Tokyo Electric Power Co. (TEPCO) operator of the stricken Daiichi nuclear power plant in Fukushima prefecture said Tuesday cooling operations were stopped at its No. 4 reactor unit's spent fuel pool, due to workers damaging an electrical cable. TEPCO in a statement said that workers who were drilling at the time damaged the cable while they were drilling near electrical equipment, causing an alert and the shut down of cooling at the No. 4 spent fuel pool as well as the halting of an ongoing operation to remove hundreds of spend nuclear fuel rods from the spent pool. The beleaguered utility said that the resumption of operations to start cooling operations would take approximately two hours and that the temperature of the water was unlikely to rise to levels deemed dangerous. TEPCO was first made aware of the incident at around 9:40 a.m. this morning and the utility said the cooling system shut down approximately five minutes later. The operator of the plant, which saw multiple meltdowns following a massive earthquake-triggered tsunami knocking out the plant's vital cooling systems in March 2011, sparking the worst nuclear accident since Chernoybyl in 1986, also said Tuesday a fire was triggered by the damage to the cable, although workers were able to extinguish this, the utility said. Since the initial meltdowns, TEPCO has been beset with a myriad of problems, the latest of which saw the utility on Feb. 13. state that samples of water it tested contained radioactive cesium at levels"never seen before"by the embattled utility. TEPCO said there was a new leak at the site of a well located just 50 meters from the adjacent Pacific Ocean and confirmed that the levels of cesium found in its groundwater samples were as high as 54,000 becquerels per liter of cesium 137 and 22,000 becquerels per liter of cesium 134. The levels of cesium detected were 600 times higher that the government regulation for contaminated wastewater allowed to be released into the ocean, with the samples testing 30,000 times higher for cesium 137, compared to samples taken just a week earlier. The utility has failed to locate the source of the leak, in another major failing of TEPCO to contain the ongoing nuclear crisis. The Japanese government on Jan. 15 injected 4 trillion yen (38. 3 billion U.S. dollars) in additional state backing to help the ailing utility deal with a string of mishaps at its facilities as it works towards decommissioning its stricken, yet volatile reactors. Despite the injection of fresh capital, TEPCO is still eying dumping toxic water into the Pacific Ocean as it fails to contain in makeshift storage tanks -- the source of a number of previous leaks -- a massive daily influx of water needed to cool the battered reactors, while nuclear experts believe that other methods need to be traversed before contaminating the ocean. Dumping radioactive water into the ocean is of grave concern to local fisheries cooperatives as the potential for radioactive materials to spread to marine life remains a distinct possibility, despite TEPCO's assurances the levels of radioactivity will be kept well below the government's and regulator's limits. The overall decommissioning of the plant is expected to take around 40 years, with the removal of all nuclear fuel from the No. 4 reactor building being completed by the end of this year, however, TEPCO said it had only successfully removed around 9 percent of more than 1,500 unused and spent fuel assemblies in the reactor building's storage pool.