May 1998

- Armenia - Bulgaria - Czech Republic - Hungary

- Kazakhstan - Lithuania - Russia - Slovakia

- Ukraine - United States - Cross-Cutting Activities - Planned Activities

Welcome to the May Activity Report, which documents safety improvements achieved in May at Soviet-designed nuclear power plants through U.S. and host-county cooperation. This report replaces the biweekly activity report and is available online or in hard-copy form. To request a hard-copy version or to provide comments or suggestions, send an e-mail message to marye.hefty@pnl.gov.

Chornobyl Unit 3 Completes 10-Month Maintenance Outage

Operators at the Chornobyl nuclear power plant (NPP) returned Unit 3 to power operation on May 13, after being shut down for a scheduled maintenance outage since July 21, 1997. The reactor reached its full 925-megawatt capacity on May 19.

Chornobyl Units 1, 2, 3, and 4. Unit 3 can be seen in front of the most distant ventilation stack, which is mounted on an auxiliary equipment building that connects the operating Unit 3 to the shelter over Unit 4.

Deteriorating welds in the reactor's cooling system led to a massive effort to repair 338 cracks using equipment and inspection techniques provided by the U.S. Department of Energy (DOE) and Russia. In response to an urgent request from Chornobyl plant management, the United States sent five pipe lathe/weld-preparation machines and valve-seat resurfacing equipment to Chornobyl to assist with the repair work. The equipment helps maintain the integrity of pipes and greatly reduces the risk of leaks that could result in loss of cooling water to the reactor. Prior to receiving the equipment, workers cut pipes by hand, which led to both safety and precision concerns, and had to remove leaking valves from the piping for repairs.

A new Russian-developed ultrasonic inspection technique that assesses pipe weld quality based on analytical concepts also was used to examine reactor piping for repairs at the request of Ukraine's Nuclear Regulatory Administration. The technique is credited with detecting flaws that needed repair in some of the large-diameter pipe welds.

More than 700 workers were involved in the weld detection and repair efforts and other outage activities intended to improve Unit 3 operating safety. Other work included replacing 59 fuel channels, establishing an emergency operating center, commissioning an additional waste fuel storage heat exchanger, replacing direct-current batteries, installing equipment to measure the reactor's (neutron) void coefficient, and completing an in-service inspection of reactor process tubes and the graphite stack.

With U.S. support, Chornobyl Unit 3 also recently implemented the first-ever set of symptom-based emergency operating instructions (EOIs) for a Ukrainian NPP. The EOIs are depicted in a set of table-mounted flow charts that outline specific actions for reactor operators to take to stabilize the plant in an emergency. "With symptom-based instructions, operators don't wait to determine the cause of the problem. Rather, they act on the symptoms to include all possible causes," said Don Draper, Pacific Northwest National Laboratory project manager. Once the plant is stable, operators can then implement event-based EOIs to solve the problem.

The United States has provided millions of dollars in training and equipment to help protect workers from industrial and radiological work hazards. Workers have been trained on proper use of operating procedures, routine maintenance activities, and quality assurance practices.

Current plans are for Unit 3 to operate until November 1, 1998, when it will be shut down again for its scheduled annual repairs.

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Novovoronezh Unit 3 Safety Parameter Display System Delayed. The outage for Novovoronezh Unit 3 has been delayed until mid-August due to an unforeseen shutdown of Unit 5. The safety parameter display system (SPDS) cannot be installed until Unit 5 starts up allowing Unit 3 to begin its outage. A protocol has been submitted to Rosenergoatom (REA) for use with Gosatomnadzor (GAN) for approving the SPDS and turning it over to the power plant. All major regulatory issues have been addressed, and GAN is determining if any additional actions are required prior to turnover. (Mike Durst, PNNL, 509-372-4698)

Leningrad SPDS Tested Successfully. On May 7, the formal factory acceptance test for the Leningrad Unit 4 SPDS was conducted at the ZAT facility in Pribram, Czech Republic. The tests were performed by Westinghouse and RDIPE staff and were witnessed by representatives of the U.S. team and Parsons Power, and Russian representatives from Leningrad NPP, GAN, and VNIPIET. The system passed all of the tests. Parsons Power technical staff inspected the system and identified 10 minor deviations from the system specifications. These deviations were corrected before the end of May. After customs clearance is received, the system will be shipped to Leningrad NPP for installation. Leningrad Unit 4 will enter an extended outage in June at which time installation can begin; installation is expected to be completed by the end of summer 1998. The SPDS then will be commissioned for pilot operation. (Rich Denning, PNNL, 614-424-7412)

Progress Continues for Kola In-Depth Safety Assessment. A Kola in-depth safety assessment project meeting took place in Moscow April 25 through 30. Representatives of Kola NPP, Kurchatov, Gidropress, Argonne National Laboratory (ANL), and Science Applications International Corporation (SAIC) attended. Participants discussed a new schedule for accelerating Phase I of the project—the Level 1 internal events probabilistic risk assessment (PRA) for Unit 4. The goal is a preliminary quantification of the PRA by September 1998. The participants also made plans and prepared task orders to accelerate Phase IV of the project—the design-basis accident analysis for Units 1 and 2. They reached an agreement on a plan for finalizing guidelines and completing a RELAP computer model of Unit 1 by October 1, 1998. (Philip Pizzica, ANL, 630-252-4847)

Novovoronezh In-Depth Safety Assessment Principals Review Progress. On April 21, U.S. experts working on the Novovoronezh in-depth safety assessment project met in Moscow with Atomenergoproekt, the subcontractor who will support the PRA work under the plant leadership. Participants discussed various technical and organizational details. On April 22 through 24, a project meeting took place at Novovoronezh NPP. Participants discussed progress of the systems description and data collection task (which is about two-thirds complete), support for the RELAP model of Unit 3, and status of the task order for the PRA that should be signed very soon. (Philip Pizzica, ANL, 630-252-4847)

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Training Program Implemented at Zaporizhzhya NPP. Personnel from Zaporizhzhya NPP, Brookhaven National Laboratory, the Engineering Technical Center on Personnel Training for Nuclear Energy (ETC), General Physics Corporation, and Khmelnytskyy NPP implemented a pilot training program for chemical operators at Zaporizhzhya NPP during the week of May 18. This implementation is the culmination of four working visits to Zaporizhzhya NPP to develop the pilot course as part of the U.S. effort to transfer training technology from the Khmelnytskyy training center to other NPPs in Ukraine. (Peter Kohut, BNL, 516-344-4982).

Nuclear Regulatory Administration Approves EOI Regulation. Regulation for development, implementation, and use of symptom-based EOIs for VVER reactors in Ukraine has been drafted by the Ukrainian State Scientific and Technical Center (SSTC) and approved this month by Ukraine's Nuclear Regulatory Administration. This regulation awaits Ministry approval before implementation. Future plans call for the EOI regulation to be expanded to include the RBMK EOIs. All regulation is scheduled to be implemented by January 1999.

As required by the new EOI regulation process, the SSTC has completed several on-site inspections at Zaporizhzhya NPP. During these inspections, SSTC staff observed the verification and validation process for four symptom-based EOIs. The SSTC staff also conducted a comparison study of the simulator to the Unit 5 control room. The purpose of this study was to ensure the applicability of the simulator to perform verification and validation of the Unit 5 symptom-based EOIs. Additional on-site inspections are planned in which additional verification and validation and operator training will be observed. (Kent Faris, PNNL, 509-372-4068)

South Ukraine Unit 1 to Receive SPDS Ahead of Schedule. On May 4, the U.S. team exercised a contract option approximately 1 year ahead of schedule to install a SPDS in South Ukraine Unit 1. The SPDS will be implemented this calendar year in three phases: Phase I involves mostly hardware installation (e.g., signal cable) and will occur during this summer outage. After Phase I, 8 of 38 safety parameters will be available to NPP staff. Phase II is scheduled during power operation this fall and will involve completing an additional 15 safety parameters. The final phase will involve completing the safety parameters and is scheduled for the winter outage. Burns and Roe Enterprises, Inc., is the main contractor for implementing SPDSs in all 11 Ukraine VVER-1000s. Westinghouse Electric Corporation is the main subcontractor to Burns and Roe. (Frank Panisko, PNNL, 509-372-4472)

Installation Begins for South Ukraine Unit 3 SPDS. Installation of the SPDS has begun for South Ukraine Unit 3. All equipment was shipped to the plant on May 18, and all necessary regulatory approvals have been obtained. The hardware is being installed during this outage. Additional capability will be installed this summer and fall, and the remaining site acceptance testing will be completed by mid-1999. (Mike Durst, PNNL, 509-372-4698)

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Chornobyl Initiatives

Ukraine Waives Customs Fees and Releases Safety Equipment. The customs authority of Ukraine finally has agreed to waive fees typically imposed for shipment inspection, paperwork processing, and storage, and to release from impoundment several million dollars worth of U.S.-supplied safety equipment destined for the Chornobyl Shelter. Much of the equipment, needed for worker safety improvements at the Shelter, has been impounded since 1997 (some since July 1997).

Among the first equipment released are components of a million-dollar neutron monitoring system. This system monitors and documents the state of subcriticality of the nuclear-fuel-containing masses in the lower elevations of the Shelter. Also released from impoundment is equipment for radiation safety and dosimetry, industrial safety, and suppression of radioactive dust. (Bryan Gore, PNNL, 509-372-4121)

Course Development Continues at Chornobyl Shelter. On May 25, training experts from Sonalysts began working at the Chornobyl Shelter to continue the development of training materials for a radiation protection technician pilot training program. Until June 5, training experts will work at the Shelter on this pilot program that is being developed to take into account the unique environment encountered in the Shelter. The pilot course will be implemented in fall 1998. (Peter Kohut, BNL, 516-344-4982)

Ventilation Stack Repair Milestone Reached. On May 9, the 50% completion milestone was reached for repairs to the damaged ventilation stack between Chornobyl Units 3 and 4. The external bracing that supports the stack was seriously damaged by the 1986 accident, resulting in the possibility that the stack might collapse when heavily stressed by a small earthquake, high wind, or heavy snow loading. Collapse of this stack could result in significant damage to the operational Unit 3 or the Shelter.

The completed repairs involved replacing one horizontal brace that was completely torn away in the accident, replacing six diagonal braces that were seriously damaged, and welding the "strongback" supports over three structurally significant dents in vertical braces. Radiation doses received by workers during the repairs were substantially lower than preliminary estimates due to worker training on a full-scale mock-up of part of the bracing framework.

The remaining repairs (which include strengthening the stack foundation located inside the building, replacing additional damaged braces, and strengthening dented braces) will be completed by July. Repair completion will return the ventilation stack and its bracing to its full design strength. This project is funded by DOE, Canada, and Ukraine. Ukrainian organizations are performing the structural analysis, repair design, contracting, and project management. (Bryan Gore, PNNL, 509-372-4121)

Chornobyl Shelter Project

Consortium Selected for Shelter Implementation Plan. A consortium has been selected to carry out a plan aimed at stabilizing the concrete shelter that now covers the damaged Unit 4 reactor building of Chornobyl NPP.

Bechtel National, Inc., will lead a consultant group that includes the French utility Electricité de France and the Battelle Memorial Institute in managing the Shelter Implementation Plan designed to stabilize the Chornobyl Shelter, reduce the risk of any future release of contamination into the environment, and minimize occupational exposure. The contract award from Ukraine's Ministry of Energy is for a two-year initial phase of work that is scheduled to get under way shortly. The entire project will eventually extend over 96 months, with completion set for 2006. Included in the Shelter Implementation Plan will be 22 tasks, all of which will be carried out under the management of a single project management unit.

The Bechtel-led consortium will provide such services as conceptual engineering, cost estimating, scheduling, project management, and the preparation of design and procurement packages needed to acquire detailed design, equipment supply, and construction services. In addition, the consortium will support the development of all necessary permits and regulatory documents. The consortium's involvement is an outgrowth of efforts by the U.S. team as part of DOE's work since 1995 to address immediate safety concerns at Chornobyl so that work could begin to prevent and mitigate the potential collapse of the Shelter. (Dennis Kreid, PNNL, 509-375-2170)

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Systematic Approach to Training Workshop Continues for Ignalina NPP Personnel. On May 18, a four-week workshop began on the Systematic Approach to Training (SAT) methodology for personnel from Ignalina NPP at the General Physics Corporation offices in Aiken, South Carolina. The workshop is the initial activity as part of a joint DOE and International Atomic Energy Agency project to improve training capabilities at Ignalina NPP. Participants continued to learn about such training topics as task analysis, course design, course development, instructor skills, and test development. Also, during the workshop, the participants will begin the development of materials for the control room reactor operator training course. The materials will be completed during three additional working visits to Ignalina NPP, culminating in a pilot program presentation. (Peter Kohut, BNL, 516-344-4982)

Structural Analysis Workshop Held for Lithuanian Energy Institute.
ANL hosted a workshop from April 27 to May 2 to provide training on the use of ANL's NEPTUNE and TEMP-STRESS structural analysis codes. Two representatives from the Lithuanian Energy Institute (LEI) attended the training sessions given by ANL experts. This first workshop introduced LEI staff members to the nonlinear analysis capabilities of the two computer codes. NEPTUNE and TEMP-STRESS will be used by LEI for structural safety assessment of the Ignalina RBMK-1500 accident localization system. The structural safety assessment will assess the current safety level of the accident localization system and identify areas for safety improvements. (Ronald Kulak, ANL, 630-252-4681; Phillip Pfeiffer, ANL, 630-252-4589)

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Simulator Projects Reviewed. Projects aimed at providing full-scope and analytical simulators for Russian and Ukrainian NPPs were reviewed in Moscow during the last week in April. Reviewers included representatives from VNIIAES and Balakovo, Novovoronezh, Bilibino, Kola, and Kalinin NPPs from Russia, and Zaporizhzhya NPP and Energoatom from Ukraine. Staff from GSE Power Systems and U.S. team members also participated. All project activities and the general status of each project were reviewed. The simulator projects are proceeding as scheduled. Selected specific issues will be discussed during the respective country Coordinating Committee meetings. The final acceptance test of the Novovoronezh analytical simulator also was reviewed. It is scheduled to be completed and turned over to the plant for training in early July. (Peter Kohut, 516-344-4982)

Thermo-Mechanical Training Loop Operational at Smolensk Training Center. The U.S. team has provided a thermo-mechanical loop to the Smolensk Training Center. The loop is a matrix of piping, valves, pumps, heat exchangers, and controllers coupled together to allow the transport, heating, cooling, and pressurization of an internal working fluid. The loop design is intended to provide hands-on training to several different disciplines of maintenance craft personnel (e.g., mechanics, pipefitters, electricians, instrument mechanics, welders, millwrights, and radiation technicians). The thermo-mechanical loop provides training on the following: pump/motor alignment, vibration signature technology training, anomaly detection using an infrared camera, valve packing replacement, leak repair, heat exchanger tube ultrasonic testing, control loop calibration, and transmitter calibration.

This type of trainer, which is used widely in U.S. NPPs, allows many scenarios to be simulated involving the integration of many crafts to correct a given situation. For instance, a control valve replacement may require the coordination of welders, pipefitters, instrument technicians, operations, and health physics personnel. In this manner, the loop provides a training setting on plant-like equipment in a controlled environment without the operational and radiological hazards associated with similar activities in the real plant. The loop for craft personnel is analogous to the control room simulator for operators. Final acceptance testing of the loop was conducted at the Smolensk Training Center at the end of May. (Grigory Trosman, DOE, 301-903-3581; Ray Pugh, PNNL, 509-372-4103; Thomas Vehec, PNNL, 509-372-4072)

Data Collection/Analysis Training Conducted for Reliability Database Project. On May 4 through 8, Kyiv State University hosted a meeting on probabilistic safety assessment topics related to component reliability data collection and analysis. The most recent Western experience and the new Leningrad NPP data collection procedures also were presented. In attendance were representatives from Energoatom, VNIIAES, six Ukrainian NPPs, six Russian NPPs, and contractors from Information and Technology (INIT) and NOVATOR. Participants signed a protocol proposing the formation of a working group on data collection. The proposal states that the working group should consist of representatives from the utilities, contractors, and the NPPs, and the group should meet on a regular basis to ensure that consistent data collection methodologies are being implemented from plant to plant. (Grigory Trosman, DOE, 301-903-3581; Thomas Vehec, PNNL, 509-372-4072)

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• "*" indicates the event is a new item or has been changed from the last report.
• "TBD" means the event date or location is to be determined.