Nuclear sector
How to evaluate and control the risks associated with the structures of a nuclear power plant? What decision-aiding tools can be put in place? How can performance goals be achieved? Which actions should be prioritised and planned for?
OXAND can answer all of these questions with specific solutions thanks to our expertise and experience in the civil engineering of nuclear power plants. This is a sector in which OXAND is heavily involved, as it contributes to the reduction of greenhouse gas emissions.
OXAND has the know-how to intervene at all stages of a project: from feasibility studies (including the evaluation of the choice of technologies or procedures), up until the development of managerial master plans for the extension of a structure's lifespan. In bringing assistance to owners and operators of nuclear power plants, OXAND is a neutral and independent service provider with regard to all players in the nuclear sector whether they be engineers, contractors or technical managers.
Oxand's solutions for lifecycle management of nuclear installations
OXAND can offer solutions at any stage in a project in order to better manage its lifecycle: from project inception right up until decommissioning. The diagram below illustrates the key phases in the life of a nuclear installation, as well as the types and periods of intervention proposed by OXAND. To find out more, click on the category that interests you in the legend just below the main diagram.
Sustainable design
To finish well, you must begin well. The sustainability of a nuclear installation should be taken into account in the early design stages of the project in order to guarantee an optimised lifespan as well as high performance operation.
Oxand offers:
- Recommendations to improve the reliability of design and construction
- The incorporation of the latest scientific methods and knowledge as well as our experience in the nuclear sector as well as others which present similar structures and problems to overcome (eg: LNG)
- Improvement of sustainability of designs and reliability of security margins
- Guarantee of long-term performance thanks to the prevention of risks during operation
Example projects :
- Safety assessment for the design of nuclear waste storage structures Details...
- Risk analysis of containers for storage of radioactive waste Details...
Monitoring/inspection
In order to be able to control the risks associated with the ageing of a nuclear installation, it is essential to define and put into place a monitoring system as well as an adapted inspection program as early as possible. Monitoring generates data which is essential to allow tracking and updating of a structure's risk profile, and hence for the optimisation of repair or maintenance works and the anticipation of faults in vulnerable zones. The analysis of data from monitoring and inspection can help to present a strong case to nuclear security authorities when necessary, for example to justify a lifespan extension.
Oxand offers:
- With Ageing Monitoring™ Details..., the complete package for the long-term monitoring of a structure, including the installation and maintenance of the necessary equipment, the archiving and analysis of data, and the use of data in updating risk profiles and forecasting faults
- The control and monitoring of ageing mechanisms
- Recommendations for optimised interventions (repairs, maintenance, etc)
- Cost reduction and increased efficiency of inspection/monitoring systems
- Anticipation and prevention of faults
- Decision-making aids for repairs/maintenance
- Facilitated safety demonstration to justify lifespan extension
Example projects:
- Ageing Monitoring™ for prestresesd concrete confining structures Details...
- Design of a system to monitor the effects of corrosion on the pipes of cooling circuits of seafront nuclear power plants Details...
Impact of construction defects
Variations between the ‘as designed' and the ‘as built' can have large and sometimes unforeseen impacts on the functioning and condition of a nuclear installation in both the short and long-term. The analysis and evaluation of these impacts is therefore desirable in order to improve lifecycle management.
Oxand offers:
- Short, medium and long-term impact analyses on structure function
- A neutral and independent expertise on defaults/disorders, with no influence from builders/contractors
- Short-term
- Control of commissioning deadlines
- Assistance to owners/operators for commissioning
- Assistance to owners/operators for safety demonstrations to nuclear safety authorities
- Long-term:
- Control of costs for the correction of construction defects
- Guarantee of the safety level of a structure
- Prioritisation of the long-term interest of the owner versus the short-term interest of the builder/contractor
- Guarantee of the maintenance of structures
Example projects:
- Risk analysis of impact of potential grouting defects at the ends of steel prestressing cables Details...
- Managing the impacts of construction defects for the sustainable design of LNG reservoirs Details...
Guarantee and control of the sustainability of repairs
Repair works are often expensive both in terms of direct cost as well as in terms of ensuing periods of unavailability of the structure. The sustainability and quality of repairs must therefore be ensured in order to avoid subsequent supplementary repair work.
Oxand offers:
- Assistance in the technical choices for sustainability (repair methods, materials…)
- Recommendations for execution methods and control procedures
- Verification of the quality and the sustainability of repairs while taking account of time constraints
- Gains on the total cost of maintenance due to optimisation and durability of repairs
- Improved performance due to prevention of faults resulting from poor repairs
- Minimised financial losses due to optimisation of periods of unavailability during repair work
Example projects:
- Study of potential harmfulness of grouting defects at the head of steel prestressing cables Details...
- Evaluation of the early-age stresses in radioactive waste storage containers Details...
Capitalisation of ‘as built' data
In order to fully exploit initial ‘as built' data for the improvement of the lifecycle management of a nuclear installation, the information must first be collected and organised in a logical manner. This allows the establishment of a realistic diagnosis of the installation, which will serve for the duration of the exploitation period to aid in planning maintenance work, identifying vulnerable areas of a structure, anticipating ageing degradation, etc...
Oxand offers:
- Creation of a detailed « snapshot » of a structure, giving an overall vision of its actual condition
- The capitalisation of data and construction feedback
- The management and quality of assurance of this information
- Long-term management of assets based on sound past experience
- Reliable decision-making aids based on a realistic diagnosis
Example projects:
- Risk analysis of cooling towers Details...
- Capitalisation of initial information for the sustainable design of LNG reservoirs Details...
Management and monitoring of ageing processes
Ageing mechanisms represent an inevitable risk for the civil engineering of a nuclear installation. Reinforced concrete reactor buildings with prestressing cables, for example, are subject to numerous ageing phenomena linked to the concrete (creep, shrinkage…), the reinforcing steel (corrosion, loss of section…) and the prestressing tendons (loss of tension…). The effective management of these complex and interdependent mechanisms requires a comprehensive expertise based on experience feedback.
In the same way, seaside nuclear power plants have to face the ageing of nuclear reactor cooling piping systems. Whatever are the materials of those systems (concrete, metal, composite material, polymer), the utility has to plan and anticipate the refurbishment of its infrastructures. Before taking an important decision on how to repair or maintain the systems, Oxand?s risk analysis know-how will provide the owner with the technical expertise required visibility.
See attached References in piping maintenance and composite materials. Details...
Oxand offers:
- Study of the impacts of ageing mechanisms on the availabilty of a structure
- Identification of key phenomena in terms of impact on the lifespan of a structure
- Diagnosis and forecasting of a structure's condition and the associated risks
- Optimisation of maintenance and monitoring concerning risks, by a ranking of costs and benefits
- Decision-making support to plan and prioritise actions
- Decision-making support on the question: maintain, repair or rebuild?
Example projects:
- Control of risks linked to the decision to extend the lifespan of industrial cooling circuits Details...
- Corrosion risk assessment of various design options for a cooling system Details...
- Prediction of the evolution of the deformation and cracking of cooling towers Details...
- Risk analysis of cooling towers Details...