| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a zinc injection method which is capable of further increasing a zinc ion concentration of an aqueous carbonic acid solution including zinc ions, which is to be injected into a nuclear reactor pressure vessel, and is capable of suppressing precipitation of zinc.SOLUTION: A zinc injection device 1 provided with a closed loop including a carbon dioxide gas dissolution tank 2 and a zinc dissolution tank 3 filled with a zinc oxide is used for zinc injection to water supply piping. An aqueous carbonic acid solution generated by release of carbonic acid gas from a carbonic acid gas supply pipe 17 to the carbonic acid gas dissolution tank 2 is supplied to the zinc dissolution tank 3 to dissolve zinc in the zinc oxide in the zinc dissolution tank 3. The aqueous carbonic acid solution containing zinc is circulated in the closed loop to increase the zinc concentration. In an injected liquid tank 39 of a pH controller 14, an aqueous carbonic acid solution is generated by supply of carbonic acid gas from the carbonic acid gas supply pipe 17. The aqueous carbonic acid solution not containing zinc in the injected liquid tank 39 is injected to a zinc injection pipe 28 to which the aqueous carbonic acid solution containing zinc is discharged, so that the zinc concentration of the aqueous carbonic acid solution in the zinc injection pipe 28 is reduced.</p> |
