Dismantling of Rheinsberg Nuclear Power Plant

The dismantling project provides for the immediate staged dismantling of the nuclear power plant mainly with internal staff whilst making use of the experience of maintenance and reconstruction gained at Rheinsberg Nuclear Power Plant.

This means:

The dismanting of all technical equipment
The dismantling of contaminated building structures
Demolition of the building after release from the Atomic Energy Act
Disposal or recycling of waste and residual materials accumulating in the process (disposal)

The immediate dismantling of the nuclear plant was given priority over a possible safe enclosure as the building design (no containment construction) presents too great a technical and financial challenge for safe enclosure, the existing functional technical equipment, for example lifting gear would have to be renewed for subsequent dismantling and the necessary competent and experienced staff are on hand when the plant is switched off.

Proposals to shut down and dismantle Rheinsberg Nuclear Power Plant were developed at the beginning of the 1990s and a cost and time estimation for all necessary work was compiled and agreed upon with the proprietors.

In April 1995 the competent nuclear supervisory authority for the federal state of Brandenburg gave permission for the shutting down and partial dismantling of Rheinsberg Nuclear Power Plant. The dismantling of the nuclear plant commenced directly afterwards.

The Decommissioning and Dismantling Process

Decommissioning phase 1991 – 2001

The prerequisites for dismantling were created during the decommissioning phase, which comprises the period between the cessation of power operation, i.e. the production of electrical energy and the removal of the fuel from the nuclear plant.

Phasing out and dismantling as from 2001

Infrastructure equipment which was necessary for the maintenance of the site up to the end of dismantling was operated in the phasing out and dismantling period remaining after removal of the fuel.

Dismantling phases beginning in 1995 up to completion of the project in 2025

The work was divided into eight dismantling stages in order to create manageable work stages with regard to the formulation of the necessary paperwork, the approval process and the practical realization of the project.

The total mass of the nuclear plant to be dismantled is approximately 342.000 tonnes; approximately 63,000 tonnes thereof are contaminated with radioactive substances.

Show all dismantling stages

In compliance with the corresponding official approvals work is being carried out according to the following principles and time sequence:

Dismantling outside of the controlled area (stage 1) from 1995

Dismantling of secondary cycle machinery and electrical plant no longer needed (mainly in the machine hall) whilst conserving the building fabric including transport and supply facilities for use during further dismantling of the nuclear power station.

Dismantling within the controlled area (stages 2 - 6) from 1996

Incremental dismantling of equipment, beginning with parts with low contamination and continuing to highly contaminated/activated parts up to the reactor pressure container.

Establish demolition conditions in the main buildings (stage 7) from 2009

Removal and establishment of radiological conditions for subsequent demolition

Demolition of the main building and infrastructure which is no longer needed (stage 8)

Release from supervision under nuclear legislation and demolition of buildings and infrastructure which is no longer needed.

Wir setzen Maßstäbe.
Mit Sicherheit.

Current Works

The final work to remove hot spots in the special drainage system for the residual operating system is currently in progress.

A major improvement in working conditions for staff during dismantling and disposal of piping and plant components has been achieved with the significant lowering of the local dose rate in these areas.

Outlook

Decontamination work is in progress in various rooms in the controlled area in preparation for clearance measurement and building demolition. This means for example that wall coatings are being removed by means of shavers or contaminated concrete structures are being removed with diggers.

Change requests are currently being negotiated with the authorities and the surveyor in preparation for decommissioning of the ventilation system and renewal of the fire protection equipment in the controlled area and also relocation of the control room (setting up of a new control room).

What happened so far

In 1995, 74 new fuel assemblies in six pipe containers were sold to the USA.

Parallel to the demolition work, three CASTOR® transport and storage containers loaded with 220 spent fuel elements in 1996.
A fourth CASTOR® container was loaded with 26 special fuel elements which came mainly from research projects in 1999.

On 9th May 2001 all four CASTOR® container were transported to Lubmin to the Interim Storage Facility North (ISN).

The secondary cycle in the machine hall and the central block were dismantled from July 1995 to December 1997.

The main equipment of the primary cycle (steam generator and main cooling pumps including piping and steel constructions were dismantled between May 1997 and August 1998. This was followed by the dismantling of primary cycle auxiliary systems (e.g. closed air cooling systems, additional make-up system, intermediate cooling circuit) up to 2002.

The special water treatment system was dismantled in four stages. Preparatory decontamination work was first carried out to reduce their radiation level.

Dismantling of the vaporiser systems and equipment were completed in March 2008.
The outer tank operating systems and containers were then dismantled. During operation, they absorbed large quantities of water from the primary cycle before treatment in the special water treatment system.

The upper rooms of the special water treatment building were gutted as from 2009 in preparation for the dismantling of the building structures. Packing parts and piping were removed from the building in order to establish the radiological prerequisites for the further procedure with the building. This is complicated and time-consuming due to the special room structure.

Dismantling of activated components - DaK

The main focus in 2005 and 2006 was the setting up of dismantling technology for the reactor pressure container components. Since these components were located in the core zone area they were the most highly activated parts. Dismantling was carried out under water due to the resulting radiation.

Dismantling of the activated reactor components was completed by the end of 2008.
the dismantled components were removed in mosaic containers. 122 containers were loaded which have been brought to the northern interim storage facility in Lubmin in 61 road transports.

The cable ring carrier with its protective plate was sawn out and the rotation lock in the reactor shaft was loosened before the annular water tank was removed from the reactor.
The RWB with a weight of 82 tonnes was parked on the pre-dismantling facility in the reactor hall at the beginning of July 2010 and positioned for the first wire saw cut. The RWB was then cut into 12 segments with the wire saw which were subsequently sawn to the correct size for transport on a further dismantling facility. Work was complete by March 2011 and the containers with the components were transported to Lubmin into the central storage facility.
The dismantling technology again served to condition the reactor shaft.
All dismantling facilities were demolished afterwards. The equipment of the wet dismantling station was used within EWN GmbH for dismantling services in other power plants.

Der Reaktordruckbehälter (RDB) wurde als ganzes Bauteil ausgebaut, nachdem die Einbauten demontiert waren.
Dies erfolgte statt der geplanten Zerlegung des RDB am Standort des KKW Rheinsberg, um die Strahlenbelastung für das Personal, die Kosten und den zeitlichen Aufwand zu reduzieren. Er wurde per Schienentransport in das Zwischenlager Nord zur Abklinglagerung gebracht und wird dort später zerlegt.

The hot cell in the reactor building is a peculiarity of the Rheinsberg power station site which is used mainly for research activities (investigation of fuel element casks, the absorber casks and the reactor steel samples) in the operating phase.

After elimination of interfering edges, the first demolition step was the remote clearance of the approximately. 3.8 m deep water-filled security shaft.
In a second stage, the hot cell waste water system was dismantled with special remote handling tools in 2009 and replaced with a new system.
In the subsequent dismantling stages the equipment within the hot cell, the operator room and the lock complex by autumn 2012.

The demolition of the infrastructure of the hot cell (including ventilation, media supply and disposal systems) took place later when the reactor building room complex was gutted.

Storage Facility for Liquid and Solid Waste

Lager für flüssige und feste radioaktive Abfälle

During the operation of a nuclear power plant, radioactively contaminated liquid and solid waste is produced. There was no final repository available for this waste in East Germany as nuclear energy started to be used. For this reason, a final repository for operational radioactive waste, the repository for liquid and solid waste, was set up at the site of the Rheinsberg Nuclear Power Plant. Waste from both the Rheinsberg Nuclear Power Plant and also from the Greifswald Nuclear Power Plant was stored there.

After the repository for liquid and solid radioactive waste had been emptied in October 1998, the dismantling of equipment and the demolition of the first building (concrete monolith and old oil store) in the vicinity of the final repository.

Following the reopening of the Morsleben (ERAM) repository in 1994 until its closure in autumn 1998, the operational waste was disposed of there. Afterwards, the operational waste from the ALfR was stored in the Interim Storage Facility North (ISN). Those were:

Cement-solidified liquid radioactive waste (including evaporator concentrates)
Solid mixed waste from the solid radioactive waste storage facility,
radioactively contaminated solids separated by means of decanters from the radioactive evaporation residues in the warehouse for liquid radioactive waste

The demolition of the concrete monolith, the waste oil warehouse and the car and container washing was completed in the years 2000/2001. The radioactively contaminated building materials of the concrete monolith were brought to the ISN for interim storage.

The ALfR-fest had to be excavated after emptying to a depth of 6 meters, in order then to build an enclosure for the demolition of the building structures. The demolition of all 13 chambers and the bottom plate included the decontamination by milling and caulking. With the filling of the pit, the demolition was completed in 2006.

The ALfR liquid was disassembled after emptying the containers. The above-ground rooms could be broken off after the free measurement without enclosure in the years 2006 and 2007.

The remaining building structures of the camp were uncovered. Non-released partial structures are broken off under the enclosure. The released partial structures could be broken off outside the enclosure.

Shoring within the enclosure became necessary to recover contaminated soil and explore the radiological situation in the deeper layers. For this purpose, qualified and officially confirmed radiological measurement procedures and programs are used.

The systems and channels buried on the grounds of the ALfR, such as the walk-in corridor between the main building and the ALfR liquid, were first uncovered, cleared and then dismantled in parallel with the demolition work of the ALfR liquid before the terrain profiling.

Disposal

One important prerequisite for the dismantling of Rheinsberg Nuclear Power Plant is the safeguarding of continuous disposal of all waste and residual materials which accumulate during the dismantling process.

The following disposal routes were and are used:

Disposal of used fuel elements which were located on the site at the time the plant was switched off in four CASTOR® type transport and storage containers into the Interim Storage Facility North set up at the site of Greifswald Nuclear Power Plant
Transport of the radioactive operational and shutdown waste to the final repository for radioactive waste in Morsleben (ERAM) up to its closure in 1998 and after this to the Interim Storage Facility North for further processing and for subsequent transport to a final storage facility,
Non-radioactive residual material and residual material cleared after clearance measurement are reintroduced to the recovered substance cycle or disposed of as waste if they cannot be recycled.

For each individual part, the individual data and the disposal route are completely documented: material quality, radiation intensity, weight, location of the removal, type of disposal.