WHY CHOOSE Radiation shielding windows

  • Robust : ultra impact resistant
  • Quality : high mechanical properties of glass
  • Transparency : optical quality (no mirror effect)
  • Maintenance : can be repaired at low cost and easily cleaned with common cleaning products

VIDEO: Radiation shielding windows



After many years of research and development, Lemer Pax is today a leader in lead glass block manufacturing. 

The Lemer Pax range of radiation shielding windows includes four different types of designs to meet the needs of our customers:

  • Type A: Lead glass block
  • Type B: Lead glass window (with steel or stainless steel frame)
  • Type C: Lead glass shielded window with steel or stainless steel frame incorporating shielding
  • Type D: Multi-block lead glass radiation shielding window (designed for very high attenuation requirements)

Lemer Pax relies on two technologies: ordinary cast lead glass blocks and laminated lead glass blocks. The latter are designed to guarantee unrivalled mechanical strength, particularly in terms of impact resistance, and are repairable.

Radiation shielding windows : Applications

Radiation shielding windows are mainly used in industry and research, in waste reprocessing plants and laboratories. They guarantee optimal visual control during operations carried out on radioactive sources or materials inside hot cells.

To determine the necessary attenuation of the radiation shielding window, a number of specifications must be taken into account:

  • The nature and thickness of the wall into which the window will be fitted
  • The nature of the reference radionuclide and its activity (or for X-rays, the generator specifications)
  • The desired dose rate on the operator side
  • The position of the radioactive source (distance from the inner wall)
  • The annual exposure time and operating time for calculating the accumulated dose

This information makes it possible to select the type or types of glass to be used for the window:

  • High density lead glass (LPX 650 – LPX700 – LPX800) for its high radiation attenuation capacity,
  • Stabilised lead glass (LPX200) for its attenuation and resistance to radiation without darkening
  • Stabilised glass (LPX100) for its high resistance to radiation

Under exposure to constant high radiation, the glass can lose its transparency (use limit of high density blocks: 103 Gy).

The radiation shielding window may also act as a firestop.

Type A radiation shielding windows: lead glass block

With our monoblock cast glass or ultrastrong laminated glass technologies, Lemer Pax supply frameless glass panels or slabs under the Type A name. From stabilized glass panels to high-density leaded glass blocks, they have different grades and characteristics.

Type B radiation shielding windows: lead glass blocks integrated into a frame

This is a type A glass block integrated into a stainless steel or steel frame, making it easy to handle and integrate into your projects.

The interface between the glass block and its frame ensures continuity of biological protection.

Type C radiation shielding windows: lead glass window with its shielded frame

This is a block of type A glass integrated into an armored frame. The frame incorporates a biological lead shield encased in a stainless steel or steel casing. Handling points are also integrated into the frame.

Its design ensures continuity of biological protection between the wall and the glass block.

This is a complete unit, ready to install in the wall opening of your hot cell.

Our technologies will meet all your project requirements:

  • Design integrating the passage of a remote manipulator or handling tong/ ball joint system
  • Porthole incorporating several shades of glass
  • Atmosphere inerting enclosed in the window
  • Circular shape
  • Dimensioning in relation to expected viewing angles

Type D radiation shielding windows: Multi-block shielded lead glass window

Type D windows are generally made up of 3 or 4 sub-assemblies:

  • Steel sheath part (embedment wall liner) : This is the metal frame that will later house the armored window. It is integrated into the wall during the civil engineering (or masonry) construction phase, and thus embedded in the concrete. It contributes to the window’s biological protection. The hot side is made of stainless steel and, together with the Alpha glass, contributes to the watertightness of the hot cell.
  • Shielded window: allowing vision into the hot cell while ensuring biological protection, it consists of one or more glass blocks integrated into a metal frame. Several functions can be integrated according to project requirements, notably to control the enclosed interior atmosphere (desiccant, nitrogen inerting, etc.).
  • Alpha glass: this is the watertight containment barrier on the hot side. It is therefore the part closest to the radioactive source. The choice of material grade is therefore closely linked to its proximity and the dose rate of the radioactive source. See our next page on this subject.
  • As an option, depending on project requirements and the technology chosen for the operator-side glass panel (laminated or monoblock), protective glass may be required. See our next page on this subject.

1 I Alpha glass (on the radiation side)

2 I The steel or cast iron frame (hot side)

3 I Window composed of a steel frame integrating one or more blocks of anti-radiation glass

4 I Protective glass (on the operator side)

Normal angle of vision / Extreme angle of vision

Steel sheath part (or embedment wall liner) for Type D window à incorporer au mur de génie civil

  • For maintenance or window replacement, we can adapt to the existing sleeve.
  • Our «Window» sheaths can also be used to accommodate remote manipulator sheaths, or wall penetrations for electrical cables or gas pipes.

In addition to this range of radiation shielding windows, Lemer Pax also offers the following products:

Alpha glass: protection and confinment screen

Alpha glass is the containment sealed barrier of the hot cell. Located on the hot side behind the shielded window, and attached to the inner casing of the hot cell, it provides a seal between the radioactive environment and the front viewing and operating zone.

It also acts as a mechanical protective screen for the glass panels making up the shielded window.

It comprises a vision panel, seals and, in most cases, a stainless steel frame. Our patented, organic-free Alpha glass is highly resistant to radiation (> 108 Gy), and requires no maintenance whatsoever while the window is in operation.

Depending on your project requirements, Lemer Pax offers a wide range of technical possibilities:

  • Vision panel material shade according to source type, activity and positioning
  • Removability : from inside the hot cell, by remote or manual operation, or from the outside, after dismantling the shielded window.
  • Patented sealing system consisting of a metal alloy gasket that is not sensitive to irradiation. This system, with no organic gaskets, eliminates the need for maintenance operations during operation of the hot cell
  • Design that allows daily leak testing during operation, to ensure seal quality
  • Very high level of tightness, down to a leak rate of less than 1×10-4cm3/sec

Protective glass

Placed on the cold side, they protect the leaded glass blocks, and can also serve as a second watertight barrier, depending on the application. As an option, Lemer Pax offers a 2-hour firewall version, to isolate the hot zone from the front handling zone.

Machined lead glass glove box walls

Lemer Pax’s low-activity lead-glass glovebox panels enable you to work safely with your radioelements, protected from radiation.

These glove-box panels guarantee leaktight containment when working in a special atmosphere.

They can be supplied as a single panel or integrated into a stainless steel frame.

All types of technical glass requiring protection against radiation

Glasses, camera optics, etc. As a global solutions provider, Lemer Pax is able to meet your most specific needs in terms of technical anti-radiation glass.


France © 2024 - Lemer Pax