BENTONITE-QUARTZ SAND AS THE BACKFILL MATERIALS ON THE RADIOACTIVE WASTE REPOSITORY

An investigation of the contribution of quartz sand in the bentonite mixture as the backfill materials on the shallow land burial of radioactive waste has been done. The experiment objective is to determine the effect of quartz sand in a bentonite mixture with bentonite particle sizes of -20+40, -40+60, and -60+80 mesh on the retardation factor and the uranium dispersion in the simulation of uranium migration in the backfill materials. The experiment was carried out by the fixed bed method in the column filled by the bentonite mixture with a bentonite-to-quartz sand weight percent ratio of 0/100, 25/75, 50/50, 75/25, and 100/0 on the water saturated condition flown by uranyl nitrate solution at concentration (Co) of 500 ppm. The concentration of uranium in the effluents in interval 15 minutes represented as Ct was analyzed by spectrophotometer, then using Co and Ct, retardation factor (R) and dispersivity () were determined. The experiment data showed that the bentonite of -60+80 mesh and the quartz sand of -20+40 mesh on bentonite-to-quartz sand with weight percent ratio of 50/50 gave the highest retardation factor and dispersivity of 18.37 and 0.0363 cm, respectively. Keywords: bentonite, quartz sand, backfill materials, radioactive waste

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THE USE OF FLY ASH AND ZEOLITE MIXTURE AS BACKFILL MATERIAL IN THE RADIOACTIVE WASTE REPOSITORY

Indonesian Journal of Chemistry ◽

10.22146/ijc.21808 ◽

2010 ◽

Vol 5 (3) ◽

pp. 302-308

Author(s):

Herry Poernomo ◽

Noor Anis Kundari ◽

Burhani J W

Keyword(s):

Fly Ash ◽

Radioactive Waste ◽

Dispersion Coefficient ◽

Nitrate Solution ◽

Fixed Bed ◽

Weight Ratio ◽

Weight Percent ◽

Backfill Material ◽

Fly Ash Zeolite ◽

Effective Dispersion

An investigation of the contribution of fly ash in the fly ash-zeolite mixture as the backfill material on the shallow land burial of radioactive waste has been done. The experiment objective is to know the effect of zeolite particle size and fly ash-zeolite weight ratio on physical properties such as permeability (K) and dispersion characteristic such as effective dispersion coefficient (De) in the fly ash-zeolite form as backfill material. The experiment was carried out by the fixed bed method in the column filled by the fly ash-zeolite mixture with a fly ash-to-zeolite weight percent ratio of 100/0, 80/20, 60/40, 40/60, 20/80, 0/100 in the water saturated condition flown by uranyl nitrate solution at concentration (Co) of 500 ppm. The concentration of uranium in the effluents in interval 15 minutes represented as Ct was analyzed by spectrophotometer, then using Co and Ct, data effective dispersion coefficient (De) in the backfill material were determined. The experiment data showed that -400 mesh fly ash and -70+80 mesh zeolite on fly ash-to-zeolite with weight percent ratio of 40/60 with K = 5.00x10-5cm/second and De = 1.11.10-5 cm2/second can be used as backfill material. Keywords: backfill material, fly ash, radioactive waste, zeolite

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DISPERSION AND SORPTION CHARACTERISTICS OF URANIUM IN THE ZEOLITE-QUARTZ MIXTURE AS BACKFILL MATERIAL IN THE RADIOACTIVE WASTE REPOSITORY

Indonesian Journal of Chemistry ◽

10.22146/ijc.21729 ◽

2010 ◽

Vol 6 (3) ◽

pp. 261-267

Author(s):

Herry Poernomo ◽

Noor Anis Kundari

Keyword(s):

Particle Size ◽

Radioactive Waste ◽

Nitrate Solution ◽

Fixed Bed ◽

Weight Ratio ◽

Weight Percent ◽

Raw Material ◽

Radioactive Waste Repository ◽

Backfill Material ◽

Waste Repository

The experiment of sorption and dispersion characteristics of uranium in the zeolite-quartz mixture as candidate of raw material of backfill material in the radioactive waste repository has been performed. The objective is to know the effect of zeolite and quartz grain size on the zeolite-to-quartz weight ratio that gives porosity (ε), permeability (K), and dispersivity (α) of uranium in the zeolite-quartz mixture as backfill material. The experiment was carried out by fixed bed method in the column filled by the zeolite-quartz mixture with zeolite-to-quartz weight percent ratio of 100/0, 80/20, 60/40, 40/60, 20/80, 0/100 wt. % in the water saturated condition flowed by uranyl nitrate solution of 500 ppm concentration (Co) as uranium simulation which was leached from immobilized radioactive waste in the repository. The concentration of uranium in the effluents represented as Ct were analyzed by spectrophotometer Corning Colorimeter 253 every 15 minutes, then using Co and Ct uranium dispersivity (α) in the backfill material was determined. The experiment data shown that 0.196 mm particle size of zeolite and 0.116 mm particle size of quartz on the zeolite-to-quartz weight ratio of 60/40 wt. % with ε = 0.678, K = 3.345x10-4 cm/second, and α = 0.759 cm can be proposed as candidate of raw material of backfill material in the radioactive waste repository. Keywords: backfill material, quartz, radioactive waste, zeolite

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PHYSICAL CHARACTERISTICS OF FLY ASH NANO PARTICLES AS BACKFILL ON THE RADIOACTIVE WASTE REPOSITORY

Indonesian Journal of Chemistry ◽

10.22146/ijc.21560 ◽

2010 ◽

Vol 9 (1) ◽

pp. 28-36

Author(s):

Herry Poernomo

Keyword(s):

Fly Ash ◽

Radioactive Waste ◽

Migration Rate ◽

Nitrate Solution ◽

Fixed Bed ◽

Nano Particles ◽

Radioactive Waste Repository ◽

Fly Ash Zeolite ◽

Backfill Materials ◽

Waste Repository

Characterization of fly ash nano particles as backfilled material candidate in the radioactive waste repository has been done. The objective of this research is to determine the permeability (K) and migration rate (Vr) of uranium in the backfilled material of fly ash, zeolite, and zeolite + fly ash mixtures. The experiment was carried out by the fixed bed method in a column contains fly ash, or zeolite, or zeolite+fly ash mixtures. It was filled with the saturated water and was flown by uranyl nitrate solution of 500 ppm as the simulated uranium. The uranium effluents was sampled in every 15 minutes and it was analyzed using spectrometer. The concentration of which represented as Ct and by using concentration profile of Co/Ct, then Vr of uranium in the backfilled material can be determined. The experiment result showed that ≤ 38 mm of fly ash particles sizes could improve the characteristic feature of 196 mm of zeolite sizes as backfilled material with the decreasing permeability values from Kzeolite = 4.06x10-3 cm/s to Kzeolite+fly ash = 5.00x10-5 cm/s and the decreasing of the migration rate from Vr zeolite = 1.65x10-4 cm/s to Vr zeolite+fly ash = 2.91x10-6 cm/second. Keywords: fly ash, zeolite, backfill materials, uranium migration, radioactive waste repository

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Investigation of novel composites to be used as backfill materials in radioactive waste disposal facilities

Journal of Radioanalytical and Nuclear Chemistry ◽

10.1007/s10967-019-06809-x ◽

2019 ◽

Vol 322 (2) ◽

pp. 455-465

Author(s):

N. A. Abdel Reheim ◽

M. Abdel Geleel ◽

Ashraf. A. Mohammed ◽

E. R. Atta ◽

Emtithal A. Elsawy ◽

...

Keyword(s):

Radioactive Waste ◽

Waste Disposal ◽

Radioactive Waste Disposal ◽

Backfill Materials

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Sorption-Capacity Limited Retardation of Radionuclides Transport in Water-Saturated Packing Materials

MRS Proceedings ◽

10.1557/proc-44-369 ◽

1984 ◽

Vol 44 ◽

Author(s):

C. Pescatore ◽

T. Sullivan

Keyword(s):

Sorption Capacity ◽

Retardation Factor ◽

High Level Waste ◽

Radionuclide Transport ◽

Breakthrough Time ◽

Packing Materials ◽

Sorption Data ◽

Waste Package ◽

High Level ◽

Water Saturated

AbstractRadionuclides breakthrough times as calculated through constant retardation factors obtained in dilute solutions are non-conservative. The constant retardation approach regards the solid as having infinite sorption capacity throughout the solid. However, as the solid becomes locally saturated, such as in the proximity of the waste form-packing materials interface, it will exhibit no retardation properties, and transport will take place as if the radionuclides were locally non-reactive. The magnitude of the effect of finite sorption capacity of the packing materials on radionuclide transport is discussed with reference to high-level waste package performance. An example based on literature sorption data indicates that the breakthrough time may be overpredicted by orders of magnitude using a constant retardation factor as compared to using the entire sorption isotherm to obtain a concentrationdependent retardation factor.

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Determination of Technetium and Selenium Transport Properties in Laboratory Soil Columns

MRS Proceedings ◽

10.1557/proc-127-957 ◽

1988 ◽

Vol 127 ◽

Author(s):

J. A. Del Debbio ◽

T. R. Thomas

Keyword(s):

Transport Properties ◽

Soil Column ◽

Retardation Factor ◽

Soil Columns ◽

Water Contact ◽

Near Surface ◽

One Dimensional ◽

High Level ◽

Water Saturated

ABSTRACTLaboratory studies are being conducted to measure the transport properties of various radionuclide species through soil columns. The studies are being conducted to support evaluations for potential near-surface disposal of high-level radioactive waste (HLW) calcine stored at the Idaho National Engineering Laboratory. The data will be used to model radionuclide transport through the vadose (unsaturated) zone of the site under various water-contact scenarios. Retardation factors and dispersion coefficients for technetium and selenium species have been measured in water-saturated soil columns made up of sediments taken from 12 and 35 meters below the surface. A one-dimensional, convective-dispersive, solute-transport equation was fitted to column effluent data by optimizing three parameters (retardation factor, dispersion coefficient and pulse time) using a non-linear, least-squares fitting routine. The data indicated no retardation of the pertechnetate ion (TcO4-)and selenate ion (SeO4-) and a large retardation of the selenite ion (SeO3-) relative to water transport through the soil column.

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Groundwater Geochemistry Near the Storage Sites of Low-level Radioactive Waste: Implications for Uranium Migration

Procedia Earth and Planetary Science ◽

10.1016/j.proeps.2013.03.130 ◽

2013 ◽

Vol 7 ◽

pp. 288-291 ◽

Cited By ~ 6

Author(s):

Olga L. Gaskova ◽

Anatoly E. Boguslavsky

Keyword(s):

Radioactive Waste ◽

Low Level ◽

Groundwater Geochemistry ◽

Uranium Migration ◽

Low Level Radioactive Waste

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The Advantages of a Salt/Bentonite Backfill for Waste Isolation Pilot Plant Disposal Rooms

MRS Proceedings ◽

10.1557/proc-333-911 ◽

1993 ◽

Vol 333 ◽

Author(s):

B.M. Butcher

Keyword(s):

Radioactive Waste ◽

Pilot Plant ◽

Selection Criteria ◽

Final State ◽

Government Regulations ◽

Waste Isolation Pilot Plant ◽

40 Cfr 191 ◽

Backfill Materials ◽

The Impact ◽

Sorption Potential

ABSTRACTThis paper concludes that a 70 wt% salt/30 wt% bentonite mixture is preferable to pure crushed salt as backfill for disposal rooms in the Waste Isolation Pilot Plant. The performance of two backfill materials is examined with regard to various selection criteria related to compliance with the transuranic radioactive waste standard 40 CFR 191, Subpart B, such as the need for low liquid permeability after closure, chemical stability, strength, ease of emplacement, and sorption potential for brine and radionuclides. Both salt and salt/bentonite are expected to consolidate to a final state of permeability ≤ 10-18 m2, which is adequate for satisfying government regulations for nuclear repositories. The real advantage of the salt/bentonite backfill depends, therefore, on bentonite’s potential for sorbing brine and radionuclides. Estimates of the impact of these properties on backfill performance are presented.

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Modified Grape Seeds: A Promising Alternative for Nitrate Removal from Water

Materials ◽

10.3390/ma14174791 ◽

2021 ◽

Vol 14 (17) ◽

pp. 4791

Author(s):

Marija Stjepanović ◽

Natalija Velić ◽

Mirna Habuda-Stanić

Keyword(s):

Nitrate Removal ◽

Nitrate Solution ◽

Fixed Bed ◽

Synthetic Wastewater ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Grape Seeds ◽

Promising Alternative ◽

Intraparticle Diffusion Model

The aim of this work was to investigate grape seeds as a potential adsorbent for nitrate removal from water. Grape seeds were modified by quaternization and the applicability of the modified grape seeds (MGS) was evaluated in batch adsorption experiments. Fixed bed adsorption and regeneration studies were carried out to determine the regeneration capacity of MGS. The maximum adsorption capacity of 25.626 mg g−1 at native pH (6.3) for nitrate removal by MSG was comparable to that of the commercial anion exchange resin Relite A490 under similar conditions. The percent removal of nitrate from model nitrate solution was 86.47% and 93.25% for MGS, and Relite A490, respectively, and in synthetic wastewater 57.54% and 78.37%. Analysis of the batch adsorption data using isotherm models revealed that the Freundlich model provided a better fit to the data obtained than the Langmuir model, indicating multilayer adsorption. In kinetic terms, the results showed that the adsorption followed the pseudo-first order model. By investigating the adsorption mechanism, the results suggest that the intraparticle diffusion model was not the only process controlling the adsorption of nitrate on MGS. In column experiments (adsorption/desorption studies), three adsorption cycles were tested with minimal decrease in adsorption capacities, implying that this alternative adsorbent can be successfully regenerated and reused.

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