radioactive contamination eh perspective wendy ......2016/06/04 · fareham borough council tips...
TRANSCRIPT
Fareham Borough Council
Radioactive Contamination
EH perspective
Wendy Shakespeare
Contaminated Land Officer
Fareham Borough Council
• Fareham Borough Council experiences
• HMS Daedalus
• Similarities & Differences with other con land investigations
• Quick look at RCLEA
• Development – Tips to make development run more smoothly
• Watchpoints
Overview
Fareham Borough Council
• Many military and ex-military sites
• 2011 MOD released a list of 15 radioactive contaminated
sites in UK
HMS Daedalus
DARA Gosport
Guardian (2011) http://www.theguardian.com/environment/2011/dec/20/mod-radioactive-world-war-two
Fareham Borough Council Experiences
Fareham Borough Council
• 1917 RNAS Lee on Solent
• Significant role during 1st
and 2nd World Wars
• Decommissioned 1996
• Purchased by public sector
1996
• 2012 Enterprise Zone
HMS Daedalus
Fareham Borough Council
• 2011 Outline planning application for retail, employments,
residential, community use, hotel, clubhouse, allotments,
public open space and landscaping –Approved
• 2011-present – numerous individual applications under the
outline
HMS Daedalus
Fareham Borough Council
• Desk Study
• Gap Analysis 2001
• Radiological survey 1996 of
Fire Training Ground
• Remediation exercise of FTG –
confirmation 1998
• Phase 2 radiological
investigation 2003
• Surface walkover 2004 & 2005
(100% coverage accessible
areas GPS)
• Intrusive investigation 2005 (69
trial pits)
HMS Daedalus – Radioactivity
Fareham Borough Council
• Radium 226
• Max activity of 4 Bq/g
• Max contact dose of 1.3µSv/h
• 11.39mSv/yr
HMS Daedalus
Fareham Borough Council
Background
PHE – average UK radiation dose is 2.7 mSv/yr
Part IIa
• An effective dose of 3 mSv/yr
• An equivalent dose to lens of eye 15 mSv/yr
• An equivalent dose to skin of 50 mSv/yr
Dose Levels - National Background and Part IIa
Fareham Borough Council
Recommendations of LQS submitted with Outline Application
• Remedial target of 0.3mSv/yr (residential uses)
• 0.34Bq/g
No longer appropriate – RCLEA revised 2011
• 3 mSv/y - RSGV is 35Bq/kg or 0.035Bq/g
• 2.6 mSv/y - concentration on site of 30Bq/kg or 0.03Bq/g
HMS Daedalus
Fareham Borough Council
• Process same - Desk study, site investigation, risk
assessment (RCLEA), remediation, validation.
• Soil sampling, soil gas sampling (esp Radon), water
sampling, indoor air monitoring
• Non intrusive & Intrusive survey methods
• Take account of background concentrations
Similarities
Fareham Borough Council
• Exposure pathways – inhalation of soil gas (Rn-222), soil ingestion,
ingestion of vegetables and soil on vegetables (internal radiation),
• Application of principles of BS10175: 2011+ A1:2013 and BS 5930:1999
• Minimising cross contamination during SI – spoil heaps, purged water
• ALARP applies in risk assessment and remediation
Similarities
Fareham Borough Council
• Exposure pathways – External whole body irradiation, skin
external irradiation (RCLEA)
• Types of equipment used – scintillation detectors
• Waste Disposal – Environmental permitting (need EA
permission in place before start digging)
Differences
Fareham Borough Council
DEFRA (2006) Industry Profile Industrial activities which have used material containing
radioactivity
http://uk.practicallaw.com/cs/Satellite?blobcol=urldata&blobheader=application%2Fpdf&blobke
y=id&blobtable=MungoBlobs&blobwhere=1247264181979&ssbinary=true
Common Contaminants
Fareham Borough Council
Tips For LA
• Speak to the specialist advisor undertaking the work – what
equipment, limitations – detection, background concentrations, detection
limits, size of area surveyed and size of anomalies (grid size), sampling
• Speak to the EA – especially about permitting requirements https://www.gov.uk/government/collections/radioactive-substances-regulation-for-non-nuclear-
sites
Development
Fareham Borough Council
• Speak to PHE https://www.phe-protectionservices.org.uk/
01235 825313
• Refer to guidance – Ciria W30 good practice guidance for site
characterisation, RCLEA CLR 12, 13 & 14
• Use Soil Guideline Values in RCLEA (CLR 13)
• Use RCLEA to generate doses if you know activity on site.
Development
Nuclear Industry Group for Land Quality (2011) Qualitative risk assessment for land
contamination, including radioactive contamination
Fareham Borough Council
Tips for Developers • Employ specialist Radiation Consultant – consider if need RPA
• Arrange meeting with LA environmental health & planning prior to works starting
• Get consultants to review any previous radiological surveys
• Undertake new radiological surveys well in advance of starting on site
• Make a note of areas that cannot be surveyed and agree when this will be
surveyed
• Maintain dialogue through regular site meetings
• Consider contamination at depth
• All surveys have limitations – discovery strategy, toolbox talks and inform LA of
found items – speak to consultant again
Development
Fareham Borough Council
• Areas not surveyed e.g. surface concrete, roads
• Surveyed at depth?
• Correct material surveyed – not imported materials
• Radionuclides not picked up by the equipment
• Hiring of scintillation detectors and self assessment
• Units of measurement in assessment and conversions
between units of measurement
• Moving soil/ reduced digs/ drainage excavations – changes
to soil profile
Watchpoints