One tera becquerel equals 1 trillion becquerels.
At that time, the estimated cesium release was 'equal 168 Hiroshima bombs' as the atomic bomb atomic bomb dropped on Japan during World War II had only released 89 tera becquerels of cesium.
On Wednesday, TEPCO released revised estimates of the amount of radiation leaked from Fukushima.
The new estimated calculated the level of cesium released to be 360,000 tera becquerels.
That is 24 times higher than last August's estimate and represents a cesium leak equal to 4,023 Hiroshima bombs.
The estimate is also more than 4 times Chernobyl which is estimated to have released 85,000 tera becquerels of cesium radiation into atmosphere.
TEPCO's newly revised estimates of the Fukushima leak are also not all-inclusive and do not cover the entire date range from the start of the disaster.
The estimate of the total atmosphere release is based on data collected from between March 12 to 31, 2011,
TEPCO states the amount of radiation released into the atmosphere in April and during the following months is likely to be only 1% of the amount released in March.
That amount is considered to be 'insignificant' and is not included in the new estimate.
The estimated amount of radiation leaked into Pacific Ocean was extrapolated from data collected from March 26 to September 30, 2011.
TEPCO warned this data was collected from a 'small amount of data acquired in a limited area' and further warned 'further data still needs to be collected to review the validity' of their estimates.
The new estimate also did not provide figures for the amount of radiation leaked into the water pits that run beneath the Fukushima's nuclear reactors or for radiation leaked into contaminated water that TEPCO has collected into storage tanks.
Last June, TEPCO estimated the amount of radiation leaked into the underground water pits to be up to nearly to two times higher than the amount of radiation released into the atmosphere.