NPP origin LILW
National Radioactive Waste Repository
The function of the National Radioactive Waste Repository (NRWR) in Bátaapáti is the disposal of the low and intermediate level waste (LILW) originating from the Paks Nuclear Power Plant. The radioactive waste from the operation of the nuclear power plant is stored on the site until its transfer to the repository. Most part of the solid waste is loaded, if possible in compacted form, into 200 l drums. The liquid waste is collected in tanks. The waste can be disposed of only in solid form, therefore, the liquid waste will be solidified in the nuclear power plant prior to the transfer to the repository. Such type of waste will arise also during the dismantling of the nuclear power plant and will be disposed of together with the operational waste.
Waste acceptance, transport and interim storage
For safety reasons the NRWR accepts only waste packages, which fulfill the acceptance criteria approved by the regulatory body. The strict control begins already on the site of the nuclear power plant. Every drum is subject to a check for damage, gamma-dose rate measurement at a distance of 1 m, and surface contamination test by smear sampling. In addition, a software tool, developed for this purpose, is used to check whether the activities in the drum are within the limits specified for the disposal site.
The waste packages are transported from Paks to Bátaapáti by a special purpose vehicle with a special regulatory license. 16 drums loaded into 4 transport frames can be put on the vehicle. The transport operations shall be subject to the provisions of the European Agreement concerning the International Carriage of Dangerous Goods (ADR).
The vehicle used for the transport of the waste is received at the central building of the disposal site. Following an inspection, the vehicle moves on to the technological storage building in the controlled zone where the transport frames are placed by a crane in their storage place. The technological storage building has a storage capacity for 3000 drums. Before disposal the drums are placed into reinforced concrete disposal containers, nine drums into each container. The drums are fixed with inactive mortar and after 7 days of hardening the containers can be transported into the underground disposal chamber.
Description of the repository
Two inclined shafts serve the construction and operation of the subsurface part of the facility, where the disposal of the waste takes place. The shafts, each with a length of 1700 m and an inclination of 10%, were excavated parallel, at a distance of 25 m from each other. Both of them have a cross section of 21-25 m2. The length of the first disposal chamber, the I-K1 chamber is 90 meters, the section size is almost 96 m2 and its depth from the surface is about 250 meters. In the I-K1 chamber 537 concrete containers can be disposed of, that means about 4833 drums with radioactive waste.
In parallel to the commissioning of the first disposal chamber, PURAM started to optimize the disposal system of the NRWR, taking into account new waste package types. The main aim of this optimization project was to use the available disposal rooms more effectively, maintaining the same level of safety.
The result was a new disposal design, which is based on a new waste package (the so called compact waste package) with a thin walled steel container that can accommodate four drums of solid waste. The void between the drums and the wall of the container will be filled with active grout using radioactive liquid waste in the nuclear power plant. The compact waste packages will be placed in a reinforced concrete vault within the disposal chamber. The disposal chamber I-K2 is established already in this way. In order to further increase the active-inactive ratio in the chamber volume, the shape of the disposal chambers (beginning with chambers I-K3 and I-K4) is fitted to the new disposal design.
The national regulation in force requires that during the operation of the facility the retrieval of the waste packages shall be assured.