Products & Services
ModuCon® - Modular Containment System
The Modular Containment System has been used by Nuvia and its clients for many years. It was originally developed for the decommissioning of plant contaminated by plutonium. The system has an impressive track record of over 20 years' reliable routine use with highly toxic and radioactive materials. It is now widely used in the nuclear industry for maintenance, decommissioning and waste handling purposes.
Our experience of users’ problems has shown that the system often provides the only solution that offers an acceptable combination of safety and economy.
The ModuCon® system is tailored to suit the requirements of each user, and the enclosure can be as large or small, simple or complex as the job demands. The standard panels (900 mm wide) are easily handled and assembled. Non-standard panels are readily available and the enclosure may incorporate any of the following options:
- Entry/exit area with (optional) shower or wet swabbing area
- Ports for material “posting” and services
- Windows for viewing and lighting
- Mobile ventilation and filtration plant
- Lifting equipment
Constructing ModuCon®
Erection of the designed containment may be carried
out by a Nuvia team or by customer staff; a combined
team is often the best. First the floor is prepared, and
the requirements for this vary. Existing substrates may
be utilised or covered with a heavy duty strippable
coating. However, a false plywood floor is often laid
to provide a firm platform and working base. The false
floor is overlaid with tough PVC and protective
coatings. When wet operations are to be carried out
an integrated steel bunded base can be provided.
Assembly is simple and quick using bolts through the
flanged panels.
In preparation for radioactive or toxic operations the containment is sealed and protected by application of a pliable coherent coating (tie down coating) which can be easily removed later by physical stripping. The coating is applied by airless spray, for speed and efficiency, but it may also be applied by brush or roller in smaller units.
Air extraction is desirable and often mandatory to ensure controls are adequate to contain the hazardous material. Existing building extract systems can only occasionally be utilised and so mobile ventilation units are incorporated in the design to ensure that correct depression and flows are maintained. The extract systems vary in size and sophistication to suit the task in hand; for example a small containment handling wet, low toxicity wastes could use a considerably simpler extract plant than decommissioning glove boxes containing dry plutonium oxide.
For the control of wastes the ModuCon® system incorporates purpose built waste ports to allow direct packing into drums outside the containment. This avoids repeated handling and contamination of the drum.
Operations within ModuCon®
Safety cases have been prepared to permit a wide
range of operations within ModuCon®. For example,
plasma arc and other size reduction cutting methods
are used in decommissioning work and ultra high
pressure water jetting is currently deployed in
descaling and other decontamination tasks. During
work, entry and exit procedures must be strictly
followed to prevent spread of toxic material. Often, a
supplementary unit is attached to allow for change of
personal protective equipment (PPE), washing or
showering as the hazards dictate. A purpose built
shower tunnel or air lock is necessary for highly toxic
materials, but often a simple containment is adequate.
During dusty operations involving particularly toxic materials such as plutonium, asbestos or beryllium, successive tie down coatings may be applied to fix dusts and reduce airborne risks and recontamination. This is now routine housekeeping practice at many establishments and not only reduces risks but can reduce the PPE requirements as the job progresses, from full air suits to free breathing.
Dismantling and Re-Use
On completion of the work a final tie down coating is
applied to the inside of the containment. This
sandwiches contamination between layers. This is
then removed by physically stripping the coating for
safe disposal and producing minimal secondary
waste. The panels are left clean and can be handled
and transported without any special precautions.
ModuCon® panels have been re-used many times in
different configurations and on different sites or
facilities.
Cleaning & Decontamination
During manufacture, particular attention is paid to the
internal faces of the ModuCon® panels to ensure that
they are smooth and unblemished in order to facilitate
decontamination. The method of decontamination
depends on the nature and extent of the
contamination. For mild contamination, simple
methods such as wiping with a damp swab will
suffice.
Where more severe contamination is anticipated the following technique employing strippable coating has proven highly successful:
- After assembling the ModuCon®, seal the panel joints with self-adhesive PVC tape.
- Apply one or two layers of strippable coating (by brush, roller or spray) to the interior.
- Carry out the planned work within the containment.
- Apply a further layer of strippable coating to trap the contamination in a sandwich.
- Peel off the strippable coating.
- Check no contamination remains.
- Dismantle the ModuCon®.
Support Services
Other services that can be supplied with ModuCon®
include:
- Consultancy and advice on potential applications of ModuCon® design from experienced users.
- An efficient installation service.
- Training or advice in:
– planning and estimating tasks employing ModuCon®.
– ModuCon® working methods.
– pressurised suit working.
– use of associated equipment and decommissioning tools.
ModuCon® customers profit from Nuvia’s extensive
experience in handling hazardous materials, and may
contract with Nuvia for a complete decommissioning,
decontamination and waste disposal service.
Nuvia is the UK’s largest independent provider of radiation safety services. A full Health Physics service can be provided if the tasks involve working with ionising radiation.
Nuvia can provide:
- Initial consultancy.
- Operational advice.
- Workplace monitoring and instrumentation.
- Routine and emergency dosimetry and record keeping.
- Radiation protection advice and safety training.
- Reactor outage support to the nuclear industry.
- 24 hr, 365 day availability.
Nuvia also has a training ModuCon® and can provide ‘Certificated Training Courses’ in the use of PPE and operational procedures within a ModuCon®/PSA.