A recently disclosed Tepco documentation indicates total emissions estimates of both plutonium 239 and neptunium 239 for the first 100 hours of the catastrophe. This leaked Tepco document  Open here in original Japanese text: https://docs.google.com/file/d/0B-lM5qg9ztErNGUyMzFkMGUtYTY0NC00YWJhLTg0YjItNmE4MDMzMzAxZTFl/edit?hl=en_US&pli=1
suggests a release of 1.2 trillion bq of pu-238,pu-239,p-240 and pu-241 collectively and 76 trillion bq of Np-239 within the first 100 hours of the catastrophe. Our goal with this study included developing atmospheric dispersion plots of these emissions and modeling radionuclide concentrations at receptors worldwide. We then publish these results to the partMOM application for public analysis.
Which is: Study: Modeling Fukushima NPP Pu-239 and Np-239 Atmospheric Dispersion: Authoring authority: The DataPoke Foundation, a non-profit organization in the state of California, remains dedicated to developing and distributing scientific applications to the public for use free of charge.