Post on 21-Jul-2020
Deep Geologic Repository Joint Review Panel Commission d’examen conjoint du projet de stockage dans des couches géologiques profondes
PMD 13-P1.9B
File / dossier : 8.01.07 Date: 2013-09-29 Edocs: 4208116
Supplementary Information Presentation from Ontario Ministry of Northern Development and Mines In the Matter of Ontario Power Generation Inc.
Renseignements supplémentaires Présentation du Ministère du développement du nord, des mines de l’Ontario À l’égard de Ontario Power Generation Inc.
Proposed Environmental Impact Statement for OPG’s Deep Geological Repository (DGR) Project for Low and Intermediate Level Waste
Étude proposée pour l’énoncé des incidences environnementales pour l’Installation de stockage de déchets radioactifs à faible et moyenne activité dans des couches géologiques profondes
Joint Review Panel September 16 to October 12, 2013
Commission d’examen conjoint Du 16 septembre au 12 octobre 2013
Ontario Ministry of Northern Development and Mines
Submission 2 to the Joint Review Panel
Public Hearing Proposed Bruce Deep Geological Repository
Hydrogeology and Hydrochemistry
Sept. 30th, 2013
Context for MNDM Comments • MNDM maps Quaternary geology and Paleozoic bedrock
geology with focus on characterizing groundwaters across southern Ontario.
• MNDM will: – summarize some new findings on Devonian bedrock
groundwater chemistry relevant to DGR site – comment on regional karst mapping, hydrogeology and
hydrochemistry in context of regional stratigraphy and topography.
• Technical Support Document: – geoscience studies and scientific methods were appropriately
conducted, there are no substantive science topic gaps. – geological conclusions are consistent with the geoscience data.
09/30/2013 MNDM Groundwater Comments - Proposed Bruce DGR 2
MNDM Geological Comments Shallow and Intermediate Groundwater Flow Systems and
Hydrogeochemistry • Context for MNDM Groundwater Comments:
– MNDM hydrochemistry studies in the freshwater overburden and shallow bedrock groundwater systems, covering the regional study area of the DGR (published 2011, Ontario Geological Survey (OGS) Miscellaneous Release Data 283);
– MNDM sampling sources differ from those reported on by NWMO (domestic wells for the MNDM versus discrete sampling for NWMO). MNDM scale is also different providing pan-provincial context.
• Comment: – The Phase 1 Regional hydrochemistry report is comprehensive and well written – MNDM Ambient Groundwater Geochemical database is newer and contains important new
information; – MNDM provides geochemical evidence for widespread karst (cavern formation) in the Lucas
Formation extending from the proposed DGR site more than 100 km southward. • Implications:
– Important to address the presence of karst in the Lucas Formation in later phases of study as karst influences regional groundwater transport and may present geotechnical challenges during future construction phases;
– Geochemical evidence: Deep groundwater has been isolated from Intermediate and Upper groundwater for millions of years.
– TSD and MNDM groundwater quality data serve as robust groundwater quality baseline suitable for long-term monitoring of the proposed DGR influence on local and regional environment;
– Science collaboration would enable both organizations to characterize, model, and understand groundwater flow systems at different scales; we would welcome further science collaboration on groundwater studies.
09/30/2013 MNDM Groundwater Comments - Proposed Bruce DGR 3
MNDM - OGS Groundwater Geoscience Program
Outputs 3-5 years
3D Sediment Mapping
3D Bedrock & Groundwater Mapping
Ambient Groundwater Geochemistry
Activities Outputs 1-3 years Outcomes Government
Priorities
3D Block Model
Groundwater Resource Study
Aquifer vulnerability + recharge potential
Tools
Safe, sustainable use of groundwater.
Discovery + characterization of new groundwater sources
Informed policy + planning
Quality of Life
Economy
Chemo + sequence stratigraphic framework
Hydro-geologic units (HGUs)
Groundwater Resource Study
Public data + information releases
09/30/2013 MNDM Groundwater Comments - Proposed Bruce DGR 4
09/30/2013 MNDM Groundwater Comments - Proposed Bruce DGR 5
• Buried bedrock valleys and troughs
• Ambient Groundwater bedrock sample locations
• Water levels and ground-water flow are controlled by bedrock topography
09/30/2013 MNDM Groundwater Comments - Proposed Bruce DGR 6
• Water levels that plunge below the bedrock surface suggest karst (caverns)
• Most apparent in Breathing Well Zone; also occurs to the north toward the DGR
• Much of this void-space in the Lucas Formation is a result of gypsum dissolution
• High strontium is an indication that all the gypsum has dissolved
MNDM Groundwater Comments - Proposed Bruce DGR
from: Ian Clark et al. Geology 2013;41:951-954
Figure 2. Stratigraphy and porewater tracer profiles at Bruce nuclear site (Ontario, Canada). Small dark points represent mean of four replicate extractions. Colored discs are 3-point running averages. Groundwater measurements (light blue discs) are for shallow groundwaters and three deep water-bearing units: Lower Silurian Salina A1 dolostone, Guelph Formation dolostone, and Cambrian sandstone. VSMOW—Vienna standard mean ocean water; mbgs—meters below ground surface; kgw—kilogram water.
Deep flow zone
Intermediate flow zone
Upper flow zone
Aquiclude
(Modern water)
(Water <2 million years old)
(Water millions to 100’s millions years old)
Geochemical evidence: Deep water in proposed DGR site has been isolated from Intermediate and Upper waters for millions of years.
©2013 by Geological Society of America
09/30/2013 7
Deep vs. Shallow boreholes & Phanerozoic Geology
Deep flow zone
Intermediate flow zone
Upper flow zone
Aquiclude
09/30/2013 8
Niagara Escarpment Karst
DEVONIAN Onondaga Escarpment Karst
Grenville Province Precambrian Shield
Marble Karst
Tucker Smith Sinkhole
Brunton, F.R. and Dodge, J.E.P. 2008. Karst of Southern Ontario and Manitoulin Island; Ontario Geological Survey, Groundwater Resources Study No.5, 100p.
Karst Map of Southern Ontario & Manitoulin Island – GRS 5
Proposed DGR Site
9
Conceptual Topography / Gravity-driven Bedrock Groundwater Flow paths, Southern Ontario
Guelph Fm (brecciated/absent) Eramosa Fm (absent) Goat Island Fm (paleokarsted) Gasport Fm (variable thickness) Rochester Fm (locally present) Irondequoit Fm (regional in ON) Fossil Hill (Merritton) Fm Cabot Head Fm (aquitard)
Approximate location of Proposed DGR Site
09/30/2013 MNDM Groundwater Comments - Proposed Bruce DGR 10
MNDM Concluding Remarks • DGR geoscience studies and scientific methods for proposed
DGR were appropriately conducted, there are no substantive gaps in key science data, and DGR conclusions are consistent with the geoscience data.
• Divergence between MNDM and DGR scientific items do not likely undermine confidence in the future geological suitability of the DGR.
• Results presented today on nature of regional karst in Devonian-age Lucas Formation (upper potable water flow system) should be taken into account if construction moves forward.
• Geochemical evidence indicates: Deep water has been isolated from Intermediate and Upper water for millions of years.
• MNDM thanks the Joint Panel Review Board for the opportunity to participate in the public hearing related to the Deep Geologic Repository Joint Review Panel.
09/30/2013 MNDM Groundwater Comments - Proposed Bruce DGR 11