Alan Parkinson
March 2003
By way of background and introduction, I was appointed a member of MARTAC, the Maralinga Rehabilitation Technical Advisory Committee, in 1993. In 1994, I was appointed the government’s representative to oversee its contract with Australian Construction Services (ACS), the project manager for the first phases of the project. ACS was purchased by GHD in August 1997, and I continued as the government’s representative overseeing their work. I was also the government’s representative overseeing the contract with Geosafe. I was removed from all appointments in December 1997, but then became an adviser to the Maralinga Tjarutja and so continued to receive a great deal of information about the project.
MARTAC was an advisory body which met three or four times a year. After my departure they had to rely on GHD for information about the project. No member of MARTAC had any day-to-day contact with the project as I had. This intermittent contact with the project is quite apparent in the draft MARTAC Final Report. The report is incomplete or misleading in many instances, and in some it is simply wrong.
It is quite apparent
from the report that there has been a concerted effort by MARTAC (and others?)
to discredit ISV and the company applying the technology at Maralinga.
With the addition of some inside information, this effort is much more
visible. The addition of this inside information also adds to the impression
that:
a. MARTAC had little
understanding of ISV technology.
b. Requirements were
constantly changing.
c. MARTAC stepped
outside its terms of reference.
________________________________________
We in MARTAC discussed the application of ISV at Maralinga on several occasions. Noting that every member of MARTAC voted for ISV and all agreed that it was a far superior method of waste disposal compared with any other option, some of our discussions are relevant here.
There was always the question of how we could know that melting had reached the bottom of the pit being treated. But there was general agreement that since any uncontained debris would be under a 500 tonne rock it was not a serious issue. To give some assurance that all debris was treated, when treatment of the pits started, Geosafe were instructed to continue treatment 600 mm beyond the reported depth of each pit, of course with an increase in cost.
The contract signed between the Commonwealth and Geosafe in June 1996 required Geosafe to design and build the equipment and then use it to treat the 21 debris pits at Taranaki. The price for this work was based on information about the size of the pits provided by Britain and Geosafe thought this would require 26 ‘melts’. As soil removal continued into the area of the pits, huge quantities of debris were uncovered - the pits were at least three times larger than had been reported. So the treatment of the 21 pits would require 40 melts‚ and the project would obviously cost more than had been quoted.
Acceptance Criteria
A basic requirement
of any contract is a statement of what has to be achieved. Some seven months
before the contract was signed, MARTAC developed some draft acceptance
criteria:
* there should be
a high degree of confidence that contaminated soils and debris within the
pits are completely vitrified and all materials either melted or encased
in the vitrified product
* temperatures of
the melt at the base of the pit to reach a specified level, to be advised
following the report of the Phase 2 trials at the intermediate scale
* most of the plutonium
should be distributed within the vitreous/ceramic component of the ISV
product.
Later MARTAC said that the temperature to be attained was 1,600 C or as high as possible above the melting point of steel. These criteria are repeated at page 128 of the draft report, but a slightly different version appears at page 129, and then page 208 quotes what MARTAC believed to be their intent. These criteria were rather impractical, so would have been difficult to confirm, and they never made their way into the contract. Nowhere does the report admit this fact.
The two most important features of these draft criteria to note are that there was no requirement to melt steel, and no requirement to encase all of the plutonium.
Step 1 of the chart on page 195 of the draft report is an attempt to portray these criteria as contractual. Step 4 of that chart claims that ARPANSA (which at the time was ARL) reviewed the finding of a report prepared by Ansto about ISV. It says they did this without knowledge of the criteria. But at that time, Keith Lokan was a member of MARTAC and the Director of ARL, so they did have access to the draft criteria.
The Commonwealth claimed that there were some criteria accepted by both sides of the contract, and at meetings of the Consultative Group in May and August 1999 agreed to provide them to the Maralinga Tjarutja but never did so. Andrew Collett’s notes of the second meeting show: “Alan Parkinson [asked]: Can we have a copy of the acceptance criteria of the melts. It was previously promised.” When I severed my contact with the project in mid-April 2000, we still had not received the promised criteria.
After the first pit had been treated, MARTAC decided it should check to see how the resultant block compared with their criteria. John Morris, a member of MARTAC, took on the task of comparing the block with the criteria. But instead of allowing the block to cool naturally, the soil was removed from around the block and the block was then drenched with cold water. This cracked the block in the reverse fashion of pouring boiling water into a crystal bowl.
At page 222, MARTAC states: "The Taranaki blocks were not monoliths as they had fractured during cooling.” And in a footnote to that page they add: "Monoliths could have been advantageous at Taranaki, had they been produced, as they would have contained no open pathways to the atmosphere through which air and water could have penetrated to attack the steel masses. This matter would not have attained any significance, however, if the ISV treatment had incorporated all of the pit contents and if it had melted all of the steel contents, to ensure the transfer of all plutonium to the oxide phase of the melts.” Why should MARTAC criticise the cracked ISV blocks when it is quite clear that the blocks were cracked because of the water drench that they applied?
From then on MARTAC
were much more involved than would be expected of an advisory committee.
At page 220, under the heading MARTAC's Quality Assurance (QA) Program
is the statement that MARTAC's QA program had two main components:
* Verification that
all the waste components were incorporated or encased into the ISV ceramic
phase.
* Verification that
the plutonium was uniformly mixed within the ceramic phase of the melt.
It seems the purpose of the MARTAC QA program was to find evidence that ISV did not satisfy the non-contractual criteria. It was not in MARTAC's terms of reference to be so involved in the project. The Quality Assurance program should have been the responsibility of Geosafe or GHD. Step 7 of the chart on pages 195-196 show that MARTAC "reviewed melts against original criteria. This should have been done by the project manager GHD.
Plutonium under ISV Blocks
Long before the ISV treatment of pits started, it was generally accepted that some uncontained plutonium beneath the ISV block would be acceptable. This view continued after the treatment got under way. In a paper, ‘MARTAC Recommendations to ISR - Remediation of Pits’, dated 29 April 1999, Keith Lokan, a member of MARTAC, and previously Director of the Australian Radiation Laboratory, said: "I still consider that, in view of the engineering trials and the outcomes so far, that the product is ‘good’, in that it incorporates/encapsulates the plutonium in a very stable waste form. I am not swayed much by arguments about intrusion, deliberate or inadvertent. I do not think that a tiny remainder below or at the edge of a buried 400 tonne block presents a significant intrusion risk (recall Peter Burns view at the last MARTAC that up to 10 grams would be acceptable).”
Another statement at a meeting of the Consultative Group held on 13 April 1999 confirms that containment of all plutonium was not a requirement. The minutes show: "Dr Williams noted that unincorporated plutonium at the bottom of a pit was not a major concern to ARPANSA ....”
Even after the hybrid option had been adopted and some debris was to be vitrified ex situ, the regulator did not require or expect all of the plutonium to be encapsulated. In a letter to Jeff Harris of DPIE dated 4 August 1999, Dr John Loy, the CEO of ARPANSA said: "For the ex situ vitrification to proceed there would also need to be a clear demonstration that ISV could incorporate the majority of plutonium contamination into a melt. Without such a demonstration it cannot be accepted that ISV encapsulates the contaminated material in the melt matrix. ARPANSA would require these issues to be resolved before it could approve the use of ISV in this option.” The looseness in distinguishing between in situ and ex situ vitrification is apparent.
But the statement in the draft report (page 218) is different. It says "ARPANSA (Loy, 1999) pointed out at this stage (30 July 1999) that the inability of ISV to incorporate all debris brought into question the ISV process, particularly when large quantities of contaminated steel were involved. It stated that it would require a clear demonstration that ISV satisfactorily encapsulated the contaminated material in the melt matrix before it could approve the use of ISV in the hybrid option.
The draft report omits the sentence: "For the ex situ vitrification to proceed there would also need to be a clear demonstration that ISV could incorporate THE MAJORITY of plutonium contamination into a melt.” (emphasis added)
So any comments in the draft report about plutonium under any ISV block should be discounted. For example, the strange and somewhat meaningless statement on page 223: "The presence of this pedestal, meant that unincorporated and transferable plutonium contamination lay at a distance below the ground surface which was not acceptable to the regulator.” It doesn’t say how much plutonium, where it could be transferred, nor how deep below ground surface, and there is no reference to any statement from the regulator saying this was unacceptable.
At pages 227 to 229, MARTAC presents very brief information of the exhumation of the ISV blocks. In nearly every case, they note that there was no contamination found beneath the blocks demonstrating without doubt that vitrification was encapsulating all of the contamination. The list does however note for Pit 4: "reasonably high contamination levels were found on the underside” and for Pit 13: "elevated readings were recorded” and Pit 15: "high gamma levels were found on the steel ... and ... with high gamma levels” and Pit 19A: "found to be slightly contaminated”. None of these statements are worth much, they need to be quantified. It is not good enough to use meaningless terms such as these in what is really a report by scientists. This is particularly so if the levels of contamination can be accepted. Note Pit 15 is a "special” case which I return to below.
Steel in the ISV Blocks
Great play is made by MARTAC of unmelted steel in the blocks. As the draft criteria show, there was never any requirement to melt steel. The requirement was for the pit contents to be melted OR ENCASED in the matrix. Consideration of the contamination on steel would show that it is not necessary for it to be melted. Any plutonium would only be on the surface of the steel, so as long as the surface is scavenged and the plutonium enters the melt, then the remainder of the steel does not matter - it isn’t contaminated.
The report tries to make capital about unmelted steel in the block of Pit 15. I saw those steel plates during my last visit to Maralinga, and they certainly existed. The heat of the ISV treatment had caused the plates to meld together so it was really one large lump of steel. What the report does not admit to is that the plates had been covered by at least a metre of hard rock. This would have been acceptable had the rock remained in place instead of being broken away in the so-called QA exercise.
This unmelted steel was used by MARTAC and Senator Minchin in an attempt to discredit ISV. In a letter dated 6 August 1999 to the Maralinga Tjarutja, Senator Minchin said "Also, doubts have been raised as to the quality of the vitrified product with unmelted steel which is still contaminated being found in the bottom of at least two of the melts only some two metres below the surface.”
But they have not acknowledged anywhere the fact that GHD instructed Geosafe to stop melting of that pit by facsimile dated 17 October 1998 which states: "This fax provides written confirmation of the advice to terminate melt 8, Pit 15 today. This decision is based on careful consideration of the data provided ...”
Whether there was any intention to mislead the reader about the melting of steel or otherwise is not clear. There is an unusual note on page 227 which says: "In the majority of cases a large steel conglomerate was found at the base of each melt. [Except Pits 17 and 18, in which steel contents were melted (if you want to note this).]” It was always expected that there could be some steel found at the base of the block. Why could not MARTAC simply report that the blocks of Pits 18 and 17 (the last two pits to be treated) were perfect - they satisfied all of the non-contractual criteria.
To show how illogical is the stance by MARTAC and ARPANSA we have only to compare even partially encased debris in a vitrified lump with no encasement at all in the simple burial of debris.
Lead Under ISV Blocks
MARTAC demonstrates its lack of understanding of the ISV technology and basic heat transfer as early as the Executive Summary of the draft report. Page 6 recounts MARTAC's puzzlement at the shortfall in the amount of lead found in vitrified blocks. After the ISV blocks were exhumed, MARTAC used a metal detector and seemed surprised to find some nine tonnes of lead in fissures under the blocks. This suggests that they did not understand the basic heat transfer mechanism employed by ISV.
The process starts with a molten pool at the top of the pit and a temperature gradient to the bottom of the pit. Somewhere along that gradient, the temperature would be at the melting point of lead and so the lead would melt long before the molten pool had descended to that level. Most of the lead would trickle down to the bottom of the pit and never enter the molten pool. That is basic heat transfer.
At page 222 MARTAC says: "Lead metal in the pit debris was not generally processed by the ISV treatment and a substantial proportion of the total lead inventory escaped from the pits during the processing.” Why should that surprise them?