UK uses multiple site data to save over 1 billion pounds on decom
Decommissioning contractor Magnox is building a body of multiple site learnings which have reduced cost risks associated with waste transfer, experts told Nuclear Energy Insider.
European decommissioning demand is set to hike in the coming years, increasing the importance of accurate cost estimates for utilities pressured by low wholesale power prices.
The number of European nuclear power plants in decommissioning is expected to rise from 76 in 2015 to around 110 in 2020, Jorg Klasen, Director Nuclear Decommissioning Services at German operator EnBW Kernkraft, said in May 2016.
In 2016 the OECD Nuclear Energy Agency’s (NEA) published a report on the costs of decommissioning, which analyzed data collected from NEA member countries to develop cost-effective strategies and realistic cost estimates.
The NEA presented the UK Nuclear Decommissioning Authority’s (NDA) five-year decommissioning strategy to place ten Magnox sites into care and maintenance (C&M) as one of six European case studies.
Magnox, owned by Cavendish Fluor Partnership, is the contractor responsible for managing 12 UK nuclear sites owned by the NDA.
The Magnox optimized decommissioning plan (MODP) delivered savings of 1.3 billion pounds ($1.6 billion) and cut time to C&M by 34 years, driven by learnings shared between sites.
Number of shutdown reactors by country (as of August 2013)
Source: OECD's 'Costs of Decommissioning Nuclear Power Plants' (2016). Data source: IAEA
While the NEA has looked to provide greater data transparency to improve cost estimates, experts say it would be difficult to develop international standardized cost benchmarks due to differing national regulations and logistical challenges.
John Mathieson, Head of International Relations at the UK Nuclear Decommissioning Authority (NDA), told Nuclear Energy Insider that a previous joint costing program with the French decommissioning organization EDF CIDEN concluded it was not feasible to benchmark costs between the countries. The project compared EDF’s French plants with similar UK plants.
“It’s very difficult because there are so many variables involved in plant costs such as the cost of waste disposal and its transport and storage, as well as the labor needed to take the nuclear power plant down,” he said.
Martyn Jenkins, Managing Director of Enkom Consulting, said different regulatory standards and varied labor costs make comparisons between European countries inconclusive. Understanding the factors that drive national decommissioning costs will drive more efficient estimates, he said.
A ‘Lead and Learn’ concept implemented by Magnox from 2010 onwards was pivotal to realising major savings. Jenkins said the standardization of programs and the Lead and Learn concept implemented by Magnox yielded like-for-like data, which could be compared and used more effectively as decommissioning progressed across all the sites.
“The principle is to analyze data for commonalities and anomalies and not simply to look for how to decrease costs, but to increase confidence and decrease the uncertainty in the numbers. Then we have like-for-like data, which can be used to compare going forward and allow informed decisions to be made,” he said.
Lead and Learn
Under the Lead and Learn program, experience, knowledge and data from an accelerated decommissioning program for the two 125 MW reactors at Bradwell were applied to reduce costs across multiple UK sites. Bradwell ceased operations in 2002.
The MODP aimed to optimize decommissioning plans by prioritizing management of high level hazardous material, maximizing revenue generation and accelerating decommissioning time to C&M entry, Jonathan Jenkin, Stakeholder Relations at Magnox, told Nuclear Energy Insider.
Although the individual Magnox sites have their differences, they have much in common and the Lead and Learn concept enabled activities and techniques to be trialled at Bradwell, before being rolled out to other sites, he said.
At Oldbury, which housed two 217 MW reactors, the Lead and Learn program used experience of solving technical issues to shorten the project duration by seven months and could create up to 300,000 pounds in project savings, Rob Taylor, Ponds Campaign Manager at Magnox, said.
“We come in with an awareness of previous operations and we know how to do the work efficiently. We get the on-site team together and run through the job and how it’s been done before at other sites before we work together on how it can be improved and how it will work at this particular site,” Taylor told Nuclear Energy Insider.
Central to the cost reduction was the characterization of spent fuel rods in redundant fuel skips stored in the wet ponds, he said, where low level radioactive waste is allocated to a repository and intermediate level waste is prepared for interim storage.
Analysis of previous characterization work undertaken on more than a hundred skips at Chapelcross, as well as data gathered on skips at similar sites Sizewell and Dungeness, showed that classification of the Oldbury skips was not necessary, he said.
Applying Lead and Learn to this work saved 75,000 pounds and allowed the team to start cleaning up the ponds seven months early, which will provide another opportunity for further savings, Taylor said.
The MODP ended in 2016, but Jenkin said the new parent body Cavendish Fluor is finalizing new lifetime plans for each of the Magnox sites in order to optimize project execution and further minimize costs.
“Plans will build on and be informed by the MODP plans inherited by Cavendish Fluor as well as the experience gained during that period,” he said.
By Karen Thomas