Neutron shielding for demanding conditions: VYAL™ resins

Result of a 20+ years R&D, patented VYAL™ resins are designed to withstand the most severe conditions. They are already in use for neutron protection in hundreds of transport/storage casks and for on-site shielding of naval & civil nuclear reactors.

• The Challenge

  Protection from radiation is a priority in every nuclear-related activity and shielding from neutrons is especially a concern. Moreover, traditional neutron shielding materials lack the thermal and mechanical properties required to meet the requirements of highly complex nuclear activities:

  • high temperatures,
  • shock resistance,
  • stability over time,
  • fire resistance,

  • etc.

  All that with easiness in manufacturing and work execution.

  
  

  
  

• The Solution

  A family of new neutron shielding materials was developed by Orano NPS for nuclear spent fuel in storage facilities and transport/storage casks, showing high shielding, mechanical and thermal capabilities.

  These innovative materials are composed of a thermosetting resin. The cross-linking of the polymer leads to a rigid three-dimensional lattice, solid and resisting to extreme conditions (up to 180°C for long-term use). 

  Their shielding ability for neutron radiation is related to a high hydrogen content (for slowing down neutrons) and a high boron content (for absorbing neutrons). Atomic concentrations are equal to 5.1022 at/cm³ for hydrogen and 9.1020 at/cm³ for boron.

  The manufacturing process is very simple, as it consists in mixing the fillers and pouring at ambient temperature. So it is reliable, easy to implement and allows a perfectly customised product:

  • it can either be poured in situ or machined from pre-manufactured blocks, allowing for complex form factors,
  • its fire-resistance allows for welding directly around it, unlike other neutron shielding materials.

  
  

• Key Features

  • High neutron-shielding efficiency
  • Solid, high density, inert and long-lasting material: 60-year lifetime
  • High temperature performance: up to 180 °C for long-term use
  • Lightness
  • Shapeable and easy implementation
  • M1 Fire, M0 Fumes
  • Unique mechanical properties: 
    Young modulus: 4300 MPa (compression at 23 °C)
  • Thermal conductivity:
    • 0,807 W/m·K at 40 °C
    • 0,821 W/m·K at 160 °C
  • Specific heat
    • 1,07 J/g·°C at 40 °C
    • 1,59 J/g·°C at 160 °C
  • BIW (Banal Industrial Waste): easy management of surplus and wasted material

  
  

   

• Expertise & Experiences

  Orano NPS’ VYAL^TM resin family is already widely used for neutron protection in hundreds of transport and storage casks of radioactive materials (TN 24 family, MX family, TN Eagle…) and for on-site shielding for naval & civil nuclear reactors (e.g., Framatome’s EPRs)

  With several decades of experience in neutron protection, both in the development of customised materials and in product implementation, Orano NPS has developed extensive capabilities, at your service:

  • conception of neutron protections:
    • design (shielding, structure, interfaces, implementation and tooling),
    • mechanical, seismic, thermal and shielding calculations,
    • safety demonstrations,
  • supply:
    • procurement & inspections,
    • testing,
    • assembly & installation.

  
  

  
  

• Your Benefits at a glance

  • The VYALTM resin has long-standing mechanical & thermal characteristics and performances, guarantying a safe long-term utilisation under constraint conditions:
    • Lifetime of at least 60 years
    • Up to 180°C for long-term use
    • Lightness (no overload on structures/packages)
    • Self-extinguishable product

  • Perfect customisation: easy-to-work capability (poured at ambient temperature and machinable) for easy implementation in complex designs with high level of constraints

  • Rely on Orano NPS’ expertise for your neutron-protection needs:
    • Design
    • Supply
    • Services

  
  

  
  

• Links

  

  Nuclear Package and Safety