Saturday, October 25, 2014

Fukushima Plume from March 2011 Approximately 200PBq from Iodine131, Cesium134, and Cesium137 Alone

Giuseppe A. Marzo  (2014) Atmospheric transport and deposition of radionuclides released after the Fukushima Dai-chi accident and resulting effective dose. Atmospheric Environment Volume 94, September 2014, Pages 709–722

[Asbstract] On 11 March 2011 an earthquake off the Pacific coast of the Fukushima prefecture generated a tsunami that hit Fukushima Dai-ichi and Fukushima Da-ini Nuclear Power Plants.From 12 March a significant amount of radioactive material was released into the atmosphere and dispersed worldwide. 

Among the most abundant radioactive species released were iodine and cesium isotopes. By means of an atmospheric dispersion Lagrangian code and publicly available meteorological data, the atmospheric dispersion of 131I, 134Cs, and 137Cs have been simulated for three months after the event with a spatial resolution of 0.5° × 0.5° globally.

The simulation has been validated by comparison to publicly available measurements collected in 206 locations worldwide. Sensitivity analysis shows that release height of the radionuclides, wet deposition velocity, and source term are the parameters with the most impact on the simulation results.
The simulation shows that the radioactive plume, consisting of about 200 PBq by adding contributions from 131I, 134Cs, and 137Cs, has been transported over the entire northern hemisphere depositing up to 1.2 MBq m−2 nearby the NPPs to less than 20 Bq m−2in Europe.[end]

Majia here: This simulation addresses a tiny fraction of the 1000 radionuclides released into atmosphere and ocean by Fukushima: 
Over 1000 Radioactive Elements released by Fukushima Daiichi (source: TEPCO to ratchet up efforts to decontaminate water
Moreover, the simulation doesn't include three plus years of daily emissions into the atmosphere and ocean. Here is a representation of typical daily emissions from unit 1. TEPCO 1 cam 2014-10-26 04:45 AM: