1. Overview of the EPRI Groundwater Assessment Program
Presented at: RETS-REMP Workshop, June 26-28, 2006
Mashantucket, CT
Eric L. Darois, M.S., CHP
Dave Scott, M.S., CPG, LEP
EPRI Consultants (RSCS, Inc.)
Sean Bushart
EPRI
Ron Cardarelli, M.S.
CN Associates, Inc.

2. Program Objectives and Scope
Phase 1:
Perform a site-specific assessment of Groundwater Contamination Risks.
Bring Lessons-Learned to each site from Prior Groundwater Investigations.
2 to 4 Days, 2 Professionals
Health Physics/REMP
Geologist/Hydrogeologist
Prepare site-specific report with recommendations based on assessment
Phase 2:
Develop Industry Guideline on Groundwater Protection
Phase 3:
Advanced Nuclear Project – Groundwater Protection Lessons Learned in development of new nuclear plants

3. RETS/REMP 2005 Discussion
Ground Water Monitoring Guidance for Nuclear Power Plants (EPRI Report No )
150-page EPRI Report
Two Decommissioning Sites
One Operating Site
Historical Review
Requirements
Potential Source Locations
Investigation Methods and Tools
Determining Occurrence, Nature, Extent
Sampling Considerations
Data Analysis and Interpretations
Recommended GW Monitoring as Part of REMP

4. Assessments/Experience Performed and Gained
Yankee Rowe (Decommissioning)
Connecticut Yankee (Decommissioning)
TMI EPRI Assessment
Braidwood Assistance
Indian Point Assistance

5. Observations & Recommendations
Define Program Objectives
Radionuclides, MDCs, and “Positive” Results
Sampling Regime
Sampling Methods
Data Assessments
Sampling Methods and Field Parameters
Consider Preventative Maintenance Programs for Wells
Consider Soil Sampling for H-3 Sources

6. Observations & Recommendations (Con’t)
Investigation Complexity Results in Wide Variation in Duration
Sand-Laden Aquifer
Fractured Bedrock
Deep Bedrock
Barriers to GW Flow

7. Observations & Recommendations (Con’t)
Tritium Saturated Concrete
Documentation of Spills and Leaks
Soil Contamination Events
Secondary Water
Tank Leaks
SFP “Minor” Leaks
Resource Needs not Recognized
Data Management

8. Observations & Recommendations (Con’t)
Data Management
Electronic Data vs Paper
What Radionuclides?
MDAs ?
Required vs Achieved
Sample Event Planning
Sample Control
Data Control
Data Assessment
Statistical Analysis
Trend Analysis

9. Recognize the Iterative Process of GW Investigation
Proceed with a phased approach that implements a “scientific method”
Develop a Conceptual Site Model (CSM)
Evaluate the existing site data (hydrogeology, source areas, contaminant distribution, transport mechanisms)
Formulate a preliminary CSM (hypothesis) that explains the observed data
Collect data: drill monitoring wells, sample and analyze GW, and conduct hydrogeologic testing
Evaluate and interpret the resulting data

10. Designing a GW Investigation
Evaluate possible sources of contaminants
Evaluate possible radionuclides
Determine GW flow directions & mechanisms
Install monitoring wells
Drilling methods
Overburden wells
Bedrock wells
Screen Depths
Measure GW levels
Sample and analyze GW
determine concentrations
Determine distribution

11. Tools for the Investigation
Water-level monitoring
Precipitation (primary input to GW)
Surface water (tidal interaction with GW)
Ground water (flow direction and gradient)
Water-level measurement techniques
Electronic measuring tapes
Synoptic measurements in a set of wells
Data-logging pressure transducers
Continuous measurements in selected wells

12. Example of GW Level Data Logging

13. More tools… Bedrock Borehole Logging Tracer studies Isotopic GW dating
Packer Testing

14. Ground Water Sampling
Flow-through measurement cell to determine when samples are representative
Temperature pH
Turbidity
Dissolved oxygen
Specific conductance
Water-level meter
Bailed Samples
Low Flow Sampling Methods

15. Observations/Guidance
Potential Primary GW Sources (10 to 50 Million pCi/L):
Spent Fuel Pools
Refueling Water Storage Tanks
Sumps
Secondary Sources
Secondary Water Spills and Leaks
Possible Large Volume
Primary Radionuclides of Concern Sr-90, Co-60, Cs-137, and H-3.
Tritium is the most mobile and pervasive.

16. Conclusions State Regulations May Require Additional Considerations
Engage Stakeholders Through All Phases
GW investigations are Iterative
Maybe Years To Complete
Need a Conceptual Site Model
Additional Interest in
EPRI Assessments
Will Help to Implement
NEI Initiative