Assessment of the Jabiluka Project : report of the Supervising Scientist to the World Heritage Committee
Johnston, A.; Prendergast, J. B.; Bridgewater, Peter
E-Publications; E-Books; PublicationNT; Supervising Scientist Report; 138
Alligator Rivers Region
Main report--Appendix 2 of the Main Report. Submission to the Mission of the World Heritage Committee by some Australian Scientists ... --Attachment A. Johnston A. and Needham S. 1999. Protection of the environment near the Ranger uranium mine--Attachment B. Bureau of Meteorology 1999. Hydrometeorological analysis relevant to Jabiluka--Attachment C. Jones, R.N., Hennessy, K.J. and Abbs, D.J. 1999. Climate change analysis relevant to Jabiluka--Attachment D. Chiew, F and Wang, Q.J. 1999. Hydrological anaysis relevant to surface water storage at Jabiluka--Attachment E. Kalf, F. and Dudgeon, C. 1999. Analysis of long term groundwater dispersal of contaminants from proposed Jabiluka mine tailings repositories--Appendix 2 of Attachment E. Simulation of leaching on non-reactive and radionuclide contaminants from proposed Jabiluka silo banks.
Uranium mill tailings - Environmental aspects - Northern Territory - Alligator Rivers Region; Environmental impact analysis - Northern Territory - Jabiluka; Uranium mines and mining - Environmental aspects - Northern Territory - Jabiluka; Jabiluka - Environmental aspects
Supervising Scientist Report; 138
1 volume (various pagings) : illustrations, maps
https://hdl.handle.net/10070/462403; https://hdl.handle.net/10070/462400; https://hdl.handle.net/10070/462405; https://hdl.handle.net/10070/462406; https://hdl.handle.net/10070/462408; https://hdl.handle.net/10070/462409; https://hdl.handle.net/10070/462411
5 Climate change modelling also suggests that there could be a significant increase in the magnitude of PMP events, with increases of up to 30% being suggested. Possible increases of this magnitude should be taken into account in the final design of the Jabiluka water management system by increasing the height of exclusion bunds. This is an action that can be incorporated at the detailed design stage. The storage of uranium on the surface Modelling of the water management system at Jabiluka under current climatic conditions This review has included hydrological modelling of the water management system at Jabiluka using a stochastic daily water balance model which incorporates the recommendations of this review on the appropriate rainfall record and evaporation, a realistic distribution of evaporative losses in the ventilation system throughout the year, and a simple soil water capacity model for runoff. The system modelled was the Jabiluka Mill Alternative Original Concept but with tailings returned to the mine void rather than in tailings ponds at the surface. The model has enabled estimates to be made of the storage capacity required as a function of exceedence probability over the 30 year mine life under current climatic conditions. The probability that the pond volume proposed by ERA in the PER (810,000 m3) would be exceeded over the life of the mine is about 1 in 1000. The pond volume required to achieve an exceedence probability of 1 in 10,000 over the life of the mine would be about 940,000 m3. Review of the hydrological model adopted by ERA The Supervising Scientist has reviewed the hydrological model adopted by ERA in the design of the water management system at Jabiluka. This review has resulted in a number of recommendations for improvement of the model. The effect on the volume of the water storage pond arising from the adoption of these recommendations is as follows: The inclusion of interannual variability in evaporation and the inverse relationship between rainfall and evaporation leads to an increase in the required pond volume of about 3%. The use of a simulated distribution of monthly rainfall rather than distributing annual rainfall to each month in fixed proportions determined from a typical distribution leads to an increase in the required capacity by about 1.7%. The use of a more realistic distribution of ventilation system losses between the Wet and Dry seasons rather than a constant value for each month leads to an increase in the required capacity by about 1.2%. The use of pan factors recommended in this review rather than those used by ERA in the PER results in an increase in the required volume of about 2.5%. The use of a daily water balance model rather than a monthly model leads to an increase in required pond volume of about 1.4%. The use of conceptual rainfall-runoff model rather than fixed runoff coefficients leads to a decrease in the required pond volume of about 0.4%.