• Latest Version, 2024 Assessment
• 2018 assessment

Concentrations of radionuclides in the Celtic Sea and the Greater North Sea

Monitoring to determine radionuclide concentrations and to assess radiological risk to the marine environment has confirmed that doses received by people and wildlife continue to be well below the UK national and European regulatory limits and that the UK target has been achieved. 

Background

UK Target on Radionuclides  

This indicator is used to assess progress against the target set out in the Marine Strategy Part 1 (HM Government, 2012) which requires that concentrations of substances identified within relevant legislation and international obligations are below the concentrations at which adverse effects are likely to occur.   

Key pressures and impacts  

Radioactive materials have many applications from the generation of electricity (for example, Trawsfynydd Power Station as shown in Figure 1) to diagnostic tools in medicine. As a result, small quantities of radioactivity may be released into the environment as discharges, emissions and losses from nuclear licensed sites and from non-nuclear facilities such as medical establishments. In addition, from the non-nuclear sector, small quantities of naturally occurring radioactive material may be released into the environment as discharges from the offshore oil and gas industry. 

Figure 1. Trawsfynydd Nuclear Power Station (Crown Copyright; RIFE 27, 2022). 

Measures taken to address the impacts 

The main measures to protect people and wildlife is the regulation of radioactive waste under the Environmental Permitting (England and Wales) Regulations 2016 (EPR 16), (HM Government, 2016), Environmental Authorisations (Scotland) Regulations 2018 (Scottish Government, 2018) and under the Radioactive Substances (Modification of Enactments) Regulations (Northern Ireland) 2015 (Statutory Rules of Northern Ireland, 2018). Radioactive discharges are strictly controlled, generally discharge levels have reduced and a strategy is in place to further reduce discharge levels in the future.

Monitoring, assessment and regional cooperation

Areas that have been assessed: 

Assessments were  conducted at the scale of the UK-portion of the Greater North Sea (GNS) and Celtic Seas (CS) MSFD sub-Regions,  with emphasis on those seawaters receiving discharges from UK nuclear establishments, which are shown in Figure 2, with different symbols representing the different nuclear industries operating in the United Kingdom. Furthermore, a monitoring agreement has been identified using 15 OSPAR monitoring areas and the radionuclides and environmental compartments for which data are to be collected, as a basis for the reporting and evaluation of concentrations of radioactive substances in the OSPAR maritime area. These OSPAR monitoring areas are shown and listed in Figure 3 and includes how these compare to the main OSPAR marine areas. 

Figure 2 Licensed nuclear sites discharging radioactivity into the marine environment, from Radioactivity in Food and the Environment (RIFE), 2021 (RIFE 27) (Environment Agency, Food Standards Agency, Food Standards Scotland, Natural Resources Wales, Northern Ireland Environment Agency and Scottish Environment Protection Agency, 2022) 

Figure 3:  OSPAR monitoring areas identified for the establishment of baselines on concentrations of radioactive substances 

Monitoring and assessment methods: 

Each year, marine environmental samples (including water, sediment, and biota) are collected routinely from UK seas around the nuclear licensed sites, which are presented in Figure 2, including from those locations required for the OSPAR purposes. The results of annual monitoring programmes are used to assess the radiological risk and to check whether doses are well below the UK national regulatory limit (annual limit of 1 mSv, for members of the public). 

The types of sample species and radionuclides for monitoring are selected, by the responsible UK environmental agencies, on the basis of a risk-based review in 2012 (Food Standards Agency, 2012) and previous radiological monitoring surveys.  The environmental samples are collected according to annual schedules and analysed to the standards of formally accredited methods (International Organisation for Standards, 2017). 

Assessment thresholds: 

The International Commission on Radiological Protection (ICRP) provides guidance on assessing radiological dose to the public. These dose standards are embodied in UK national policy on radioactive waste. The radionuclide concentrations are compared with UK regulatory limits of dose. 

Regional cooperation:  

The UK played a leading role in preparing the OSPAR Fifth Periodic Evaluation of Radioactive Substances which evaluates progress made on reducing discharges from the nuclear and non-nuclear sectors alongside an assessment of environmental concentrations.  

Further information

Most recent Radioactivity in Food and the Environment (RIFE) report (provides background for Figures 1 to 5, inclusive): 

https://webarchive.nationalarchives.gov.uk/ukgwa/20231023170654mp_/https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1114928/RIFE-27-Radioactivity-in-food-and-the-environment-2021.pdf 

OSPAR Radioactive Substances (RAS) 3rd periodic evaluation: 

http://www.ospar.org/documents?v=7135  

OSPAR RAS 4th periodic evaluation:  

http://www.ospar.org/documents?v=35337 

OSPAR RAS 5th periodic evaluation (provides background for Figure 2):  

https://oap.ospar.org/en/ospar-assessments/quality-status-reports/qsr-2023/other-assessments/5pe/#3-environmental-concentrations-in-the-north-east-atlantic  

Assessment method

Radiological monitoring and assessment are supported by discharge and trend observations and analyses of specific radionuclides and species at locations (with specific associated issues). Most are detailed in the RIFE report series.   

Results

Results and assessment of progress:  

Findings from the 2012 UK Initial Assessment pointed out that doses of radioactivity received by people and wildlife continue to be well within regulatory limits. 

Latest findings:   

Radiological monitoring and assessment are supported by discharge and trend observations and analyses of specific radionuclides and species at locations (with specific associated issues). 

Status assessment:     

Radiological assessments confirm that doses received by people and wildlife continue to be well below the UK national regulatory limit.  

Trend assessment: 

Concentrations of radionuclides in seafood (fish and shellfish) have generally shown a downward trend or have continued to decline.  

Regarding specific radionuclides, environmental concentrations of 99Tc have generally decreased in fish and shellfish (the triangle, diamond and square series in Figure 4 for fish, lobsters and winkles, respectively) over the period 2010 to 2021 (please note that the values for winkle and plaice have been multiplied to the same magnitude as the lobster data). This is in response to declining discharges at Sellafield (the vertical bars in Figure 4) over the same period. 

Figure 4 Technetium-99 liquid discharge from Sellafield and concentrations in plaice, lobsters and winkles near Sellafield, 2010 to 2021 (RIFE 27, 2022). 

²¹⁰Po in seafood around Whitehaven have decreased and levels in crustacean are continuing to be within or close to the expected range of natural sources. The largest contribution to dose to seafood consumers is from ²¹⁰Po, but these doses remain well within regulatory limits, as shown in the Sellafield bar plot, which is shown as plot “V” on Figure 5 (the other plots on the figure show the generally decreasing doses around UK nuclear licensed sites).  Numerical data for these plots are available in Table 1.3 of RIFE 27 and in Table 1 of this assessment. 

²²⁶Ra, ²²⁸Ra and ²¹⁰Pb discharged from the offshore oil and gas industry fell by about 25% (2000-2006) and continue to reduce in line with declining production.  

Figure 5. ‘Total doses’ around the UK’s nuclear sites due to radioactive waste discharges and direct radiation (2010 to 2021). All doses are well below UK regulatory limits (RIFE 27, 2022). 

Table 1. Trends in 'total doses' (mSv) from all sources (RIFE 27, 2022) 

Site	2010	2011	2012	2013	2014	2015
Aldermaston and Burghfield	<0.005	<0.005	<0.005	<0.005	<0.005	<0.005
Amersham	0.22	0.22	0.22	0.22	0.14	0.14
Barrowa			0.057	0.076	0.055	0.051
Berkeley and Oldbury	0.011	0.006	0.014	0.010	<0.005	<0.005
Bradwell	0.13	0.048	<0.005	<0.005	<0.005	0.017
Capenhurst	0.26	0.095	0.085	0.080	0.17	0.13
Chapelcross	0.029	0.037	0.011	0.024	0.014	0.022
Derby	<0.005	<0.005	<0.005	<0.005	<0.005	<0.005
Devonport	<0.005	<0.005	<0.005	<0.005	<0.005	<0.005
Dounreay	0.047	0.018	0.017	0.012	0.012	0.010
Dungeness	0.022	0.021	0.015	0.021	0.021	0.014
Faslane	<0.005	<0.005	<0.005	<0.005	<0.005	<0.005
Hartlepool	0.025	0.025	0.015	0.024	0.027	0.022
Harwell	0.018	0.017	0.018	0.010	0.016	0.017
Heysham	0.057	0.025	0.025	0.028	0.023	0.023
Hinkley Point	0.014	0.014	0.013	0.022	0.022	0.016
Hunterston	0.067	0.050	0.032	0.021	0.021	0.025
LLWR near Driggb	0.18	0.18	0.30	0.061	0.22	0.42
Rosyth	<0.005	<0.005	<0.005	<0.005	<0.005	0.006
Sellafieldb	0.18	0.18	0.30	0.076c	0.22	0.42
Sizewell	0.020	0.021	0.021	0.021	0.020	0.021
Springfields	0.17	0.13	0.068	0.060	0.050	0.050
Torness	0.025	0.020	0.020	0.020	0.020	0.020
Trawsfynydd	0.028	0.012	0.025	0.017	0.013	0.014
Whitehavenb	0.18	0.18	0.30	0.061	0.22	0.42
Winfrith	<0.005	<0.005	<0.005	<0.005	<0.005	0.014
Wylfa	0.007	0.008	0.006	<0.005	0.007	0.013

Radioactive fragments continue to be detected and removed from Sellafield and Dounreay beaches. Both beaches remain open and there is no risk to beach users. Part of the beach at Dalgety Bay is closed and, as a protection measure, shellfish harvesting has been banned.  The overall health risks at Sellafield to beach users from fragments are very low. Monitoring programmes continue to locate and retrieve fragments from the foreshores. Environmental concentrations were predicted using models to assess the dose rates to reference organisms for authorised discharge.  All but two of the habitat sites were less than an agreed threshold of 40 μGy h-1, with habitat assessments indicating the environment has or could be adversely impacted in these two habitat sites. 

Conclusions

Continuation of monitoring programmes, reported in the annual publication of Radioactivity in Food and the Environment (RIFE) series, confirm that radioactivity levels in UK waters currently pose no risk of harm to humans or wildlife.   

References

Radioactivity in Food and the Environment (RIFE) Report Series: 

https://www.gov.uk/government/publications/radioactivity-in-food-and-the-environment-rife-reports  

RIFE 27, 2022: 

https://webarchive.nationalarchives.gov.uk/ukgwa/20231013184744mp_/https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1114928/RIFE-27-Radioactivity-in-food-and-the-environment-2021.pdf 

 

OSPAR Radioactive Substances (RAS) 3rd periodic evaluation: 

http://www.ospar.org/documents?v=7135  

 

OSPAR RAS 4th periodic evaluation:  

http://www.ospar.org/documents?v=35337  

 

OSPAR RAS 5th periodic evaluation (provides background for Figure 3):  

https://oap.ospar.org/en/ospar-assessments/quality-status-reports/qsr-2023/other-assessments/5pe/#3-environmental-concentrations-in-the-north-east-atlantic  

Authors

Alastair Dewar¹ 

Centre for the Environment, Fisheries and Aquaculture Science 

Assessment metadata

Assessment Type	UK Marine Strategy
	UK_CSSEG_D8_contaminants
	Radionuclides
Point of contact email	marinestrategy@defra.gov.uk
Metadata date	Monday, April 1, 2024
Title	Radionuclides
Resource abstract
Linkage	Radioactivity in Food and the Environment (RIFE) Report Series (at https://www.gov.uk/government/publications/radioactivity-in-food-and-the-environment-rife-reports)
Conditions applying to access and use	© Crown copyright, licenced under the Open Government Licence (OGL).
Assessment Lineage
Dataset metadata
Dataset DOI	See RIFE-27 report (2022).  https://webarchive.nationalarchives.gov.uk/ukgwa/20231013184744mp_/https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1114928/RIFE-27-Radioactivity-in-food-and-the-environment-2021.pdf

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