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
70 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%. The combined effect of adopting the recommendations of this review on each of the above topics rather than the model used by ERA is that the pond volume required to achieve a given exceedence probability will increase by about 10%. Use of pond evaporation rather than enhanced evaporation in the ventilation system The use of pond evaporation rather than enhanced evaporation in the ventilation system would lead to a reduction in the required storage capacity of about 30% because the full evaporative capacity would be available from the commencement of operations rather than achieving its maximum effect only after 10 years of operation. It is recommended that ERA, in its detailed design of the Jabiluka water management system, uses increased pond evaporation rather than enhanced evaporation in the ventilation system. In making this recommendation, it is recognised that some enhanced evaporation in the ventilation system as a result of dust suppression procedures is inevitable. This will need to be modelled carefully by ERA to achieve the optimum water management system. Partitioning the water retention pond into three or four compartments with connecting spill ways and a water pumping system is one way in which control of evaporative losses could be achieved. Evaporative losses in dry spells could be minimised by pumping all remaining water into one of the compartments and could be maximised in wetter periods by using the full evaporative capacity of all of the compartments. It is recommended that ERA consider this approach in the detailed design of the water management system at Jabiluka.