Japan's fight against its nuclear crisis suffered another setback today after efforts to cement a cracked concrete pit at a crippled nuclear reactor failed. The nuclear complex has been spewing radioactivity since March 11, when a mega earthquake and ensuing tsunami knocked out power, disabling its cooling systems and allowing radiation to spill from the overheating reactors. Yesterday, crippled Fukushima Dai-ichi nuclear plant was found to have been discharging highly radioactive water into the Pacific Ocean. Later in the day, Tokyo Electric Power Co. (TEPCO) said it had found a crack in the pit at its No.2 reactor, which they believed was the source of the contaminated water. Soon after the discovery, the plant's operator started filling the pit with cement to seal the crack and prevent more contaminated water from seeping into the ocean. However, after pouring concrete into the pit with a 20-centimeter crack, workers found the crack was still discharging heavy doses of radiation, which was over 4,000 times the legal limit. After the failed attempt, TEPCO's engineers are struggling to devise new tactics such as using water-absorbent polymer to prevent further leakage of contaminated water into the sea.