Irish Sea from Sellafield: remobilisation revisited. Journal of Radiological Protection 33 (2) p261

http://www.cefas.defra.gov.uk/publications-and-data/publication-abstract.aspx?abstract=6753

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More contamination in Scotland here..

Clean up radioactive contamination at beach, Gordon Brown tells MoD

Former PM demands ministry should take responsibility for using Dalgety Bay in Fife as a landfill site after second world war

guardian.co.uk, Tuesday 9 July 2013

Gordon Brown is to lead a Commons debate to demand MoD ‘owns up’ its role in radioactive contamination at Dalgety Bay in Fife, Scotland. Photograph: Joel Ryan/AP

Former prime minister Gordon Brown is demanding the Ministry of Defence “owns up” and takes responsibility for radioactive contamination at a beach.

Brown will lead a Commons debate on Tuesday, highlighting a letter which he says proves the ministry had already accepted blame.

The memo shows the MoD was willing to take action as early as 1990 for contamination at Dalgety Bay in Fife.

Brown, who is the MP for the area, said: “This letter shows that the ministry must now own up, clean up, pay up and hurry up.

“The MoD must undo the damage done by months of vacillation, half-truths and outright denials that sadden me and undermine the credibility of its position on radiation contamination across former MoD sites in the UK.

“In 1990, the ministry was prepared to accept their responsibility. It is arrogant beyond advice and dogmatic beyond belief for the MoD to refuse to accept responsibility now. This is a damning indictment of the MoD.”

Contamination is thought to stem from residue of radium-coated instrument panels used on military aircraft which were incinerated and put in landfill in the bay area at the end of the second world war.

The letter, exchanged between the MoD and Scotland Office minister Lord James Douglas Hamilton, states that about 800 aircraft, containing radium-coated equipment, were scrapped in the area.

“This information, together with the nature of the contaminated debris which has been found, leaves little doubt as to the origins of the contamination and it is likely that there is more material buried in the area inland from the beach,” the letter states.

It continues: “MoD appear to have experience dealing with similar problems and I am glad to report that they seem willing to help both with further monitoring and with any remedial action which may be necessary.”

Last week, the Scottish Environment Protection Agency concluded the MoD deposited a large amount of ash and clinker on the coast before the town of Dalgety Bay was developed. It said significant amounts of material remain buried on the coast and continue to erode and re-contaminate the area.

But the MoD said it has concerns over the “adequacy and validity” of Sepa’s approach to the report.

Brown fears Sepa will have to declare Dalgety Bay a radiation-contaminated area, the first such site in the UK.

“It would be extraordinary that in a Britain that has nuclear storage sites, nuclear processing sites, nuclear weapons and nuclear waste, the beautiful beach at Dalgety Bay would stand out as the first and only radiation-contaminated site in the country,” he said.

“No one wants a radiation-contaminated beach on their doorstep and it is time for the MoD to accept they are the polluter of Dalgety Bay.”

Responding to Sepa’s findings last week, a spokesman said: “MoD will consider the report findings in detail and respond to Sepa in due course, but has concerns over … risk assessment and its [Sepa’s] approach to the report. MoD has demonstrated a serious commitment to voluntarily assisting Sepa, the Scottish government and the Dalgety Bay Forum in dealing with the situation at Dalgety Bay.

“The department continues to work with Sepa to identify the likelihood and scale of the residual risks and the requirement for remedial action. MoD continues to fund, at its own cost, monitoring arrangements at Dalgety Bay in line with previous commitments.”