scholarly journals Radioactive waste disposal facility, high activity parts storage area, and spent fuel storage facility: design criteria

1964 ◽  
Author(s):  
Keyword(s):  
Radioactive Waste ◽  
High Activity ◽  
Waste Disposal ◽  
Radioactive Waste Disposal ◽  
Design Criteria ◽  
Storage Facility ◽  
Spent Fuel ◽  
Disposal Facility ◽  
Fuel Storage ◽  
Storage Area

A long term baseline and variability of natural radionuclides in groundwater at the Vaalputs low-level radioactive waste disposal facility, Namaqualand, South Africa: regional implications

2020 ◽  
Vol 123 (1) ◽  
pp. 105-116 ◽  
Author(s):  
H.C.F. Pretorius ◽  
M. Tredoux ◽  
M.A.G. Andreoli ◽  
P.D. Vermeulen
Keyword(s):  
Radioactive Waste ◽  
Waste Disposal ◽  
Structural Damage ◽  
Near Field ◽  
Natural Radionuclides ◽  
Radioactive Waste Disposal ◽  
World Health ◽  
Disposal Site ◽  
Spent Fuel ◽  
Disposal Facility

Abstract Vaalputs is the only South African nuclear waste disposal facility; it is licensed to dispose of low and intermediate level radioactive waste. Possible disposal of long-lived waste, potentially including spent fuel rods, prompted a study to establish a baseline of naturally-occurring radionuclides from the U and Th decay chains in the groundwater of Vaalputs. This baseline was created by investigating a dataset containing 25 years of analyses of the groundwater at the Vaalputs site. The behaviour over time, of 23 radionuclides in groundwater samples from 13 annually and three quarterly sampled boreholes, was evaluated and integrated in order to establish changing trends in the activities of radionuclides, the relative contributions of individual radionuclides to total radiation levels and how these were influenced by groundwater conditions. 238U levels showed a natural anomaly in the near-field of the disposal site that was attributed to the underlying basement rocks (granites) which are anomalously enriched in U. A set of duplicate samples from 2009 determined that the activity ratio of 234U/238U in the groundwater of Vaalputs is 4.1; this is ascribed to more rapid leaching of 234U relative to 238U, because of increased crystal structural damage around sites surrounding 234U atoms. High levels of 226Ra, unsupported by 238U, were found in groundwater from boreholes on the western side of the property: this groundwater yielded low values for 234U/238U, lower pH and stronger oxidizing conditions than groundwater from the rest of the area. The absence of overlying sedimentary rocks, which tend to ameliorate the effects of high radiation from granites by absorption, is suggested as the reason for the different geochemical conditions of the groundwater from boreholes in the west. This suggestion may apply to those boreholes elsewhere in Namaqualand with low published concentrations of 238U, but exceptionally high levels of α -and β-emitters. 232Th and its daughter radionuclides yielded radiation levels far below the guideline of 1 Bq.L-1 specified by the World Health Organization; this result is in line with the known low mobility of Th in groundwater systems.

scholarly journals UPPER FILLER MATERIAL APPLIED IN CAVERN TYPE RADIOACTIVE WASTE DISPOSAL FACILITY

2016 ◽  
Vol 72 (3) ◽  
pp. 234-248
Author(s):  
Shin-ichi TAKECHI ◽  
Toshiyuki SASAKI ◽  
Kosuke YOKOZEKI ◽  
Hiroshi SHIMBO ◽  
Yoshihiro AKIYAMA ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Waste Disposal ◽  
Radioactive Waste Disposal ◽  
Filler Material ◽  
Disposal Facility

Method of Designing Bentonite/Sand Mixture to Achieve the Target Permeability

1994 ◽  
Vol 353 ◽  
Author(s):  
Hitoshi Nakashima ◽  
Takashi Ishii ◽  
Tatsuro Nagasawa ◽  
Nobuhide Ogata ◽  
Hideo Komine
Keyword(s):  
Radioactive Waste ◽  
Waste Disposal ◽  
Void Ratio ◽  
Radioactive Waste Disposal ◽  
Permeability Test ◽  
Sand Mixture ◽  
Compaction Test ◽  
Disposal Facility ◽  
Effective Component ◽  
Effective Void Ratio

AbstractBentonite/sand mixture is expected to be an effective component of barriers for radioactive waste disposal facility. Impermeable mixture can be obtained through enrichment of the bentonite content,but it is difficult to estimate a permeability of bentonite/sand mixture before permeability test. At designing of bentonite/sand mixture, we have to decide which sand to be used, and what bentonite content is. But.this means that designing will be a time-consuming task. In this report, we made many kinds of bentonite/sand mixtures using some kinds of sand with different bentonite content, and permeability tests were conducted for these mixtures. After examination of the permeability tests results, the effective void ratio of bentonite/sand mixture which was obtained by compaction test, is an efficient parameter for estimation of the permeability. Last of all, we propose the method of designing bentonite/sand mixture using the effective void ratio.

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