Removing the buildings and plant left behind by 50 years of nuclear industry activity will call for much work-a-day demolition contracting. But dismantling highly radioactive reactor cores, removing and repackaging waste from lifeexpired storage ponds and silos, and remediating thousands of cubic metres of contaminated soils will also pose some of the toughest challenges engineers are likely to face anywhere in the UK in the next 20-30 years.
The NDA was formed in April to act as a client organisation for the pressing job of clearing up the UK's civil nuclear legacy before it becomes a major environmental hazard.
It is directly funded by the government and its brief, in a nutshell, is to accelerate the pace of nuclear clean up.
It has assumed ownership of 20 sites, which are currently being managed on its behalf by their former owners, UKAEA and British Nuclear Group (BNG).
Next year the NDA will begin the process of putting management and decommissioning contracts for all 20 sites out to competition.
Though UKAEA and BNG will bid to retain their existing site management licences, there is no guarantee that they will be successful, as they go head to head for the first time with the keenly commercial likes of CH2M Hill, Bechtel, Washington Group, Jacobs, Fluor, Amec and Serco.
Site management licensees, known as Tier 1 contractors, will receive funding from the NDA. Some are expected to carry out design and contracting activities directly, but most will engage teams of specialist Tier 2 and Tier 3 subcontractors to deliver projects: This is where opportunities for most construction companies will arise.
NDA is being non-prescriptive about how work is carried out.
'We propose largely to frame contracts around the outputs and end states we require; we intend to say 'what' not 'how', ' states the NDA's draft strategy.
Contracts will be let on a cost reimbursable basis with performance-based incentives for achieving objectives faster or for a lower cost than targeted - although site funding limits will be imposed, there will be lists of allowable and disallowable costs, and parent company guarantees will be required to ensure costs do not escalate wildly.
The length of contracts will vary depending on site complexity and how long the decommissioning is expected to take.
Although contracts that perform well are likely to be extendable, straightforward sites with longer decommissioning periods will be retendered at regular intervals. However, for very complex sites such as Sellafield, it is anticipated the Tier 1 contractor will need an extended period to gain sufficient understanding of the site and all its issues. Longer re-bid periods will therefore apply.
NDA strategy 'We want to deliver both high hazard reduction and early site restoration. In order to achieve this, we must increase our level of spend on actual decommissioning and clean-up activities. We have set ourselves a target of spending at least £1bn of our annual [£2bn] budget on decommissioning and clean up within five years, ' the NDA strategy says.
'We will drive down the cost of operations and decommissioning.
We have a Public Service Agreement (PSA) target to secure a 10% reduction in our liabilities by 2010. We also have a PSA target for delivering annual efficiency gains of 2% from 2006/07. We have begun this process by asking our contractor to make savings of 7% this year and 5% next year.'
Easy versus risky NDA would like to accelerate the full decommissioning of the UK's 11 Magnox reactors to less than 25 years, compared to approximately 50 years under old plans.
But this will only happen if budgets allow, after 'high hazard facilities' - such as the heavily contaminated and leaking B30 storage pond at Sellafield known locally as 'Dirty 30' - have been tackled. The NDA is applying for increased government funding to enable it to press forward on all fronts.
What needs to be done The term nuclear decommissioning brings to mind intricate cutting apart of reactor buildings, but all the NDA's 20 sites contain greater or lesser quantities of contaminated soil. At the most intensely polluted site, Sellafield, there is an estimated 20Mm 3 of contaminated ground, resulting from leaks in decrepit waste storage facilities.
How decommissioning and clean up operations are tackled depends substantially on the strategies adopted by the government for the storage or disposal of low, intermediate and high level waste. Options for the long term management of ILW and HLW are being reviewed and consulted on by the government's Committee on Radioactive Waste Management (CoRWM), which is expected to present its recommendations in July next year.
To make management of the huge volumes of toxic waste that will arise from decommissioning operations as easy as possible, the NDA has stated its support for construction of deep geological disposal facilities.
Stakeholder consultation The NDA is revisiting assumptions about the eventual end states of all its 20 sites and is asking local people for their views as to whether they should be returned to greenfield state, converted into business parks or used, perhaps, for construction of a new generation of nuclear power stations or for the storage of nuclear waste. For details email strategy. consultation@nda. gov.
Safety Nuclear safety, industrial health and safety, security and environmental protection at nuclear licensed sites are the responsibility of the site licence companies - the Tier 1 contractors.
Key questions The NDA at present spends only £200M of its £2bn annual budget on decommissioning. How will it achieve the 50/50 balance between decommissioning and maintenance spend targeted within the next five years?
When will the detailed site assessment and costing for Sellafield be made public?
When will the decommissioning programme peak, and what is the annual spend expected to be?
What are the most significant decommissioning challenges?
How many contractors at Tier 1, 2 and 3 are there likely to be?
What length of time will contracts run for?
What rewards will be available to contractors for finding innovative ways of reducing risk?
What is the NDA's risk management strategy - is there a danger of risk dumping?
How will the NDA ensure that Tier 1 contractors do not abuse their subcontractors?
How much is known about the design and construction of old facilities?
How much has poor past practice, inadequate maintenance, and leakage contributed to the decommissioning challenge?
Does the NDA know enough about the sites it now owns to act effectively as a client?
What will happen if the Commission on Radioactive Waste Management does not come out in favour of a deep geological disposal facility for intermediate and high level waste?
How quickly are new waste storage or disposal facilities needed to allow the NDA to meet its accelerated decommissioning timetable?
What will the decommissioned sites be used for?