Mapping and Predicting Radionuclide Contamination for Decontamination Planning

Transcription

1 Mapping and Predicting Radionuclide Contamination for Decontamination Planning LBNL Overview Jens Birkholzer, LBNL 1

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3 Basic Approach of Decontamination Work Principles set by ICRP 100 msv/y 20 msv/y 1 msv/y Emergency exposure situation: Emergency countermeasures required Reduce additional exposure dose rate to 20 msv/y or less. Existing exposure situations Long-term goal: Reduce additional exposure dose rate to 1 msv/y; decrease by 50% in 2 years The national government undertake decontamination work Long term efforts are needed in high dose area Municipalities develop and implement decontamination plans The national government provides financial and technical support 3

4 Clean-Up of Roads and Pavements high pressure water road cleaner surface stripping blasting Iron shot blasting Ice blasting

5 Fukushima-TRACE Project Process Erosion Transport Sedimentation

6 Data and Prediction 1. Data Integration and Statistical Analysis 2. Data Management 3. Prediction and Scenario Analysis

7 Mapping and Analyzing Radionuclide Contamination Critical for Decontamination planning and Future prediction Challenges Highly heterogeneous Different types and footprints Large Uncertainty Airborne Vehicle-borne Hand-held Core samples

8 Managing Data for Science and Public Uses 1) Combine data from different sources e.g. JAEA and other Japanese databases e.g. US-DoE supported studies and other data from Fukushima and Chernobyl 2) Integrate with models Chernobyl NPP Cooling pond Floodplain 3) Incorporate related ancillary information 4) Science-centered data products e.g. QA/QC, gap-filling, statistical analysis e.g. time-series plots, map-based visualization, contour plots

9 Predicting Radionuclide Migration in Fukushima Watersheds Multi-Scale Catchment to Watershed Predictions Despite impact of the Fukushima Daiichi Nuclear Power Plant accident in March 2011, there is a lack of understanding and predictive capability for the migration of radionuclides at the catchment to watershed scale. Need to understand behavior of individual compartments (farmland, forest soils, water bodies, and groundwater systems) and their interactions. Predictive modeling based on high resolution characterization is needed to evaluate effectiveness of active and passive remediation options.

10 Ogi Dam Watershed Monitoring and Soil Loss Studies Field Observatory in Ogi Dam Watershed Small constrained basin representative of larger watersheds with good data on subsurface geology, near surface soils, land use types Small plots with detailed sampling of leaf litter, soil transport, overland and groundwater flow, precipitation Both deciduous forest (primarily chestnut) and a evergreen cedar dominant forest

11 Soil and Cs Losses from Basins 11 Ukedo River Basin and Ogaki Dam Basin Contributions from each basin Ogaki Dam Basin Ogaki Dam Ukedo River Area (km 2 ) Soil loss (t/y) Ukedo River Basin Forest in River Basin Ogaki Dam Basin Ukedo River Basin Takase River Initial Cs (Bq) Cs loss (Bq) Cs remain in Dam(Bq) Cs to sea (Bq) Forest occupies 79% of River Basin but only accounts for 28% of total soil loss. Most of the soils are collected into rivers and dams and eventually discharged into sea. Around 60% of Cs loss is contributed from the Ogaki Dam Basin. Japan Atomic Energy Agency

12 Ogi Dam Watershed Models

13 Backup

14 Above/Below-Ground Data Integration Above/Below-ground Monitoring Subsurface mapping Aerial imaging App. R [Ohm.m] Watershed-scale Remote Sensing Datasets Muti/Hyperspectral (Vegetation indices) Hill shade Slope DEM Electrical Resistivity Tomography A outcrop Weathered Km (Courtesy: B. Dafflon) 14 14

15 Bayesian Geostatistical Estimation Methods Estimate spatially heterogeneous properties Integrate multi-type multiscale datasets (borehole, core samples, geophysics, remote-sensing) in a consistent manner Uncertainty characterized Lower/upper bounds Robust decision-making Synthetic Example True field and point measurements Low-resolution data Estimated field Estimated soil moisture across the Arctic tundra site based on remote sensing and geophysical datasets (Wainwright et al., 2012) 15

16 Connecting Databases Focus on building the data management system and enabling integration across data sources e.g. JAEA and other Japanese databases e.g. US-DOE supported studies at Chernobyl and Fukushima

17 Science Centered Design for User Interfaces Define use cases describing typical data usage scenarios and resulting plots/visualizations Develop user-driven visualizations and user interfaces Develop a science question oriented interface to the underlying data