Anomalous90Sr deposition during the fall, 1995 at MRI, Tsukuba, Japan

Abstract

We have observed an anomalous 9~ deposition at the Meteorological Research Institute (MR1), Tsukuba, Japan during the fall of 1995. This anomalous 9~ deposition was confirmed by the re-analysis of the sample, the associated lowest 137Cs/9~ activity ratio and high r/s ratio, etc. We discuss the cause of this anomalous 9~ deposition and conclude that the anomalous 9~ may come from an accidental release of nuclear battery, etc,

Atmospheric radioactivity over Tsukuba, Japan: a summary of three years of observations after the FDNPP accident

“…Based on the timescale of this contamination, however, the source should be neither very local nor very small. This episode shows some similarities to the case in fall 1995 in Tsukuba (Igarashi et al 1999b). We also assume unidentified, unreported incidents of burning and/or melting of industrial 90 Sr sources in the Far East region as a possible explanation, such as the Algeciras (Spain) incident in 1998 with its 137 Cs source of The increases seem to be attributable to the transport of primary radioCs from the accident site 3.7 TBq (Estevan 2003).…”