” In-situ measurements of radionuclides in the ocean are needed to validate and tune the models.
These data will provide insight into the important processes associated with the movement of theseparticles throughout the ocean.
” Immediate data/sampling required includes:
o Near real-time access to raw data from JAMSTEC sampling
o Near real-time access to raw data from any near-shore TEPCO water sampling
o Radionuclide sampling of effluent from Fukushima Dai-ichi to include data on rate of outflowand times of discharge
o Initial surface sampling would be needed immediately to understand concentrations within the surface mixed layer.
- Sampling could be done via drifters, buoys, autonomous devices or other platforms capable of detecting surface or sub-surface concentrations.
- Positions are needed in general arcs away from the source every 5 km out to 30 km.
- Detections starting at the north and working southward, focusing on near-coastal concentrations to the north and sea-ward concentrations to the east and south of the source is ideal.
o Radionuclide sampling along the coast, north and south of the site, at intervals of 5 km.
o Occasional atmospheric and oceanic estimates of radionuclide gradients both IVO the plant and in areas where DOE indicates that there are (or expected to be) major areal deposits.
o Targeted ocean observations of radionuclides along cross sections of the Kuroshio current.
Vertical cross sections are needed to better understand vertical mixing.
* NOAA needs access to DOE’s atmospheric radiological data along with estimates of dispersion including information on cesium and iodine. Digital data (vs. graphics) are required starting from the time of the incident. NOAA has had some progress working with DOE, but needs to verify the data they have Is what the modelers need.
” Other sampling required to refine models and processes:
o A sentry arc-line of daily radionuclide observations from near the source out to 100 km away, ideally with measurements every 5 km out to 50 km and larger measurement spacing (10km) outwards. Along these arcs, measurements are needed from the ocean surface to a depth of 200 m with a vertical resolution of 10 m.
o Ocean observations of radionuclides at greater distances, +200 km, for modeling of long-term, global transport and concentrations.
o Real-time wind data at Fukushima Dai-ichi for air-deposition effects.
o Sediment radionuclide concentrations near-shore to refine particle settling calculations and local effects.
Observations Needed for Ocean Plume Modeling Effort – Pages From C142018-02CX-3