STOCKHOLM, July 11 (Reuters) - A fire broke out on Friday on the roof of a turbine facility at Sweden's Ringhals nuclear power plant but was brought under control, rescue services said.
A spokesman for the plant said there was no risk to the reactor.
"It's ... a fire on the roof of one of the turbine facilities at Ringhals 2," said Fredrik Akesson, of the fire brigade in Varberg. "I would say it's under control."
Stockholm - A reactor at the Swedish nuclear plant Ringhals has been offline for a month after problems with auxiliary coolant pumps were detected during annual maintenance work, the plant said Friday. Two of the three auxiliary pumps had "insufficient capacity," Ringhals spokesman Gosta Larsen told local media.
The maintenance work began early May and the problems were detected during the overhaul.
STOCKHOLM (AFX) - The Swedish government has asked the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA), to inspect its Forsmark nuclear power plant after a series of incidents that have raised concerns about atomic safety in the country.
The decision follows a request from Vattenfall, which owns the Forsmark nuclear plant on Sweden's east coast.
 INES 1 |
Incorrect calculation of an algorithm in overload protection devices for local power distribution at Ringhals 2 NPP. |
While performing preventive maitenance on a transformer in the local power distribution system at Ringhals 2 NPP, a trip of the redundant transformer occured after 32 minutes at 60% load. When the protection device was searched for faults an algorithm (E-prom) in the overload device was found not correct. The fault was introduced on 44 out of 58 protection devices at the yearly outtage 2001.
INES 2 |
Closed valves in the containment spray pumps' suction lines during the non-nuclear phase of start-up after refueling |
During start-up procedures while the reactor temperaturewere still far below operational values it was detected that the valves at the containment spray pumps' suction were closed in contrary with their required open position. The testing instructions were not clear. A similar event occurred recently at unit 2.
INES 1 |
Automatic protection system disconnected during non nuclear heat up after refuelling |
After refueling in cold shutdown all safety systems were tested and normally connected. Afterwards the automatic activation of safety functions was disconnected which was not noted due to human error. Some sixteen hours after start of the non nuclear heat up, when the temperature and the pressure in the reactor were still far below operational values, the failure was discovered and correct at once.
INES 1 |
Two out of four diesel generators unavailable due to loose connection to the voltage regulator |
During periodic testing it was found that two of the four diesel generators were unavailable because the slide screw in two slide type terminal blocks was not properly tightened. Due to the loose connection the respective voltage regulator failed to function properly.
INES 1 |
DEVIATION FROM TECHNICAL SPECIFICATIONS |
On November 15, the reactor operator observed an increasing temperature downstream one of the pressurizer safety valves indicating internal leakage. The operational manager decided, after consulting the plant engineering staff and the Ringhals Safety Committee, to reduce the Reactor Coolant System (RCS) operating pressure. At 15.1 MPa the internal leakage terminated. The normal operating pressure is 15.5 MPa.
On December 8, during a planned stop, the safety valve was replaced and the operational pressure was returned to 15.5 MPa.
INES 1 |
ROUTINE SURVEILLANCE REVEALS: STEAM GENERATOR SAFETY VALVES OPEN AT HIGHER PRESSURE THAN SPECIFIED AT THE RINGHALS 2. 3 AND 4 PWRS |
During routine testing of Unit 2 the safety valve on a steam generator opened at solmewhat higher pressure than specified. Similar failures were detected at the other steam generators and also at Unit 3 and 4.
Justification of rating:
Degradation of defence in depth without initiator
Safety function availability: Adequate
Initiator frequency/initiator probability: Medium/possible
