Construction of a new shaft (Asse 5)
To recover the waste that has been stored in the Asse mine, it is planned to place it in special transport casks (overpacks) underground. Only after this has been done can the waste be safely recovered from the mine. An additional shaft (shaft Asse 5) is required for the recovery. That is also one of the results of the expert workshop that took place in Brunswick in January 2012.
Constructing the Asse 5 shaft could be tackled independently of the results of the trial phase (fact finding). That is one of the results of another expert workshop carried out by the BfS in September 2012 in Wolfenbüttel. On the occasion of this workshop options to speed up the planned retrieval of the waste were discussed.
Objective of the construction of shaft Asse 5
So far, the mine has had the main shaft Asse 2 with which fresh air, persons and material need to be transported at the same time. Furthermore, there is a mine shaft with the help of which maximum three individuals can be simultaneously transported out of the mine in the event of an emergency.
Possible site of the new shaft (click chart to enlarge)
With regard to the planned retrieval, waste and personnel need to be transported in separate shafts.
- It is planned to use the existing main shaft of Asse (shaft Asse 2) to transport persons.
- According to current plans, the waste to be retrieved from Asse is to be transported over the new shaft Asse 5.
Thus, radiation protection will be ensured when the waste will be removed and retrieval will be enabled. Furthermore, this would contribute to improving considerably the entire supply of fresh air (ventilation) and transport of materials.
The new shaft Asse 5 will also be available as second adequate shaft for man haulage, which would improve the escape route situation underground. Thus, more persons could work underground at the same time.
Status of planning works
According to public procurement law, the concept and licensing planning for the construction of a new shaft was tendered and awarded Europe-wide. Works already started at the end of 2010.
The planning of the new open shaft will probably take several years. This will also comprise the selection of a suitable site and the necessary geological exploration drillings.
An expert report is already available for the selection of a shaft site. The report proposes a site situated about 500 metres to the east of the existing shaft Asse 2. It needs to be ascertained by means of exploration drillings underground and above the surface whether this site is actually suitable. Only after the exploration drillings have been evaluated can be decided finally whether the shaft can be built at this site. However, necessary works for a later exploration can start in parallel.
The next steps
The drilling underground
As the proposed site for a new shaft is situated in a special protected landscape area (FFH), the rural district of Wolfenbüttel issued a dispensation for the exploratory drilling above surface.
Concrete works can start after a decision has been taken as to the selection of an area for a first exploration drilling. At first an operating plan was submitted to the Landesamt für Bergbau, Energie und Geologie (LBEG) for approval of the establishment of a drilling area and an operating plan approval of the exploration drilling Parallel to this, the setting up of the drilling area and the drilling works were tendered.
The approval of the LBEG for setting up the drilling area has been given to the BfS; works will soon be taken up. The licence for the exploration drilling is expected to be granted shortly.
Regarding the exploration drilling for the new shaft Asse 5, the Asse-GmbH commissioned orders to
- Build the access road,
- Set up the drilling area, and
- Subsequently carry out the exploration drilling.
Prior to starting the drilling, a period of several months needs to be calculated for purchasing and setting up a drilling apparatus that is suitable for the great drilling depth (mobilisation phase of the drilling contractor). Additionally, comparatively complex works to seal the surface of the drilling area are required to protect the surrounding FFH-area. According to the current planning, drilling works will start next year; they are accompanied by geo-physical measurements to gain more information about the underground.
The exploration of the shaft site also requires carrying out drillings underground. Starting from the shaft, horizontal drillings are to be worked from the 574-m level and the 700-m level in the direction of the planned bottom landing of shaft Asse 5.
Parallel to the other works being carried out, these drillings are currently being planned in detail and the documents for the licences under Mining Law are being developed. Apart from the operating plans, this includes the granting of exemptions for works in areas where no safety clearance can be kept to the margin of the salt dome. The works underground also require the provision of escape routes for the event of an emergency (such as fire). For this purpose, special so-called escape containers are currently being purchased.
Extensive preparations, among others, to guarantee mining safety are necessary for the drillings underground. According to current plans, they will be taken up next year.
Possibilities of speeding up the process
In order to speed up retrieval, experts and representatives of the federal state and citizens’ initiatives discussed the issue at an expert workshop in September 2012 in Wolfenbüttel. It was discussed that it would potentially speed up things if the new shaft Asse 5 and the interim storage facility were planned ahead of schedule and were constructed independently of the evaluation of results from the fact-finding.
The results gained in the underground and above-ground exploration drillings for shaft Asse 5 which need to provide the basis and boundary conditions are necessary for further planning and realisation steps.
As part of the procedure under Mining Law for a new shaft, an environmental impact assessment must be carried out, as well, and a plan-approval procedure under Mining Law must be carried out. On the occasion of the workshop in September 2012, it was forecast that such a plan-approval procedure under Mining Law for sinking the shaft would take at least two years. During that time and during the sinking of the shaft, though, the relevant nuclear planning for the shaft construction could be pushed.