The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Abstracts Sessi<strong>on</strong> 36<br />
4) PRELIMINARY STUDY OF CRYOGENIC CUTTING TECHNOLOGY FOR DISMANTLING HIGHLY<br />
ACTIVATED FACILITIES - 16006<br />
Sung-Kyun Kim, Korea Atomic Energy Reserach Institute (Korea);<br />
D<strong>on</strong>g-Gyu Lee, Kune-Woo Lee, Korea Atomic Energy Research Institute (Korea)<br />
Cryogenic cutting technology is <strong>on</strong>e of the most suitable technologies for dismantling nuclear facilities due to the fact that a<br />
sec<strong>on</strong>dary waste is not generated during the cutting process. In this paper the feasibility of cryogenic cutting technology has been<br />
investigated by using a computer simulati<strong>on</strong>. In the computer simulati<strong>on</strong>, a hybrid method combined with the SPH (smoothed particle<br />
hydrodynamics) method and with the FE (finite element) method was used. And also, a penetrati<strong>on</strong> depth equati<strong>on</strong>, for the<br />
design of the cryogenic cutting system, was used and the design variables and operati<strong>on</strong> c<strong>on</strong>diti<strong>on</strong>s to cut a 10 mm thickness for<br />
steel were determined. Finally the main comp<strong>on</strong>ents of the cryogenic cutting system were developed <strong>on</strong> the basis of the obtained<br />
design values.<br />
5) ABRASIVE BLASTING UNIT (ABU) - 16270<br />
Georg Braehler, Philipp Welbers, NUKEM Technologies GmbH (Germany);<br />
Gianfranco Brunetti, Diederik van Regenmortel, Joint Research Centre (Italy); Mike Kelly, Nuvia Limited (UK)<br />
As active nuclear facilities outlive their useful life and are decommissi<strong>on</strong>ed, they produce c<strong>on</strong>siderable quantities of slightly<br />
c<strong>on</strong>taminated comp<strong>on</strong>ents. <str<strong>on</strong>g>The</str<strong>on</strong>g> burden of dealing with this waste in both an envir<strong>on</strong>mentally resp<strong>on</strong>sible and efficient way has been<br />
a key factor that has driven the nuclear industry to seek soluti<strong>on</strong>s from wider industrial applicati<strong>on</strong>s. <str<strong>on</strong>g>The</str<strong>on</strong>g> methods to reduce the<br />
quantity of c<strong>on</strong>taminated waste are becoming more refined as the remarkable ec<strong>on</strong>omic benefits of dec<strong>on</strong>taminati<strong>on</strong> and subsequent<br />
recycling of materials are realised. Maximising the amount of material that can be released from a nuclear site, following dec<strong>on</strong>taminati<strong>on</strong><br />
is a key achievement in view of envir<strong>on</strong>mental impact and waste disposal costs c<strong>on</strong>siderati<strong>on</strong>s. Dry dec<strong>on</strong>taminati<strong>on</strong><br />
methods are preferred, due to lower volumes of sec<strong>on</strong>dary waste and their easier handling, as compared with wet methods.<br />
NUKEM Technologies GmbH was c<strong>on</strong>tracted to supply a dry, automated drum belt (tumbling) Abrasive Blasting Unit (ABU)<br />
to the Joint Research Centre (JRC) of the European Commissi<strong>on</strong> in Ispra/Italy. <str<strong>on</strong>g>The</str<strong>on</strong>g> ABU was installed in the centralised radioactive<br />
waste management area of the JRC. <str<strong>on</strong>g>The</str<strong>on</strong>g> unit is to be employed for the dec<strong>on</strong>taminati<strong>on</strong> to clearance levels of slightly c<strong>on</strong>taminated<br />
metal comp<strong>on</strong>ents and, where practical, c<strong>on</strong>crete or heavy c<strong>on</strong>crete (density ~3200kg/m3) blocks.<br />
Am<strong>on</strong>g the several possibilities of adapting c<strong>on</strong>venti<strong>on</strong>al abrasive units to nuclear applicati<strong>on</strong>s, an automatic tumbling machine<br />
was preferred, due to the larger output and (mainly) to the ease of operati<strong>on</strong>, with minimum direct handling of c<strong>on</strong>taminated material<br />
by operators, thus satisfying the ALARA principle. C<strong>on</strong>siderati<strong>on</strong> was also given to Belgoprocess succesful experience with a<br />
predecessor, similar unit.<br />
6) DECOMMISSIONING OF THE A-1 NPP LONG-TERM STORAGE FACILITY - 16299<br />
Jan Medved, VUJE, Inc. (Slovakia); Ladislav Vargovcik, ZTS VVU KOSICE a.s. (Slovakia)<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> paper deals with experience, techniques and new applied equipment durig undergoing decommissi<strong>on</strong>ing process of the A-<br />
1 NPP l<strong>on</strong>g-term pool storage and the follow-up decommissi<strong>on</strong>ing plan. For rad-waste disposal of the l<strong>on</strong>g-term pool storage<br />
(where most of the c<strong>on</strong>taminants had remained following the removal of spent fuel) special equipment has been developed,<br />
designed, c<strong>on</strong>structed and installed. <str<strong>on</strong>g>The</str<strong>on</strong>g> purpose of this equipment is the restorage, drainage and fragmentati<strong>on</strong> of cartridges (used<br />
as a spent fuel case), as well as treatment of sludge (located at the pool bottom) and of the remaining liquid radwaste.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> drainage equipment for cartridges is designed for discharging KCr2 soluti<strong>on</strong> from cartridges with spent fuel rods into the<br />
handling storage tank in the short-term storage facility and adjustment of the cartridges for railway transport, prior to the liquidati<strong>on</strong><br />
of the spent fuel rod. <str<strong>on</strong>g>The</str<strong>on</strong>g> equipment ensures full remote visual c<strong>on</strong>trol of the process and exact m<strong>on</strong>itoring of its technical<br />
parameters, including that of the internal nitrogen atmosphere c<strong>on</strong>centrati<strong>on</strong> value. Cartridges without fuel and liquid filling are<br />
transferred to the equipment for their processing which includes fragmentati<strong>on</strong> into smaller parts, dec<strong>on</strong>taminati<strong>on</strong>, filling into<br />
drums with their sealed closing and measurement of radioactive dose. For the fragmentati<strong>on</strong>, special shearing equipment is used<br />
which leaves the pipe fragment open for the following dec<strong>on</strong>taminati<strong>on</strong>. For cleaning the cartridge bottom from radioactive sludge<br />
water jet system is used combined with slow speed milling used for preparing the opening for water jet nozzle. <str<strong>on</strong>g>The</str<strong>on</strong>g> sludge from<br />
the cartridge bottom is fixed into ceramic matrix.<br />
7) USE OF FULL RECOVERY HYDROLASING EQUIPMENT FOR FACILITY DECOMMISSIONING - 16325<br />
Scott Martin, Scott Adams, S.A.Robotics (USA)<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> removal of surface c<strong>on</strong>taminati<strong>on</strong> is a major challenge for nearly all nuclear facilities undergoing, or awaiting, decommissi<strong>on</strong>ing.<br />
C<strong>on</strong>venti<strong>on</strong>al means of surface dec<strong>on</strong>taminati<strong>on</strong> can expose workers to unnecessary hazards, and are often not fit-for-purpose<br />
due to size c<strong>on</strong>straints or weight restricti<strong>on</strong>s. Additi<strong>on</strong>ally, c<strong>on</strong>venti<strong>on</strong>al methods are not always easily deployed remotely due<br />
to their complexity or required services. <str<strong>on</strong>g>The</str<strong>on</strong>g> use of ultra high pressure water for surface dec<strong>on</strong>taminati<strong>on</strong>, known as hydrolasing,<br />
is recognized as a technology which can be used in various applicati<strong>on</strong>s requiring surface removal. Hydrolasing is an advantageous<br />
technology for many reas<strong>on</strong>s including its versatility, overall simplicity and relative ease of remote deployment.<br />
For the nuclear industry, <strong>on</strong>e of the largest challenges with regards to the use of hydrolasing is the requirement for the full<br />
recovery of the injected water and removed solids. For n<strong>on</strong>-nuclear applicati<strong>on</strong>s, there is often no requirement for recovery of the<br />
liquid and solid waste, which has led to few system designs which will recover the waste in full. S.A. Robotics experience with the<br />
deployment of ultra high pressure water systems for nuclear applicati<strong>on</strong>s has shown that full recovery of injected water and<br />
removed solids is achievable in both underwater and in-air applicati<strong>on</strong>s. Innovative equipment and system design have allowed S.A.<br />
Robotics hydrolasing systems to achieve near 100% solid and liquid recovery during c<strong>on</strong>crete hydrolasing. This technology has<br />
been deployed for Fluor Hanford at Hanfords K-Basins, as well as for UKAEA as part of the Windscale Piles decommissi<strong>on</strong>ing<br />
project.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> purpose of this paper is to provide a short descripti<strong>on</strong> of the hydrolasing process and the associated waste issues, describe<br />
the unique design features of S.A. Robotics hydrolasing systems which combat these issues, and provide an overview of two of the<br />
hydrolasing projects that S.A. Robotics has completed.<br />
105