Type: RBMK-1000
Units: Three
Total megawatts (net): 2,775 (925 per unit)
Location: Desnogorsk, Smolensk (Russian Federation)
Dates of initial operation:
For an overview of the principal strengths and deficiencies of Soviet-designed plants, see Soviet Nuclear Power Plant Designs.
In February 1994, a transformer caught fire outside the plant complex. The fire was extinguished within 30 minutes, and the plant did not shut down.
Between 1983 and 1993, the plant's availability factor averaged 76 percent. But financial difficulties have reduced output at the plant. In August 1994, some 350 of the plant's employees refused to leave the plant in protest over a four-month delay in payment of salaries. In September, the plant reportedly had only one unit on line. The other two units were down for maintenance and awaiting spare parts. Cash shortages were said to be delaying the units' return to service.
According to a Russian news agency report in late January 1995, the Smolensk plant was operating at about 50-percent capacity, and had enough fuel for only another 10 days of operation.
Safety Analysis Report. As part of the International Atomic Energy Agency's (IAEA) program on the safety of RBMK reactors, a safety analysis report of Smolensk's Unit 3 was used as the basic document for an IAEA review of the program in June 1993. Smolensk 3--a second-generation RBMK design--is one of two reference units for the program. The other is Lithuania's Ignalina 2.
At the meeting, held at the Smolensk plant, 100 experts from the West, IAEA and the former Soviet Union discussed concerns raised at a review meeting a year earlier at IAEA headquarters in Vienna.
Three issues from the Vienna meeting were discussed in detail: core monitoring and control, component integrity, and accident mitigation. Five other issues were discussed in less detail: support and safety systems, instrumentation and control, seismic safety, fire protection, and operational safety.
The reviewers made a number of recommendations with respect to design solutions and proposed improvements to Smolensk 3, including:
The feasibility of installing an additional reactor-shutdown system should be considered.
Further validation of accident-analysis results should be carried out, considering in particular the adequacy of the computer codes used.
Separation of plant protection and control functions should be considered a priority.
An analysis should be undertaken aimed at reducing the number of valves in the primary circuit without affecting the functions of the circuit or making maintenance more difficult.
Fire protection should be improved.
The experts also made a number of observations, including:
The unit's safety systems have a good level of redundancy.
No major seismic problems have been identified for structures or equipment.
Reactor operators are skilled and experienced, but heavy demands are placed on them by the frequent manual adjustments required to control power levels and channel flow.
Many of the elements necessary for safe operation and good performance are in place, but many safety practices are dictated by rules from external organizations, which may result in a passive and unquestioning attitude toward safety.
WANO Exchange Visits. The World Association of Nuclear Operators has sponsored several exchange visits involving the Smolensk plant. The plant has hosted personnel from the following plants:
In addition, personnel from Smolensk have visited the following plants:
TACIS Aid. Under the European Union's TACIS--technical assistance program to CIS countries--Scottish Nuclear was awarded a contract in 1993 to plan the installation of a system for controlling and scheduling maintenance activities at the Smolensk plant. Scottish Nuclear's Torness plant was twinned with Smolensk in 1991.
Plant Twinning. The Smolensk plant is twinned with Germany's Unterweser plant and the U.K.'s Torness plant.
U.S. Assistance. As part of the U.S. government's assistance program, experts completed a fire-hazards walkdown of Smolensk to determine what kind of remedial equipment would be required. Under the program, the plant is receiving such equipment as sprinkler heads, control panels, self-contained breathing apparatus and sealants.
Simulation, Systems, and Services Technologies Co. (S3 Technologies) received approval by the U.S. Department of Energy to support the construction of a control room simulator for Smolensk.
Spent Fuel Facility. Rosenergoatom--the Russian nuclear operating organization--awarded a contract in 1994 to the French company SGN/Reseau Eurisys to build a spent fuel dry storage facility at Smolensk. The facility would be capable of storing 5,000 metric tons of spent fuel. The first stage of facility was to have been operational in June 1995, but according to a Russian news agency report, construction was repeatedly delayed because of Russia's failure to maintain payment. The same report noted that the plant's existing spent fuel storage area was more than 90 percent full in June 1995. The contract has now been canceled.
ASSET Mission. An IAEA ASSET mission visited the Smolensk plant July 19-30, 1993. The team reviewed 316 events that had occurred between September 1983 and May 1993. Of these, the team considered 168 to be safety-relevant events; 16 of them were classified as Level 1 on the International Nuclear Event Scale, two were classified as Level 2 and the rest were Level 0.
After analyzing the events, the team identified 12 areas of recurring faults:
From these recurring faults, the team then identified seven significant problems impinging on safety. In all cases, appropriate corrective action had been taken, but only two were considered resolved. In the case of three recurring fault areas, the team commented on plant corrective actions:
6 kV system--redesign of the protection system has addressed voltage surges, and consequent cable damage is being addressed.
Control rod and protection system--many of the problems in this system have been addressed by installing correct capacity contractors on the 48V system.
Inadequate maintenance procedures--implementation of a schedule for routine maintenance and testing has improved the identification of problems before they occur in operation, but limitations in maintenance history and operational experience feedback result in too many instances of failure to operate as expected.
The team identified two problems--lack of quality in maintenance work and operator errors during testing--as being of significant outstanding concern.
The team noted that plant management was dedicated to the prevention of plant disturbances. In addition, the systematic surveillance program set up by management was helping to detect latent weaknesses. But further improvement is needed, and the team offered a number of suggestions and recommendations in this respect. Among them:
Plant management should consider enhancing the "usability" of procedures by ensuring the participation of both operations and maintenance staff in their preparation.
Plant management should extend the requirement for systematic requalification testing to all maintenance work.
Plant management should extend the use of formal root-cause analysis to the investigation of all safety-relevant deviations.
December 1995
