Provided is a method for treating radioactive iodine contained in steam discharged from a nuclear power facility, including a filling step of filling an air-permeable container with a granulated radioactive iodine adsorbent of zeolite X, wherein ion exchange sites of the zeolite X are substituted with silver so that a size of minute pores of the zeolite X is suited to a size of a hydrogen molecule, and the radioactive iodine adsorbent has a silver content of 36 wt % or more when dried, a particle size of 1020 mesh, a hardness of 94% or more, and a water content of 12 wt % or less when dried at 150 C. for 3 h and thereby reduced in weight; and a flow passing step of passing a flow of the steam discharged from the nuclear power facility, through the container filled with the radioactive iodine adsorbent.

The present disclose is directed to a method for controlling iodine levels in wet scrubbers, and, in particular, recirculating wet scrubbers by removing the iodine from the scrubbing solution, such as by using ion exchange, absorption, adsorption, precipitation, filtration, solvent extraction, ion pair extraction, and an aqueous two-phase extraction.

Provided are an adsorbent for trapping a radioactive iodine gas generated in a process of oxidizing a nuclear fuel at a high temperature after use and a method of preparing the same, and more particularly, a radioactive iodine gas adsorbent which is formed of bismuth as a main component, thereby exhibiting an excellent radioactive iodine gas trapping capability and an excellent thermal stability after trapping, and a method of preparing the same. An adsorbent for trapping a radioactive iodine gas prepared by a method of preparing an adsorbent for trapping a radioactive iodine gas according to the present disclosure may effectively trap a radioactive iodine off-gas generated in a nuclear fuel pre-treated oxidizing process after use. Particularly, the adsorbent may trap iodine in a larger amount, which is twice or more, than a silver-containing zeolite widely used to trap a radioactive iodine gas, and the trapped iodine forms a stable compound, which is more advantageous for long-term storage. In addition, since an iodine gas is trapped using inexpensive bismuth, instead of expensive silver, in consideration of trapping a large amount of a radioactive iodine gas, the adsorbent has very excellent economic feasibility.

Provided are a filtration material for filtered venting and a filtered venting device that are more effective in adsorbing radioactive iodine than in the conventional art and are useful for addressing severe accidents. The filtration material for filtered venting comprises granulated zeolite L, wherein at least a portion of the ion exchange sites of the zeolite L are substituted with silver. Of the ion exchange sites, a constitution ratio (a/b) of ion exchange sites (a) substituted with silver to ion exchange sites (b) not substituted with silver is 25/75-55/45. The zeolite L has a silver content of 7-12 wt % on a dry weight basis.

The phosphazene covalent organic framework (COF) is a material with high efficiency to improve the removal of iodine from nuclear waste. The COF can be obtained by a solvothermal reaction of hexa(4-formyl-phenoxy)cyclotriphosphazene and 1,3,6,8-tetra(aminophenyl)pyrene. The resulting three-dimensional phosphazene COF has iodine uptakes as high as 9.4 g g.sup.1 due to its 3D framework with higher specific surface areas and interconnected channels.

The phosphazene covalent organic framework (COF) is a material with high efficiency to improve the removal of iodine from nuclear waste. The COF can be obtained by a solvothermal reaction of hexa (4-formyl-phenoxy)cyclotriphosphazene and 1,3,6,8-tetra(aminophenyl)pyrene. The resulting three-dimensional phosphazene COF has iodine uptakes as high as 9.4 g g.sup.1 due to its 3D framework with higher specific surface areas and interconnected channels.

The phosphazene covalent organic framework (COF) is a material with high efficiency to improve the removal of iodine from nuclear waste. The COF can be obtained by a solvothermal reaction of hexa(4-formyl-phenoxy)cyclotriphosphazene and 1,3,6,8-tetra(aminophenyl)pyrene. The resulting three-dimensional phosphazene COF has iodine uptakes as high as 9.4 g g.sup.1 due to its 3D framework with higher specific surface areas and interconnected channels.

Disclosed is an apparatus for reducing floating radioactive material in a containment building capable of reducing radioactive material in the event of a major accident in a containment building such as a nuclear power plant. A radioactive material reduction unit configured to reduce radioactive material in the air is provided upstream of a flow induction unit configured to induce an air flow through catalytic reaction with hydrogen in the air in the event of a major accident. The flow induction unit may have a replaceable modular form. The radioactive material reduction unit may include an adsorber module configured to remove gaseous radioactive material, such as iodine or an iodine compound. The adsorber module may have a replaceable modular form. In addition, the radioactive material reduction unit may further include an aerosol filter fixed to an inlet to remove particulate radioactive material.

Implementations are described herein that include producing sorbents that include a polymeric material and a zero-valent metal. An amount of radioactive iodine can be captured using the sorbent to produce iodine-loaded sorbents. Additionally, the iodine-loaded sorbents can be encapsulated in one or more metallic materials.

The phosphazene covalent organic framework (COF) is a material with high efficiency to improve the removal of iodine from nuclear waste. The COF can be obtained by a solvothermal reaction of hexa(4-formyl-phenoxy)cyclotriphosphazene and 1,3,6,8-tetra(aminophenyl)pyrene. The resulting three-dimensional phosphazene COF has iodine uptakes as high as 9.4 g g.sup.1 due to its 3D framework with higher specific surface areas and interconnected channels.