Constructing method for delaying corrosion of radioactive waste disposal container in concrete disposal vault

A constructing method for delaying corrosion of disposal containers for storing radioactive waste disposed in a concrete disposal vault, the method comprising:

• a first disposal container stacking process, wherein first two or more of the disposal containers are stacked on a bottom surface of the concrete disposal vault and the first two or more of the disposal containers are spaced apart from one another;
• a first backfill filling process, wherein a first backfill is filled and cured, the first backfill being defined by space formed between and over the first two or more of the disposal containers, to form a first layer including the first two or more of the disposal containers and the first backfill;
• a second disposal container stacking process, wherein second two or more of the disposal containers are stacked on a top surface of the first layer and the second two or more of the disposal containers are spaced apart from one another;
• a second backfill filling process, wherein a second backfill is filled and cured, the second backfill being defined by space formed between and over the second two or more of the disposal containers, to form a second layer including the second two or more of the disposal containers and the second backfill;
• a repetitive process, wherein the second disposal container stacking process and the second backfill filling process are repeated to form a plurality of layers including the first layer, the second layer and a top layer, each of the plurality of layers including the respective two or more of the disposal containers and the respective backfill, such that a space is formed on the top layer at a top of the concrete vault;
• a pH control backfill filling process, wherein a pH control backfill including pH control capsules is filled and cured in the space formed on the top layer at the top of the concrete vault;
• and
• a cover stacking process, wherein a concrete cover is stacked on the top of the concrete vault for sealing the concrete vault,
• wherein each pH control capsule includes an alkali metal powder enclosed by a water-soluble cellulose-ether shell and is configured to dissolve upon exposure to rainwater and release the alkali metal powder.