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Tuesday, 8 November 1983
Page: 2445

Question No. 407

Ms McHugh asked the Minister for Home Affairs and Environment, upon notice, on 25 August 1983:

(1) How many infringements of the environmental requirements at the (a) Nabarlek and (b) Ranger uranium mining operations were reported to the Supervising Scientist by (i) Queensland Mines Limited and (ii) Ranger Uranium Mines Proprietary Limited between April 1982 and June 1983.

(2) What are the (a) descriptions and (b) details of the infringements, and what were the dates of these reports.

Mr Cohen —The answer to the honourable member's question is as follows:

(1) Under clause 5 of both the Ranger and Nabarlek environmental requirements the companies are required to ensure that all staff and persons for whom they are responsible observe the provisions of the environmental requirements. The mining companies have agreed to report all infringements and other unusual events to the Northern Territory Department of Mines and Energy and to give a copy of such reports to the Supervising Scientist for the Alligator Rivers Region and the Northern Territory Land Council.

The Supervising Scientist has advised me that most incidents reported are of a minor nature and do not constitute infringements. Other incidents while considered to be minor or potential infringements have no significant impact on the environment. Between April 1982 and June 1983:

(a) (i) Queensland Mines Limited reported two incidents which were considered to be minor or potential infringements but to have no significant impact; and

(b) (ii) Ranger Uranium Mines Pty Ltd reported nine incidents of which eight were minor or potential infringements having no significant impact and one was significant and is subject to further investigation.

(2) The description and details of the incidents which occurred between April 1982 and June 1983 and were considered to be infringements, and the dates they were reported by the companies or came to the notice of the Supervising Scientist, are listed below. All except the one marked with an asterisk are considered to be minor or potential infringements but not to have had significant impact. The one marked with an asterisk is significant and is subject to further investigation.

Date of report to

Date of incident

Description and details

Supervising Scientist


22 and 26 July 1982 The pipeline returning water from the stockpile Runoff Pond to the Mill ruptured along a welded seal during operation. Less than 30m3 of water escaped from the restricted release zone. Except for nitrogen, sulphate , radium and manganese contents that were within limits of some local natural waters, the water quality was within National Health and Medical Research Council drinking water standards. Following investigation, the supervising authorities concluded that no damage had occurred or was likely to occur to the environment.

28 July 1982

4 March 1983 A minor leak from a tailings line in the plant area was detected during routine surveillance and reported by the company. Less than 1m3 of tailings sprayed over the top of the retaining bund a distance of approximately 3m outside the restricted release zone. The leak appears to have been caused by a gradual internal abrasion of a pipe at a defect point. Clean-up of the spilled tailings and the contaminated earth was effected and soil samples were taken after the clean-up. No significant environmental or public health damage occurred.

4 March 1983


24 May 1982 The emission rate measured from the yellowcake packing area scrubber was exceeding the allowable limit of 1.5 kg per day of uranium. Revised calculations showed that the limit had also been exceeded on 12 March 1982. The scrubber was immediately shut down and overhauled. Blockage of some water spray nozzles by scale was found to be the cause. After the overhaul the emission rate was found to be within the allowable limit. A filter has been installed to reduce the likelihood of such blockages in the future and a further control measure is being investigated. Analyses are now reported to management immediately, rather than in a monthly report.

24 June 1982

*5 July 1982 Two workers in the Ranger yellowcake packaging room were knocked over by a large spillage of uranium oxide product (approximately one tonne of yellowcake) when attempting to clear a blocked bin packaging chute. Both are reported to have been wearing respirators when they commenced the task but these were dislodged by the falling product and then removed during the attempt to avoid and stem the flow. The spillage was successfully stopped and the area cleaned of contamination under the control of the radiation safety officer. Whole body counting and assessment at both the Australian Radiation Laboratory and the Australian Atomic Energy Commission revealed one worker's radiation dose as a result of this intake was virtually at the annual limit. The matter is still under investigation by the Northern Territory Department of Health. Questions about the adequacy of the company's radiation safety practices were taken up with the company and the relevant Northern Territory supervising authorities by the Supervising Scientist. As a result, supervision and operating practice in the Ranger packaging area was subsequently tightened to avoid further incidents of this sort. I have directed the Supervising Scientist to report on this incident under sub-section 36 (3) of the Environment Protection ( Alligator Rivers Region) Act 1978. As required by this Act the report will be tabled in Parliament.

6 July 1982

On a number of days through June to early July 1982

Sulphur dioxide emission from the Ranger sulphuric acid plant exceeded slightly the limits set by the General Authorisation. Investigations suggest difficulties of temperature control and progressive deterioration of catalyst beds as the cause of a cyclical variation in plant efficiency. Averaged over the long term, the emission would not give cause for concern nor has environmental detriment been detected at ground level.

25 June, 6 and 8 July 1982

1 February 1983 Less than 1 tonne of low grade ore (0.002 to 0.05 per cent U308) was washed to outside the Restricted Release Zone together with some 150 m3 of storm water. This minor infringement resulted from the blockage of a drain which occurred during heavy rainfall. Clean-up commenced immediately with the ore being returned to within the restricted release zone. As a remedial measure the company raised the bund wall in the affected area in order to reduce the likelihood of any future spillage. The Northern Territory Director of Mines has concluded from investigations that any contaminants were greatly diluted by the clean storm water run-off and that no environmental detriment is expected from the incident. The Supervising Scientist concurs with this assessment.

1 March 1983

9 February 1983 About 200 litres of diesel fuel was spilled at a borefield 800m south of the mine pit. No significant impact occurred outside the immediate area of the spill.

8 March 1983

23 February 1983 Some modification work to the yellow-cake scrubber exhausts resulted in seven company and contractor personnel being exposed to airborne radioactive contamination above the derived levels contained in the Code of Practice on radiation Protection in the Mining and Milling of Radioactive ores ( 1980). The exposures occurred over a short period and were estimated to have been less than 5 per cent of the annual limit for designated workers.

25 February 1983

9 March 1983 A labourer was exposed to a radioactive dust concentration above the derived levels set down in the abovementioned code. The Australian Atomic Energy Commission and the Australian Radiation Laboratory were requested to carry out measurements on the exposed person (using a 'whole body counter') to try to determine how much radioactive material may have been retained in the body. Measurements demonstrated only that any uranium in the body was less than the detection limit of the equipment.

15 March 1983

March 1983 A minor infringement occurred when a small volume of sewage escaped from the reticulation system in Jabiru East. This was due to the entry of stormwater into the system together with numerous foreign bodies which blocked the pumps and caused the burn out of the pump motors. No significant environmental damage occurred.

13 April 1983

22 April 1983 A minor infringement occurred in that a small quantity (less than 50 litres) of diesel oil is reported as having escaped into Gulungul Creek System at a borehole installation known as 74/1. No environmental detriment is expected from this incident.

4 May 1983