Complex sentence: TEPCO reported that the Caesium-134 levels in the well water were at 9,000 becquerels per Litre, 150 times the legal level, while Caesium-137 measured 18,000 becquerels, 200 times the permitted level.
Split into simpler sentences: TEPCO reported that the caesium-134 levels in the well water were at 9,000 becquerels per Litre, 150 times the legal level. While Caesium-137 measured 18,000 becquerels, 200 times the permitted level.