The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
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Abstracts Sessi<strong>on</strong> 43<br />
radioactivity was generally less than 0.5 Bq L -1 as recommended for drinking water. Only <strong>on</strong>e water supply from a local spring to<br />
a village exceeded the recommended limit for alpha radioactivity in drinking water with 1.12 Bq L -1 . <str<strong>on</strong>g>The</str<strong>on</strong>g> overall assessment of<br />
water radioactivity in this uranium mining regi<strong>on</strong> indicated that water resources were not significantly c<strong>on</strong>taminated by the historic<br />
radium and uranium mining. Nevertheless, acid mine waters from Urgeiriça and Bica mines still require treatment to prevent dispersal<br />
of the acid and radi<strong>on</strong>uclides into the aquifer.<br />
SESSION 43 - URANIUM MINING AND MILLING SITES ER<br />
1) DESIGN IMPROVEMENTS AND ALARA AT U.S. URANIUM IN SITU RECOVERY FACILITIES - 16415<br />
Steven Brown, SENES (USA)<br />
In the last few years, there has been a significant increase in the demand for Uranium as historical inventories have been c<strong>on</strong>sumed<br />
and new reactor orders are being placed. Numerous mineralized properties around the world are being evaluated for Uranium<br />
recovery and new mining / milling projects are being evaluated and developed . Ore bodies which are c<strong>on</strong>sidered unec<strong>on</strong>omical<br />
to mine by c<strong>on</strong>venti<strong>on</strong>al methods such as tunneling or open pits, can be candidates for n<strong>on</strong>-c<strong>on</strong>venti<strong>on</strong>al recovery techniques,<br />
involving c<strong>on</strong>siderably less capital expenditure. Technologies such as Uranium In Situ Leaching / In Situ Recovery (ISL / ISR -<br />
also referred to as soluti<strong>on</strong> mining), have enabled commercial scale mining and milling of relatively small ore pockets of lower<br />
grade, and are expected to make a significant c<strong>on</strong>tributi<strong>on</strong> to overall world wide uranium supplies over the next ten years. Commercial<br />
size soluti<strong>on</strong> mining producti<strong>on</strong> facilities have operated in the US since the mid 1970s.<br />
However, current designs are expected to result in less radiological wastes and emissi<strong>on</strong>s relative to these first generati<strong>on</strong> plants<br />
(which were designed, c<strong>on</strong>structed and operated through the 1980s). <str<strong>on</strong>g>The</str<strong>on</strong>g>se early designs typically used alkaline leach chemistries<br />
in situ including use of amm<strong>on</strong>ium carb<strong>on</strong>ate which resulted in groundwater restorati<strong>on</strong> challenges, open to air recovery vessels<br />
and high temperature calcining systems for final product drying vs the zero emmisi<strong>on</strong>svaccum dryers as typically used today.<br />
Improved c<strong>on</strong>tainment, automati<strong>on</strong> and instrumentati<strong>on</strong> c<strong>on</strong>trol and use of vacuum dryers in the design of current generati<strong>on</strong> plants<br />
are expected to reduce producti<strong>on</strong> of sec<strong>on</strong>dary waste byproduct material, reduce Rad<strong>on</strong> emisi<strong>on</strong>s and reduce potential for employee<br />
exposure to uranium c<strong>on</strong>centrate aerosols at the back end of the milling process.<br />
2) RADIONUCLIDE TRANSFER FROM URANIUM MINE WATER TREATMENT PONDS TO VEGETATION - 16260<br />
Fernando P. Carvalho, Instituto Tecnológico e Nuclear (Portugal);<br />
João M. Oliveira, Magarida Malta, Nuclear and Technological Institute (Portugal)<br />
Sulphuric acid was used in large amounts for in situ leaching and static leaching of uranium ore in uranium mines at Portugal.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> producti<strong>on</strong> of uranium ceased years ago and at several mines water treatment plants still are in operati<strong>on</strong> to neutralize pH of<br />
acid mine waters and to remove radioactivity before releasing treated water into surface water streams. Sludge from water treatment<br />
is decanted and deposited in p<strong>on</strong>ds which, as wet areas, develop sp<strong>on</strong>taneous vegetati<strong>on</strong> and attract biota such as insects and<br />
birds. Distributi<strong>on</strong> of uranium series radi<strong>on</strong>uclides in these p<strong>on</strong>ds was investigated in the mud, overlaying water, and sp<strong>on</strong>taneous<br />
vegetati<strong>on</strong>. Radi<strong>on</strong>uclide c<strong>on</strong>centrati<strong>on</strong>s in the sludge reach about 41 000 Bq kg-1 for 238U, 1 700 Bq kg-1 for 226Ra, and 1 200 Bq<br />
kg-1 for 210 Bq. This paper reports <strong>on</strong> the bioavailability of radi<strong>on</strong>uclides from the sludge to sp<strong>on</strong>taneous vegetati<strong>on</strong> growing in the<br />
p<strong>on</strong>ds area, such as grass, rush and reeds, and discusses potential transfer of these radi<strong>on</strong>uclides into the food chain.<br />
3) COMPLETION OF THE SOUTH ALLIGATOR VALLEY REMEDIATION, NORTHERN TERRITORY,<br />
AUSTRALIA - 16198<br />
Peter Waggitt, IAEA (Austria); Mike Fawcett, Fawcett Minesite Rehabilitati<strong>on</strong> Services (Australia)<br />
13 uranium mines operated in the South Alligator Valley of Australias Northern Territory between 1953 and 1963. At the end<br />
of operati<strong>on</strong>s the mines, and associated infrastructure, were simply aband<strong>on</strong>ed. As this activity preceded envir<strong>on</strong>mental legislati<strong>on</strong><br />
by about 15 years there was no remediati<strong>on</strong>.<br />
In the 1980s it was decided that the whole area should become an extensi<strong>on</strong> of the adjacent World Heritage, Kakadu Nati<strong>on</strong>al<br />
Park. As a result the Comm<strong>on</strong>wealth Government made an inventory of the aband<strong>on</strong>ed mines and associated facilities in 1986. This<br />
established the size and scope of the liability and formed the framework for a possible future remediati<strong>on</strong> project. <str<strong>on</strong>g>The</str<strong>on</strong>g> initial program<br />
for the reducti<strong>on</strong> of physical and radiological hazards at each of the identified sites was formulated in 1989 and the works<br />
took place from 1990 to 1992. But even at this time, as throughout much of the valleys history, little attenti<strong>on</strong> was being paid to<br />
the l<strong>on</strong>g term hopes and plans of the traditi<strong>on</strong>al land owners.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> Aboriginal Traditi<strong>on</strong>al Owners, the Gunlom Land Trust, were granted freehold Native Title to the area in 1996. <str<strong>on</strong>g>The</str<strong>on</strong>g>y<br />
immediately leased the land back to the Comm<strong>on</strong>wealth Government so it would remain a part of Kakadu Nati<strong>on</strong>al Park, but under<br />
joint management. One c<strong>on</strong>diti<strong>on</strong> of the lease required that all evidence of former mining activity be remediated by 2015.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> c<strong>on</strong>sultati<strong>on</strong>, and subsequent planning processes, for a final remediati<strong>on</strong> program began in 1997. A plan was agreed in<br />
2004 and, after funding was granted in 2005, works implementati<strong>on</strong> commenced in 2007. An earlier paper described the planning<br />
and c<strong>on</strong>sultati<strong>on</strong> stages, experience involving the cleaning up of remnant uranium mill tailings and other mining residues; and the<br />
successful implementati<strong>on</strong> of the initial remediati<strong>on</strong> works. This paper deals with the final planning and design processes to complete<br />
the remediati<strong>on</strong> works, which is due in 2009. <str<strong>on</strong>g>The</str<strong>on</strong>g> issues of final c<strong>on</strong>tainment design and l<strong>on</strong>g term stewardship are addressed<br />
in the paper as well as some comments <strong>on</strong> less<strong>on</strong>s learned through the life of the project.<br />
4) GUNNAR URANIUM MINE ENVIRONMENTAL REMEDIATION - NORTHERN SASKATCHEWAN - 16102<br />
Joseph Muldo<strong>on</strong>, Laurier Schramm, Saskatchewan Research Council (Canada)<br />
Thirty-six now-aband<strong>on</strong>ed uranium mine and mill sites were developed and operated in Northern Saskatchewan, Canada, from<br />
approximately 1957 through 1964. During their operating lifetimes these mines produced large quantities of ore and tailings. <str<strong>on</strong>g>The</str<strong>on</strong>g><br />
Gunnar Mine is located <strong>on</strong> the shores of Lake Athabasca, the 22nd largest lake in the world. <str<strong>on</strong>g>The</str<strong>on</strong>g> Gunnar mine (open pit and underground)<br />
produced over 5 milli<strong>on</strong> t<strong>on</strong>nes of uranium ore and nearly 4.4 milli<strong>on</strong> t<strong>on</strong>nes of mine tailings. <str<strong>on</strong>g>The</str<strong>on</strong>g>re is an estimated<br />
2,710,700 m3 of waste rock that abuts the shores of Lake Athabasca. After closure in the 1960‘s, the Gunnar site al<strong>on</strong>g with all of<br />
the other uranium mine and mill sites were aband<strong>on</strong>ed with little remediati<strong>on</strong> and no reclamati<strong>on</strong> being d<strong>on</strong>e. <str<strong>on</strong>g>The</str<strong>on</strong>g> governments of<br />
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