The 12th International Conference on Environmental ... - Events

Abstracts Session 36
4) PRELIMINARY STUDY OF CRYOGENIC CUTTING TECHNOLOGY FOR DISMANTLING HIGHLY
ACTIVATED FACILITIES - 16006
Sung-Kyun Kim, Korea Atomic Energy Reserach Institute (Korea);
Dong-Gyu Lee, Kune-Woo Lee, Korea Atomic Energy Research Institute (Korea)
Cryogenic cutting technology is one of the most suitable technologies for dismantling nuclear facilities due to the fact that a
secondary waste is not generated during the cutting process. In this paper the feasibility of cryogenic cutting technology has been
investigated by using a computer simulation. In the computer simulation, a hybrid method combined with the SPH (smoothed particle
hydrodynamics) method and with the FE (finite element) method was used. And also, a penetration depth equation, for the
design of the cryogenic cutting system, was used and the design variables and operation conditions to cut a 10 mm thickness for
steel were determined. Finally the main components of the cryogenic cutting system were developed on the basis of the obtained
design values.
5) ABRASIVE BLASTING UNIT (ABU) - 16270
Georg Braehler, Philipp Welbers, NUKEM Technologies GmbH (Germany);
Gianfranco Brunetti, Diederik van Regenmortel, Joint Research Centre (Italy); Mike Kelly, Nuvia Limited (UK)
As active nuclear facilities outlive their useful life and are decommissioned, they produce considerable quantities of slightly
contaminated components. <strong>The</strong> burden of dealing with this waste in both an environmentally responsible and efficient way has been
a key factor that has driven the nuclear industry to seek solutions from wider industrial applications. <strong>The</strong> methods to reduce the
quantity of contaminated waste are becoming more refined as the remarkable economic benefits of decontamination and subsequent
recycling of materials are realised. Maximising the amount of material that can be released from a nuclear site, following decontamination
is a key achievement in view of environmental impact and waste disposal costs considerations. Dry decontamination
methods are preferred, due to lower volumes of secondary waste and their easier handling, as compared with wet methods.
NUKEM Technologies GmbH was contracted to supply a dry, automated drum belt (tumbling) Abrasive Blasting Unit (ABU)
to the Joint Research Centre (JRC) of the European Commission in Ispra/Italy. <strong>The</strong> ABU was installed in the centralised radioactive
waste management area of the JRC. <strong>The</strong> unit is to be employed for the decontamination to clearance levels of slightly contaminated
metal components and, where practical, concrete or heavy concrete (density ~3200kg/m3) blocks.
Among the several possibilities of adapting conventional abrasive units to nuclear applications, an automatic tumbling machine
was preferred, due to the larger output and (mainly) to the ease of operation, with minimum direct handling of contaminated material
by operators, thus satisfying the ALARA principle. Consideration was also given to Belgoprocess succesful experience with a
predecessor, similar unit.
6) DECOMMISSIONING OF THE A-1 NPP LONG-TERM STORAGE FACILITY - 16299
Jan Medved, VUJE, Inc. (Slovakia); Ladislav Vargovcik, ZTS VVU KOSICE a.s. (Slovakia)
<strong>The</strong> paper deals with experience, techniques and new applied equipment durig undergoing decommissioning process of the A-
1 NPP long-term pool storage and the follow-up decommissioning plan. For rad-waste disposal of the long-term pool storage
(where most of the contaminants had remained following the removal of spent fuel) special equipment has been developed,
designed, constructed and installed. <strong>The</strong> purpose of this equipment is the restorage, drainage and fragmentation of cartridges (used
as a spent fuel case), as well as treatment of sludge (located at the pool bottom) and of the remaining liquid radwaste.
<strong>The</strong> drainage equipment for cartridges is designed for discharging KCr2 solution from cartridges with spent fuel rods into the
handling storage tank in the short-term storage facility and adjustment of the cartridges for railway transport, prior to the liquidation
of the spent fuel rod. <strong>The</strong> equipment ensures full remote visual control of the process and exact monitoring of its technical
parameters, including that of the internal nitrogen atmosphere concentration value. Cartridges without fuel and liquid filling are
transferred to the equipment for their processing which includes fragmentation into smaller parts, decontamination, filling into
drums with their sealed closing and measurement of radioactive dose. For the fragmentation, special shearing equipment is used
which leaves the pipe fragment open for the following decontamination. For cleaning the cartridge bottom from radioactive sludge
water jet system is used combined with slow speed milling used for preparing the opening for water jet nozzle. <strong>The</strong> sludge from
the cartridge bottom is fixed into ceramic matrix.
7) USE OF FULL RECOVERY HYDROLASING EQUIPMENT FOR FACILITY DECOMMISSIONING - 16325
Scott Martin, Scott Adams, S.A.Robotics (USA)
<strong>The</strong> removal of surface contamination is a major challenge for nearly all nuclear facilities undergoing, or awaiting, decommissioning.
Conventional means of surface decontamination can expose workers to unnecessary hazards, and are often not fit-for-purpose
due to size constraints or weight restrictions. Additionally, conventional methods are not always easily deployed remotely due
to their complexity or required services. <strong>The</strong> use of ultra high pressure water for surface decontamination, known as hydrolasing,
is recognized as a technology which can be used in various applications requiring surface removal. Hydrolasing is an advantageous
technology for many reasons including its versatility, overall simplicity and relative ease of remote deployment.
For the nuclear industry, one of the largest challenges with regards to the use of hydrolasing is the requirement for the full
recovery of the injected water and removed solids. For non-nuclear applications, there is often no requirement for recovery of the
liquid and solid waste, which has led to few system designs which will recover the waste in full. S.A. Robotics experience with the
deployment of ultra high pressure water systems for nuclear applications has shown that full recovery of injected water and
removed solids is achievable in both underwater and in-air applications. Innovative equipment and system design have allowed S.A.
Robotics hydrolasing systems to achieve near 100% solid and liquid recovery during concrete hydrolasing. This technology has
been deployed for Fluor Hanford at Hanfords K-Basins, as well as for UKAEA as part of the Windscale Piles decommissioning
project.
<strong>The</strong> purpose of this paper is to provide a short description of the hydrolasing process and the associated waste issues, describe
the unique design features of S.A. Robotics hydrolasing systems which combat these issues, and provide an overview of two of the
hydrolasing projects that S.A. Robotics has completed.
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