Treatment and conditioning of radwaste
The treatment and conditioning of radwaste refer to procedures the objective of which is to increase safety and economical efficiency of radwaste management. The main part of these procedures are performed in an nuclear installation named ôTechnologies for treatment and conditioning of radwasteö operated by SE-VYZ. The facilities focused only on treatment of radwaste from NPP A1 decommissioning are operated by the same operator as a part of this decommissioned nuclear installation. Experimental and research treatment plants are operated by V┌JE. A facility for the treatment and conditioning of operational liquid radwaste from NPP Mochovce is under preparation and a start of construction is foreseen in 2004.
Technologies for treatment and conditioning of radwaste
The nuclear installation ôTechnologies for treatment and conditioning of radwasteö consists mainly of two bituminization plants and Bohunice Conditioning Centre (BSC RAW). Bituminization plants with capacity of 120 l/hour each are determined for bituminization of concentrates from VVER type NPPs and from A1 NPP Bohunice which are put into 200 l drums. The first one has been in operation since 1994 and its modification for discontinuous bituminization of ion-exchange resins and sludge is under way. The second one the commissioning of which has been finished successfully is now under licensing process for operation. At the end of 2001 total amount of concentrates treated by bituminization reached 941,7 m3.
BSC RAW is the basic installed facility for final radwaste conditioning is. Besides cementation the technologies of incineration, fragmentation, high-pressure compaction as well as evaporation are used for radwaste treatment and conditioning at BSC RAW. Due to a complexity of commissioning of individual technologies, BSC RAW commissioning was divided in two phases which were realised in 2000. At the beginning of 2001 ┌JD issued the permission for BSC RAW operation on the basis of assessment of commissioning report. 144 pieces of FRC containers have been filled in during BSC RAW operation in 2001. As much as 51 t of solid radwaste and 3,9 m3 of liquid radwaste were incinerated, 85,7 t of solid radwaste were compacted and 186 m3 of concentrates were treated by cementation.
V┌JE Trnava treatment facilities
Two treatment facilities are operated by VUJE Trnava. The bituminization plant has been out of operation during 2001 and incinerator with additional cementation facility have been used only for experimental purposes.
Disposal of radwaste
The disposal represents the final step in the radwaste management process in the frame of which the radwaste packages are permanently placed into the radwaste repository. The safe disposal is assured by separation of conditioned waste from the environment using both engineering and natural barriers.
National near surface repository in Mochovce
This facility is determined for the disposal of low and intermediate level short-living radwaste in special FRC containers as additional engineering barrier of repository. The repository construction was finished in November 1992. Modifications of facility as well as additional documentation recommended by IAEA experts mission were finished in 1998 - 1999. 52 containers with radwaste were disposed of during the commissioning of this nuclear facility after ┌JD issued permission in 1999. Operational permission was issued by ┌JD after assessment of repository commissioning report in September 2001. At the end of 2001 totally 122 containers were disposed of.
It is assumed that during design operational lifetime the installed NPPs will produce 2500 t of spent nuclear fuel and 3700 t of radwaste unacceptable for Mochovce repository (including radwaste generated at NPP A1) and their deep geological disposal will be necessary.
Development of deep
geological disposal facility in Slovakia started in 1996. In the frame of this project the
preparatory works have begun and activities oriented to public involvement have been
realised. On the basis of preliminary evaluation of existing geological data 15 sites
potentially appropriate for underground repository were identified. Further investigation
has led to reduction of this number to 4 sites in two possible host rocks which have been
proposed for more detailed research.
Transport of radwaste
The transport of radwaste as a part of the radwaste management system enables connection of its individual elements. The licensing procedure of radwaste transport consists of two steps. The approval of transport equipment is the first step and the second one represents a permit for the transport of radwaste in this equipment. On the basis of introduced approach 4 types of transport equipment were approved and respective permits for waste transport were issued in 2001. Progressively the validity of previous permits, as they can be issued only for one year, has been prolonged. It allows to update the transport provisions. During 2001 approximately 365,5 t of solid radwaste and 474 m3 of liquid radwaste was shipped to the individual radwaste treatment technologies. 115 filled FRC containers e.g. 356,5 m3 of solid and solidified radwaste were shipped to the repository.
The assessment activities
were focused on reviewing of the safety documentation of activities, which were described
before, on approving of technical specifications for operation safety and on an approving
of quality assurance programmes. The evaluation of transport safety was focused on
capability of fully loaded transport equipment to withstand defined loading under
different transport conditions, especially for frequent transports.
The attention of UJD is
permanently focused on an increasing of radwaste management safety during the transfer of
waste into more stable solid form as well as on development of new procedures for
treatment and conditioning of remaining waste. Measures resulting from bituminization
facilities inspections were focused on a permanent decreasing of fire risk. The inspection
activity of UJD at BSC RAW was oriented on composition and inventory declaration and on
the improvement of package quality from the integrity point of view. The inspection
activity at RU RAW was mainly focused on commissioning process. The minimisation of RAW
generation and the record keeping for the whole radioactive waste management system were
the main goals of inspection activities at all nuclear installations.