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Sellafield Food Monitoring 2012

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Presentation on theme: "Sellafield Food Monitoring 2012"— Presentation transcript:

1 Sellafield Food Monitoring 2012
November Sellafield EHSC Sellafield Food Monitoring 2012 Dr Alastair Dewar Cefas (Lowestoft) This presentation describes Sellafield monitoring in under the responsibility of FSA – In Monitoring associated with terrestrial food carried out by AHVLA in Weybridge and marine food by Cefas in Lowestoft Cefas Environment & Ecosystems (Lowestoft and Whitehaven)

2 Consultation Announcement
November Sellafield EHSC Food Standards Agency Consultation Announcement The FSA has completed a consultation on their programme of monitoring for radioactivity in food. The FSA’s chosen option is for an optimised programme which is risk based and in line with current international best practice and guidance. This will enable the FSA to continue to meet the UK’s legal and international obligations relating to radioactivity in food and protect the safety of the food-chain. For further information, please contact: Chris Thomas Tel: Last year announced that FSA were launching a consultation on their programme of monitoring for radioactivity in food. The FSA’s chosen option will be for an optimised programme which is risk based and in line with current international best practice and guidance. This will enable the FSA to continue to meet the UK’s legal and international obligations relating to radioactivity in food and protect the safety of the food-chain.

3 November 2013 Sellafield EHSC
Updates in RIFE 18 More detail on ‘representative person’ in Summary and Section 1 e.g. Summary , Page 10 New Sellafield and Springfields trend data - Fig & 2.4 More detail on ‘representative person’ given in Summary and Section 1 - as requested by EHSC (last Nov) Two new figures showing trend data for Sellafield and Springfields Sell - Cs-137 in brown trout The Cs-137 concentration in brown trout was 37 Bq kg-1 in 2012 and significantly lower than those in 2011 and 2009 (360 Bq kg-1 and 300 Bq kg-1, respectively), but similar to that in 2010 (33 Bq kg-1). Additional enhanced activity concentrations in fish were also detected periodically in earlier decades. The changes in concentrations were likely to be due the combined effects of Sellafield discharges and fallout from Chernobyl, accentuated by the movement of such fish in the Calder river system. Spring - gas/liquid discharges and monitoring results -Cs-137, Np-237, Tc-99, Total U, Th-234 (similar to 5 year report) Figure 2.4 shows the trends over time (2004 – 2012) of uranium discharges and total uranium radionuclide concentrations in food (cabbage). Over the period, concentrations of uranium were also found in soil around the site, but the isotopic ratio showed that they were naturally-occurring. Total uranium was detected in cabbage samples during the period (no data in 2006), but the concentrations were very low. The apparent peak of uranium in cabbage in 2007 was also low and significantly less than that found in soil samples.

4 Sellafield Habits Surveys
November Sellafield EHSC Sellafield Habits Surveys Latest 1 Year Review (Aquatic - FSA/EA/ONR August (other updated habits information, Sellafield, LLWR, Springfields, Barrow, Dumfries and Galloway, Hunterston) 2012 Shellfish consumption and intertidal occupancy review In 2012, a full habits survey was conducted in the vicinity of the Low Level Waste Repository (LLWR), - approximately 5 km to the south-east of the Sellafield site. Due to the close proximity of these sites, the aquatic survey areas are the same, and therefore, the data obtained for aquatic pathways during the 2012 LLWR survey have been used in this 2012 Sellafield review report. Data for the following aquatic pathways were obtained: the consumption of fish, crustaceans, molluscs, wildfowl and salt marsh grazed sheep meat; intertidal occupancy; handling of fishing gear and sediment. Parton in North to Tarn Bay in south including Drigg – included all intertidal areas and extended 11 km off shore

5 Sellafield Habits Surveys 2003 - 2012
November 2013 Sellafield EHSC Sellafield Habits Surveys Consumption rates (kg y-1), Adult (high-rate groups), 2003 – 212 In the 2012, annual survey, changes were found in the amounts and mixes of species consumed (Papworth et al., 2013). The consumption rates decreased for molluscs and fish, whilst total crustacean consumption and occupancy rates over sediments increased in 2012, by small amounts.

6 Sellafield Total Doses 2012
November 2013 Sellafield EHSC Sellafield Total Doses 2012 Total Dose (all major sources) mSv (0.18 mSv in 2011) Most exposed age group: adults - mollusc consumers (adult marine plants /algae at high rates in 2011) Contributors: mSv seafood/external (nuclear industry discharges) (0.068 mSv, 2011) (revision in the amount of mollusc consumption of most exposed people) 0.22 mSv seafood (historic Whitehaven discharges) (0.11 mSv in 2011) (increase in Po-210 in locally caught crustaceans & consumption rates) Total Dose (gaseous/direct) mSv (0.010 mSv in 2011) Most exposed age group; infants (1y) - root vegetables at high-rates Total Dose (liquid) mSv (0.18 mSv in 2011) Most exposed age group; adults - molluscan shellfish at high-rates In 2012, the highest total dose was assessed to have been 0.30 mSv, or 30 % of dose limit to members of the public (Table 2.18). The most exposed age group was adults, who were high-rate consumers of molluscan shellfish (also as 2010). This represents a change in the people representative of those most exposed, from high-rate consumers of locally harvested marine plants in 2011, and a significant increase from the total dose of 0.18 mSv in This was mostly attributable to an increase in concentrations of Po-210 in locally caught crustaceans and from the higher rates consumed (from the revision of habits information) by the people representative of those most exposed in 2012, compared to those in 2011. The contribution to the total dose of mSv in from artificial radionuclides (including external radiation) was higher than in 2011 (0.068 mSv). The increase in the contribution to the total dose from 2011 was mostly due to the revision in the amount of mollusc consumption (from the revision of habits information) of the most exposed people. In 2012, the dose to people receiving the highest total dose from the pathways predominantly relating to gaseous discharges and direct radiation was mSv (Table 2.18) and unchanged from 2011 (values rounded to two significant figures). The most exposed age group were infants (1y) who were high-rate consumers of root vegetables. This represents a change in the people representative of those most exposed, from high-rate consumers of milk in 2011. The people receiving the highest total dose from the pathways predominantly relating to liquid discharges are the same as those giving the maximum total dose for all sources and pathways. For 2012, those sites where the public received the highest doses were Amersham and Sellafield with doses of 0.22 and 0.30 mSv, respectively. The dose received near Amersham was dominated by direct radiation from sources on the site. In comparison, the highest doses in 2011 were Amersham, Sellafield and Springfields. The decrease in the ranking of the Springfields site was established following a detailed survey of exposure pathways in 2012. Highest total doses were Sellafield & Amersham, with doses of 0.30 and 0.22 mSv, respectively.

7 Sellafield - Contributions to total doses 2003 – 2012
November 2013 Sellafield EHSC Sellafield - Contributions to total doses 2003 – 2012 All sources 2011 Most important pathway fish 55 % crustaceans 24 % sediments 12 % molluscs 9 % radionuclides : Po % Am % Pu-239/ % 2012 Most important pathway crustaceans 63% fish 19 % molluscs 13 % sediments 5% radionuclides : Po % Am-241 9% Pb-210 6% Pu-239/240 4% In %s, the most significant contributors to the total dose in 2012 were from consumption of crustaceans, fish, molluscs and from external exposure over sediments (63, 19, 13 and 5 per cent, respectively), The most important radionuclides were polonium-210, americium-241, lead-210 and plutonium (65, 9, 6 and 4 per cent, respectively). In 2012, the contributing radionuclides from artificial radionuclides were mostly americium-241 (33 per cent) and to a lesser extent plutonium (15 per cent) and iodine-129 (14 per cent). The contribution from external exposure was 19 per cent (32 per cent in 2011). Overall trend - The larger step changes (from 2004 to 2005 and from to 2009) due to variations in naturally-occurring radionuclides (mainly polonium-210 and lead-210). The changes in the intervening years (from 2005 to 2007) were mainly a result of changes in seafood consumption rates. The decrease in 2010 was due to both reductions in naturally-occurring radionuclides concentrations (polonium-210) and consumption rates, whilst the variation in the radionuclide contributors in 2011 (from previous years) resulted from a change in the people representative of those most exposed (from consumers of molluscan shellfish to locally harvested marine plants). The largest proportion of the total dose, up till 2008 and again in 2011 and 2012, was mostly due to enhanced naturally-occurring radionuclides from the historical discharges at Whitehaven and a smaller contribution from the historical discharges from Sellafield. From 2008 to 2010, the net result of progressive reductions of the naturally-occurring radionuclides contribution to the total dose has been a relative increase in the proportion from artificial radionuclides. In 2012, the artificial radionuclides giving the largest contribution to the total dose were Am-241, Pu and I-129. Recent and current discharges of technetium-99 contributed approximately 1 per cent of the dose (from artificial radionuclides and external exposure), whilst I-129 contributed approximately 14 per cent, to the Sellafield seafood consumers in 2012.

8 Sellafield - Contributions to total doses 2003 – 2012
November 2013 Sellafield EHSC Sellafield - Contributions to total doses 2003 – 2012 Gaseous and direct radiation sources Contributors: Consumption : milk 82% Potatoes 10 % Most important radionuclides : Sr-90 33% Co-60 17% Cs % Ru % Contributors: Consumption : domestic fruit 30% root vegetables 28% potatoes 27% other domestic vegetables 11% Most important radionuclides : Ru % Sr-90 19% The most exposed age group - were infants (1y) -who were high-rate consumers of root vegetables. This represents a change in the people representative of those most exposed, from high-rate consumers of milk in 2011. The most significant contributors in 2012 to the total dose for children were from the consumption of domestic fruit, root vegetables, potatoes and other domestic vegetables (30, 28, 27 and 11 %, respectively), the most important radionuclides were Ru-106 and Sr-90 (64 and 19 %, respectively). Other age groups received less exposure than the 1 year-old children total dose of mSv in 2012 (adult: 0.007; 10y: 0.008; prenatal: <0.005). Up until 2007, the total dose was reducing each year because of the permanent shut down of Calder Hall Power Station on the Sellafield site which ended gaseous discharges of Ar-41 and S-35. In 2008, the assessment method included Co-60 results (below LoD) because detectable activity was observed in other samples from the terrestrial environment. This increased the total dose over previous years. The relative increase and the change in the radionuclide contributors in 2009 (and not observed thereafter) resulted from the increase of total caesium in game and the change of the age group representative of the most exposed. In 2012, the variation in contributions to the highest total dose was due to a change in the people representative of those most exposed.

9 Sellafield Terrestrial Monitoring 2012
November Sellafield EHSC Sellafield Terrestrial Monitoring 2012 Milk collected from ~ 17 local farms on a weekly basis and bulked into weekly, monthly or quarterly samples & Non-milk (animals and crops) Gaseous discharges in 2012 were generally similar to 2011 (decrease in Sb-125, Kr-85 and I-129) Low concentrations and similar to previous years Time trends: C-14 relatively constant ; Cs-137 and Sr-90 decreasing; Actinides much lower than sea-foods Revision to permit (June 2012) including a rationalisation of gaseous discharges - Ru-106 & Radon-222 limits revised As above (bullets 1 - 3) Bullet 4 -Trends Discharge bar chart (Right hand scale TBq - units not shown) Maximum concentrations in milk Over the whole period, concentrations of C-14 were relatively constant, Cs137 concentrations (and Sr-90 to a lesser extent) were declining overall. Gaseous Discharges, Radionuclides in milk,

10 Sellafield Marine Monitoring 2012
November Sellafield EHSC Sellafield Marine Monitoring 2012 ~ 300 samples covering seasons, commercial and ‘wild food’ species - determination of broad range of nuclides Liquid discharges; generally similar to 2011 (tritium, C-14, Cs-137, Am-241, Cm & I-129 slightly lower in 2012) Concentrations generally similar to those in 2011 Plutonium radionuclides and Am-241 generally similar in shellfish Revision to permit (June 2012) - Ru-106 revised As above

11 Carbon-14 in fish/shellfish
November Sellafield EHSC Time Trends (2003 – 2012) Carbon-14 in fish/shellfish General for following graphs - Discharge bar chart (Right hand scale TBq - units not shown - Lines activity concs in crust, mol and fish. 10 years trend - Overall discharge variation reflects quantity of MAGNOX reprocessing Discharge in decrease in discharge compared to 2011 Food conc in similar trend as in previous years - slight increase in lobsters and winkles after lag time from 2011

12 Cobalt-60 in fish/shellfish
November 2013 Sellafield EHSC Time Trends (2003 – 2012) Cobalt-60 in fish/shellfish Reductions in discharge in recent years – decrease in relatively low as in recent years in winkles/lobsters – place already very low x 100 reported

13 Technetium-99 in fish/shellfish
November 2013 Sellafield EHSC Time Trends (2003 – 2012) Technetium-99 in fish/shellfish Tc-99 discharges met the 2006 target for the UK national discharges strategy Continued low Tc-99 discharges form much earlier years – still relatively low concs over last 3 years, with minor varaitions

14 Caesium-137 in fish/shellfish
November 2013 Sellafield EHSC Time Trends (2003 – 2012) Caesium-137 in fish/shellfish Generally declining from beginning of period, 90% estimated from remobilisation from sediments – more mobile element - environmental variability but slight increase in Cs-137 in winkles in 2012

15 Plutonium-239+240 in fish/shellfish
November Sellafield EHSC Time Trends (2002 – 2011) Plutonium in fish/shellfish Fish + Crustacean generally stable whole period slightly elevated level in lobsters in 2007 (scatter 100x). Smaller over increases in discharges recent (4) years – lobsters in 2012 (scatter 100x) slightly higher than 2011

16 Americium-241 in fish/shellfish
November Sellafield EHSC Time Trends (2003 – 2012) Americium-241 in fish/shellfish No clear trend within inevitable data scatter Generally stable, within reasonable scatter with time – remobilisation major contributor – small in-growth from Pu-241 – lobsters in 2012 (scatter 100x) slightly higher than same trend as Pu

17 November 2013 Sellafield EHSC
Food Standards Agency Internet site For further information including: RIFE Report 2012 (plus CD supplement) Food Standards Agency’s provisional monitoring results for 2013 The advert If you would like to express any views please

18 Thanks for the invitation,
November 2013 Sellafield EHSC Thanks for the invitation, And your attention For further information for Cefas reports


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