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Maralinga clean-up is safe.



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13 March 2000              00/63 

MARALINGA CLEAN-UP IS SAFE  Senator Nick Minchin, Minister for Industry, Science and Resources, today confirmed that the methods used in the clean-up of the main test sites at Maralinga were safe. 

Senator Minchin was responding to unfounded claims on ABC radio today that there were safety concerns with the burial of plutonium in deep (10-15 m deep) trenches under a capping of clean soil of at least 5 metres. 

"Some isolated individuals are indulging in scaremongering about the safety of the clean-up process at Maralinga with no scientific basis to their claims", Senator Minchin said. 

The clean-up methods used were approved by the independent regulator, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), consistent with guidelines issued by the National Health and Medical Research Council.  

Earlier this month ARPANSA certified that the main clean-up had been completed safely: 

"ARPANSA also certifies that the burial trenches at Taranaki, TM 100/101 and Wewak have been constructed consistent with the national Code of Practice for the Near-Surface Disposal of Radioactive Waste." 

Letter to Senator Minchin from Dr John Loy, CEO of ARPANSA 

It is accepted that burial is a safe method of disposal because plutonium is only a hazard to humans if inhaled, ingested or absorbed through cuts. External exposure to plutonium does not pose health risks. 

The Maralinga Rehabilitation Project has largely involved the remediation of areas contaminated by plutonium during the so-called 'minor trials' from 1955-1963. These trials did not involve nuclear explosions, but rather the detonation of nuclear devices with conventional high explosives to simulate accidental detonation and its consequences. 

The rehabilitation involved removing surface soil from plutonium-contaminated areas and the treatment of a number of contaminated debris pits.  

Prior to commencing the Project, the Government appointed an advisory committee consisting of eminently qualified Australian and overseas scientists with major experience in geology, nuclear and radiation issues. 

The committee recommended the burial of plutonium-contaminated surface soil, and

agreed that two options were acceptable, safe and viable for the 21 disposal pits.  

The safe options were either exhuming the pits and reburying them in rock with five metres of cover, or a technique called in-situ vitrification (ISV) which involved the contents of the pits being melted together into a glass block. 

ISV was initially chosen because it may have been safer for the workers if the pits had contained significant amounts of plutonium.  

In March 1999 an explosion occurred in one of the pits being subject to ISV. The cause of that explosion has not been determined. However, no worker was injured nor exposed to any radiation.  

Following the explosion, the independent committee of experts reassessed whether ISV should continue, or the alternative safe method of reburial be adopted. 

The committee decided that exhumation and reburial was a safer option than ISV for three reasons, namely:  the pits contained less plutonium that previously thought, ● techniques for the safe exhumation and burial of plutonium had been developed

during the remediation process, and ●

the ISV process is impractical where one is unsure of the contents or margins of the pits.   ●

As part of this process, an independent risk assessment report of the burial option was commissioned from AEA Technology. ARPANSA analysed the risk assessment and concluded that exhumation and reburial was consistent with the Code of Practice for the Near-Surface Disposal of Radioactive Waste in Australia (1992). 

The Maralinga Tjarutja are optimistic about the opportunities for eco-tourism and education, and for their community generally now the land has been rehabilitated. Their optimism can only be put in doubt by unsubstantiated allegations about the clean-up process. Such threats to the Maralinga Tjarutja's future should not be made without foundation.  

Contact: Kate Harvey, Senator Minchin's office, 02 6277 7580 

             Jeff Harris, Department of Industry, Science and Resources, 02 6213 7520 

An explanatory booklet is available from the Department of Industry, Science and Resources web site at: www.isr.gov.au/media/2000/march/maralinga_booklet.doc 

A set of frequently asked questions is available at: www.isr.gov.au/media/2000/march/maralinga_questions.doc 

A copy of the AEA Technologies Assessment of Human Intrusion into Burial Trenches at Maralinga, Australia is available from Senator Minchin's office. 

CMR107-00