Patent Number: 
Section: claims

1. A reactor containment vessel basket configured for placement in a reactor containment vessel that includes a spray device having a spray ring mounted near an inside ceiling of the reactor containment vessel so that the basket is subject to spray from the spray ring, the basket comprising:an upper surface opening which is formed on an upper surface of the basket;a lower surface opening which is formed on a lower surface of the basket and is covered by a mesh wire net; anda plurality of containment units arranged with predetermined first spaces in a stacked manner in a length direction, each of the containment units being configured to contain a pH adjuster and to allow for said spray from the spray ring to contact each of said plurality of containment units. 2. The basket according to claim 1, further comprising a plurality of partition plates respectively provided in the first spaces between the containment units. 3. The basket according to claim 2, wherein the partition plates are inclined with respect to a lateral direction. 4. The basket according to claim 3, further comprising a plurality of inflow guide plates which are formed in a plate shape extending upward in the height direction, respectively provided on an upper side end of the inclined partition plates, each of the inflow guide plates guiding the solvent that flows into each of the containment units. 5. The basket according to claim 3, further comprising a plurality of outflow guide plates which are formed in a plate shape extending downward in the height direction, respectively provided on a lower side end of the inclined partition plates, each of the outflow guide plates guiding the pH adjuster solution that flows out from each of the containment units. 6. The basket according to claim 1, wherein each of the containment units includes a plurality of divided containment units divided at predetermined second spaces perpendicular to the first spaces. 7. The basket according to claim 6, wherein the second spaces between the divided containment units are formed to extend along a flow direction of the pH adjuster solution. 8. A pH adjusting device including the basket according to claim 1 comprising:a cooling water inflow vessel that is configured to contain the basket therein and that is configured to store cooling water therein; anda cooling water outflow unit that causes the pH adjuster solution produced from the pH adjuster dissolved in the cooling water in the cooling water inflow vessel to flow out. 9. The basket according to claim 1, whereinthe upper surface opening is covered with a coarse mesh wire net, andthe mesh wire net of the lower surface opening is finer than the coarse mesh wire net.