Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
  • G21F9/04—Treating liquids
  • G21F9/06—Processing
  • G21F9/10—Processing by flocculation
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
  • G21F9/04—Treating liquids
  • G21F9/06—Processing
  • G21F9/12—Processing by absorption; by adsorption; by ion-exchange

Definitions

• Microcrystalline, difficultly soluble salts which are isotopic with radioactive ions, are formed by precipitation on the surface of a support in an agitated liquid suspension of the support.
• a liquid in which said radioactive ions are dissolved is passed through a column and contacted in said column with said salts bonded to the surface of the support. This results in an isotopic exchange between said salts and ions.
• radioactive sewage can be purified by an ion exchange.
• the ions of the crystal lattice of a precipitate are in a state of thermodynamic equilibrium with the isotopic ions which are present in a solution (liquid phase) in contact with the precipitate (solid phase).
• a solution liquid phase
• solid phase precipitate
• Ions which were originally in solution occupy sites in the lattice of the solid phase and ions of the lattice are dissolved.
• the contact times are of an order of seconds.
• the radioactive solution is sucked through a thin layer of a difiicultly soluble salt which has just been precipitated.
• the process according to the invention enables a rapid and complete exchange of isotopes and an ultimate reduction of the radioactive matter to a very small volume.
• the following significant aspects are considered:
• Difi icultly soluble salts of various systems can be prepared in microcrystalline form and fixed in a fine three-dimensional distribution (impregnation).
• the wadding which is impregnated with the difiicultly soluble salts can be stored and does not lose its exchange capacity and may be used without need for preceding chemical operations such as precipitation or the like.
• the impregnated wadding has a high exchange capacity so that it can be used in a column process for decontaminating large amounts of liquid.
• EXAMPLE 1 The precipitation with equirnolar amounts results in a formation of approximately equivalent crystals, which are free of a surplus of cations or anions at their surface. This prevents the formation of a double electrical layer at the crystal-soultion phase boundary; such double electrical layer could result in undesired secondary effects.
• EXAMPLE 2 The wadding is impregnated as in Example 1 but YCl .6H 0 and Na HPO are used instead of Sr(NO EXAMPLE 3
• the wadding is impregnated as in Example 1 but Sr(NO and YCl .6H O are added at the same time and are precipitated simultaneously with a solution of Na SO and Na HPO
• EXAMPLE 4 The wadding is impregnated as in Example 1 but AgNO and an NaI solution are used.
• EXAMPLE 5-DECONTAMINATION 0.5 gram of a cellulose wadding impregnated according to Example 3 was suspended in H 0 and introduced in a column 30 centimeters long and 2.5 centimeters in diameter. The cellulose column had a height of 5 centimeters. A cock and a superimposed frit slab were provided at the lower end of the column. In other experiments, the frit plate in the column was replaced by glass wool so that a high flow rate was obtained.
• An Sr-90 stock solution which contained 23 milligrams Sr(NO 100 milliters as a carrier, 0.5 milliliter was pipetted from said stock solution and filled up to 10 milliliters. The activity was measured in a liquid counting tube and amounted to 14678 pulses per 30 seconds as an average of 10 measurements. These 10 milliliters were diluted to 250 milliliters and the diluted solution was passed through the prepared column at a flow rate of about 200 milliliters per minute. Various samples of 10 milliliters each were taken from the effluent and measured. It was found that the activity of the total volume was about 40 pulses per 30 seconds, which is less than 0.3% of the original activity.
• a process of extracting dissolved radioactive ions from a liquid which comprises passing said liquid through a column and contacting said liquid in said column with microcrystalline, ditficultly soluble salts, which are iso topic with the dissolved radioactive ions and bonded to the surface of a support, to effect an isotopic exchange between said difiicultly soluble salts and said dissolved radioactive ions, said support consists of a loose, bulky material, and said salts being dispersed Within said material.
• said support consists of a substance selected from the class consisting of cellulose acetate and cellulose nitrate.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Measurement Of Radiation (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7526060

Family Applications (1)

Country Status (4)

Cited By (4)

Families Citing this family (4)

• 1966
  • 1966-07-11 DE DE19661564656 patent/DE1564656A1/de active Pending
• 1967
  • 1967-07-05 GB GB30864/67A patent/GB1146794A/en not_active Expired
  • 1967-07-10 FR FR1583660D patent/FR1583660A/fr not_active Expired
  • 1967-07-10 US US651977A patent/US3563890A/en not_active Expired - Lifetime

Also Published As

Similar Documents