Information about science based innovations, solid facts to support decision-making, performance and business development for VTT’s partners, customers and anyone interested in high technology and its applications.
A magazine on science, technology and business

Posiva

​​​​​

Posiva is a pioneer in nuclear waste management

Leena Koskenlaakso | 8.12.2016

​The world’s first final disposal 
repository for nuclear fuel will begin operating in Eurajoki in the early 2020s, as planned. Posiva has provided the basis for the 
final disposal project, through 
extensive and thorough research.

At the beginning of the next decade, the world’s first final repository for spent nuclear fuel will begin opera­ting close to the Olkiluoto nuclear power plant on the west coast of Finland. The final disposal of spent nuclear fuel from the power companies Teollisuuden Voima and Fortum will take place in massive, copper-cast iron disposal canisters around 400 metres deep in the bedrock at Olkiluoto. 

 
– The intention is to continue operations at the repository for 100 years. After then, all underground openings will be backfilled and the above-ground facilities will be dismantled and landscaped.  No supervision measures are required for this passive solution, says Tiina Jalonen, Senior Vice President, Development, at Posiva.

 
– There is huge international interest in us.

 
Posiva_7.jpg

 

Hazardous materials will remain underground

Final disposal will be based on multiple barriers, ensuring that no spent radioactive fuel contaminates the natural environment or comes within reach of people. 

 
The bedrock will serve as a natural barrier. This will be complemented by man-made, engineered barriers. These will include copper-cast iron disposal canisters in which the fuel elements will be placed; a buffer of bentonite clay surrounding the canisters in the deposition holes, in order to hinder water flow and protect the canisters from damage; filling the tunnels with clay containing backfill material; and plugging the tunnel’s mouth. 

 
– Various models have shown that, even if one or more of the barriers fails, no harmful substances will reach the ground surface, says Johanna Hansen, Project Coordinator. 

 
Posiva_5.jpg

 

Construction progressing in phases

The safety of final disposal has been ensured by thorough planning and multi-year research projects in which VTT has participated. 

 
– Testing is now underway in the ONKALO underground research facility. The construction of ONKALO has enabled us to study the bedrock at Olkiluoto and the construction methods 
developed. We have recently been testing the final disposal procedures. ONKALO research 
facility will be completed during this year, and later it will be a part of the repository, says Jalonen.

 
Construction of the repository will begin as soon as ONKALO is ready. The ventilation and hoist equipment are already being built. They will serve ONKALO in the initial stage, as well as the repository later on.

 
Construction work has also begun on the foundations of the encapsulation facility. In the encapsulation facility, the spent nuclear fuel will be dried and placed in canisters, which will be closed, welded, inspected and sent to the final disposal repository or interim storage. 

 
– Passages have already been built to the underground storage facilities. We will begin building the central tunnels during the next phase and the actual final disposal tunnels in a few years’ time. The first underground final disposal areas are now under planning, Hansen says. 

 

R&D programmes providing further details

– In our current R&D programmes, we are exploring additional issues related to the safety of final disposal; the Finnish Radiation and Nuclear Safety Authority STUK required Posiva to resolve such issues when granting it a construction license in November 2015, says Jalonen. 

 
The programmes involve studying the final disposal canisters and spent fuel, the buffers, the backfilling and plugging of the tunnels, the repository site and preparations for production. In addition to fulfilling the requirements set by STUK, the goal is to obtain additional information for the design and construction of the encapsulation and final disposal facility. 

 
– This is important work. Posiva’s employees feel that it is great to be part of this project. We are highly motivated by the idea of solving the global nuclear waste challenge, says Jalonen. 

 

Setting their sights on a permit

Further information is also needed for a so-called safety case, which Posiva must complete in order to apply for a operating license for the final disposal site. Posiva intends to submit the safety case in 2020. 

 
A great deal of planning and testing is required in order to obtain the license. Posiva must also demonstrate that final disposal will work as assumed. 

 
– The planning phase of a full-scale system test is now under way. We will perform a final disposal test in demo facilities and deposition holes at ONKALO, where we will use prototype machines intended for installing the engineered barriers as well as existing, actual barrier components. Of course, we will not yet be using spent fuel in the canisters, says development engineer Pasi Rantamäki.

 
VTT is acting as the main consultant in the design of the system tests. 

VTT involved in technical development work

– VTT has long played a key role in our R&D work. We have been using VTT’s expertise in areas such as canister design, the thermal dimensioning of the repository, cement and clay materials development, and the development, testing and modelling of the bentonite clay buffer. This will enable us to evaluate the long-term behaviour of the final disposal system. VTT is also playing a major role in the development of the inspection techniques for the canisters, says Jalonen. 

 
– Our multi-disciplinary final disposal project is being supported by VTT’s many areas of expertise. In certain sub-areas, VTT experts have often been able to introduce a new and innovative method from a completely different field, says Hansen.  

 
Jalonen points out that the scientific community behind VTT has brought credibility to its work.  

 
– The building and maintenance of trust are very important in our field, she points out.

 
The Posiva personnel are highly satisfied with VTT’s systematic practices and prompt reports. They also praise VTT for recruiting skilled staff in place of retiring experts. 

 
Jalonen explains that Posiva no longer does its own basic research, but sources it externally when necessary. 

 
Posiva_13.jpg
 

Successful research cooperation

The closure of the repository was studied as part of the joint European DOPAS project, which will end in August. Under the POPLU sub-
projects, VTT participated in a full-scale plugging demonstration carried out in ONKALO. 

 
Edgar Bohner, the manager of VTT’s Infrastructure Health Team, led the instrumentation and monitoring team, which performed the instrumentation for the POPLU test plug and developed the pressure testing and water leakage monitoring equipment. Our collaboration went well, and we achieved excellent results, says Programme Manager Petri Koho of Posiva, who is serving as Project Manager for POPLU. 

 
– Our team is supporting Posiva in identifying the best and safe final disposal solutions. We develop materials and our specialism lies in the development of low pH concrete, Bohner says.

 
Bohner’s team mates are designing barriers and are investigating the industrial manufacture of buffer blocks from bentonite clay. Among other innovations, they are developing wireless sensors that send monitoring signals from the final disposal repository to the outside world. The team recently received an order for the design of test arrangements for full-scale system testing to be performed in ONKALO. 

 
Posiva and VTT have been collaborating for around twenty years. Antti Poteri, a Principal Scientist at VTT, already performed research for Posiva’s predecessor, the nuclear waste agency of TVO. His special area is modelling. 

 
– My research focuses on the migration of radionuclides through the bedrock. Our modelling calculations were used as a part of the safety case that was prepared in support of the Posiva’s construction license application.   Posiva is now getting prepared to submit its application for an operating license of the final repository and the research focus has moved to drawing up a new safety case, Poteri says. 


 
Posiva

  • An expert organisation established in 1995.
  • In charge on behalf of its owners of the final disposal of spent nuclear fuel and other expert tasks related to nuclear waste management.
  • Owners: Teollisuuden Voima (TVO) 60%, Fortum Power and Heat 40%.
  • Personnel: around 80 persons + some 200 subcontractors and consultants. 
  • Turnover 2015: around EUR 63 million.
  • Its service business subsidiary, Posiva Solutions, was founded in 2016.

 

 

VTT Impulsehttps://www.vttresearch.com/ImpulseVTT Impulse
Impulse 1/2018https://www.vttresearch.com/Impulse/Pages/Impulse-1-2018.aspxImpulse 1/2018
Tracking peoplehttps://www.vttresearch.com/Impulse/Pages/Tracking-people.aspxTracking people
A birthday gift from us to ourselveshttps://www.vttresearch.com/Impulse/Pages/A-birthday-gift-from-us-to-ourselves.aspxA birthday gift from us to ourselves
Are environmental claims believable?https://www.vttresearch.com/Impulse/Pages/Are-environmental-claims-believable.aspxAre environmental claims believable?
Matti Apunen: At the core of the solutionhttps://www.vttresearch.com/Impulse/Pages/At-the-core-of-the-solution.aspxMatti Apunen: At the core of the solution
At the digital forefront of mininghttps://www.vttresearch.com/Impulse/Pages/At-the-digital-forefront-of-mining.aspxAt the digital forefront of mining
Automation gives packages wingshttps://www.vttresearch.com/Impulse/Pages/Automation-gives-packages-wings.aspxAutomation gives packages wings
Cell screening leads to new cancer treatmentshttps://www.vttresearch.com/Impulse/Pages/Cell-screening-leads-to-new-cancer-treatments.aspxCell screening leads to new cancer treatments
Challenges conceal opportunitieshttps://www.vttresearch.com/Impulse/Pages/Challenges-conceal-opportunities.aspxChallenges conceal opportunities
Comfy but energy efficient homeshttps://www.vttresearch.com/Impulse/Pages/Comfy-but-energy-efficient-homes.aspxComfy but energy efficient homes
Finland on its way towards low-carbon year 2050https://www.vttresearch.com/Impulse/Pages/Finland-on-its-way-towards-low-carbon-year-2050.aspxFinland on its way towards low-carbon year 2050
VTT Impulsehttps://www.vttresearch.com/Impulse/Pages/MainPage.aspxVTT Impulse
S Group believes in a multi-channel modelhttps://www.vttresearch.com/Impulse/Pages/S-Group-believes-in-a-multi-channel-model.aspxS Group believes in a multi-channel model
We must maintain Finland as an attractive target for investmenthttps://www.vttresearch.com/Impulse/Pages/We-must-maintain-Finland-as-an-attractive-target-for-investment.aspxWe must maintain Finland as an attractive target for investment
Business for transportationhttps://www.vttresearch.com/Impulse/Pages/Business-for-transportation.aspxBusiness for transportation
Petri Kalliokoski: Artificial intelligence moves from words to deedshttps://www.vttresearch.com/Impulse/Pages/Petri-Kalliokoski-Artificial-intelligence-moves-from-words-to-deeds.aspxPetri Kalliokoski: Artificial intelligence moves from words to deeds
Digital ecosystems are emerginghttps://www.vttresearch.com/Impulse/Pages/Digital-ecosystems-are-emerging.aspxDigital ecosystems are emerging
Converting rags to design clotheshttps://www.vttresearch.com/Impulse/Pages/Converting-rags-to-design-clothes.aspxConverting rags to design clothes
Jari Gustafsson: Old and new workhorses as recession beatershttps://www.vttresearch.com/Impulse/Pages/Old-and-new-workhorses-as-recession-beaters.aspxJari Gustafsson: Old and new workhorses as recession beaters
Transport gets smarthttps://www.vttresearch.com/Impulse/Pages/Transport-gets-smart.aspxTransport gets smart
Same old routine for the next 100 yearshttps://www.vttresearch.com/Impulse/Pages/Same-old-routine-for-the-next-100-years.aspxSame old routine for the next 100 years
A future without wastewater?https://www.vttresearch.com/Impulse/Pages/A-future-without-wastewater.aspxA future without wastewater?
Modelling and simulation facilitateshttps://www.vttresearch.com/Impulse/Pages/Modelling-and-simulation-facilitates.aspxModelling and simulation facilitates
All sights on generationhttps://www.vttresearch.com/Impulse/Pages/All-sights-on-generation.aspxAll sights on generation
Before information gets lost in numbershttps://www.vttresearch.com/Impulse/Pages/Before-information-gets-lost-in-numbers.aspxBefore information gets lost in numbers
Designers needed in printed technologyhttps://www.vttresearch.com/Impulse/Pages/Designers-needed-in-printed-technology.aspxDesigners needed in printed technology
Health benefits and efficiency without sacrificing food qualityhttps://www.vttresearch.com/Impulse/Pages/Health-benefits-and-efficiency-without-sacrificing-food-quality.aspxHealth benefits and efficiency without sacrificing food quality
Serious efforts to boost the Finnish economyhttps://www.vttresearch.com/Impulse/Pages/Serious-efforts-to-boost-the-Finnish-economy.aspxSerious efforts to boost the Finnish economy
The creative force of change managementhttps://www.vttresearch.com/Impulse/Pages/The-creative-force-of-change-management.aspxThe creative force of change management
Defence Forces seek a head starthttps://www.vttresearch.com/Impulse/Pages/Defence-Forces-seek-a-head-start.aspxDefence Forces seek a head start
World in 2030 - answers to tomorrow’s questionshttps://www.vttresearch.com/Impulse/Pages/World-in-2030-answers-to-tomorrows-questions.aspxWorld in 2030 - answers to tomorrow’s questions
The story of Finlandhttps://www.vttresearch.com/Impulse/Pages/The-story-of-Finland.aspxThe story of Finland
It is the duty of entrepreneurs to seek growthhttps://www.vttresearch.com/Impulse/Pages/It-is-the-duty-of-entrepreneurs-to-seek-growth.aspxIt is the duty of entrepreneurs to seek growth
Tua Huomo: Energy production and use – smart choices have an impacthttps://www.vttresearch.com/Impulse/Pages/Energy-production-and-use–smart-choices-an-impact.aspxTua Huomo: Energy production and use – smart choices have an impact
Media production and housing services are preparing for the 5G networkshttps://www.vttresearch.com/Impulse/Pages/Media-production-and-housing-services-are-preparing-for-the-5G-networks.aspxMedia production and housing services are preparing for the 5G networks
Miniaturising devices to fit on your palmhttps://www.vttresearch.com/Impulse/Pages/Miniaturising-devices-to-fit-on-your-palm.aspxMiniaturising devices to fit on your palm
Developers of the futurehttps://www.vttresearch.com/Impulse/Pages/Developers-of-the-future.aspxDevelopers of the future
Open-source infrastructure in product development for the electromechanical industryhttps://www.vttresearch.com/Impulse/Pages/Open-source-infrastructure-in-product-development-for-the-electromechanical-industry.aspxOpen-source infrastructure in product development for the electromechanical industry
Pilot plants forge innovative ideas into business activitieshttps://www.vttresearch.com/Impulse/Pages/Pilot-plants-forge-innovative-ideas-into-business-activities.aspxPilot plants forge innovative ideas into business activities
VTT’s spin-off GrainSense puts a laboratory in farmers’ handshttps://www.vttresearch.com/Impulse/Pages/VTTs-spin-off-GrainSense-puts-a-laboratory-in-farmers-hands.aspxVTT’s spin-off GrainSense puts a laboratory in farmers’ hands
Digitalisation in closing the gaphttps://www.vttresearch.com/Impulse/Pages/Digitalisation-in-closing-the-gap.aspxDigitalisation in closing the gap
Intelligence for machineshttps://www.vttresearch.com/Impulse/Pages/Intelligence-for-machines.aspxIntelligence for machines
Matti Apunen: A problem called excellencehttps://www.vttresearch.com/Impulse/Pages/Matti-Apunen-A-problem-called-excellence.aspxMatti Apunen: A problem called excellence
Better beer based on long-term researchhttps://www.vttresearch.com/Impulse/Pages/Better-beer-based-on-long-term-research.aspxBetter beer based on long-term research
From ideas to major innovationshttps://www.vttresearch.com/Impulse/Pages/From-drawing-board-to-major-innovation.aspxFrom ideas to major innovations
Intelligent transport – a trump card for Finnish exportshttps://www.vttresearch.com/Impulse/Pages/Intelligent-transport-a-trump-card-for-Finnish-exports.aspxIntelligent transport – a trump card for Finnish exports
We cannot afford not to have robotshttps://www.vttresearch.com/Impulse/Pages/We-cannot-afford-not-to-have-robots.aspxWe cannot afford not to have robots
Return on investmentshttps://www.vttresearch.com/Impulse/Pages/Return-on-investments.aspxReturn on investments
What's going on in Australia?https://www.vttresearch.com/Impulse/Pages/Whats-going-on-in-Australia.aspxWhat's going on in Australia?