Groundwater Monitoring at Sellafield NO MARKING REQUIRED Groundwater Monitoring at Sellafield Annual Data Review 2012 Date: 28th November 2013 15 November 2018 2 NO MARKING REQUIRED

Presenters Amy Stamper (Sellafield Ltd) NO MARKING REQUIRED Presenters Amy Stamper (Sellafield Ltd) Groundwater Technical Support for Land Quality Julian Cruickshank (Sellafield Ltd) Technical Lead Land Quality 15 November 2018 3 NO MARKING REQUIRED 3

Groundwater Monitoring NO MARKING REQUIRED Groundwater Monitoring The groundwater monitoring programme is a requirement of the Sellafield Ltd Environmental Permits covering radiological and non-radiological substances. The EA provide the requirements in the CEAR. The CEAR and Environmental Permits stipulate that an annual groundwater data review is produced. The focus of this review is to evaluate recent groundwater analytical data and to identify any significant year-on-year changes of groundwater quality. Approximately 1000 samples were collected from 176 locations. Analysis suites cover radiological/non-radiological determinants, and geochemical indicators. In addition water quality measurements also taken. Include following point in addition to wording on slides: Contam land & groundwater on SL site jointly regulated by EA & ONR Assessment of both rad/non rad data includes: why samples were late or not obtained required analysis was not undertaken detection limits were not achieved Water quality measurements undertaken to determine the nature of the groundwater and monitor changes over time 15 November 2018 4 NO MARKING REQUIRED

Average Total Alpha Activity 2012 NO MARKING REQUIRED Average Total Alpha Activity 2012 The review presents annual averages for both rad/non-rad data for a number of analytes Probably worth noting: Results presented are not depth specific (average concs of all data from all piezometers collected at that location) Colours used in this presentation slightly different to those presented in the report (to make clearer) Larger diameter points represent where average concentration have exceeded WHO guideline levels for safe drinking water. These guidelines are cited for reference only and do not reflect acceptable radionuclide levels in a regulatory context. Total Alpha (Left hand plot = site wide, right hand plot = point of interest) Results similar to last year- spatially & concentration Screening results for alpha-emitting rads indicate measured alpha concs in large majority of wells below the detection limit (0.03Bq/L) WHO exceeded in 3 wells (NW sep) At some locations- individual alpha-emitting rads contributing to total alpha activity have been made. Results show: U isotopes (specifically U234/238) dominate alpha activity across site 3 wells for U >WHO (same 3 as T.Alpha) Samples also analysed for Pu-239+240 & Am-241. Concs low & no samples exceeded WHO 15 November 2018 5 NO MARKING REQUIRED

Average Total Beta Activity 2012 Results similar to last year- spatially & conc Many wells >WHO: Majority in sep Small no outside sep (predominately south) 1 offsite> WHO In all cases- Sr90 predominant beta-emitting rad (same spatial pattern) Fewer samples for Sr90 exceeded WHO than total beta (mainly due to less stringent standard for this rad compared with the screening analysis for T.beta) Other beta-emitting rads are also analysed including: Cs-137, Pu-241, C-14, Cl-36, I-129- Plots in annual report for these Concentrations for these were low Results similar to last year- conc & spatially Few results exceeded WHO- those that did were in Sep

Average Tritium Activity 2012 NO MARKING REQUIRED Average Tritium Activity 2012 H3 & tc-99 are both relatively mobile nuclides in GW and are also monitored- on SL site Both similar to last year Tritium Highest H3 concs both within sep & SW direction towards coast Annual averages 6 wells >WHO 15 November 2018 7 NO MARKING REQUIRED

Average Technetium-99 Activity 2012 Detectable in low levels in many samples All annual averages below WHO Highest = between SW corer of sep main gate

Radiological Exceedances NO MARKING REQUIRED Radiological Exceedances Analytical results must be investigated and reported to the regulators when any result exceeds the mean plus 4 standard deviations of the previous 12 results There were 67 radiological exceedances during 2012, from a total of 4642 analysis results. The majority were likely due to statistical variation within the dataset. A large proportion of exceedances showing a trend of interest were to the south of Separation area. Investigations showed increases were likely associated with historical contamination rather than new sources. Just over 1% of total analysis (1.4%) 15 November 2018 9 NO MARKING REQUIRED

Non-radiological Data Review NO MARKING REQUIRED Non-radiological Data Review Complies with the requirements of the Environmental Permit, and is accomplished using same CEAR monitoring network. During the calendar year 2012, 4000 analytical results covering a suit of 24 non-radiological contaminants were generated. The average concentration and spatial distribution of non-radiological data showed a similar distribution to the 2011 dataset. Overall the distribution of pH values was similar to last year. There were 49 exceedances. Major ion data allow groundwater types to be determined. Monitoring non-radiological contaminants of concern complies with the requirements of the environmental permit, and is accomplished using same CEAR monitoring network. During the calendar year 2012, 4000 analytical results covering a suit of 24 chemo-toxic contaminants were generated. The average concentration and spatial distribution of non-radiological data showed a similar distribution to the 2011 dataset. This reflects limited changes in subsurface water quality. All hydrocarbon and organic contamination found to date are at very low levels and consistent with long term industrial use. The example provided here is for Total Petroleum Hydrocarbons (TPH). The majority of TPH values for 2012 were below the detection limit & there were only a few detectable TPH values at discrete locations. The highest detectable TPH (in well 6113) was determined to be from surface water runoff from the car park into the headwork’s (remedial actions completed to prevent this). Other TPH shown returned to below the detection limit after the detected results. Overall the distribution of pH values was similar to last year. With 69% between 6 & 7 (inline with natural waters) There were 49 exceedances. Down from last year large no considered anomalous (20)- just over 40% of total again…all exceedances were investigated- likely due to statistical variation rather than new contaminant sources There is now enough major ion data which has been used to allow for GW types to be classified, these are presented using stiff diagrams for each quarter within the annual report. As the dataset grows, this will be assessed over time to enable to site to better understand the nature, extent & degree of subsurface conditions. 15 November 2018 10 NO MARKING REQUIRED

NO MARKING REQUIRED Compliance Review An annual review of compliance against the approved CEAR. During 2012, 13 samples could not be collected 17 samples did not have the complete analysis suite carried out. Proposal of changes to the programme based on new results. Additional notes to make: In the compliance review reasons are provided: why samples were late or not obtained required analysis was not undertaken detection limits were not achieved The chart shows that: 13 samples could not be collected….. Just over 1% of total planned samples Improved since last year (56 samples couldn’t be collected) The main reason for this was piezometers that produced an insufficient water volume or a poor quality sample 17 not having required analysis: Main reason was high concentration of another radionuclide in the sample that interfered with the target radionuclide Chart shows compliance better this year. Proposal of changes each yr… Also considers years compliance issues and any changed site conditions for example- continuing to develop network- introducing new wells, decommissioning wells etc 15 November 2018 11 NO MARKING REQUIRED

2012 Groundwater Monitoring Summary NO MARKING REQUIRED 2012 Groundwater Monitoring Summary There has been no significant year-on-year change in the overall distribution concentrations in Sellafield groundwater. Nuclide concentrations from this year’s groundwater samples are similar to those reported in previous years. Current concentrations of nuclides in groundwater samples collected from offsite are below the WHO safe drinking water guidelines. http://www.sellafieldsites.com/land/ Look ahead; the Groundwater Programme BAT Assessment. Maps within this document are reproduced by permission of Ordnance Survey on behalf of the HMSO. (c) Crown copyright and database right 2011. All rights reserved. Ordnance Survey Licence number 100047376. (NDA - Sellafield Ltd.) 15 November 2018 12 NO MARKING REQUIRED