The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
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Abstracts Sessi<strong>on</strong> 18<br />
After the evaluati<strong>on</strong> of the experience made during the transport and the radiological measurements and samplings taken from<br />
the RPV unit 1, the strategy for the dismantling of the reactors was changed. <str<strong>on</strong>g>The</str<strong>on</strong>g> reactor pressure vessels of the units 1 to 4 and<br />
the reactor internals of the units 3 and 4 should be removed as complete parts and stored as shielded large comp<strong>on</strong>ents in the ISN.<br />
In summer 2005 EWN applied for the new strategy at the resp<strong>on</strong>sible licensing authority and in August 2007 this license was granted.<br />
In November 2007 the reactor pressure vessels of the units 1 and 2 were transported into the ISN. <str<strong>on</strong>g>The</str<strong>on</strong>g> transport of the reactor<br />
pressure vessels and the internals from units 3 and 4 is planned in the period from March till September 2009.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g>se transports of the reactor pressure vessels and internals show that the dismantling of the reactors with dismantling and<br />
interim storage of large comp<strong>on</strong>ents could not <strong>on</strong>ly be an alternative for cutting but could also be favored from the ec<strong>on</strong>omical and<br />
radiological point of view.<br />
2) TECHNOLOGY DEVELOPMENT FOR DECOMMISSIONING IN FUGEN AND CURRENT STATUS - 16108<br />
Koichi Kitamura, Japan Atomic Energy Agency (Japan);Kazuya Sano, Yasuyuki Nakamura,<br />
Akira Matsushima, Masahiro Ishiyama, Hidehiko Matsuo, Masashi Tezuka, Takahiro<br />
Haneda,Japan Atomic Energy Agency (Japan)Reginald Coomans, Tecnubel (Belgium)<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> decommissi<strong>on</strong>ing program of proto-type Advanced <str<strong>on</strong>g>The</str<strong>on</strong>g>rmal Reactor (ATR) FUGEN has started in 2008 as first decommissi<strong>on</strong>ing<br />
of the commercial-scale water reactor. It c<strong>on</strong>sists of four periods, c<strong>on</strong>sidering the transportati<strong>on</strong> of spent fuels and the<br />
radioactive decrease of highly activated materials. It is expected that the whole program of decommissi<strong>on</strong>ing will be completed<br />
until 2028.<br />
Now, the decommissi<strong>on</strong>ing is under the first period, spent fuels and heavy water has been carrying out from FUGEN, and a<br />
part of the turbine system with relatively low radioactive c<strong>on</strong>taminati<strong>on</strong> has been dismantled.<br />
FUGEN has a complicated core structure c<strong>on</strong>sisting 224 fuel channels with pressure tubes and calandria tank, etc. and used<br />
heavy water as moderator, unlike other light water reactor (LWR). <str<strong>on</strong>g>The</str<strong>on</strong>g> materials of the core structure were highly activated due to<br />
a l<strong>on</strong>g term operati<strong>on</strong>, tritium and C-14 were generated, and the facilities were c<strong>on</strong>taminated by them. Thus, it is important to study<br />
the dismantling technology of the reactor core and the dec<strong>on</strong>taminati<strong>on</strong> technology, c<strong>on</strong>sidering characteristics of FUGEN such as<br />
core structure and radioactive inventory in advance.<br />
In this presentati<strong>on</strong>, the c<strong>on</strong>tents of the decommissi<strong>on</strong>ing program and its current status such as dismantling work of a part of<br />
the turbine system, the studying situati<strong>on</strong> of dismantling technology of reactor core using Abrasive Water Jet (AWJ) which is a candidate<br />
of cutting technologies, the examinati<strong>on</strong> of tritium dec<strong>on</strong>taminati<strong>on</strong> in heavy water system, the study of dec<strong>on</strong>taminati<strong>on</strong><br />
technology for C-14 will be presented mainly.<br />
3) SEEKING THE OPTIMUM SOLUTION FOR REACTOR DECOMMISSIONING WASTE – 16391<br />
Lisa Hughes, NDA (UK)<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> current baseline plan for reactor decommissi<strong>on</strong>ing waste in the UK is to package the waste in to approved c<strong>on</strong>tainers pending<br />
geological disposal. <str<strong>on</strong>g>The</str<strong>on</strong>g> waste arising from reactor decommissi<strong>on</strong>ing currently accounts for 35% by volume of the total waste<br />
destined for geological disposal in the UK. <str<strong>on</strong>g>The</str<strong>on</strong>g> majority of this waste (approximately 30% by volume of the UK total) is graphite<br />
from reactor cores.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> NDA Strategy published in March 2006 and the current NDA business plan both made a commitment to explore management<br />
and treatment opti<strong>on</strong>s for reactor graphite waste. Since this commitment NDA has carried out a work programme <strong>on</strong> graphite<br />
opti<strong>on</strong>s. CoRWM’s recommendati<strong>on</strong> <strong>on</strong> reactor decommissi<strong>on</strong>ing wastes in 2006 and Governments resp<strong>on</strong>se also recognised the<br />
need for alternative soluti<strong>on</strong>s for all wastes arising from reactor decommissi<strong>on</strong>ing.<br />
Since the publicati<strong>on</strong> of these reports NDA has initiated the Reactor Decommissi<strong>on</strong>ing Wastes project. This project will examine<br />
the hazard reducti<strong>on</strong> and potential cost benefit of opti<strong>on</strong>s of alternative management of reactor decommissi<strong>on</strong>ing waste. This<br />
will focus <strong>on</strong> Magnox reactors in the NDA estate, but in c<strong>on</strong>sidering the positi<strong>on</strong> with regard to the large waste graphite liability,<br />
will also take account of the eventual decommissi<strong>on</strong>ing of graphite moderated AGR reactors owned by British Energy.<br />
This paper will provide an overview of the project, the proposed approach, opti<strong>on</strong>s under c<strong>on</strong>siderati<strong>on</strong> and timescales for<br />
development.<br />
4) MODELLING OF RADIATION FIELDS AND ESTIMATION OF DOSES DURING<br />
DISMANTLING OF RBMK-1500 REACTOR EMERGENCY CORE COOLING SYSTEM - 16247<br />
Povilas Poskas, Audrius Sim<strong>on</strong>is, Lithuanian Energy Institute(Lithuania)<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g>re is <strong>on</strong>ly <strong>on</strong>e nuclear power plant in Lithuania Ignalina NPP. <str<strong>on</strong>g>The</str<strong>on</strong>g> INPP operated two similar units with installed capacity<br />
of 1500 MW (each). RBMK-1500 were commissi<strong>on</strong>ed in 12/1983 and 08/1987, and the original design lifetime was projected out<br />
to 2010 and 2015 respectively. But the first Unit of Ignalina NPP was shutdown December 31, 2004, and sec<strong>on</strong>d Unit will be closed<br />
down in 2009.<br />
In relati<strong>on</strong> with this, implementati<strong>on</strong> of new technologies for treatment and c<strong>on</strong>diti<strong>on</strong>ing of radioactive waste, c<strong>on</strong>structi<strong>on</strong> of<br />
the interim dry storage facility for spent nuclear fuel and preparati<strong>on</strong> of the licensing documents for decommissi<strong>on</strong>ing of the Unit<br />
1, and some other projects were implemented or are under implementati<strong>on</strong> at Ignalina NPP. Implementati<strong>on</strong> of dismantling activities<br />
requires detailed knowledge of the radiological situati<strong>on</strong> at the Unit 1. General Radiological Characterizati<strong>on</strong> Program for<br />
Ignalina NPP Unit 1 based <strong>on</strong> NUREG-1575 was prepared in 2005-2006 and approved by Regulatory Bodies.<br />
In 2008 development of the dismantling projects at Ignalina NPP Unit 1 has been started. Dismantling project of the emergency<br />
core cooling system (Building 117/1) is the first project in this field. Based <strong>on</strong> the radiological surveys data, detailed modeling of<br />
the radiati<strong>on</strong> fields has been performed using VISIPLAN 3D ALARA Planning tool computer program (SCK CEN, Belgium). So,<br />
in this paper detailed informati<strong>on</strong> <strong>on</strong> radiati<strong>on</strong> fields modelling, proposals for optimizati<strong>on</strong> of the radiati<strong>on</strong> doses to the pers<strong>on</strong>nel,<br />
and emergency core cooling system equipment dismantling is presented.<br />
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