ML090960663
| ML090960663 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 03/26/2009 |
| From: | Sherrie Taylor Bechtel Corp, Florida Power & Light Co |
| To: | Office of New Reactors |
| Nguyen C NRO/DNRL 301-415-1177 | |
| References | |
| Download: ML090960663 (22) | |
Text
Hydrogeological Site Features Turkey Point Units 6 & 7 Stewart Taylor Technology Manager, Bechtel Corporation March 26, 2009
2 The information provided in the following presentation is of a preliminary nature and is considered DRAFT
3 Presentation Overview Data Sources Regional Hydrostratigraphic Units Floridan Aquifer System
- Upper Floridan aquifer
- Middle confining unit
- Lower Floridan aquifer (Boulder zone)
Boulder Zone
- Hydraulic and geochemical properties
- Deep well injection Regional Groundwater Flow Fate and Transport of Injectate
4 Data Sources Bush, P. and Johnston, R., Groundwater Hydraulics, Regional Flow and Groundwater Development of the Floridan Aquifer System in Florida and in parts of Georgia, South Carolina and Alabama, Professional Paper 1403-C, U.S. Geological Survey, 1988.
Maliva, R.G., and Walker, C.W., Hydrogeology of Deep-Well Disposal of Liquid Wastes in Southwestern Florida, USA, Hydrogeology Journal, 6: 538-548, 1998.
Maliva, R.G., Guo, W., and Missimer, T., Vertical Migration of Municipal Wastes in Deep Injection Well Systems, South Florida, USA, Hydrogeology Journal, 7: 1387-1396, 2007.
Meyer, F., Hydrogeology, Ground-water Movement, and Subsurface Storage in the Florida Aquifer System in Southern Florida, Regional Aquifer-System Analysis-Floridan Aquifer System, Professional Paper 1403-G, U.S. Geological Survey, 1989.
Miller, J.A., Hydrologic Framework of the Floridan Aquifer System in Florida and in Parts of Georgia, Alabama, and South Carolina, Professional Paper 1403-B, U.S. Geological Survey, 1986.
Miller, J.A., Ground Water Atlas of the United States, Alabama, Florida, Georgia, and South Carolina, Hydrologic Atlas 730-G, U.S. Geological Survey, 1990.
Reese, R., Hydrogeology and the Distribution and Origin of Salinity in the Floridan Aquifer System, Southeastern Florida, Water-Resources Investigations Report 94-4010, U.S. Geological Survey, 1994.
Reese, R., and Richardson, E., Synthesis of the Hydrogeologic Framework of the Floridan Aquifer System and Delineation of a Major Avon Park Permeable Zone in Central and Southern Florida, Scientific Investigations Report 2007-5207, U.S. Geological Survey, 2008.
5 Regional Hydrostratigraphic Units Source: Reese and Richardson (2008)
6 Regional Hydrostratigraphic Units Surficial Aquifer System The permeable hydrogeologic unit contiguous with the land surface that is comprised principally of unconsolidated to poorly indurated, siliciclastic deposits.
Includes Biscayne aquifer 20-400 ft thick Source: Miller (1990)
7 Regional Hydrostratigraphic Units Intermediate Aquifer System / Confining Unit
- All rocks that lie between and collectively retard the exchange of water between the overlying surficial aquifer system and the underlying Floridan aquifer system
- Interlayered aquifer/aquitard system comprised of Hawthorn Group sediments
- Up to 900 ft thick
- Brackish water quality Source: Miller (1990)
8 Regional Hydrostratigraphic Units Floridan Aquifer System Vertically continuous sequence of interbedded carbonate rocks of Tertiary age that are hydraulically interconnected by varying degrees and with permeabilities several orders of magnitude greater than the hydrogeologic systems above and below.
Comprised of shallow-water limestone and dolomite beds 2300 to 2400 ft thick in southern Florida Brackish to marine water quality Source: Miller (1990)
9 Floridan Aquifer System Upper Floridan Aquifer Porous limestones / dolomites 100 to 400 ft in thickness Transmissivities of 10,000 to 60,000 ft2/d Brackish water quality Middle Confining Unit Interbedded, low permeability dolomites and limestones About 900 ft thick in SE Dade County Vertical hydraulic conductivities of 10-7 to 101 ft/d (10-10 to 10-2 cm/s)
Lower Floridan Aquifer Permeable dolostones separated by less permeable limestones Up to 2000 ft in thickness Lower dolostone termed Boulder Zone and highly transmissive Marine water quality Source: Maliva and Walker (1998)
10 Boulder Zone Geology Intervals of cavernous and fractured dolomites in the Early Eocene Oldsmar Formation Occurs at a depth of about 2900 ft near site Transmissivity 3,200,000 to 24,600,000 ft2/d Water Quality Geochemically similar to modern seawater (35,000 mg/L TDS)
Anomalous water temperature (nominally 50°F near coast)
Use Wastewater disposal by deep well injection Oil field brines, municipal and industrial wastewater Source: Miller (1990)
11 Regional Groundwater Flow Variations in water quality, hydraulic head, and water temperature within the carbonate rocks that make up the Floridan aquifer system in southern Florida suggest that the flow system is complex. (Meyer, 1989)
Regional flow in Boulder Zone difficult to assess due to:
- Limited number of hydraulic head observations
- Very high transmissivities very low hydraulic gradients
- Transitory effects of tides (ocean and atmospheric)
USGS (Meyer, 1989) determined regional flow patterns from
- Temperature data
- Water quality data
- Groundwater age dating
- Hydraulic head data
12 South Floridan Plateau Source: Meyer (1989)
Site
13 Generalized Hydrogeologic Section Source: Meyer (1989)
14 Groundwater Temperature (°F)
Relative Age (y) in Boulder Zone Source: Meyer (1989)
Site Site
15 Potentiometric Surface Upper Floridan Aquifer Source: Meyer (1989)
Site
16 Regional Groundwater Circulation Source: Meyer (1989)
17 Time Scales for Groundwater Circulation
- Measureable C-14 activity in Upper Floridan aquifer suggests source younger than 40,000 years
- Transit times from aquifer recharge areas >> 40,000 years
- C-14 attributed to upwelling from Lower Floridan aquifer
- Percent Modern Carbon (PMC) in Upper Floridan aquifer 3.3% PMC 6.5%
- Apparent age (before 1950)
Age = -8033 ln (PMCx10-2) 22,000 y Age 27,000 y Source: Meyer (1989)
Site
18 Injectate Characteristics Injection Rates
- Cooling tower blowdown 12,500 gpm for reclaimed water source (COC = 4) 58,000 gpm for marine water source (COC = 1.5)
- Normal plant releases 3 gpm Physical Characteristics
- Reclaimed water source Salinity = 4 x 1,000 mg/l = ~4,000 mg/L TDS Temperature = 92°F = 33.2°C Density = 997.607 kg/m3
- Marine water source Salinity = 1.5 x 35,000 mg/l = ~52,500 mg/l TDS Temperature = 92°F = 33.2°C Density = 1033.721 kg/m3
19 Injectate Characteristics Ambient Boulder Zone Water Salinity = 35,000 mg/l TDS Temperature = 60°F = 15.6°C Density = 1025.866 kg/m3 Density Differences
- Reclaimed water source Injectate (997.607 kg/m3) < groundwater (1025.866 kg/m3)
Positively buoyant
- Marine water source Injectate (1033.721 kg/m3) > groundwater (1025.866 kg/m3)
Negatively buoyant
20 Injectate Transport - Reclaimed Water Source Injection Well Injectate
21 Injectate Transport - Marine Water Source Injection Well Injectate
22 Postulated Injectate Fate and Transport Initial spreading of injectate bubble governed by buoyancy-driven flow and geologic structure Dissolution of injectate into ambient groundwater with subsequent advective transport along ambient groundwater pathways and attenuation due to:
- Hydrodynamic dispersion
- Retardation
- Radioactive decay Plausible groundwater pathways could:
- Be confined to the saline, Lower Floridan aquifer No potential exposure
- Include upwelling to the brackish, Upper Floridan aquifer Travel times > 10,000 y