Areva eyes five-year decommissioning timelines under faster model
New tools and multi-tasking strategies are set to dramatically shorten spent fuel transfer and reactor segmentation phases as new business models combine technical innovations and financial expertise to reduce costs, Sam Shakir, Chief Executive Officer of Areva Nuclear Materials (ANM), told Nuclear Energy Insider.
As low wholesale prices continue to impact the competitiveness of nuclear power plants and accelerate closure plans, new ownership models are being introduced to raise the efficiency of decommissioning practices.
Around 15 U.S. nuclear reactors are reportedly at risk of closure in the absence of regulated price support and operators have been urged to decommission closed units as fast as possible to minimize costs and avoid unforeseen risks.
In a new trend, companies have formed joint decommissioning groups to combine technical expertise with financial security and position themselves for an expected growth in decommissioning demand. These new entities are acquiring plant operating licenses and more recently, spent fuel liabilities, to raise overall project efficiency.
In February, French-owned nuclear group Areva and U.S. demolition specialists Northstar created a new joint decommissioning company which plans to acquire the complete and permanent ownership of decommissioning assets, including used nuclear fuel.
The new joint company, Accelerated Decommissioning Partners (ADP), is designed to provide a "one-stop" final decommissioning solution for the original operator and introduce technological, regulatory and financial efficiencies to lower project durations and costs.
The latest technologies and optimized strategies could see the dismantling and decontamination (D&D) of U.S. nuclear plants completed within five years of shutdown, Shakir told Nuclear Energy Insider.
"It's definitely doable because we are shrinking the spent fuel movement duration dramatically," Shakir said.
This duration would be several years faster than current U.S. records and in line with projections from EDF, the French state-controlled group which benefits from being the engineer-architect and operator of all 58 of France’s reactors.
"Though each [U.S] nuclear reactor site has its own characteristics, technological advancements in managing radioactive waste could reduce major activities," Shakir said.
Running costs for a shutdown nuclear plant with fuel still in the cooling pool are typically between $25 million and $30 million per year, driven by labor requirements. This cost falls dramatically after the fuel has been transferred to dry storage on the Independent Spent Fuel Storage Installation (ISFSI).
Nuclear decommissioning costs by category (indicative)
Data source: Electric Power Research Institute's 'Decommissioning Experiences and Lessons Learned' report. (2011).
The ADP company will use Extended Optimized Storage (EOS) canisters to shorten the duration time for the transfer of used fuel from reactor to dry storage and advanced radioactive waste canisters to allow earlier storage and transport of dismantled reactor components.
The EOS canisters have high heat load capacity and are licensed to transfer fuel after just two years of spent fuel storage in the reactor pool.
"These measures reduce the labor costs associated with staffing emergency plans before the reactor fuel pool can be decommissioned...If we are able to shrink the [fuel transfer] time by a year or two, we are able to save a significant amount of cost for decommissioning these sites," Shakir said.
Areva is also developing more advanced technologies that could enable the transfer of used fuel to dry storage earlier than two-years cooling, Shakir said.
"From the perspective of the used fuel’s thermal power and neutron and gamma radiation source strength, the optimal minimum cooling time is one year in the used fuel pool before transfer to dry storage," he noted.
ADP will deploy new tools and dry storage technologies to carry out reactor internal segmentation while spent fuel is being transferred to the storage pad.
These technologies include remotely-operated underwater tools to segment reactor pieces in shapes and weights which optimize loading into the storage canister and fulfil regulatory requirements for a site transport and disposal.
“[These tools] allow us to complete the internal segmentation, which is one of the critical path activities, prior to the fuel pool being decommissioned…That again buys us approximately a years’ time in the overall schedule," Shakir said.
ADP also predicts savings from using the modular storage design to optimize storage pad construction and security costs. Areva’s NUHOMS Matrix storage module uses an “overpack” design which allows staggered placement of horizontal canisters and reduces the size of the storage pad by up to 45%, according to the company.
"That eliminates the need to enlarge IFSFI sites beyond their current boundaries therefore saving us again more time and cost and shrinking the security footprint required once the plant has gone," Shakir said.
ADP will also benefit from Northstar's significant equipment and experience in demolition and environmental remediation. The U.S. company operates across multiple sectors including nuclear power, petrochemicals, commercial high-rise and military facilities.
Northstar's nuclear sector experience includes the dismantling and decontamination of five U.S. federal reactor facilities and decommissioning support for 10 Magnox reactors in the UK.
Northstar has subcontracted Areva for the Vermont Yankee project and it will leverage many of the same technology and process efficiencies as the ADP model.
"We continue to monitor the performance of our methods and equipment and optimize that...The first opportunity will be at Vermont Yankee, when we deploy there in about a year," Shakir said.
The decommissioning team will deploy learnings on segmentation cutting techniques and handling of segmented materials gained by Areva on the 640 MW Wurgassen BWR decommissioning project in Germany. Areva completed the disassembly and packaging of the reactor pressure vessel and internals on time and on budget, according to the company.
Wurgassen reactor pressure vessel segmentation
Source: Areva Nuclear Materials (ANM).
The Vermont Yankee project will also provide learnings on U.S. stakeholder and regulatory engagement as it will include the transfer of spent fuel ownership.
"We have the first engagement with the NRC over how to take over a site like this with fuel included," Shakir noted.
Dialogue thus far has focused on project experience, community safety, technical capability and financial security, he said.
Decommissioning specialist EnergySolutions was the first non-utility company to acquire a 10CFR50 plant operating license in the U.S. EnergySolutions recently formed a joint company with engineering group AECOM to win the decommissioning contract for Southern California Edison’s (SCE’s) 2.2 GW SONGS nuclear power plant.
AECOM has experience in the removal of contaminated components, systems and demolition of non-safety related structures and the collaboration with EnergySolutions underlines the trend towards more comprehensive decommissioning solutions supported by higher capital entities.
ADP plans to combine nuclear liabilities experience with new innovative financing structures to optimize capital deployment and reduce costs, Shakir told Nuclear Energy Insider.
Under their proposed ownership transfer model, the ADP partners have developed a "unique approach" which they believe reduces the financial assurance costs of decommissioning projects, Shakir said.
"We have developed some proprietary methods that we believe are win-win for the regulator and for us and reduce the overall cost of executing the project," he said.
Economies of scale
The ADP partners are already in talks with Entergy over the decommissioning and dismantling of two U.S. nuclear reactor sites following their planned shutdown. An assessment of the terms of transfer ownership of the sites and used fuel inventories is expected to conclude at the end of 2017.
Entergy shut down its Vermont Yankee plant in 2014 and plans to close its 811 MW Palisades nuclear power plant in October 2018 followed by the 688 MW Pilgrim plant in 2019 and the 2 GW Indian Point nuclear plant in 2020-2021.
With more closure announcements expected in the coming years, multi-site decommissioning portfolios offer economies of scale through optimized deployment of specialist teams.
Costs can be reduced by keeping equipment and labor fully deployed while leveraging synergies in the management of sites and spent fuel, Shakir said.
"That's really one of the drivers in our model," he said.
Nuclear Energy Insider