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

Session 55-56 Abstracts
6) PLASMA ARC CUTTING EXPERIMENTS USING RADIOACTIVE MATERIALS FOR EVALUATION OF
AIRBORNE DISPERSION RATIO - 16106
Taro Shimada, Japan Atomic Energy Agency (Japan); Atsushi Takamura, Science System Laboratory (Japan); Atsushi
Kamiya, Nihon Advanced Technology (Japan); Takenori Sukegawa, Tadao Tanaka, Japan Atomic Energy Agency (Japan)
Experiments for airborne dispersion ratio of radionuclides during plasma arc cutting were carried out in a contamination control
enclosure, using stored radioactive metal wastes arising from the decommissioning activities of Japan Power Demonstration
Reactor, which was a boiling water type reactor. Neutron induced-activated piping and surface contaminated piping were segmented
into pieces using air plasma arc cutting, using a current power was 100A. In addition, similar experiments for contaminated piping
of the Advanced <strong>The</strong>rmal Reactor, Fugen were carried out.
As a result, dispersion ratios for activated piping were 0.2 to 0.7% of Co-60 and 0.4% of Ni-63 under the condition with a covered
cap on the head. And those for surface contaminated piping were from 18 to 23%. In addition, those for vertically segmented
piping which simulated flat plate were from 34 to 43%. <strong>The</strong>re was no difference of dispersion ratios between stainless steel and
carbon steel base materials. All values obtained were smaller than the Handbook recommended value of 70% for contaminated
materials.
7) THE DEVELOPMENT AND EFFICACY OF THE CONTINUED OPERATIONS SAFETY REPORT - 16067
Jonathan Francis, University of Central Lancashire (UK); Gavin Smith, Sellafield Limited (UK);
Ian D Nickson, John Tyndall Institute for Nuclear Research (UK)
<strong>The</strong> requirement to build a safety case is fundamental to the public governance of nuclear sites. Through the Nuclear Safety
Directorate, the public permits operators of nuclear licensed sites to design, build, operate, decommission, dismantle (and manage
the waste arising from) a facility and ultimately remediate the site. <strong>The</strong> Health & Safety Executive has published a plethora of material
to explain the principles of the permissioning philosophy; the non-prescriptive approach by which operators are led to consider
and manage risks and develop safe operating procedures.
Since before the turn of the Millenium, there has been ongoing and relatively rapid change in the ownership and organisational
structure of those charged with operating and/or decommissioning at the Sellafield site. <strong>The</strong> potential for this change to affect
operations, record and documentary control systems and consequently, the possible threat to the maintenance of design intent led
to the development of a new process: the Continued Operations Safety Report (COSR).
8) PLANNING FOR DECOMMISSIONING OF AN IRRADIATION FACILITY USED
FOR RESEARCH PURPOSES IN CUBA - 16120
Juan Carlos Benitez-Navarro, Mercedes Salgado-Mojena,CPHR (Cuba);
Evelio Soto Alvarez, Daniel Fraga Acosta, CENSA (Cuba); Jose Quevedo, Yolanda Perez, CNSN (Cuba)
<strong>The</strong> National Center for Animal Health (CENSA) used an irradiator (model Gammacell 500) for sterilizing medical and pharmaceutical
devices and supplies. <strong>The</strong> facility was commissioned in 1989 and was in operation until 2008. It has to be shut down as
the safety mechanisms might become not effective.
According to Cuban regulations, the Institution has to apply for a Decommissioning Licence. For that, the following documents
should be prepared and presented to the Regulatory Authority: Plan for shutting down, Decommissioning plan and Safety Manual.
<strong>The</strong> institution (CENSA) requested the decommissioning services to the Center for Radiation Protection and Hygiene (CPHR).
<strong>The</strong> irradiator facility Gammacell 500 contains twelve Co-60 radioactive sources, model C-198. <strong>The</strong> total activity was 1069
TBq (28900 Ci) in December 1994, after the sources were replaced by the manufacturer. <strong>The</strong> total activity at present is less than
200 TBq. <strong>The</strong> irradiator has two compartments: a sample chamber or cylinder, where sample trays rotate around the sources when
they are loaded into this chamber (while in the irradiate position), providing dose uniformity; and the source storage container, a
lead cylindrical container located behind the sample chamber.
SESSION 56 - POSTERS: PROJECTS IN PROGRESS
1) REAL SYSTEM ANALYSES OF PA RELEVANT PROCESSES IN SEDIMENTS:
THE RUPRECHTOV NATURAL ANALOGUE SITE - 16342
Vaclava Havlova, Nuclear Research Institute Rez plc.(Czech Republic); Ulrich Noseck, Gesellschaft für Anlagen- und
Reaktorsicherheit (GRS) mbH (Germany); Melissa Denecke, Wolfgang Hauser, FZK INE (Germany), Juhani Suksi,
Helsinki University (Findland); Kazimierz Rozanski, AGH (Poland)
Component RTDC 5 of the EC Integrated Project FUNMIG (2004–2008) was aimed to study real system processes, relevant
to performance assessment (PA), in sediment formations that can form overlying layers of geological repository host rocks. <strong>The</strong>
study comprises both laboratory and in-situ work, focused on the Ruprechtov natural analogue site. <strong>The</strong> scope of scientific activities,
addressed within the frame of FUNMIG RTDC 5 is presented here. Moreover, integration of results from other components as
FUNMIG RTDC 2 into the real system description and vice versa is demonstrated.
<strong>The</strong> project scientific activities proceeded from investigation of specific issues (e.g. natural organic matter study) to a more
integral investigation and characterisation of the complex natural U system, in particular the characterisation of the immobile U
phases combining sophisticated analytical methods, and finally to generalizing real system analyses, e.g. the evaluation of hydrological,
geochemical and environmental isotope data in order to characterize the hydrogeological flow regime and the carbon chemistry
in the system.
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