Liquid Radioactive Waste Disposal Research Articles

Some problems with determination of alpha-active nuclides during decommissioning of nuclear power plant A-1

The first step in decommissioning of NPP is connected with defueling and successful disposal of liquid radioactive wastes (LRW), both from previous production and all work connected with this step. These require precise knowledge about the concentration of radioactive nuclides presented, especially alpha-emitters in all material fluxes arising in sich work (namely shut-down after some accident). This paper reports, results of the determination of U, Pu, Am and Cm by means of both the commonly used and the newly developed radiochemical procedures in various types of materials, e.g., LRW, aerosol filters, ashes resulted from incineration technology, metal surfaces, decontamination solutions etc.

Biological elimination rates of radioisotopes by mallards contaminated at a liquid radioactive waste disposal area.

The biological elimination of nine gamma-emitting radioisotopes was studied in mallards (Anas platyrhynchos) which were released onto liquid radioactive waste pounds in southeastern Idaho. After 68, 75 or 145 days, the ducks were removed from the contaminated environment and placed in metabolic cages. Whole-body and feces-urine counts were made for 51 days and then the ducks were sacrificed and dissected for tissue analyses. The biological elimination of radioisotopes were fit to two compartment models using non-linear least squares estimation. Fecal-urine data substantiated two-compartment elimination of all radionuclides. Biological half-lives in mallards were 10 days (131I), 22 days (140Ba), 86 days (51Cr), 32 days (58Co), 26 days (75Se), 67 days (65Zn), 10 days (134Cs), 67 days (60Co) and 11 days (137Cs). Body burdens in ducks were at 90% of equilibrium with the radioactive waste pond water at the time of removal from the waste ponds. Tissue distribution of radionuclides on the day of removal from the ponds showed gut to have the highest concentrations followed by feather, liver and muscle. After 51 days in metabolic cages, feather had the greatest radionuclide concentrations followed by liver, muscle and gut. Liver contained the greatest variety of radionuclides and muscle the smallest. Biological elimination rates for the major dose-contributing nuclides (134Cs and 137Cs) to humans consuming contaminated waterfowl tissue indicate that the dose to man could be reduced substantially due to the rapid elimination of these radionuclides by mallards. Contaminated waterfowl would receive most of the internal dose in the first month after leaving the contaminated environment indicating that long-term doses would be inconsequential.

Radiation Doses to Waterfowl Using a Liquid Radioactive Waste Disposal Area

Radiation doses from radionuclides in a contaminated environment and from radionuclides ingested were determined for 7 species of waterfowl using a liquid radioactive waste disposal area in southeastern Idaho. Lifetime doses to wild waterfowl from internally deposited radionuclides averaged 700 + 1,000 (SD) mrad with a projected maximum dose of 4,000 mrad. External radiation doses from radionuclides in the waste pond environment averaged 80 ? 20 mrad/day for wing-clipped mallards (Anas platyrhynchos). The average and maximum total doses to wild ducks, from both external and internal radionuclides, were 1,180 and 5,600 mrad, respectively. Waterfowl contained higher radionuclide concentrations and received higher doses from internal radionuclides than other birds and small mammals studied in the liquid radioactive waste disposal environs. The ecological implications of waterfowl inhabiting a liquid radioactive waste disposal area are discussed. J. WILDL. MANAGE. 46(4):905-914 The use of nuclear waste disposal areas by birds and their consequent uptake of radioactive isotopes has been documented (Hanson and Kornberg 1956, Willard 1960, Brisbin et al. 1974, Straney et al. 1975, Domby et al. 1977, Cadwell et al. 1979, Craig et al. 1979, Halford et al. 1981). Although investigators have considered the potential radiation dose to man consuming waterfowl, no literature was found on radiation doses received from internal and external sources by birds frequenting a contaminated waste

Factors Affecting Radionuclide Availability to Vegetables Grown at Los Alamos

AbstractA field study was conducted in 1977 on 238, 239Pu and 137Cs availability to zucchini squash (Curcurbita melopepo, hybrid seneca) and green bush beans (Phaseolus vulgaris, Landreths stringless) grown under home‐garden conditions in an area at Los Alamos National Laboratory used for treated radioactive liquid waste disposal. Radionuclide concentrations were measured as a function of tissue type, height above the soil, fertilization regime, and for the squash, food‐cleansing procedures. Analysis of variance procedures were used to analyze the data.Ratios of the concentration of a radionuclide in oven‐dried vegetation to dry soil ranged from 0.0004 to 0.116 for the Pu isotopes, and from 0.051 to 0.255 for 137Cs. Fertilization with cattle manure reduced the Pu concentration ratios by 30% and 137Cs by 50%. Vegetative parts sampled within 20 cm of the ground surface were contaminated about four times as much as those parts growing further from the ground surface. About 65% of the contamination was removed by washing, indicating the presence of surficial contamination. The 50‐year radiation dose commitment to humans consuming vegetables from the garden plot would be less than 0.05 mrem and would be due almost entirely to 137Cs.

Radionuclide concentrations in waterfowl using a liquid radioactive waste disposal area and to the potential radiation dose to man.

Over 3100 ducks, geese, swans and American coots (Fulica americana) were censused at the Test Reactor Area (TRA) radioactive leaching ponds on the Idaho National Engineering Laboratory (INEL) Site from January 1974 through March 1978. Twenty-six ducks and two American coots were collected from the TRA ponds from January 1974 through December 1977, and tissues were analyzed for gamma-emitting radionuclides. Duck tissues contained up to 29 radionuclides. Total average and maximum radionuclide concentrations were highest in gut followed by feathers, liver, muscle and skin. Chromium-51 had the highest relative radionuclide concentration identified (130,000 pCi/g-gut and 37,500 pCi/g-feathers). Cesium-137 was the predominant radionuclide in muscle with a maximum concentration of 4070 pCi/g. Edible duck tissues (muscle, liver and skin) had lower radionuclide concentrations than non-edible tissues (gut and feathers). The total amount of radioactivity being exported from the TRA environs during the 4-yr study period was estimated to be 5 × 10−3 Ci. Cesium-137, 134Cs, and 131I contributed 98% of the calculated potential radiation dose equivalent to man. The potential whole-body and thyroid dose commitment to man from consuming one waterfowl that was contaminated with the average radionuclide concentrations observed would be 12 and 7 mrem, respectively.

Studies on Dinonylnaphthalene Sulphonic Acid as Liquid Ion Exchanger for Radioactive Liquid Waste Disposal (Part 1)

ジノニルナフタリンスルポン酸を放射性廃液の処理において液体陽イオン交換体として利用することの基礎的研究を行なった。20数種の元素について分配係数を測定して, 選択係数を求めた。選択係数は3価の金属イオンに対してもっとも高く, ついで1価, 2価の金属イオンの順であった。希土類元素に対しては, 選択係数は原子番号の増加とともに減少する。またγ線照射に対するジノニルナフタリンスルポン酸の安定性について検討を行なったが少なくとも4.08×106Rまでは影響がなかった。

Sorption Phenomena Significant in Radioactive Waste Disposal: ABSTRACT

Disposal of radioactive liquid wastes poses a particularly vexing problem, as these wastes contain various radionuclides and chemicals used in processing operations which are potentially dangerous, even in low radionuclide concentrations. Sorptive properties of minerals, particularly ion-exchange reactions, have been studied for potential direct application in waste treatment and for defining the fate of radionuclides when released to soils and geologic formations. Because most waste streams normally contain stable ion concentrations far in excess of radioactive ions, sorption reactions of interest are those which exhibit high selectivity for the radionuclides. Structural and/or steric factors are generally of highest significance in selective reactions. Micaceous minerals selectively sorb radiocesium from high sodium, aluminum, or calcium solutions, primarily because of favorable structure. Zeolitic minerals show selectivity for certain ions by excluding other ions whose size exceed lattice parameters. Some sorbents show selective sorption reactions under particular pH conditions; thus alumina and related hydrous oxides selectively sorb radioactive cobalt and radiostrontium in alkaline sodium systems. In addition to the exchange reactions, sorb nt properties, such as flocculation, swelling, and absorption of liquids and chemical properties of radionuclides, are important considerations in waste-disposal operations and management. In practical applications of the sorptive phenomena in waste disposal, it is necessary to know the solution characteristics, sorbent properties, and formation characteristics, as well as the interactions of these factors. In the hydraulic fracturing technique employed at Oak Ridge, the waste-solution characteristics influence the choice of sorbents used to prepare waste-cement slurries. The high sodium salt concentration requires attapulgite instead of bentonite, and illite is added to fix radioactive cesium. To immobilize the mix after injection underground, cement is added which further complicates the reactions and behavior of the clay slurries. The behavior during injection and ultimate setting of the grout is further influenced by the characteristics of the formation. Each underground disposal operation will require understanding of the environment into which the waste is placed. The final facility and technique should be tailored to meet the requirements of maintaining safe operation, as well as of insuring long-term safety for future generations. End_of_Article - Last_Page 2091------------

Experimental storage of liquid radioactive wastes in deep geologic formations

1. Studies were made on a commercial scale of the disposal of liquid radioactive wastes in deep formations. The equipment and monitoring systems which were installed assured smooth and uninterrupted operation of the plant. 2. The acceptance of the delivery well stabilized at 1.2 m3/day per meter of overpressure after the initial startup and adjustment period. 3. The investigations showed that with favorable hydrogeologic conditions, the disposal of radioactive water in deep formations can be carried out on a commercial scale. 4. Based on engineering and economic calculations, and on operating experience, it was established that underground burial of wastes had an economic advantage over the evaporation method.

Physicochemical conditions of underground disposal of radioactive wastes

1. A basic study of physicochemical conditions necessary to evaluate underground disposal of liquid radioactive wastes was undertaken. 2. Conditions governing burial of decontamination waste streams at the NIIAR site are described. 3. Efficient technological schemes providing for a stable liquid phase with wastes compatible with the geological host medium were arrived at. 4. General conditions for sorption of radioactive isotopes in burial of waste waters in a stratum containing highly mineralized stratal water are discussed.

The NRL high level radiation laboratory: Part I: Structural design and construction features

The High Level Radiation Laboratory of the U.S. Naval Research Laboratory was dedicated in 1964. This laboratory, which was designed as a general purpose radiation facility, has undergone the usual startup procedures and it is now possible to describe this laboratory from the perspective of more than a year of operation. Upon Part I, Structural Design and Construction Features, there will follow in consecutive issues: Part II, Laboratory Functions and Equipment, and Part III, Operating Experience. In this first of the article a description of the main structural design and construction features of the NRL High Level Radiation Laboratory is given, such as: design criteria, hot cell shielding, radiation shielding viewing windows, hot cell access and inter-cell transfer facilities, cell electrical services and in-cell lighting, ventilation system, liquid radioactive waste disposal system, safeguards system.

Hydrologic Considerations in Deep-Well Disposal of Radioactive Liquid Wastes: ABSTRACT

Disposal of radioactive liquid wastes through deep wells may be categorized as containment or confinement. Containment means the placement of wastes under conditions that preclude their movement out of a definable zone. Confinement means the placement of wastes in a zone where movement may take place under restricted conditions that can be controlled or monitored. Disposal of liquid wastes on a continuing basis by containment probably is not practical except for small quantities and may be possible in only a few areas. It is probable, therefore, that any deep disposal of radioactive liquid wastes will be by confinement of wastes in certain geologic zones through which they will move at measured rates. Hydrologic principles applied to the available data indicate that there is circulation of fluids in almost all sediments. Movement of fluids tends to be restricted in the basal parts of sedimentary basins, but any assumption that wastes introduced into a basin would not eventually move out of the basin or to the near-surface formations should be carefully scrutinized. Introduction of wastes into an anomalously low-pressure zone should not be considered safe unless the reasons for the low pressure can be explained. Data necessary to define the hydrodynamics of fluids injected through deep wells will be expensive to obtain, and many of them will have to be collected for each particular disposal site. Geochemical factors may influence greatly the movement of radioactive material in deep formations. A system of monitoring, and possibly removal, is a prime requisite of deep-well disposal of radioactive wastes. Initial disposal activities necessarily will be on an experimental basis pending the results of such monitoring. End_of_Article - Last_Page 2073------------

The thermal factor in the problem of inserting radioactive wastes into mineral deposits

The disposal of liquid radioactive wastes of radiochemical industry establishments is a complicated problem. One of the possible solutions of the problem now being considered is the insertion of the wastes into deep formations of the earth's crust. As a result of the radiation from the wastes, heat is generated and the temperature of the surrounding medium is increased, thus producing the problem of determining the temperature to which the medium is heated.

Studies on Liquid Entrainment

Bursting of gas bubbles was experimentally studied, using the liquids listed in Table 1. Large drops were caught on a slide coated with a mixture of vaseline and light mineral oil, and the diameters of the drops were measured through a microscope.The relation between the diameter of the gas bubble and the height which the drops entrained above the gas-liquid interface is shown in Figs. 3, 4 and 5, and the relation between the diameter of the gas bubble and the diameter of the drops is shown in Fig. 6. The velocity of the rising drops was calculated from Eq. (3).In the next stage, a general theoretical formula was derived for the case in which several drops were formed from a single bubble:where, N is the number of drops. Comparison of the theoretical values of the velocity of drops with the experimental data shown in Fig. 9 may verify the adequacy of the above equation, except for the case of liquids with high viscosity.A natural circulation type evaporator for radioactive liquid waste disposal was constructed, and overall decontamination factor was obtained. The factor ranged over 105 to 107 for vapor mass velocities of 200-3, 000 kg/mm2hr as shown in Fig. 12.