From NHK News :
" Tokyo Electric Power Company, or TEPCO, is set to replace leaky plastic hoses that brought cooling to a halt at the Number 5 reactor at the Fukushima Daiichi nuclear plant.
TEPCO is now searching for potential leaks and will replace these hoses. A large number of the polyvinyl chloride hoses are being used in the reactor's heat removal system.
TEPCO found water leaking from a large crack in a hose around the outlet of a temporary pump sending seawater into the Number 5 reactor's cooling system on Sunday. The cooling system was stopped for 3-and-a-half hours to replace the hose.
The operator says the hose cracked because it was bent at an acute angle and was under pressure.
The company fears other hoses may crack and will search for possible trouble and replace them.
TEPCO adds that no replacement is required for hoses that transfer highly radioactive water because they are not bent at extreme angles."