On 29th of September 1978 the pressurised water reactor Unterweser went on stream and was the most powerful reactor in the world. The Nuclear power reactor Unterweser (KKU - Kernkraftwerk] had an electrical output of 1410 MW. In the course of the energy turnaround, the reactor was turned off on the 18th of March 2011 and completely shut down by the operator E.ON Kernkraft GmbH in June 2011.
The Nuclear power reactor Unterweser was provided with two large cooling water pipes with a nominal diameter of DN 4000. These cooling water pipes were called the north and south pipe. The work began during the revision period in 2007. In this year, the rehabilitation started in the north pipe and the pipeline was not emptied.
For this purpose, the leaking joints had to be sealed with AMEX Omega seals by divers. For 35 years the company Taucher Heros in Hamburg is specialized in the constructive underwater installations as well as working in the inshore and offshore business.
The divers of Taucher Heros are of the latest technical standards and assembled the AMEX Omega seals without further complications.
Due to the length of the pipes and poor visibility only few seals could be installed during the available revision period. As a result, it was decided to drain the pipelines in the following years. On this occasion the entire damages were viewable. Furthermore the conduits ran under the river Weser and the water pressed against the non-pressurised pipes through the leaking joints from the outside. During these years the pipes were partly under water which made the installation much quicker.
- Project: Rehabilitation the cooling water pipes in the Nuclear power reactor Unterweser
- End client: E.ON-AG
- Contractor: Taucher Heros
- Country: Germany
- Construction area: KKW Unterweser
- Installation period: 2007-2009 [Revision 3 weeks per year]
- Area of application: cooling water sewer
- Number of seals: about 40 units peryear
- Nominal DN [mm]: ON 4000
- Challenge: Divers had to install theAMEX Omega seals