Presentation on theme: "Overview of the EPRI Groundwater Assessment Program"— Presentation transcript:
1Overview of the EPRI Groundwater Assessment Program Presented at: RETS-REMP Workshop, June 26-28, 2006Mashantucket, CTEric L. Darois, M.S., CHPDave Scott, M.S., CPG, LEPEPRI Consultants (RSCS, Inc.)Sean BushartEPRIRon Cardarelli, M.S.CN Associates, Inc.
2Program 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 ProfessionalsHealth Physics/REMPGeologist/HydrogeologistPrepare site-specific report with recommendations based on assessmentPhase 2:Develop Industry Guideline on Groundwater ProtectionPhase 3:Advanced Nuclear Project – Groundwater Protection Lessons Learned in development of new nuclear plants
3RETS/REMP 2005 DiscussionGround Water Monitoring Guidance for Nuclear Power Plants (EPRI Report No )150-page EPRI ReportTwo Decommissioning SitesOne Operating SiteHistorical ReviewRequirementsPotential Source LocationsInvestigation Methods and ToolsDetermining Occurrence, Nature, ExtentSampling ConsiderationsData Analysis and InterpretationsRecommended GW Monitoring as Part of REMP
4Assessments/Experience Performed and Gained Yankee Rowe (Decommissioning)Connecticut Yankee (Decommissioning)TMI EPRI AssessmentBraidwood AssistanceIndian Point Assistance
5Observations & Recommendations Define Program ObjectivesRadionuclides, MDCs, and “Positive” ResultsSampling RegimeSampling MethodsData AssessmentsSampling Methods and Field ParametersConsider Preventative Maintenance Programs for WellsConsider Soil Sampling for H-3 Sources
6Observations & Recommendations (Con’t) Investigation Complexity Results in Wide Variation in DurationSand-Laden AquiferFractured BedrockDeep BedrockBarriers to GW Flow
7Observations & Recommendations (Con’t) Tritium Saturated ConcreteDocumentation of Spills and LeaksSoil Contamination EventsSecondary WaterTank LeaksSFP “Minor” LeaksResource Needs not RecognizedData Management
8Observations & Recommendations (Con’t) Data ManagementElectronic Data vs PaperWhat Radionuclides?MDAs ?Required vs AchievedSample Event PlanningSample ControlData ControlData AssessmentStatistical AnalysisTrend Analysis
9Recognize 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 dataCollect data: drill monitoring wells, sample and analyze GW, and conduct hydrogeologic testingEvaluate and interpret the resulting data
10Designing a GW Investigation Evaluate possible sources of contaminantsEvaluate possible radionuclidesDetermine GW flow directions & mechanismsInstall monitoring wellsDrilling methodsOverburden wellsBedrock wellsScreen DepthsMeasure GW levelsSample and analyze GWdetermine concentrationsDetermine distribution
11Tools for the Investigation Water-level monitoringPrecipitation (primary input to GW)Surface water (tidal interaction with GW)Ground water (flow direction and gradient)Water-level measurement techniquesElectronic measuring tapesSynoptic measurements in a set of wellsData-logging pressure transducersContinuous measurements in selected wells
14Ground Water SamplingFlow-through measurement cell to determine when samples are representativeTemperaturepHTurbidityDissolved oxygenSpecific conductanceWater-level meterBailed SamplesLow Flow Sampling Methods
15Observations/Guidance Potential Primary GW Sources (10 to 50 Million pCi/L):Spent Fuel PoolsRefueling Water Storage TanksSumpsSecondary SourcesSecondary Water Spills and LeaksPossible Large VolumePrimary Radionuclides of Concern Sr-90, Co-60, Cs-137, and H-3.Tritium is the most mobile and pervasive.
16Conclusions State Regulations May Require Additional Considerations Engage Stakeholders Through All PhasesGW investigations are IterativeMaybe Years To CompleteNeed a Conceptual Site ModelAdditional Interest inEPRI AssessmentsWill Help to ImplementNEI Initiative