Japan’s Nuclear Safety Commission has revised downward the estimated amount of radioactive substances released from the damaged Fukushima Daiichi nuclear plant. The commission now judges that 570-thousand terabecquerels of radioactive iodine 131 and cesium 137, about 10 percent less than its earlier estimate, leaked from the plant between March 12th and April 5th. The commission put the total at 630-thousand terabecquerels in April, NHK World Radio Japan reported. The new figure was obtained by analyzing freshly released data on radiation levels measured at monitoring posts and amounts of radioactive materials in the air. The commission also believes that leakage of radioactive substances peaked from 1 PM to 5 PM in the afternoon of March 15th when explosions occurred at reactors No. 2 and No. 4. The timing is not much different than the commission’s initial estimate, but the new figures revise downward the amount of radioactive substances released during the period by 60 percent. The Japan Atomic Energy Agency is expressing confidence in its new estimates, saying they are not largely different from earlier ones and are nearly consistent with changes in radiation measurements.