DE2039130C - Process for the disposal of crushed, solid, radioactive waste materials - Google Patents

Description

3 '4

Risk of tripping due to underground water mixes and the highly active, crushed, solid waste

carefully balanced against the surrounding formation introduced into the mixture, its amount to

let be. Limitation of the radioactive components of the

It is known that low- and medium-level waste is measured. This mixture will be Mitstollc in subterranean chambers or caverns, which lead to the setting of the cement components, the lack of the mixture with cement or other means when it is introduced into the borehole are sealed. Weakly active waste materials exist and delay the break-up of formalities and a generally from liquid solutions in which the water phase in the mixture is kept upright. To relatively small amounts of radioactive substances after the introduction of the radioactive cement mixture solves are. These solutions require large storage io in which formation breaks will be a no radiovoluincn in proportion to the weight of the cement slurry contained in the active ingredients in Solution contained radioactive studs. As the Er- pumps the borehole and hardens therein to form The increase in the generation of radioactive substances is one of a kind. Preferably it is not radioactive Removal of low-level waste materials containing active ingredients in cement slurry unsatisfactory because the available underground 15 the formation fractures in the radial direction between forma'.ionen see the borehole and the radioactive cement have a limited capacity, mixture introduced, and it is through the drilling

Strongly active waste materials contain solid, insoluble loüi passed over the formation fractures water, Particles that generate a high degree of radiant energy in order to remove Ze me- * from the borehole and witness. So far they have been formed by yawing these 20 sealing rings out of cement, which do not contain any radio particles containing concrete blocks eliminated, which contains active substances and radially between the drilling then be submerged in deep ocean waters. hole and the radioactive material. Here The from these solid, highly active waste materials are proceeded in such a way that in an escaping strong radiation requires a corresponding first formation breakup, a first migratory end Shielding these waste materials. Such shearing of liquid cement and radioactive shields are costly. In addition, there is material introduced and made to harden therein always the risk of breaking the screens and that is followed by a second mixture of of the carrying away of released radioactive waste - liquid cement and radioactive material into one substances from the ocean currents. resulting second formation break-up introduced

From US Pat. No. 3,262,274 there is a ver 30 which lies vertically above the first opening and

drive to the removal of solid radioactive waste adjoining these and binding there, and that

Fall materials known, with the dry cement with finally to the formation of the closing ring of the none

mixed with aqueous liquid and then a cement containing radioactive components

the mixture containing solid waste and cement slim; η in the formation breakup radially between

while maintaining a continuous fluid 35 the borehole and each of the vertically stacked

Keitphase is pumped into a borehole. These mi-lying and independently vor.cinarder hardened

Schung \ .ird is pressurized mixtures of cement and radioactive material in the vicinity of a formation

set to break this up, whereupon the mixture is led.

is pressed into these formation eruptions and the The invention is intended in detail on the basis of

Mixture sets within the cracks. 40 drawing will be explained, in which schematically a

From British patent specification 1 054 740 there is a device for carrying out the invention

also known, a liquid radioactive cement-based method is illustrated, for example.

Mixture to add means that shows the setting of the Es

Cement component of the mixture when introduced in FIG. 1 a borehole and a mixing device

the borehole and in the formation breakthroughs 45 for the rapid mixing of dry cement, fluids

hesitating and introducing a liquid phase in the mixture of liquid and solid radioactive substances

maintained, as well as after the introduction of the tion into an earth formation through the borehole; radioactive cement mixture in the formaiionsauf- F i g. 2 shows an effective method of introducing

Fractions of a radioactive waste do not contain any radioactive components in a ring-forming one Cement slurry to pump into the borehole oo mige underground zone and the completion of the

and harden therein to form a termination. radioactive material through a ring-shaped, not

The invention is based on the object of providing a radioactive cement-containing closure that the drilling

Method of removing solid radioactive hole surrounds, and

To develop waste materials, in which the forma- Fig. 3 is a modification of Fig. 2, wherein a

For this purpose, solid waste materials pumped into the air are combined with a single, non-radioactive cement ring for insulation

be used to keep these fractures open, and several superimposed radioactive layers the solid waste is continuously used in a th against a borehole, suspended aqueous cement mixture and In F i g. 1 is a fall through a formation 2

be evenly distributed therein. drilled hole with a cemented lining

According to the invention is proceeded in the manner, 60 tube 4 is shown. In the casing 4 runs in that dry cement with at least a conventional way a cementing tubing 6 with 95 volume processor i. Water containing liquid a packer 8, which is shown schematically on the lower mixed, this mixture is stirred and indicated in the liquid end of the pipe string 6. In suitable cement mix the crushed, solid, radioactive ter depth, the packer 8 is expanded to a for-waste is entered while stirring at the same time. 65 mation zone 10, which according to the invention

According to a further feature of the invention, the method according to the invention is to be broken, for preparing the mix of dry cement The casing 4 is conventionally in the with aqueous, liquid, radioactive waste ge Zone 10 perforated to get between it and the interior

of the casing pipe 4 to establish a connection. The lining pipe 4 extending under zone 1 (1 can also come in Forlfall, or its lower Hilde can be above zone 10, in which case it does not need to be perforated / u before the formation is broken.

For mixing dry pen-shaped cement with dry, granular, water-insoluble, highly active, radioactive waste is served by one shown in FIG. 1 drawn mixing device. The cement is stored in a container 12 and mixed with liquid consisting of medium or to form a sludge consists of highly active radioactive waste and water and is supplied from a storage container 14 is. One such device for mixing dry cement and liquid to form a Cement slurry is z. B. described in Chapter 14 of the book "Petroleum Engineering" by Gatlen (Prentiss Hall Inc. 1960). The aqueous cement slurry is conveyed into a mixing container 16, in which a power-driven stirrer 18 for continuous Movement of the liquid is arranged. A container 20 becomes dry, granular, highly active, solid radioactive waste in the mixing container 16 conveyed in a certain ratio to the amount of cement fed into the container 12, what is continuously monitored and measured, such as See, for example, the U.S. Patents to Hathorn et al 3 161 203 or Copland et al 3IWO4. « is. By such measurement, the ratio of radioactive solids to the total amount can be determined the mixture can be regulated. As a result, an operator can be sure that enough solid materials are used to support the formation and too high a solid content Substances are avoided, which would prevent the hybrid and break-up processes.

In the container 16 are means for reducing friction and with the cement slurry mixed to delay the setting of the cement. Such means of retarding setting of cement in a borehole are e.g. B. in the cited book by Gatlen on page 273 described.

When the sludge is completely mixed and the solid radioactive waste is evenly distributed in it is, it is introduced into the cementing pipe 6 under pressure by means of a pump 22. The pressure the cementing liquid must be large enough to cause lateral cracks 24 in zone 10, into which the cement sludge flows. Because solid radioactive waste granules in the sludge is contained, the waste materials are embedded in the breakouts 24. Pumping continues until essentially all of the high level waste materials have been deposited in the breakouts.

In the breakout 24, the solid radioactive waste granulate G acts as a support means that keeps the breakout open. This is ensured by the walls 24a and IAb of the fracture in cooperation with the solid waste material, which at the same time prevents it from escaping from the borehole during the setting of the mud.

In the Zemcnticrungsrohr 6 is after the radioactive Sludge introduced additional cement sludge that does not contain radioactive substances and is in the container! 6 has been mixed, whereby the Lining pipe 4 above the packer 8 is sealed.

It is recommended to use the mud with means for Delay the setting of the mix to allow enough time to pump the mud into the cracks remains before the sludge can be pumped over will.

The solid, slag-active waste is usually in the form of sand or gravel. The usually sharp-angled When the breaking process is carried out, the shape of these substances corresponds to that according to the invention Method particularly advantageous. The sharp corners of the particles resist their displacement against each other and against the walls of the opening, and the particles thereby act as trapped Outriggers to keep the sediment open when the cement is being pumped into the formation and while the cement hardens.

To support the removal of radioactive waste, it is advisable to use the liquid Mix radioactive waste with water before the

so resulting liquid is mixed with cement.

The total radioactive content of the sludge should however sufficient) are kept low so as not to endanger the health of the workforce.

It is particularly important that the resulting

he concrete structure is impermeable to liquids. There Water can flow through or around the formation in which the radioactive waste has been deposited there is a risk that radioactive substances will be washed out of the concrete if it is sufficient is porous to allow water to flow through the interior of the concrete. It has shown, that the sludge according to the invention is a non-porous Concrete structure results because it does not contain emulsifiers or significant amounts of oil or other Contains additives that could cause porosity in the concrete. In particular, the Zcmcnlschlamm less than 5 ° / o of oil or other liquids which do not react with the hydraulic cement. If larger amounts of Oil or other liquids contained in the sludge can generate or form gas cause of pockets or generally contribute to a permeable concrete formation, which is undesirable is.

In Fig. 2 illustrates a method of counteracting radioactive mass dispersed in cement to isolate a borehole.

As shown, a lenticular cement layer 25 containing solid radioactive material 26 is has been introduced into a formation fracture 27 in the manner described above. After that Cement slurry containing radioactive material becomes a non-radioactive material Cement slurry, e.g. B. a ven radioactive material free hydrous cement, introduced into the borehole and pumped back into the formation.

On this mass or this plug of radioactive cement, water gets so far into the borehole 29 filled in that an annular closure 28 is formed within the opening 27. This End ring 28 is allowed to harden while the water in borehole 29 is maintained under pressure. the hardened cement closure ring 28 forms an effective plug and isolates the borehole 29 from the radioactive layers 25, reducing the risk of leakage or leaching of radioactive material from the lenticular deposits 26 into the borehole decreased Aird.

7 8

Γ i g. 3 shows a further embodiment of FIG. 2. By measuring the solid radioactive waste site

After the lenticular radioactive waste has formed during the mixing process, it becomes effective Storage 25 the non-radioactive final control is preserved. Those included in the mix ring 28 hardened and a subsequent lenticular solids can be precisely regulated so that Deposition 30 formed from radioactive material, 5 a mixture is obtained through a borehole how this can essentially be pumped with reference to FIG. To regulate the in the has been written. This process of forming the solids contained in the mixture becomes the entire Adjacent layers superimposed from the radioactive material content of the mixture Cement-containing material can be carried away. By dispersing the solids in the continues until a number of several successive sludges and their inclusion in the stacked by them Lenticular layers have been formed supported fractures or crevices is. the radioactive material effectively in the formation

The breaking up effect of each lenticular spread, this reduces the harmful effects

Layer is created after the formation of a previous layer of the heat generated by the radioactive material,

facilitated by the unevenness of the previously formed 15 The use of the solid radioactive substances as

th layers and the neighboring formations. The means to support the openings has two effects

As a result of this unevenness, the zone can easily bulge. The material is held in place by a »boot-strab« -

break. Technique the formation breaks open so that this

After the desired number of over- absorb larger amounts of the radioactive waste other layers have been formed, can ao can. The solid radioeins used as props Final layer 31 made of radioactive free active substances are effective in the breakouts Cement can be introduced, as was the case with the ab- trapped by the formation itself. Infollowing ring 28 of FIG. 2 has been described. this increases the risk that solid, highly active waste

The inventive method allows the substances to migrate back into the borehole before the

Removal of highly active solid waste in one »5 cement has set, substantially reduced or

compartments and safer ways without the risk of even being completely avoided.

Damage to staff. As the solid waste in the ring-shaped radioactive free closure, the

solid form is deposited, that is to deposit radially between the borehole and a through

Required volume is significantly smaller than the breakup formed with radioactive material

other methods, in which the solids is dissolved, prevented in an extremely simple, but special way

or otherwise converted into liquids, effectively causing radioactive contamination of the

which will then be eliminated. You can also use the borehole. With this conclusion the borehole

Carrying out the method according to the invention again and again without the risk of being present

Existing cementing equipment used radioactive material produced in the borehole

are used to introduce radioactive substances so that no additional or new provisions are required

directions need to be procured. will. This advantage in terms of security

An essential advantage of the invention is achieved without the borehole itself blocking or having to be clogged for mixing the cementitious material.
and the solid radioactive waste only takes a small amount of time. As a result of this time saving, 40 is used to isolate several superimposed lenses also the risk of radiation damage in the case of Mi- shaped layers of introduced radioactive vision from dry cement with liquid radio material. This utilization of the ring-active waste and the subsequent immediate closure saves time for the feasible additions to the solid radioactive waste of the closure process, as well as significantly reducing the amount required for this. 45 such materials and devices.

1 sheet of drawings

Claims (5)

1 2 of the vertically superimposed and independent patent claims: gig mutually hardened mixtures of cement and radioactive material is conducted. 1. Procedure for removing crushed,
solid radioactive waste, for which a 5th the shredded waste and water contain running liquid cement mixture while maintaining a continuously distributed liquid phase pumped into a borehole and this The invention relates to a method for Mix in the vicinity of a formation while removing crushed, solid, radioactive printouts is set in order to break it open, worm fiber, one of which is the shredded waste material on the mixture into the resulting forma- and water-containing liquid cement mixture tion ruptures is pressed and within the while maintaining a continuously distributive ruptures sets, thereby pumped the identified liquid phase into a borehole and shows that the mixture before its pumping 15 this mixture in the vicinity of a formation pen is produced in the borehole by applying pressure to break it open, whereupon dry cement with a volume of at least 95% of the mixture in the resulting formation Wu: .ser containing liquid breaks and is pressed within the breakouts mixes, this mixture is stirred and sets in the liquid. Cement mix of crushed, solid, radio- 20 The use of atomic energy to generate active waste with simultaneous stirring or for other purposes has an accumulation will give. of radioactive waste, which is so 2. The method according to claim 1, characterized in that it identifies the public security, that does not endanger the preparation of the mixture. The radioactivity of these substances the dry cement with water-based, liquid disintegrates so slowly that a long time passes before the Like, radioactive waste is mixed in that the waste materials are harmless enough for them to get through highly active, crushed, solid waste is fed into the mi-dissolution or other conventional process in: inrt, whereby its quantity can be eliminated. The radioactive waste delimitation of the radioactive components of the Mi- must be shielded during their decay, Schung is measured, and that this mixture 30, the shielding to be sufficiently impermeable Agents are mixed in that must bind the radioactive substances through or Cement component of the mixture can escape around the shielding when it is inserted. Ren into the borehole and formation fluid radioactive waste is generally used Delay breaks and a water phase in the three groups weakly active, moderately active and Maintain mix. 35 strongly active. Low-level waste has im 3. The method according to claim 1 or 2, characterized in general liquid form with solution of the radioactive. that after the introduction of the ven components in a liquid, the water or radioactive cement mix in the formation can be another liquid. For example can If a solution does not contain radioactive substances, the weakly active waste will be a solution containing radioactive substances Cement slurry in the borehole containing active isotopes such as strontium 90 and cesium 137, is pumped and contains therein to form an Ab-. The specific gravity of the weakly active Losing hardens. Waste solution can be greater than 1, and the radio 4. The method according to claim 3, characterized ge activity of the waste is less than 10 ^B Curie each indicates that the no radioactive loading gallon. cement sludge containing constituents in the 45 medium-active liquid waste has a radio-formation fracture in the radial direction between activity levels in the order of magnitude of 0.01 to see the borehole and the radioactive 1.0 Curie per gallon. This waste is created by haupi cement mix is introduced and that neuter in the chemical processing of bedurch the borehole above the formation fractures radiated fuel elements, the splittable material Water is passed to contain from the borehole 50. Removing cement and an end ring made of highly active liquid waste has a radioactive To form cement that did not contain any radioactive material greater than 100 curies per gallon. This contains high and radially between the borehole and active liquid waste arises during the work-up of the radioactive material. Fuel assemblies. Highly active liquids and 5. The method according to claim 4, characterized in that the sludges are usually aqueous solutions or indicates that in a first thin liquid suspensions of disintegration products. in the Formation fracture a first mixture of general, these liquid wastes have a radio-liquid cement and radioactive material activity between 500 and 10,000 Curie per gallon, and hardened therein, Except these various liquid wastes that then a second mixture of fluids must also be disposed of, the solid waste Sigen cement and radioactive material in one are highly radioactive. Has high active solid waste A radioactivity between 500 and 100,000 Curie occurred that will lead vertically above the first break per gallon. Solid waste can be used up and adjoins and sets there, material that is sintered, or granular products and that subsequently to form the final 65 contain a fluidized bed, through the highly active ring of no radioactive components containing liquid waste converted into granular solids tends cement slurry in the formation. When these solids break underground be radially between the borehole and each chert, the storage parts must because of the