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Status Report 2001 - Section 4

4.0 Ukraine Ukrainian flag

Reactor Types in Ukraine

  • One RBMK-1000 (shut down)
  • Two VVER-440/213s
  • Eleven VVER-1000s
The Ukrainian nuclear power plants participating in the cooperative effort to improve nuclear safety.

Through November 2000, Ukraine had 14 operating nuclear power reactors at five plants, all of which were involved in the U.S. cooperative safety efforts. Except for the RBMK reactor at Chornobyl, which was shut down in December 2000, Ukraine's reactors are the VVER design.

U.S. specialists work closely with Ukrainian organizations responsible for the design, construction, operation, and regulation of nuclear power plants. A US office in Kyiv provides administrative, technical, and contractual support for the cooperative safety efforts. These efforts are being conducted in the following major areas:

4.1 Increasing the Safety of Day-to-Day Operations

Management and Operational Safety Projects

Management and operational safety projects increase the ability of plant personnel to operate reactors safely. In Ukraine, these projects are organized into the following areas:

4.1.1 Personnel Training

The United States and Ukraine have established a nuclear training center at the Khmelnytskyy plant. Khmelnytskyy instructors have worked with US and Ukrainian specialists to expand the training program, teaching instructors at other plants to improve their training processes.

Picture of full-scope simulator at Khmelnytskyy nuclear power plant
US and host-country specialists have developed this full-scope simulator for training control room
operators at Ukraine's Khmelnytskyy plant. Simulators give operators hands-on experience
in responding to both routine and emergency situations.

Activities Completed

Establishment of the Khmelnytskyy Training Center. Beginning in 1993, Khmelnytskyy instructors received extensive courses in the Systematic Approach to Training, a methodology adopted at all US nuclear power plants after the 1979 accident at Three Mile Island. Training specialists from U.S.-based General Physics Corporation and Brookhaven National Laboratory worked closely with the Khmelnytskyy instructors, enabling them to adopt the methods of the Systematic Approach to Training, design training programs, and develop and conduct eight pilot training courses in operations and maintenance. Courses covered job-specific tasks, equipment maintenance, and supervision and management.

Khmelnytskyy instructors presented the first operations and maintenance training course in April 1994 and the eighth in June 1997. Trainers from the United States and the Khmelnytskyy plant also developed four general courses: 1) an introduction to the Systematic Approach to Training, 2) general employee safety, 3) organizational safety culture, and 4) instructor training. Khmelnytskyy instructors presented the first of these courses in February 1994 and the fourth in December 1997. Additionally, in December 1998, a US training expert presented a course on management and supervisory skills for Khmelnytskyy's mid- and upper-level managers.

As part of the program development, US and Ukrainian training specialists worked together to improve methodologies for evaluating training programs and documenting lessons learned. The United States provided basic equipment for the Khmelnytskyy training center, such as computers, software, and copiers. The United States also supplied specialized equipment for the pilot courses, such as soldering stations and a refueling-machine simulator.

Transferring Capabilities to Other Sites. After successfully establishing the training center at Khmelnytskyy, US and Ukrainian specialists worked together to train instructors at three other plants in Ukraine-Rivne, South Ukraine, and Zaporizhzhya. Since September 1997, a team of experts from Khmelnytskyy, the United States, and the Engineering Technical Center for the Training of Nuclear Industry Personnel in Kyiv visited each plant three times to prepare instructors and to develop a pilot training course on the Systematic Approach to Training.

In October 1997, the United States provided computers, software, and copiers for the course development work at Rivne, South Ukraine, Zaporizhzhya, and the Engineering Technical Center.

With on-site support from the team of experts, instructors at each plant presented a first pilot course in 1998. Rivne's course in April covered the calibration and repair of pressure transmitters. Zaporizhzhya instructors presented a course in May for chemical operators. South Ukraine's June course covered the repair of integrated circuit boards. In 1999, a second pilot course for unit shift supervisors was implemented at all three sites.

A control room reactor operator course also has been developed based on the initial course that was developed for Khmelnytskyy. This course now has been transferred to the other nuclear power plants in Ukraine. Support was provided to develop country standards for implementing the Systematic Approach to Training. The next activities to be implemented in this area are the development and transfer of a control room turbine operator training course and the development of a formal on-the-job-training program.

Training Improvements at Chornobyl. In a related effort, US specialists have worked with instructors at the Chornobyl plant to develop courses based on the Systematic Approach to Training. The instructors presented courses in 1997 for radiation protection technicians and control room operators. The United States provided basic and course-specific equipment for use in training development. In December 1998, a US training expert presented a course on management and supervisory skills for Chornobyl's mid- and upper-level managers.

To support improved training at Chornobyl, the United States has supplied computers, copiers, and other basic training equipment for instructors at the Slavutych Laboratory for International Research and Technology. The laboratory is the primary technical branch of the International Chornobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, which is addressing environmental, health, and safety issues created by the 1986 disaster at Chornobyl. (For details about the center and the Slavutych Laboratory, see Section 5.3.)

Work in Progress

Simulator Training. US and host-country specialists have developed plant-specific simulator exercise guides for the Zaporizhzhya Unit 5 and South Ukraine Unit 3 full-scope simulators. A simulator instructor training course was developed and presented to the training staff at each of the Ukrainian plants. Workshops are being held to exchange information on the use and management of full-scope training simulators and also to exchange experiences regarding the use of less than full-scope simulators. Support also is being provided for the development of industry standards for use and maintenance of simulators in Ukraine.

4.1.2 Simulator Development

A nuclear power plant simulator is an effective, efficient training tool used widely in the international nuclear industry. Its computer programs mimic plant conditions, giving control room operators practice in responding to routine and emergency situations.

Activities Completed

Khmelnytskyy Unit 1. The first full-scope training simulator developed with US support for a Soviet-designed nuclear power plant began operating in December 1997 at the Khmelnytskyy plant. US contractor GSE Power Systems Incorporated developed this simulator with support from LAKROM, a Russian subcontractor.

Chornobyl Unit 3. GSE produced an analytical simulator for the Chornobyl plant, which became ready for use in February 1998.

Zaporizhzhya Unit 5. The United States provided hardware and software to upgrade a full-scope simulator at Zaporizhzhya Unit 5. The upgrades were completed in June 1999.

South Ukraine Unit 3. GSE has delivered hardware and software for a full-scope simulator for South Ukraine Unit 3. The project was completed in April 2000.

Picture of full-scope simulator at Khmelnytskyy nuclear power plant
The Khmelnytskyy full-scope simulator began operating in December 1997.
An ongoing upgrade of the system was completed in 1999.

Capability Development. Staff from the Khmelnytskyy plant and Energoatom received on-the-job training in simulator technology from March 1995 to March 1996. Ukraine built on the expertise acquired through this training to establish the Engineering Technical Center. The center's objective is to develop and maintain control room simulators for plants throughout Ukraine. In January 1997, the United States delivered hardware and software for a computer complex at the center.

US instructors delivered a three-week training course at Zaporizhzhya in March 1997 on the maintenance of simulator hardware and software. At the Zaporizhzhya plant in August 1997, US instructors provided a course on the effective use of training simulators. Simulator training specialists from Khmelnytskyy and Zaporizhzhya participated, along with Engineering Technical Center personnel.

Simulator instructors from all five Ukrainian plants participated in a December 1998 course on the development and presentation of simulator training materials. Specialists from U.S.-based Sonalysts Incorporated presented the course, which included classroom instruction and extensive use of the full-scope simulator at Khmelnytskyy.

Integration of Safety Parameter Display Systems. US and host-country specialists are developing safety parameter display systems for Soviet-designed plants. The Ukrainian full-scope simulators are being upgraded to reflect this new equipment, which gives control room operators crucial information about plant conditions during emergency operations. The simulators for Khmelnytskyy Unit 1 and Zaporizhzhya Unit 5 received this upgrade in 1999. As simulators for other Ukrainian reactors are completed, safety parameter display systems will be included.

Work in Progress

Rivne Units 2 and 3, South Ukraine Unit 1, and Zaporizhzhya Unit 1. GSE, LAKROM, and the Engineering Technical Center are developing full-scope simulators for Rivne Units 2 and 3, South Ukraine Unit 1, and Zaporizhzhya Unit 1. Completion of these projects is scheduled for 2001 and 2002.

4.1.3 Emergency Operating Instructions

During an emergency, nuclear power plant operators must stabilize the reactor quickly. Symptom-based instructions, now used at all US plants and many others around the world, enable operators to quickly respond to emergencies without first determining the cause.

Experts from the Institute of Nuclear Power Operations, the World Association of Nuclear Operators, and US national laboratories mentored Ukrainian experts in the development of symptom-based emergency operating instructions and related training, implementation, and maintenance.

US experts are working with host-country specialists to perform the necessary analysis to validate the symptom-based emergency operating instructions. Analysts use computer simulations of accident scenarios to test the instructions, ensuring that they will mitigate the consequences of an accident.

Activities Completed

In March 1998, Chornobyl Unit 3 implemented a complete set of symptom-based emergency operating instructions for its RBMK reactor, the first such procedures to be instituted in Ukraine. Zaporizhzhya has drafted a complete set for its VVER-1000 reactors, and Rivne has drafted a complete set for its VVER-440/213 reactors. Before these instructions are implemented, analysts must technically validate them to ensure that they will mitigate the consequences of an accident. Additionally, the procedures must be verified, operationally validated, plant staff trained in their use, and reviews completed by the regulators.

In June 1998, US instructors provided training on technical basis calculations for validating emergency operating instructions. Participating were personnel from the Rivne and Zaporizhzhya plants, the Ukrainian subcontractor Energorisk, Ltd., and the group of analysts conducting an in-depth safety assessment at Zaporizhzhya. Specialists from Bulgaria also participated.

In September 1999, South Ukraine plant staff decided to develop a set of emergency operating instructions during a workshop at the plant.

In January 2000, representatives from Energorisk and Rivne, Zaporizhzhya, and South Ukraine nuclear power plants participated in a two-week workshop at Pacific Northwest National Laboratory in Richland, Washington, to develop scenarios for validating symptom-based emergency operating instructions.

Picture of two men previewing emergency operating instructions for the Chornobyl nuclear power plant
Sergei Chuba (left), emergency operating instruction training manager at Chornobyl nuclear power plant,
and Vladimir Zaitsev, also of Chornobyl, discuss emergency operating instructions during a
training session at the Slavutych Laboratory.

Work in Progress

To test the emergency operating instructions, host-country analysts will use computer models developed as part of the in-depth safety assessment projects. (For details, see Section 4.3.1.) Ukrainian specialists at the plants are using RELAP5, a U.S.-developed code, to create a computer model of each reactor's thermal-hydraulic system. They then will use the code to simulate the most severe accident scenarios and predict the effects of operators' use of the emergency operating instructions. The analysts now are drafting accident scenarios to use in the computer simulations.

4.1.4 Configuration Management

With support from US personnel, Zaporizhzhya specialists are creating a configuration management system for the plant.

Activities Completed

In 1997, US contractor Stone & Webster Engineering Corporation provided configuration management training for key Zaporizhzhya managers. The managers visited a US nuclear power plant to observe the use of configuration management databases. Earlier in 1997, Stone & Webster staff conducted a detailed assessment of the plant and made recommendations for establishing the configuration management system.

During 1998 and 1999, plant personnel developed preliminary databases for registering equipment, developing procedures to track operational data, and for documenting equipment maintenance.

In 1999, the United States shipped computers for use in the configuration management project at Zaporizhzhya.

Work in Progress

Ukraine specialists are developing the guidance and criteria for integrating the design basis documents, being developed as part of the in-depth safety assessment activities, into the configuration management databases.

4.1.5 Event Reporting and Analysis

Zaporizhzhya is Ukraine's pilot plant for developing an event reporting and analysis system. Plant staff members are working with Energoatom and two Ukrainian contractors, Novator Kyiv and the Crimea Scientific and Engineering Research Center, to develop the process. US contractor Conger & Elsea provided technical support.

Activities Completed

In 1997, 12 staff members from Ukrainian plants participated in training on event reporting and analysis.

In 1998, the Ukrainian team completed procedures for event investigations and root cause analyses. Zaporizhzhya personnel began implementing the procedures, which incorporate revisions based on comments from personnel at other Ukrainian plants.

In 1999, the Ukrainian team developed a system for reporting abnormal events and their causes to Energoatom and other Ukrainian plants.

Work in Progress

Ukraine specialists are developing and presenting training material on root cause analysis to 15 staff from Zaporizhzhya. Specialists are installing and testing the event database on computers at Zaporizhzhya and Energoatom. Zaporizhzhya personnel continue implementing pilot procedures and databases.

4.1.6 Quality Assurance

With US support, Ukrainian specialists have developed a national industry standard for quality assurance along with a general quality manual, and they are developing improved quality assurance procedures. Energoatom and Ukraine's nuclear power plants will work to implement the standard, manual, and procedures as they are completed.

Activities Completed

US specialists have worked extensively with staff at Ukraine nuclear power plants to improve quality assurance procedures. Activities began in 1995 at the Chornobyl plant. Work included a visit to a US nuclear power plant in 1995, course-work in the United States, and an audit of practices at the Chornobyl plant in 1996. In 1997, Chornobyl staff attended several workshops on quality assurance.

In 1998, a Ukrainian team completed a national industry standard for quality assurance and forwarded it to governmental organizations for acceptance. Also, US instructors presented a workshop on quality assurance assessment. Participants represented each Ukrainian plant, Energoatom, and the Main State Inspectorate for Supervision of Nuclear and Radiation Safety.

A U.S.-Ukrainian team presented a workshop in July 1998 on document control and records management aimed at improving procedures in Ukraine. Representatives from Energoatom and four Ukrainian plants-Chornobyl, Rivne, South Ukraine, and Zaporizhzhya-participated.

In 1999, 20 Ukrainian specialists were certified as quality assurance auditors by Ukrainian authorities. Workshops were held at Chornobyl, Zaporizhzhya, Rivne, South Ukraine, and Energoatom to train key managers on the elements of quality assurance and the new national standard.

Work in Progress

With US support, Ukrainian specialists are developing pilot procedures for document control, records management, and quality assurance assessments. Plant personnel will use the pilot procedures to develop site-specific procedures for their plants.

With US support and input, Ukrainian specialists are conducting audits of fuel handling at Rivne, environmental monitoring at South Ukraine, and implementation of the quality assurance program at Khmelnytskyy.

4.1.7 Operational Safety Infrastructure

A U.S.-Ukrainian team seeks to improve Energoatom's support for safe and reliable operations at nuclear power plants. The team includes experts from Pacific Northwest National Laboratory; US contractor, Scientech; Ukrainian contractors; Energoatom; and the Nuclear Power Plant Operational Support Institute, which was established in 1997.

Activities Completed

With support from Scientech and Pacific Northwest National Laboratory, the Operational Support Institute outlined a multi-year plan of capability development activities.

In 1999, US and Ukrainian specialists conducted a workshop on developing procedures and a database for a performance indicators program. Ukrainian personnel will use the program to monitor the safety and reliability of Ukrainian plants.

Operational Support Institute personnel completed a workshop instructed by Pacific Northwest National Laboratory experts on project management. Scientech presented a decision analysis workshop for Operational Support Institute personnel. The Institute developed a plan for a quality assurance program to be certified in accordance with the international standard ISO-9000.

Work in Progress

Operational Support Institute personnel are continuing activities to obtain ISO-9000 certification. They are developing quality assurance procedures and training staff on their use.

Ukrainian experts are completing the database for collection and analysis of plant performance data.

4.1.8 Safety Maintenance Technologies

Chornobyl Unit 3, which was shut down in December 2000, is an RBMK reactor. The United States provided equipment and training to improve maintenance practices at RBMK reactors.

Activities Completed

Picture of technician demonstrating pipe lathe/weld-preparation equipment.
A maintenance technician demonstrates the use of pipe lathe/weld-
preparation equipment. The machines are used to cut pipes precisely and prepare
them for welding, reducing the risk of leaks that could cause loss of cooling
water to the reactor core.

Pipe Lathe/Weld-Preparation Machines. The United States supplied a pipe lathe/weld-preparation machine to Chornobyl in 1996. Precision cuts with this equipment improve weld integrity, reducing the risk of cooling water leaks. Before receiving this equipment, workers cut pipes by hand.

Early in 1997, the United States provided a second pipe lathe/weld-preparation machine to Chornobyl. In late 1997, the United States provided three additional machines in response to an urgent request from Chornobyl managers. During a Unit 3 maintenance shutdown in summer 1997, technicians had discovered faulty and deteriorating welds in cooling system components. The Ukrainian Nuclear Regulatory Administration called for complete repairs of the faulty welds before the reactor could be restarted. After receiving the new pipe lathe/weld-preparation machines, maintenance workers repaired more than 300 cracks. The reactor returned to operation in May 1998.

Valve-Seat Resurfacing Equipment. The United States delivered valve-seat resurfacing equipment to Chornobyl and the other RBMK sites in August 1997, and US specialists trained workers in its use. The equipment enables technicians to repair leaking valves without having to remove them from piping systems. Use of this equipment increases the accuracy of repairs, reduces maintenance time, and maintains the integrity of pipes.

Vibration Monitoring and Shaft Alignment Systems. In October 1997, technicians at all RBMK sites received training in the use of vibration monitoring and shaft alignment equipment. Workers use the equipment to detect and correct imbalances and shaft misalignments in rotating machinery, such as pumps, motors, and turbines.

Insulation-Analysis Equipment. The United States delivered insulation-analysis equipment to Chornobyl in June 1998 and trained plant personnel in its operation. Workers use insulation-analysis equipment to detect breakdown of the insulation inside the plant's main generators and around high-voltage lines and equipment. Detecting and correcting insulation breakdown can prevent loss of electrical power to key reactor systems.

Infrared Thermography Equipment. In September 1998, Chornobyl received a U.S.-supplied infrared thermography unit. Technicians use this equipment to detect hot spots in electrical systems, identifying hazards that could lead to equipment failure and loss of power.

US specialists worked with plant personnel in October 1998 to conduct a baseline thermographic imaging survey of safety-grade electrical equipment and the electrical buses that connect safety equipment to the power source. The survey simultaneously trained technicians and identified wiring, insulation, and electrical connections that need repair. With US assistance, workers performed the necessary repairs early in 1999.

Picture of technician using infrared thermography equipment.
Technicians use a U.S.-supplied infrared thermography
unit to detect hot spots in electrical systems before equipment fails.


Picture of hots spots in an electrical junction through an infrared camera. Picture of the electrical junction without the infrared camera.
The infrared camera clearly shows hot spots in this electrical junction (left) that are not visible otherwise (right).

Training Facilities. With US funding, workers in 1997 refurbished and equipped three maintenance training rooms at Chornobyl. The site previously lacked adequate facilities for training maintenance workers.

4.1.9 Nondestructive Examination

The United States is supplying equipment for finding flaws in primary circulation and safety engineered piping systems. The United States also is supplying equipment to evaluate the integrity of steam generator tubes. Technicians use ultrasonic, x-ray, and eddy-current equipment for nondestructive examination, which enables them to evaluate pipes for tiny flaws and cracks without cutting the pipes open.

Activities Completed

Technology Transfer. In 1997, the United States delivered state-of-the-art manual ultrasonic inspection systems to the five nuclear power plants in Ukraine. Also, inspection personnel from each plant attended a six-day training course at the Khmelnytskyy plant, led by US instructors.

In 1998, the United States delivered eddy-current equipment to Energoatom to enable Ukrainian plants to conduct their own remote inspections of steam generator tubes. Previously, this work was contracted to foreign inspection services. The Croatian company, INETEC, assembled the equipment and provided training in its use.

Inspections and Training. In 1998, technicians from Zaporizhzhya and INETEC completed an inspection of 1500 steam generator tubes at the Unit 6 reactor. Zaporizhzhya technicians examined the tubes in a second reactor in early 1999. Using equipment provided by the United States, Zaporizhzhya staff continued the steam generator tube inspections of the other four units.

In 1998, specialists from Pacific Northwest National Laboratory conducted a two-week workshop at Khmelnytskyy on ultrasonic examination of pipes and welds fabricated from austenitic steel, which is subject to cracking from stress and corrosion. Representatives from all five Ukrainian plants participated.

The United States is supporting increased training in nondestructive examination. With US support, Energoatom and the National University of Ukraine have established a central training and certification facility for nondestructive examination. In 1998, workers renovated the facility's classrooms and administrative offices in Kyiv.

To support nondestructive examination projects in 1999, US specialists conducted additional training classes in the use of ultrasonic equipment. US and Ukrainian experts developed a procedure for ultrasonic inspection of welds in reactor systems. Energoatom approved the procedure in September 2000.

Picture of men looking at a pipe sample for flaws.
Experts examine an ultrasonic calibration standard. Ultrasonic equipment
is used to find flaws in pipes and welds before they become cracks or leaks.

Risk-Based Inspection. US specialists have worked with Energoatom and the Nuclear Power Plant Operational Support Institute to begin a pilot study in the use of risk-based inspection techniques. These techniques use risk as a basis for setting inspection priorities. Workers examine more frequently the components that pose the highest risk of causing core damage, loss of containment, or radiological harm outside the plant. Risk-based inspection examines the structural integrity of systems and components to ensure that they remain serviceable.

Personnel at the project's pilot plant, South Ukraine, received training in risk-based inspection techniques in October 1997. Representatives from Rivne and Zaporizhzhya also participated.

Work in Progress

Inspections and Training. Ukrainian experts and US experts are developing a process for certifying technicians as nondestructive examination specialists. The requirements will conform to international standards.

Technology Transfer. The United States is supporting establishment of a facility to manufacture eddy-current probes in Ukraine.

Risk-Based Inspection. Completion of work on developing risk-based inspection at South Ukraine plant is planned for 2001.

4.1.10 Reliability Database

With US support, Ukrainian specialists are developing a reliability database for the country's VVER reactors. The database will store maintenance and operational data regarding components of the reactors' mechanical, electrical, and instrumentation systems that are essential to safety. This information will be available to all nuclear power plants in Ukraine.

To develop the database, specialists from Energoatom and the Ukrainian Ministry of Energy are working with US experts from Pacific Northwest National Laboratory. The primary contractor for the project is Information Technologies Incorporated (INIT).

The structure of the Ukrainian database also is compatible with the generic reliability database maintained by the International Atomic Energy Agency and with the reliability database under development in Russia. (For details on the Russian database, see Section 6.1.5.)

Activities Completed

During 1998, the database development center in Kyiv received U.S.-provided computers and software for creating the database, and specialists from Energoatom, Pacific Northwest National Laboratory, and Science Applications International Corporation presented a workshop on collecting reliability data. Personnel working on the Ukrainian and Russian databases participated in the workshop, including staff from Ukrainian and Russian plants, INIT, and VNIIAES. INIT completed a software quality assurance plan for the database. Ukrainian software engineers completed the design of the database structure. The United States delivered computer equipment for Khmelnytskyy, Rivne, and South Ukraine plants, the three pilot plants that initially will have electronic access to the database. Ukrainian specialists defined the list of equipment to be controlled.

During 1999 and early 2000, Ukrainian specialists completed the construction of the reliability database structure and defined the procedures and standards for data collection. Computer servers to support electronic communications between Energoatom and the pilot plants were provided. Ukrainian specialists worked to implement the database at the Khmelnytskyy nuclear power plant. This required the study of existing databases and work processes at the plant and the subsequent generation of applications that provided the same or improved functionality while storing the relevant information in the local version of the Ukrainian reliability database.

Work in Progress

The United States will provide additional equipment to establish electronic connections between the plants and the database and to implement the database at the host-country organizations. Ukrainian specialists will continue to populate the pilot database at Khmelnytskyy with plant-specific information. In addition, Ukrainian specialists will begin work to implement versions of the database at the other Ukrainian VVER reactors as well as at Energoatom.

After implementation at each of the Ukrainian VVER sites and Energoatom, Ukrainian specialists will collect and analyze reliability information on safety-related components at VVER reactors in the host countries of Central and Eastern Europe as well as Ukraine. The project is scheduled to be completed in December 2002.

4.1.11 Conduct of Operations

In 1993, a working group began developing conduct of operations procedures for Ukrainian plants. The group was composed of representatives from host plants, nuclear energy agencies in Ukraine, industry, the Institute of Nuclear Power Operations, and the US Department of Energy.

Activities Completed

By 1996, the working group had drafted 16 standard guidelines for preparing procedures for improved management and operational controls. In December 1996, the World Association of Nuclear Operators began monitoring progress in implementing the procedures and communicating lessons learned at Soviet-designed reactors.

Zaporizhzhya, Ukraine's pilot plant for developing plant-specific procedures, had implemented 12 plant-specific procedures by December 1996. Once procedures were developed and tested, Energoatom made any necessary modifications to the standard guidelines and distributed them to other plants for use in developing their own procedures. Energoatom has approved and issued 15 final guidelines to other Ukrainian plants (two of the original 16 guidelines were combined into one guideline).

4.1.12 Operator Exchanges

In the former Soviet Union, nuclear power plant personnel had few opportunities to learn from their counterparts in other nations. To improve the cross-cultural sharing of information, the Institute of Nuclear Power Operations and the World Association of Nuclear Operators began sponsoring operator exchanges in 1989.

From 1995 to 1997, the Department of Energy funded additional exchanges. During that time, 42 staff members from three Ukrainian plants visited six US nuclear power plants to observe and discuss safe reactor operations. The Institute of Nuclear Power Operations evaluated the benefits of these visits and found that visitors adapted at their own plants policies and procedures they had observed at US plants.

The operator exchanges concluded in March 1997. Personnel from Soviet-designed plants continue to visit US plants as part of training and technology transfer for specific safety improvement projects.


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4.2 Upgrading Safety Systems

Engineering and Technology Projects

US and Ukrainian specialists are developing systems for giving plant operators crucial, up-to-the-minute information needed to correct abnormal conditions and to respond to accidents. The United States also is transferring equipment, training, and procedures to improve the operation of safety systems and reduce the risk of fires at Ukrainian plants.

4.2.1 Safety Parameter Display Systems

A safety parameter display system collects and displays critical safety information at workstations in the control room and other locations in the plant. Information on the status of key conditions, such as reactor core cooling and radioactive material confinement, is displayed in a clear format on a computer screen. The system enables operators to assess plant conditions rapidly and take quick corrective actions.

When a safety parameter display system indicates abnormal conditions, the emergency operating instructions specify the needed actions.

The Russian Research and Development Institute of Power Engineering (RDIPE) and Westinghouse Electric Company designed the system for Chornobyl Unit 3. Westinghouse manufactured the components, which were assembled by Westron, a joint venture of Westinghouse and Hartron, a Ukrainian company. U.S.-based Parsons Power coordinated the project.

Westinghouse personnel also are working with Ukrainian specialists to design systems for the 11 VVER-1000 reactors in Ukraine. These include six reactors at Zaporizhzhya, three at South Ukraine, and one each at Khmelnytskyy and Rivne. Westinghouse is manufacturing the components, and Westron is assembling them. U.S.-based Burns & Roe is coordinating the projects.


Heorhiy Balakan, shift supervisor (standing), and Stephan Stoykov, senior reactor operator.
Plant operating staff check values of critical safety parameters at South Ukraine Unit 1.
Values are displayed on two safety parameter display system computer monitors
in the reactor's main control room.

Activities Completed

In 1998, workers installed safety parameter display systems at four Ukrainian reactors-Chornobyl Unit 3, and Phase I installations for Khmelnytskyy Unit 1, South Ukraine Unit 1, and Zaporizhzhya Unit 5. US, Ukrainian, and Russian specialists collaborated to produce the systems.

In 1999, workers completed the installation and site acceptance testing of safety parameter display systems at each of these units. In addition, they completed installation of safety parameter display systems at Rivne Unit 3, Zaporizhzhya Unit 3, and South Ukraine Unit 2.

In 2000, workers completed the site acceptance testing of the safety parameter display systems at the latter three units. They also have completed the factory acceptance tests of the safety parameter display systems for both Zaporizhzhya Unit 2 and South Ukraine Unit 3. In addition, all system hardware for Zaporizhzhya Unit 4 is at Westron in Kharkiv ready to be assembled for factory acceptance tests.

Summary of Safety Parameter Display System Status in Ukraine
Location
Status of Site Acceptance Tests and Operations
Chornobyl Unit 3
Tests completed in 1999, system operational until plant shutdown in December 2000.
Developmental Unit at State Scientific
and Technical Center of Ukraine, Kyiv
Operations began June 1998.
Khmelnytskyy Unit 1
After expanding capabilities and completing testing, the system became operational in March 1999.
South Ukraine Unit 1
System became operational in June 1998. Capabilities expanded in October 1999.
South Ukraine Unit 2
System became operational in June 2000.
South Ukraine Unit 3
System became operational in December 2000.
Zaporizhzhya Unit 1
Operations planned for September 2001.
Zaporizhzhya Unit 2
System became operational in December 2000.
Zaporizhzhya Unit 3
Site acceptance tests were completed in 2000, system became operational in June 2000.
Zaporizhzhya Unit 4
Site acceptance testing and operations will be completed by January 2001.
Zaporizhzhya Unit 5
System expanded in early 1999. Testing completed, and system became operational in September 1999.
Zaporizhzhya Unit 6
Site acceptance testing and operations planned for September 2001.

Work in Progress

Installation and site acceptance tests for South Ukraine 3 and Zaporizhzhya Unit 2 were completed by December 2000. The installation and testing of Zaporizhzhya Unit 4 should be completed early in 2001.

Designers began work for safety parameter display systems in Ukraine's final two VVER-1000s at Zaporizhzhya Units 1 and 6. The installations will be completed by the fall of 2001.

A service/maintenance center is being created in Kharkiv, Ukraine, for Energoatom so repairs can be made by in-country specialists after the one-year warranty period expires on the safety parameter display systems equipment.

4.2.2 Safe-Shutdown Analysis

A safe-shutdown analysis identifies ways to reduce the risk that fire could damage the systems needed to shut down a reactor safely. To ensure safe shutdown in the event of a fire, international standards call for fire zones and backup safety systems. Each fire zone has barriers to prevent the spread of fire to other areas. Each safety system has a backup system located in a different fire zone. If fire damages one safety system, such as the emergency core-cooling pump, a backup pump can be used while operators shut down the plant.

Soviet-designed nuclear power plants, however, were not designed with the concept of fire zones to prevent the failure of backup safety systems. For example, an emergency core-cooling pump and its backup pump might be in the same fire zone. A fire in that zone could disable both pumps. The results could be overheated nuclear fuel and the release of radioactive material.

US and Ukrainian specialists are undertaking a safe-shutdown analysis at Zaporizhzhya Unit 5. Personnel from Kyiv Institute Energoproekt are performing the analysis, with technical support and training by US experts.

Activities Completed

In November 1996, US, host-country, and international specialists completed a report entitled Reactor Core Protection Evaluation Methodologies for Fires at RBMK and VVER Nuclear Power Plants. The report defines methodologies for performing safe-shutdown analyses at the two principal models of Soviet-designed reactors, RBMK and VVER. The text is published in English and Russian, and Russian, Ukrainian, and international experts have endorsed the methodologies.

In December 1996, managers from Ukrainian plants received training in the development of plant regulations based on the safe-shutdown methodologies.

In November 1998, specialists from Burns & Roe led an initial meeting and training session in Kyiv. In December, they provided detailed training in the use of the safe-shutdown methodology.

In 1999, the United States provided a computer program, REVEAL_W2, for use in the safe-shutdown analysis. The program develops a model of the plant and examines fire zones. It assumes a fire has disabled the safety systems in a zone and determines whether backup systems in other fire zones would be sufficient to shut down the plant safely. If not, analysts identify the necessary changes. The United States provided electrical circuit tracer kits to determine the paths of concealed electrical cables. US specialists will provide further training in use of the safe-shutdown methodologies.

The Ukrainian working group has completed the collection of data on Zaporizhzhya Unit 5. The data collection included identification of existing fire protection features, safe-shutdown systems equipment, and electrical power and control circuits.

Work in Progress

The deterministic portion of the analysis at Zaporizhzhya Unit 5 was started in July 2000 and is scheduled for completion in June 2001.

The entire project is scheduled for completion in December 2001. The completed analysis will identify vulnerabilities that could prevent safe shutdown in a fire, recommendations for correcting the vulnerabilities, and prioritized recommendations for plant upgrades so the most urgent and cost-effective changes can be implemented first. In a related project, US personnel are supporting Ukrainian personnel in a probabilistic risk assessment at Zaporizhzhya Unit 5 (see Section 4.3.1). US and Ukrainian specialists are coordinating the two projects.

4.2.3 Fire Protection

A fire at a nuclear power plant can be catastrophic to the plant, the workers, and the public.

Unlike US nuclear power plants, which rely on multiple automatic alarm and protection systems to detect and suppress fire, Soviet-designed plants rely on large brigades of dedicated fire personnel. These brigades need to be able to detect fires reliably and alert staff immediately. They also must have the equipment to fight fires effectively. To meet these needs, the United States is supplying basic equipment for detecting and controlling fires.


During a tour, Chornobyl Unit 3 staff show one of the new metal fire doors to US Congressional staffer Madelyn Creedon of the Senate Armed Services Committee.

During the spring of 1998, workers applied a fire-resistant coating to the structural steel in the Chornobyl Unit 3 turbine building. As shown in this photo, all of the equipment and the floor of the building were covered with plastic while the material was applied. The coating (which is white and can be seen in the photo) is to prevent damage from a fire that could result in failure of the roof - as was the case in the 1991 fire in the Chornobyl Unit 2 turbine building.

Activities Completed

Structural Steel Coating. In July 1998, workers finished installing a fire-resistant coating material on the structural steel in the Chornobyl Unit 3 turbine hall. In the event of a major fire, the coating will help maintain the integrity of the steel and prevent a collapse of the roof. A 1991 fire in Chornobyl's Unit 2 turbine hall caused parts of the roof to collapse.

Fire Doors. US specialists worked with a Ukrainian company, Askenn Concern, to develop expertise in manufacturing fire doors that meet international standards. Askenn has manufactured 250 doors for Chornobyl and 125 doors for Zaporizhzhya. Askenn completed installation of the doors in 1999.

Fire-Protection Materials. The United States has supplied Zaporizhzhya and Chornobyl with fire-retardant sealant to coat electrical cables and seal the room-to-room penetrations through which the cables pass. US specialists trained workers to apply the sealant, and application of the sealant was completed in 2000.

Fire-Detection and Alarm Systems. At Zaporizhzhya workers are installing fire detection and alarm equipment that was provided earlier in the program. Installation and commissioning of fire detection and alarm systems at Chornobyl Unit 3, and Zaporizhzhya Units 2 and 5 were completed in 2000.

Fire-Suppression Equipment. In 1995, Zaporizhzhya received variable-spray hose nozzles. In 1997, Chornobyl received 19 variable-spray hose nozzles. Five hundred handheld fire extinguishers were delivered to Chornobyl in 1999, and 300 more fire extinguishers were delivered in 2000. Workers at Zaporizhzhya are in the process of installing fire suppression equipment provided earlier in the program.

Personnel Protection Gear. Zaporizhzhya received 50 sets of fire-brigade gear in 1995. Chornobyl received 90 sets of protective gear in 1997. In 1999, the United States delivered to Chornobyl 30 breathing units for firefighters and an air compressor for filling the breathing units' air bottles. The United States also delivered 20 portable fire-brigade radios and a radio base station to Chornobyl.

Work in Progress

Installation of fire detection and alarm systems and fire suppression equipment was initiated at Zaporizhzhya Units 3 and 4 in 2000. Completion of these activities is expected in June 2001.


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4.3 Conducting In-Depth Safety Assessments

Plant Safety Assessment Projects

At a nuclear power plant, experts conduct in-depth safety assessments to determine the safety basis, identify the most significant risks, and set priorities for safety upgrades. Assessments typically involve two kinds of safety assessment methods: probabilistic and deterministic (see page 2.8).

4.3.1 Plant-Specific Safety Assessments

US experts are working with Ukrainian experts to conduct in-depth safety assessments at three lead plants in Ukraine: Rivne, South Ukraine, and Zaporizhzhya. A fourth project at Khmelnytskyy is focused on development of a process to extend the safety assessments for the lead plants to other units of similar type. US support includes the transfer of computer codes for performing safety analyses, training in the use of the codes, guidance in conducting the assessments, and review of the work performed by plant specialists. Once completed, the assessments will provide a technical basis for evaluating radiological risk and prioritizing safety upgrades.

Major computer codes transferred to the plants and their Ukrainian technical support organizations include: the CONTAIN reactor containment response code, the MELCOR reactor containment response code, the RELAP5 thermal-hydraulics code, the ORIGIN reactor radioactive material inventory calculator code, and the SAPHIRE probabilistic risk assessment code. Together, these codes provide an effective way to analyze the expected performance of nuclear reactor safety systems in an emergency.

Rivne. Plant staff members are supervising and participating in an in-depth safety assessment of Rivne Unit 1, with support from Argonne National Laboratory; US contractor, Scientech; and Ukrainian subcontractors.

In March 1998, a Ukrainian contractor installed U.S.-provided computers and software at Rivne, including a local area network. The computer system enables plant specialists to use modern U.S.-developed safety analysis codes.

Ukrainian specialists completed the project guidelines in June 1998. In July 1998, with support from US experts, the specialists began a design-basis accident analysis. Major portions of this analysis have been completed, and the work is continuing.

In September 1998, the Ukrainian specialists completed the documentation and assessment of a limited-scope probabilistic risk analysis work previously done for Rivne Unit 1 by Energorisk. In May 1999, the Ukrainian specialists began the task of building on the previous work to develop and complete the probabilistic risk assessment for Rivne. The work is continuing. In 1999, the specialists completed collecting and updating the Rivne nuclear steam supply system database, component reliability database, abnormal events database, and plant systems description. These data were used to create comprehensive RELAP5 models of the reactor's thermal-hydraulic system, which were completed in January 2000. They will use these models to simulate the reactor response during accident scenarios. In addition, Ukrainian analysts will perform simulations to support the use of symptom-based emergency operating instructions at Rivne. Ukrainian specialists also have begun data collection for a limited-scope assessment of external events and non-nuclear internal hazards, such as fire and flood, which could cause accidents leading to damage of the reactor core.

South Ukraine. In 1998, with US support, Ukrainian specialists made significant progress on a probabilistic risk assessment of abnormal events within the plant for Unit 1 at South Ukraine. The specialists also completed most preparations for a deterministic safety analysis and began a design-basis accident analysis.

Also in 1998, Ukrainian specialists completed major tasks for a level-one internal events probabilistic risk assessment. In July, they completed the validation and verification of a RELAP5 thermal-hydraulics model of the plant. They completed the success criteria analysis in September, and in November, they completed the preliminary accident sequence analysis, the systems analysis, and the preliminary risk quantification.

During 1998, the Ukrainian specialists completed most data collection and analysis tasks for the probabilistic and deterministic analyses. They completed the nuclear steam system database in January, the plant system descriptions in March, the abnormal events database in April, the component reliability database in July, and the containment database in September.

In July 1998, the Ukrainian specialists began a design-basis accident analysis. They also began a limited-scope assessment of external events and internal hazards (e.g., fire and flood hazards) that could cause accidents leading to damage of the reactor core.

During 1999, work continued on refining the results of the level-one internal events probabilistic risk assessment analysis. This work led to completion of an updated human reliability analysis in March. The final quantification of the risk assessment was completed in June 1999. Review of the final report was completed in November 1999, and the report was issued in December. Work has begun on an independent peer review and a regulatory review of the risk assessment.

Work also continued on the assessment of internal and external hazards. Guidelines for external hazards assessment were completed in March 1999 and a report on data/information collection was issued in April 1999. The screening, preliminary evaluation, and planning of additional work for man-made external hazards was completed in December 1999.

Considerable progress was made during 1999 on the design-basis accident analysis. The ORIGEN deck for the estimation of radionuclide inventories was completed in June 1999. All databases needed for the analysis were updated, and the preliminary selection of design-basis accident-initiating events and their grouping were completed in August 1999. The CONTAIN model for the calculation of containment response under accident conditions was completed in November and the MELCOR model for the calculation of accident progression was completed in December 1999. Similarly, the RELAP5 deck also was updated for design-basis accident analysis in December.

During 2000, work continued on the assessment of internal and external hazards. This effort included completion of all hazards screening, preliminary evaluation, and planning of additional efforts for internal fires (April 2000), natural-phenomena external hazards (May 2000), and internal flooding (July 2000). Progress made to date on the design-basis accident analysis includes generic ORIGEN calculations (April 2000) and preliminary engineering estimates of accident scenarios (July 2000). Detailed calculations for specific groups of accident scenarios (increase in reactor coolant inventory, decrease in reactor coolant flow rate) were completed in June 2000. The design-basis accident analysis is scheduled for completion by mid-2001.


Igor Krivolopov (seated) of the Zaporizhzhya nuclear power plant
uses a computer code to predict heat flow characteristics in reactor
operating situations. Assisting him is Carl Enderlin of Pacific Northwest
National Laboratory. Experts are using thermalhydraulics codes to identify
and evaluate risks at Ukrainian nuclear power plants.

Zaporizhzhya. With US support, Ukrainian specialists are conducting an in-depth safety assessment of Zaporizhzhya Unit 5. Plant specialists are working with personnel from a number of Ukrainian companies with Joint-Stock Enterprise EIS of Energodar having the technical lead and performing the bulk of the work. Scientech, Inc. and its Ukrainian subsidiary are providing technical support, and Argonne National Laboratory is coordinating the project. Early in 1998, the United States provided computer equipment for the assessment work. Scientech experts trained Ukrainian personnel in the methodology for conducting a probabilistic risk analysis.

During 1998, Ukrainian specialists documented all prior safety assessment work conducted at Zaporizhzhya. They also made considerable progress in the collection and analysis of the databases needed for the probabilistic risk assessment (PRA) that addresses abnormal events within the plant. In September, they completed guidelines for the PRA. Progress also was made in developing a RELAP5 thermal-hydraulic model of the plant for performing the needed deterministic safety analyses. In 1999, work progressed significantly on the PRA for abnormal events within the plant, the associated databases, and the thermal-hydraulic model. The system descriptions and the nuclear steam supply system database were completed in March 1999. A preliminary RELAP5 model of the reactor unit was completed in June, as was the final abnormal events database. The preliminary component reliability database was completed in July and the preliminary systems analysis (Fault Trees) was completed in September.

The final RELAP5 model for the reactor unit was completed in February 2000. The final systems analysis (Fault Trees) and the identification and grouping of initiation events were completed in June. The system success criteria analysis for the internal events PRA was completed in July, as was the accident sequence analysis (Event Trees). The human reliability analysis was completed in August. The accident sequence quantification and uncertainty analysis was completed early in September 2000. The results of the internal events PRA and the draft final report are currently under review by the Zaporizhzhya plant. The final report on this PRA should be completed in February 2001, at which time an independent peer review and a regulatory review of the work will begin.

Detailed plans for the design-basis accident analysis and the preliminary assessment of man-made and natural-phenomena external hazards were completed in September 2000, and work on these tasks has begun.

Khmelnytskyy. The in-depth safety assessment for Khmelnytskyy Unit 1 will be based on the Zaporizhzhya Unit 5 in-depth safety assessment. Because these two plants are similar, the assessment team developed a method of comparing the plants to determine any differences and how much of the Zaporizhzhya analysis is applicable to Khmelnytskyy. This process will save money, time, and resources and will provide Ukraine with a process for developing in-depth safety assessments for all operating reactors in Ukraine. In June 1998, Khmelnytskyy staff and Ukrainian subcontractor, Kyiv Institute Energoproekt, began working with US specialists to define the scope for an in-depth safety assessment of Khmelnytskyy Unit 1. In July 1998, a Ukrainian contractor installed U.S.-provided computers and software at Khmelnytskyy, including a local area network. The computer system enables plant specialists to use modern U.S.-developed safety analysis codes.

Specialists from Argonne National Laboratory and US contractor Science Applications International Corporation mentored Ukrainian staff in developing project guidelines. Ukrainian staff began data collection in November 1999.

In June 2000, the Khmelnytskyy technical staff completed review of the draft methodology of comparison for preparing its site-specific in-depth safety analyses and submitted it for international peer review. That review indicated that, though the Zaporizhzhya work will greatly ease the efforts at Khmelnytskyy, the analyses of Khmelnytskyy must be performed separately to reflect plant-specific conditions.

4.3.2 Transfer of Safety Assessment Capabilities

The United States is working with Ukrainian specialists to develop in-country expertise in conducting plant safety assessments.

Activities Completed

Code Training. Ukrainian specialists participated in three four-week training sessions on the RELAP5 computer code during 1997. Hands-on exercises illustrated the use of the code for performing thermal-hydraulic analyses of VVER reactors. Experts from Argonne National Laboratory and the Idaho National Engineering and Environmental Laboratory led the sessions.

In May 1998, Ukrainian specialists completed a fourth four-week training session on the RELAP5 thermal-hydraulics code. Personnel from all plants participated, along with specialists from Ukrainian organizations that will conduct peer reviews of the in-depth safety assessments under way at Ukrainian plants.

In July 2000, Ukrainian specialists participated in a three-week long training course on RELAP5 held at the Slavutych Laboratory for International Research and Technology in the city of Slavutych. Ukrainian specialists who received training included Slavutych Laboratory technical staff. Experts from the Idaho National Engineering and Environmental Laboratory led the training.

In July 1999 and April 2000, Ukrainian specialists completed a pair of two-week long training workshops on the MELCOR accident analysis computer code. The workshops were held in Kyiv and were led by experts from Argonne National Laboratory and the Institute for Electric Power Research in Budapest (VEIKI). The workshops included lecture presentations as well as hands-on exercises using the code. Ukrainians participating in the workshops included specialists from all of the VVER nuclear power plants in Ukraine as well as supporting technical organizations.

During July 2000, Ukrainian specialists from all of the VVER nuclear power plants and supporting technical organizations participated in an additional week-long workshop devoted to the MELCOR computer code. The training was conducted in Kyiv by experts from Argonne National Laboratory and VEIKI and included additional hands-on training.

In May 1999 and July 2000, Ukrainian specialists from all of the VVER nuclear power plants and associated organizations completed a pair of week-long training workshops in Kyiv on the CONTAIN containment analysis computer code. Experts from Argonne National Laboratory and VEIKI led the workshops.

In November 1998, Ukrainian specialists participated in a course in Kyiv on probabilistic risk assessment and the use of the SAPHIRE risk analysis code.

The United States provided courses in technical English during 1998, 1999, and 2000 for personnel from Ukrainian plants and technical organizations associated with Energoatom.

Information Exchanges. The United States has sponsored international forums and workshops for exchanging information on in-depth safety assessments at Soviet-designed reactors. The International Atomic Energy Agency and the Swedish International Project on Nuclear Safety also have supported this effort.

Five forums focusing on analytical methods and computational tools for conducting safety assessments have been held. The first forum was in September 1996 in Obninsk, Russia. Representatives of 10 Soviet-designed nuclear power plants were among the 75 specialists attending from around the world. Forums have continued each year in Obninsk, in September 1997, October 1998, October 1999, and October 2000. The international forums now host more than 100 participants from a dozen countries.

Two smaller workshops have focused on probabilistic risk assessment at VVER reactors. The first workshop, held in November 1996 in the Czech Republic, enabled participants to discuss such issues as loss-of-coolant accident frequencies and component reliability data. The participants-from Ukraine, Russia, the Czech Republic, Hungary, and Slovakia-requested a follow-up session.

The follow-up session, held in April 1997 in Bratislava, Slovakia, focused on improving a generic methodology for structuring and collecting data for plant-specific risk analyses. Participants came from Ukraine, Russia, the Czech Republic, Hungary, Slovakia, Romania, Holland, and Spain.

4.3.3 Validation and Verification of Computer Codes for Safety Analysis

When analysts use RELAP5 and other computer codes in safety analyses, they must make sure the codes accurately represent and predict the configuration and behavior of the reactor being analyzed. In a process called validation, analysts check the codes against test data. These data are produced by experimental facilities designed to simulate the behavior of a specific type of reactor. In a process called verification, analysts use the safety analysis codes to develop plant models and accident scenarios, then check results against data from actual reactors.

US analysts are working with Ukrainian analysts to validate the RELAP5 and NESTLE codes for application to VVER reactors.

Work in Progress

Analysis of RELAP5. US analysts are working with Ukrainian analysts from the Sevastopol Institute and National Kyiv University to conduct a limited analysis of the RELAP5 code for application to VVER reactors. RELAP5 is a U.S.-developed thermal-hydraulics code. Results of the analysis will be compared to similar analyses under way at the US and Russian International Nuclear Safety Centers.

Validation of NESTLE. US analysts are working with Ukrainian analysts from the Nuclear Power Plant Operational Support Institute to develop analysis models for the NESTLE code for use at VVER reactors. NESTLE is a U.S.-developed, neutron-kinetics code. The analysts will use the code with the RELAP5 code. Together the codes will generate a three-dimensional computer model of the thermal-hydraulic and neutron-kinetic characteristics of a VVER reactor core.


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4.4 Working Safely with Spent Nuclear Fuel

Fuel Cycle Safety Projects

Before the breakup of the Soviet Union, Ukrainian nuclear power plants shipped their spent fuel to Russia for reprocessing. Now Ukraine is working to develop in-country systems for managing spent fuel. The United States supports establishment of a dry-cask storage system for the Zaporizhzhya plant and development of spent-fuel management systems.

4.4.1 Zaporizhzhya Dry-Cask Storage

The six-reactor Zaporizhzhya plant needs more capacity for storing spent fuel since its storage pools are nearly full. The United States has worked with Zaporizhzhya to establish a dry-cask storage system, which is a safe and cost-effective alternative to storage pools.

The spent-fuel dry-cask storage project is enlarging the storage capacity at the Zaporizhzhya nuclear power plant. Workers are shown erecting the ventilated concrete cask (left), near a cask after removal of concrete forms (middle), and attaching the approval flag after acceptance of the first cask in May 1998 (right).

Activities Completed

In 1995 and 1996, US experts provided instruction in the safe use and monitoring of dry-cask systems. US and Ukrainian specialists worked together to develop cask-system operating procedures tailored to specific conditions at Zaporizhzhya. The United States transferred U.S.-developed computer codes for storage system calculations to the Ministry of Environmental Protection and Nuclear Safety of Ukraine, the country's nuclear regulatory agency.

In 1996, US contractor Duke Engineering & Services delivered cask liners, rebar, and forms for building the first three concrete casks. Zaporizhzhya personnel successfully poured the first three casks in May, June, and July 1998 and have the capability of manufacturing 12 additional storage casks per year.

Each concrete cask is designed to hold 24 spent-fuel assemblies. After the spent-fuel assemblies are inserted, the cask is back-filled with inert helium gas and a lid is welded in place. The casks may be limited to 22 spent-fuel assemblies to ensure that accidental loading of fresh fuel into a cask containing fresh water would not result in a criticality concern. The casks provide both gamma and neutron shielding and have a minimum life of 40 years. Sierra Nuclear Corporation developed steel baskets designed to hold the 24 spent-fuel assemblies inside the casks. By July 1998, the plant had received three baskets, completing the US contributions to the dry-cask storage system. Ukrainian personnel will manufacture additional baskets.

To move each filled cask through the plant to a concrete storage pad, Duke Engineering & Services delivered a self-propelled cask transporter in 1996. J&R Engineering of Mukwongo, Wisconsin, built the transporter, under contract to Duke and Sierra Nuclear Corporation.

Work in Progress

Zaporizhzhya is expected to begin using the dry-cask storage system in 2001. Once the plant does so, it will be self-sufficient in managing its spent fuel.

4.4.2 Spent-Fuel Management System

US experts are supporting Ukrainian efforts to develop a plan for managing the spent fuel from the country's five nuclear power plants. Ukrainian experts at the Slavutych Laboratory are leading the project with technical information provided by Energoatom and the Ukrainian Nuclear Regulatory Administration.

Activities Completed

In July 1998, Ukrainian specialists completed an inventory of existing and projected volumes of spent nuclear fuel. They entered the information in a database created with support from staff at the Pacific Northwest National Laboratory.

In September 1998, Ukrainian specialists completed an assessment of the regulatory procedures for licensing spent-fuel storage systems in Ukraine. In November 1998, the Ukrainian project leader for spent-fuel management participated in an International Atomic Energy Agency symposium on spent-fuel management. In 1999, the final report for the project was completed.


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4.5 Developing an Institutional and Regulatory Framework

Nuclear Safety Institutional and Regulatory Framework Projects

US and Ukrainian experts are working to develop a strong institutional framework for regulating Soviet-designed nuclear power plants. US efforts also promote host-country adherence to international nuclear safety treaties and liability conventions.

4.5.1 Liability Protection

US technical specialists supported the Department of Energy in seeking international approval of a treaty that would channel liability to the responsible operator of a Soviet-designed nuclear facility. Such liability arrangements are customary in the United States and Western Europe. The treaty also caps undue liability of contractors in US and foreign courts if a malfunction or accident occurs at a Soviet-designed nuclear facility where US contractors provided services. This Supplementary Funding Convention for Accident Compensation improves the safety of Soviet-designed nuclear power plants by permitting more extensive use of advanced safety technologies.

The Board of Governors of the International Atomic Energy Agency approved the proposed treaty in April 1997. In June 1997, leaders of the G-7 nations issued a communique' at their Denver summit on nuclear safety that welcomed the adoption of the proposed treaty.

Diplomats signed the Supplementary Funding Convention in September 1997 at the International Atomic Energy Agency's Diplomatic Conference in Vienna. US Secretary of Energy Federico Pe–a signed on behalf of the United States. Representatives from Ukraine and Lithuania were among others who signed.

The US cannot accede to the treaty until the Senate gives its advice and consent to ratification. Legislative ratification is required in other countries as well, including Ukraine and Lithuania.

4.5.2 Regulations for Emergency Operating Instructions

With US training and technical support, Ukrainian specialists have established regulations for developing, validating, and implementing symptom-based emergency operating instructions. US experts worked with Ukrainian personnel to develop the instructions (see Section 4.1.3).

In 1996 and 1997, US experts provided extensive training for regulatory personnel from Ukraine, Russia, and host countries in Central and Eastern Europe who are responsible for reviewing and approving emergency operating instructions. Workshops in November 1996 and March 1997 provided information on the development, validation, and regulation of the instructions for VVER reactors; the training and licensing of control room operators; and the role of the regulator during the approval process.

The 1996 session was the first time these regulatory personnel, all of whom work with VVER reactors, met to discuss common issues. The workshop took place in the United States. The 1997 workshop, held in Slovakia, included regulators of sites with VVER reactors in Ukraine, Russia, Bulgaria, Hungary, and Slovakia.

At a September 1997 meeting in Kyiv, experts from the Pacific Northwest National Laboratory presented information on the US approach to verification and validation of emergency operating instructions. Attending were representatives from Energoatom, the Ukrainian Nuclear Regulatory Administration, the Main State Inspectorate for Supervision on Nuclear and Radiation Safety, the State Scientific and Technical Center (SSTC), and four nuclear power plants-Chornobyl, Khmelnytskyy, Rivne, and Zaporizhzhya.

In February 1998, SSTC specialists completed the final draft of regulations and guidelines for verifying and validating emergency operating instructions for Ukraine's VVER reactors. Energoatom has approved the VVER regulations and forwarded them for certification by Ukraine's Ministry for Environmental Protection and Nuclear Safety.

In August 1998, staff from SSTC completed a series of on-site inspections at Zaporizhzhya, where Ukrainian analysts have begun verifying the plant's emergency operating instructions. SSTC staff observed the verification process and inspected the plant's control room simulator to see whether it accurately simulates the configuration and behavior of the control room's safety system components. The analysts verifying the instructions will use the simulator in their verification process.

SSTC staff also prepared regulations for the verification of emergency operating instructions for Chornobyl's RBMK reactor. In August 1998, SSTC staff participated in a workshop in the United States on "flow-charted" emergency operating instructions and regulations covering such instructions for US boiling-water reactors. Flow-charted emergency operating instructions graphically map the sequence of decisions to be made in an emergency.

4.5.3 Capability Enhancement for Ukrainian Regulators

In October 1997, representatives from the United States and Ukraine's Nuclear Regulatory Authority agreed to work together to develop a strong, independent nuclear regulatory infrastructure in Ukraine. DOE's activities in this area have been closely coordinated with the US Nuclear Regulatory Commission, the US agency that has lead responsibility for this activity.

Activities Completed

In August 1998, 10 Ukrainian regulators participated in a workshop on project management in Kyiv. With US support, a contract was put in place for translating US nuclear safety standards and regulatory documents. Personnel from SSTC hire the translators and do quality checks on the work.


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4.6 Other Projects

In 1998, the United States agreed to work with Ukraine on developing methods to increase electrical output and improve physical security at the country's nuclear power plants. This section describes the progress in these areas.

4.6.1 Capacity Factor Improvements

Ukrainian and US experts jointly studied the operating and maintenance performance of the Rivne nuclear power plant seeking to increase the capacity factor of the plant. Improving a reactor's capacity factor involves reducing downtime and increasing the reactor's output of electricity, revenue, and potentially, the funds available for safety projects. The evaluations are anticipated to apply to all 11 VVER-1000 plants in Ukraine. Some recommendations are also applicable to the VVER-440/213 plants.

The review showed that international experience is applicable to Ukrainian plants and resulted in identification of 52 specific improvements. Projects were ranked by effort, probability of success, ease of licensing, and expected savings. The project team (Rizzo, Pacific Northwest National Laboratory, Energoatom, a Ukrainian work group, personnel at Rivne nuclear plant, and others as required) developed a set of cost-effective, alternative scenarios.

A proof-of-principle task undertaken in 1999 aimed to demonstrate the effectiveness of one of the simpler efficiency improvements. Measurements taken before the October outage were compared to measurements after repairs were made and the plant was restarted. The repairs reduced condenser air in-leakage and led to an efficiency gain in the turbine generator of more than five megawatts electricity.

4.6.2 Plant Security

The US Senate Foreign Operations Appropriations Bill for Fiscal Year 1999 contained a provision for an assessment and upgrade of security measures at civilian nuclear facilities in the "New Independent States" and for identification of additional resources that would be necessary to provide a minimum-security regime at all reactors. In May 1999, specialists from Pacific Northwest National Laboratory completed a study that described the existing state of security at nuclear power plants in Armenia, Kazakhstan, Russia, and Ukraine and identified areas that needed improvement at these plants.

The Khmelnytskyy plant was chosen to be the pilot site for improving physical security at nuclear plants in Ukraine, and US and Ukrainian specialists focused their efforts and the funding resources provided on the highest priority needs, namely, improving access control for the internal, vital, and limited access areas; improving the detection, assessment, and alarm systems; and providing test and operation training programs and procedures.

A set of unguarded heavy doors (left) was all that formerly protected the entrance to the radiological area within Khmelnytskyy's reactor building. The same entrance (right) now is equipped with a proximity card reader linked electronically to the full-height turnstile to control access and personnel barrier walls extending from floor to ceiling.

Activities Completed

In 1999, the United States provided a personnel badge system to the Khmelnytskyy plant, specialists from Pacific Northwest National Laboratory conducted a workshop on physical security for Khmelnytskyy staff, independent reviewers approved the proposed program, and project staff sent out a request for proposals. In 2000, contracts were established and detailed design was approved in Ukraine and the United States. Security equipment assembly and installation was completed and testing was performed in September 2000. Training programs were developed and implemented, and the upgraded access system was commissioned by Energoatom in October 2000.

 


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