1. RETS REMP 2007 Philadelphia, PA June 25 – 27, 2007 Eric L. Darois, CHP
EPRI Guideline for Implementing a Groundwater Protection Program at Nuclear Power Plants
RETS REMP 2007
Philadelphia, PA June 25 – 27, 2007
Eric L. Darois, CHP

2. Implementing Schedule
Draft Issued March 2007 for Industry Comments
Review and Disposition Comments – June 2007
Issue Final Document – November 2007

3. EPRI Groundwater Protection Guidelines
Objectives
Provide guidance for development of robust and technically sound optimized programs for groundwater protection at nuclear power plants.
Control Licensed Material from Entering the Subsurface
Minimize Unplanned Unmonitored Releases
Minimize Long-Term Costs for Remediation

4. Participating Companies
Ameren UE
American Electric Power
American Nuclear Insurers
AREVA
Connecticut Yankee
Constellation Energy Group
Dominion
DTE Energy Co.
Duke Energy Corp.
Energy Northwest
Entergy
Exelon
FirstEnergy Nuclear Operating Co.
Florida Power & Light Co.
General Electric
Nuclear Energy Institute Nuclear Management Co.
Ontario Power Generation
Omaha Public Power District
Pacific Gas & Electric Co.
Public Service Electric & Gas Co.
PPL Susquehanna
Progress Energy
Southern Nuclear Operating Co.
Southern California Edison
South Texas Project Nuclear Operating Co.
Tennessee Valley Authority
Westinghouse
Yankee Atomic Electric Company

5. Guideline Content Evaluation of Potential Subsurface Releases
Establishing The Priority Index Values
Determining The Program Levels With The Graded Approach
Establishing a Site Conceptual Model
Locating, Installing and Testing Groundwater Monitoring Wells
Establishing a Groundwater Sampling and Analysis Process
Evaluating Sampling and Monitoring Data
Program Validation and Review
Communicating With Stakeholders and Regulators
Potential Mitigating Actions
Decommissioning Considerations

6. Appendices
Appendix A: Practical Examples Of A Graded Approach Application
Appendix B: List Of Guidance Statements
Appendix C: Non-technical Issues That May Be Considered When Determining Priority Indices
Appendix D: Sample List Of Systems, Structures And Components
Appendix E: Checklist Of Elements To Include In A Review Of Systems, Structures, Components And Work Practices
Appendix F: Determination Of Condition Of SSCs
Appendix G: Basis For ‘Hazard’ And ‘Mobility’ Priority Factor Values
Appendix H: Site Characterization And The Site Conceptual Model
Appendix I: Identifying Predominant Groundwater Flow Directions And Mechanisms
Appendix J: An Example Of A Groundwater Monitoring Procedure
Appendix K: An Example Of A Groundwater Sampling Plan
Appendix L: An Example Of A Study Conducted To Estimate The Effect Of Atmospheric Deposition Of Tritium On Groundwater
Appendix M: Fate And Transport Numerical Modeling

7. Evaluation of Potential Subsurface Releases
Historical Spills
Evaluate SSCs Containing Liquid Radioactivity
Identify Preventive Maintenance and Inspection Programs
Evaluate Work Practices
Evaluate Potential Ongoing Releases

8. Establishing Priority Index (PI) Values
Performed for:
Selected SSCs and Work Practices
Major Changes in SSCs/Work Practices
Maximum PI Score among All SSCs/Work Practices Determines Site Score
Mitigating Actions Are Allowed to Lower Score
PI Factors
Likelihood – 4 Factors
Consequence – 4 Factors

9. Determination of Contamination Risk Priority Index Methodology
Priority Index (PI)= Likelihood x Consequence x N
HL = History (0-3)
CL = Condition (0-3)
DL = Design (0-3)
PL = Pre-release Detection (1-3)
IC = Inventory (1-3)
HC = Hazard (1-3)
MC = Mobility (1-3)
PC = Post-release Detection (1-3)
N – Normalizing Factor. Resulting Scores 1 to 100

10. EPRI Groundwater Protection Guidelines: Step 1-Priority Index Determination

11. Priority Index = 76 Likelihood Priority Factors
For Site 1, The Containment Sump Re-Circ Line has a calculated PI of 76.
Likelihood Priority Factors:
History (3):
A containment sump re-circulation line has been identified as having leaked to the subsurface
Condition (2):
A pressure test of the system has did not reveal a substantial volumetric leak. However, some uncertainty over the possibility of a small leak (< 1 gpd) remains.
Design (3):
This is a single-walled subsurface pipe.
Pre-Release Detection (3):
A non-catastrophic release would not be detected until radioactive material had been detected external to the pipe.

12. Priority Index = 76 Likelihood Calculation

13. Priority Index = 76 Consequence Priority Factors
For Site 1, The Containment Sump Re-Circ Line has a the max calculated PI value.
Consequence Priority Factors:
Inventory (3):
Low volume of liquid but high concentration (~2E7 pCi/L) of tritium
Hazard (3):
This pipe likely contains Cs-137 and Sr-90 (from prior fuel defects).
Mobility (3):
Potential contamination from this source could enter a fractured bedrock system.
Post-Release Detection (2):
An onsite monitoring well is located approximately 300 feet from this pipe in the down-gradient flow path.

14. Priority Index = 76 Consequence Calculation

15. Priority Index = 50 Likelihood Priority Factors
For Site 3, the Aux Boiler Sump is unlined and may have leaked water to the environment.
Likelihood Priority Factors:
History (2):
The sump’s water inventory has been observed to vary, indicating that some of this water was lost to the environment.
Condition (2):
Various attempts in sealing the sump have not corrected the above condition.
Design (2):
The sump was sealed with a coating (which may not be functioning properly) during its original construction.
Pre-Release Detection (3):
Leakage through this sump is not detected until its entry into the environment

16. Priority Index = 50 Likelihood Calculation

17. Priority Index = 50 Consequence Priority Factors
For Site 3, the Aux Boiler Sump is unlined and may have leaked water to the environment.
Consequence Priority Factors:
Inventory (1):
Low liquid volume with a moderate tritium concentration (180,000 pCi/L).
Hazard (1):
Only very low levels of activation products have been detected in this sump.
Mobility (3):
Tritium is very mobile in the environment.
Post-Release Detection (3):
This site currently has only two onsite monitoring wells, neither of which is located down-gradient from this sump – leak from this system may not be detected in these wells.

18. Priority Index = 50 Consequence Calculation

19. EPRI Groundwater Protection Guidelines Step 2- Graded Approach Determination

20. Recommended Groundwater Protection Program (Level I “Baseline”) Design and Installation Requirements
Develop The Site Conceptual Model (5.1)
Review Aerial Photos And Engineering Drawings (5.2)
Review Previous Hydrogeologic Reports (5.3)
Evaluate Potential Receptors Of Groundwater Contamination (5.4)
Review State And Local Regulations (5.5)
Determine Groundwater Elevation (5.6.1)
Evaluate Pre-operational Groundwater And Geologic Data (5.6.2)
Determine Regional Hydrogeologic Characteristics (5.6.3)
Install Wells (5.7.1)
Determine Horizontal Distribution And Movement (5.7.2)
Establish And Document DQOs For Well Drilling (6.1)
Institute Configuration Management For Well Drilling (6.2.1)
Review Permitting Requirements For Well Drilling (6.2.2)
Ensure Sampling Accessibility (6.2.3)
Construct Monitoring Wells (6.3)
Develop And Implement A Maintenance Program For Monitoring Wells (6.4)

21. Recommended Groundwater Protection Program (Level I “Baseline”) – Sampling, Analysis, and Data Management
Establish And Document DQOs For Groundwater Sampling (7.1)
Establish Sample Collection Procedures (7.2)
Establish Analyte List(s) (7.3)
Establish MDC Requirements And Criteria For Positive Detection (7.4)
Establish Sample Volume, Container And Preservation Requirements (7.5)
Establish Sampling Schedule (7.6)
Validate Analytical Results (7.7)
Evaluate Analytical Data (8.1)
Evaluate Field Water-quality Indicator Data (8.2)
Provide For Management And Data Quality Assessment Of Analytical Data (8.3)

22. Recommended Groundwater Protection Program (Level I “Baseline”) – Data Assessment
Evaluate Background Radionuclide Concentrations (8.4.1)
Evaluate Atmospheric Deposition Of Plant-related Radionuclides (8.4.2)
Evaluate Plant-related Liquid Pathways (8.4.3)
Review And Revise The Site Conceptual Model (8.5)
Perform Initial Independent Review (9.1)
Revalidate Priority Index Ratings (9.2)

23. Recommended Groundwater Protection Program (Level II & III)
Level II (50 < PI ≤ 75)
Implement All Program Elements From Program Level I
Determine Vertical Distribution And Movement (5.7.3)
Consider Use Of Water-level Transducers (6.5.1)
Level III (75 < PI)
Implement All Program Elements From Program Levels I And II
Aquifer Test For Flow Regimes, Connectivity, Hydraulic Conductivity (5.7.4)
Conduct Geophysical Testing (6.5.2)
Consider Use Of Hydraulic Conductivity Testing (6.5.3)
Consider Use Of Hydrophysical Testing (6.5.4)
Consider Use Of Fate And Transport Numerical Modeling (8.6)

24. Establishing a Site Conceptual Model
Initial Data Input
Aerial Photos, Engineering Drawings, Construction Photos
Prior Hydrogeologic Reports
Regional Groundwater Flow Information
Ongoing Development of a CSM
Well Installations and Monitoring
Water Elevations
Groundwater Quality Data (Temp, pH, Conductivity, Concentrations, Oxygen etc..)
Flow Regimes, Connectivity and Conductivity
Horizontal/Vertical Distribution and Movement

25. Well Installation Data Quality Objectives Process – Document Process
Purpose
Depth and Well Design
Measurement of Field Water Quality Parameters During Drilling/Construction
Document Final “as-built” and Include in Configuration Management Process

26. Sampling and Analysis and Assessment
DQO Process Required
Written Sample Collection Procedures
Justify Analyte List
Specify Required Minimum Detectable Concentrations
Specify Container Types and Sample Preservation Requirements
Establish Sampling Schedule and Rationale
Establish Procedure for Data Validation
Data Base Management

27. Program Validation and Review
Periodic Independent Review
< 5 years
Revalidation of Priority Index

28. Additional Sections Communicating with Stakeholders
Potential Mitigating Actions
Decommissioning Considerations
References
Additional Technical References
Glossary

29. Summary of EPRI Guidelines and their Implementation
Development of Risk Based Index based upon SSCs
“Graded Approach Strategy” allows for optimized approach to Groundwater Monitoring by utilities
Baseline Program is a commitment from the industry to perform preventative monitoring and control, and will require some plant resources to implement
EPRI supplemental support available (GW Assessments) for implementation