Type:
Units: Three operating (two early-model VVERs--units 1 and 2--shut down in 1984 and 1990)
Total megawatts (net): 1,720 (two units at 385 each; one unit at 950)
Location: Voronezh (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.
Upgrades and remedial actions include:
Corrective actions at units 3 and 4 because of reactor-vessel embrittlement problems,
1979 repairs to shut-off valves in the primary loops of units 3 and 4 after faults were detected in welds, and
Painting of cables with fire-retardant material.
Before the break-up of the Soviet Union, planned upgrades for units 3 and 4 included:
Installation of new fast-operating valves,
A new acoustic diagnostics system,
Replacement of emergency boron-injection pumps,
Additional training to help operators deal with severe accidents,
Upgraded operating procedures, and
Expansion of in-service inspection programs.
In 1994, Russia's Department of Environment approved an environmental assessment needed for the construction of two new units at the Novovoronezh site. Units 6 and 7--1,000-megawatt reactors with passive safety features--are scheduled to come on line between 2001 and 2005, according to a protocol signed by Russia's Minister of Atomic Energy and the head of the regional nuclear administration.
U.S. Assistance. Under the U.S. government's assistance program, a working group spearheaded by the Department of Energy--with the Institute of Nuclear Power Operations playing a key role--has been assessing the condition of the two VVER-440 Model V230 units at Novovoronezh. The group's goal is to determine what upgrades are needed at other VVER-440 Model V230 units. Three "expert groups" are focusing specifically on procedures, training and management controls. When implemented, the recommended changes are expected to be applied at all VVER-440 Model V230 plants in the region and, ultimately, to all VVER-440 Model V213s and VVER-1000s.
A U.S. team observed the annealing process conducted on the reactor vessel of Novovoronezh 3 as part of a working group on the subject, sponsored by the U.S. Nuclear Regulatory Commission (NRC). (Annealing is a heat-treatment process that can extend the life of the reactor vessel.) The NRC working group concluded that Russian engineers used reliable equipment and exercised considerable technical expertise.
German Contract. Under a contract with Germany's Siemens, Novovoronezh will receive various plant systems, along with the technical expertise that will enable Russia to manufacture these systems. Equipment already provided to units 3 and 4 includes loose part, noise and vibration monitoring systems.
TACIS Project. Siemens and Electricité de France have a contract, funded by the European Union's TACIS program, to provide operator training at Novovoronezh.
WANO Exchange Visits. The World Association of Nuclear Operators has sponsored several exchange visits involving Novovoronezh. The plant has hosted personnel from the following plants:
In addition, personnel from Novovoronezh have visited the following plants:
Plant Twinning. The Novovoronezh plant is twinned with France's Penly plant, with Germany's Gundremmingen plant, and with the Diablo Canyon and Vermont Yankee plants in the United States.
IAEA Training Seminar. Although the International Atomic Energy Agency is known for its inspection missions--including its Assessment of Safety Significant Events Team (ASSET) missions --to nuclear power plants, the agency also conducts ASSET training seminars at a country's request. The seminars are designed to train operators and regulators in the use of the ASSET methodology to identify safety issues, to assess their consequences, and to eliminate the root causes of likely future accidents and incidents.
An IAEA seminar demonstrating the practical use of ASSET analysis procedures for assessment by plant personnel of operational events will be held at the plant May 21-23, 1996.
ASSET Mission (Units 3 and 4). At the request of the former Soviet government, an IAEA ASSET mission visited Novovoronezh May 13-24, 1991. The purpose of the mission was to identify operational issues relevant to safety, rate their significance to safety on the basis of the International Nuclear Event Scale, select pending safety issues for root-cause analysis, and offer recommendations on enhancing incident prevention.
Among the team's findings:
Industrial culture at the plant "compares favourably with similar units already visited by the ASSET service."
"Safety culture was found generally satisfactory."
Management's attitude toward improvements and operational safety was found to be "very open-minded and responsible."
The average capacity factor for each of the VVER-440 Model V230 units is above the world average for pressurized-water plants.
Over the past 10 years, four events considered "safety significant" occurred at units 3 and 4, in addition to seven events considered "safety relevant." According to the IAEA, programs to identify precursors to these events were not adequate.
Implementation of new measures in the management of preventive maintenance programs, root-cause analysis and other areas would help avoid safety violations in the future.
On the basis of its review, the team selected three safety issues for in-depth root-cause analysis: insufficient work coordination and control, insufficient procedural guidance, and insufficient reliability of a safety support function.
Safety Review Mission (Units 3 and 4). An IAEA safety review mission visited the Novovoronezh plant Aug. 12-31, 1991, as part of IAEA's program on the safety of VVER-440 Model V230 reactors. The mission, composed of 15 international experts, carried out an in-depth review of 12 areas:
The objective of the mission was to assess the design and operational safety aspects of the units, taking into consideration plant-specific conditions such as improvements. The team identified a number of significant areas where operational safety should be improved. The major issues included: replacement of the plant's analog VVER-440 simulator with a modern simulator; improvement of the operator training program; improvement of normal and emergency operating procedures; and achievement of a consistent standard of maintenance and housekeeping work.
The team also identified some design weaknesses that warranted special attention, including the confinement, whose behavior under accident conditions should be analyzed, and the engineered safety features, whose deficiencies required more attention to realistic safety analyses.
Follow-Up Safety Review Mission (Units 3 and 4). A consultative mission visited the plant June 28-July 3, 1993, to give advice on the actions taken in response to the IAEA's technical report on the safety of VVER-440 V230 plants as well as the 1991 Safety Review Mission's report in the context of Russia's backfitting concept for the plant.
According to the team, the plant had made satisfactory progress or completed action on the 1991 mission's recommendations. In the design area, 40 percent of the issues identified in 1991 had been partly or fully addressed. All issues are expected to have been fully addressed by 1996.
The team noted that extensive inspections of all safety-relevant components had been made, but that the integrity of the reactor pressure vessel needed special attention as a future critical issue. The team noted that short-term or compensatory measures planned for the plant's mechanical, electrical, and instrumentation and control systems should be implemented as soon as possible, especially those that increase redundancy and protection against common-cause failures of the safety systems that cool the core. The team identified several long-term measures of high safety significance, including replacement of pressurizer safety valves, installation of main steam line fast isolation valves, and installation of a new emergency power supply system.
The team noted that about 80 percent of the operational safety issues had either been resolved or were progressing satisfactorily toward resolution. It recommended a review of operating procedures at the plant to ensure that changes resulting from backfit modifications are included in the procedures. Other recommendations included: evaluation of the proposal for a full-scope simulator to determine the need for additional technical and financial assistance, and completion of upgrading of emergency-response facilities.
Follow-Up ASSET Mission (Units 3 and 4). A follow-up ASSET mission visited Novovoronezh Nov. 29-Dec. 3, 1993. The team found that considerable progress had been made in implementing the recommendations of the 1991 ASSET mission. For example, said the team, an increased proportion of events had been found by surveillance (25 percent as opposed to 4.5 percent in 1991).
The team identified three safety problems that were still pending:
Failures of safety-related equipment owing to problems with unreliable electrical components,
Insufficient assessment of equipment conformance to working conditions (quality assurance), and
Potential degradation of equipment operability owing to aging or insufficient maintenance.
The team recommended an action plan to address these problems, which included the replacement of component electrical insulation, vigorous pursuit of a proposed restructuring entailing the introduction of a quality assurance facility, and reviewing criteria for safety equipment classification and arrangements for its periodic inspection.
Technical Exchange Mission. At the invitation of the Russian government, Rosenergoatom and the Novovoronezh plant, an IAEA technical exchange mission visited the plant Nov. 27-30, 1995, in the context of the IAEA's program on the safety of VVER-440 Model V230 plants. The aim of the program is to provide both a safety evaluation and advice on measures to improve nuclear plant safety.
The purpose of the mission was to update the information available to the IAEA on the status of the plant's implementation of safety improvements, and to comment on the actions taken--with respect to both operational and design issues--in response to the IAEA's report on Model V230 plant safety.
Planned ASSET Mission. An ASSET peer review mission to Novovoronezh is scheduled for Nov. 18-22, 1996. The mission will review the plant's analysis of 12 events that reflect safety culture issues.
December 1995
