East German nuclear power projects face an uncertain future

Units 1-4 at Greifswald (East Germany) are Soviet-designed VVER 110 PWRS of the early V-230 type. A decision to close them down was taken in the light of an assessment of plant safety carried out jointly by GRS, the West German safety analysis organization, and SAAS the East German safety authority. The assessment follows on from a ''preliminary'' GRS report published in February this year which highlighted the problem of vessel embrittlement. The new report focuses on operating experience and safety system design. There are significant deficiencies in the plant's operating instructions and over the past decade there have been serious breaches of the instructions, including: operation of the plant at full power with a leak in the primary circuit purification system outside the sealed zone of the reactor building; insufficient inspection; inadequate testing of modifications to important safety systems; misoperation of reactor safety systems; inadequacies in plant condition monitoring. As regards the safety systems, some 75 measures are listed as being immediately necessary for continued operation, another 50 or so would allow operation for a limited period, while 20 more would be needed for long term operation. They include improved emergency cooling and power, instrumentation upgrades, organizational improvements, and better fire protection. (author)