Nuclear-1 EIA Credentials 35 years of experience-supply, nuclear, - PDF document

Nuclear-1 EIA Credentials � 35 years of experience-supply, nuclear, Stakeholder Workshop mining, waste, subsurface contamination St. Francis Bay 25 May 2010 � Developed St. Francis wellfields TTTHYSPUNT � Local work at Coega GEOHYDROLOGY � TMG Aquifer expert PETER ROSEWARNE: SRK CONSULTING � EIA specialist studies, eg PBMR Slide 1 Slide 2 Investigation Approach Project Team � Data review � SRK Consulting SA � Site work – hydrocensus; borehole siting; � SRK Consulting UK drilling; testing (approx 6 months spent � Council for Geoscience on site, 2.5 years in total, ongoing) � Institute for Groundwater Studies: UOFS � Data analysis � Numerical flow modelling � Freshwater Consultants � Reporting � CSIR � Ongoing monitoring Slide 3 Slide 4

Site Investigation � All bhs/springs within 5 km visited � 38 exploration boreholes drilled (plus 78 geotech bhs) � 19 Pumping tests carried out � Packer tests � Tracer test THYSPUNT � Water sample analyses GROUNDWATER LEVEL CONTOURS � Monitoring (13 data loggers) Slide 5 Slide 6 THYSPUNT THYSPUNT ZONE OF DRAWDOWN FROM DEWATERING: NO MITIGATION ZONE OF DRAWDOWN FROM DEWATERING: WITH MITIGATION Slide 7 Slide 8

Key specialist study findings Key specialist study findings � There are 3 aquifers present � Aquifers/wetlands are intimately linked � There is extensive groundwater use in � Groundwater levels show minimal Oyster & St. Francis Bay fluctuations with time/rainfall � Groundwater flow is to the south and � Downward trend since monitoring started southeast - site is at end of the flow path � Construction and operation of Nuclear-1 � There are ecologically important wetlands will require dewatering on the site Slide 9 Slide 10 Key specialist study findings Mitigating measures � Site system is naturally “buffered” by � Drawdown/contamination will be high porosity sediments; overflow into contained to the site and 1 km of wetlands; drainage by cobble layer Nuclear-1 with foundation dewatering � Ongoing monitoring being carried out to � Drawdown/contamination will be further confirm groundwater/wetlands contained to the immediate Nuclear-1 interactions surrounds with groundwater control � Further numerical flow modelling will be measures done (fine-tuning – basic findings unlikely to change) Slide 11 Slide 12

Mitigating measures � Freshwater supply will be from desalination of seawater � Construction water could be sourced from THANK YOU dewatering � Cut-off barriers to contain dewatering � Artificial recharge to maintain coastal seeps/springs � Further design work before construction Slide 13 Slide 14