April 2000 Highlights

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Ukraine United States Cross-Cutting Activities Planned Activities

Ukraine

Events database installed for testing on Zaporizhzhya computers

Ukrainian software technicians worked with computer specialists from Zaporizhzhya NPP to conduct a test installation of a specialized database at the plant in mid-April. The database is designed to hold information related to event analysis, reporting, and lessons learned (EARLL). As the pilot plant in Ukraine for database implementation, Zaporizhzhya eventually will install and use the database on its plant computer system.

The test installation, using a limited number of plant computers, enabled specialists to test the hardware, hardware interfaces, and software for collecting, analyzing, and reporting data on operating events at Zaporizhzhya. Based on the testing, specialists identified items needing resolution before the database is implemented fully at the plant.

Participants in the testing included the project manager and software technicians from Novator-Kiev (Ukrainian subcontractor), the Zaporizhzhya manager for event analysis, and computer technicians on the Zaporizhzhya NPP staff. Novator-Kiev technicians brought the database files and conducted the testing of the database on the Zaporizhzhya computers. The Zaporizhzhya staff coordinated installation, conducted testing, provided comments, and identified issues needing Novator's further resolution before finalizing the database for implementation.

Implementation of the EARLL database at Zaporizhzhya NPP will facilitate the plant's analysis and reporting of operational events at the site. After a pilot implementation period at Zaporizhzhya, U.S. and Ukrainian specialists likely will collaborate to install future versions of the database at the other nuclear power plant sites in Ukraine. (Dennis Meyers, DOE, 301-903-1418; Lief Erickson, PNNL, 509-372-4097)

Zaporizhzhya hosts training course on validating simulators

During the week of April 3, Zaporizhzhya NPP hosted a training course on verification and validation of full-scope and analytical simulators. Course presenters included technical specialists from General Energy Technologies, VNIIAES, Energoatom, Balakovo and Zaporizhzhya NPPs, and Brookhaven National Laboratory. The course was provided specifically for staff of South Ukraine, Rivne, and Zaporizhzhya NPPs who will participate in validation testing of the simulators at their respective plants.

The Brookhaven and General Energy Technologies representatives described experience with verification and validation in the U.S. nuclear industry. Related topics covered the relationship between the nuclear utility and the U.S. Nuclear Regulatory Commission, as well as regulatory requirements for both initial and periodic recertification. The group also reviewed and discussed nuclear standards related to simulator verification and validation, training programs, operator licensing, and software and hardware standards.

Ukrainian practices were reviewed and technical discussions were held regarding steps in the acceptance test program. Typical examples were presented in comparing simulator results to plant data and/or analytical calculations. Zaporizhzhya NPP staff demonstrated various transient scenarios on the full-scope simulator. A specific scenario was analyzed step-by-step with regard to plant response and how comparison and checks were made. (John Yoder, DOE, 301-903-5650; Joe Cleary, PNNL, 509-372-4079; Peter Kohut, BNL, 631-344-4982)

International Radioecology Laboratory opens in Slavutych

The official opening of the International Radioecology Laboratory (IRL) took place in Slavutych, Ukraine on March 23. The IRL was created to facilitate and expand international research on the environmental effects of the 1986 Chornobyl disaster.

Senior-level officials from the Ukrainian and U.S governments and scientific institutions attended the event, as did representatives from the international community. Representatives of Energoatom, Ukrainian National Academy of Sciences, Ukrainian State Nuclear Regulatory Administration, University of Georgia, Savannah River Ecology Laboratory, Pacific Northwest National Laboratory, U.S. Environmental Protection Agency, U.S. Peace Corps, the U.S. Department of Energy, and the Franco-German consortium RiskAudit were present. Participants were given detailed tours of the IRL facility and shown its equipment and capabilities.

Financial support for development of the IRL comes from the office of the U.S. Department of Energy's Deputy Assistant Secretary for Environmental Management. (Riaz Awan, DOE, 38-050-257-7221; Michele Dash, PNNL, 202-586-3550)

International Chornobyl Center convenes Council of Members in Slavutych

On March 30, the International Chornobyl Center convened its Council of Members (COM) meeting in Slavutych. The COM is an international advisory body to the Center on organizational and project development issues and meets on a periodic basis. Representatives from the U.S. Department of Energy, U.S. Department of State, U.S. Embassy in Kyiv, United Kingdom Department of Trade and Industry, the Franco-German consortium RiskAudit, the German government, and the Chornobyl Center were in attendance. Participants discussed the Center's current and future projects, its financial budgets, its organizational development, and planning for the Center's upcoming annual conference. The U.K. representative signaled that its scientists are interested in research activities through the Center's International Radioecology Laboratory. (Riaz Awan, DOE, 38-050-257-7221; Michele Dash, PNNL, 202-586-3550)

Progress reviewed for Zaporizhzhya safe-shutdown analysis

Engineering Planning and Management Inc. (EPM) hosted a progress meeting for participants in the safe-shutdown analysis under way at Zaporizhzhya NPP. Analysts from Kyiv Energoprojekt met with technical specialists from EPM and Brookhaven and Pacific Northwest national laboratories at EPM offices in Framingham, Massachusetts, for the four-day review in April.

Participating in the Zaporizhzhya safe-shutdown analysis review were (left to right) Ali Azarm, Brookhaven National Laboratory; Andy Minister, Pacific Northwest National Laboratory; Vadym Buyalsky, Energoprojekt; Rich Denning, Pacific Northwest National Laboratory; Victor Shenderovych, Energoprojekt; Alexander Myakinkykh, Energoprojekt; George Krasnyanskyy, Energoprojekt; and Bob Kalantari, Engineering Planning and Management.

Participants held detailed discussions on two reports documenting specific tasks completed by Energoprojekt specialists as part of the safe-shutdown analysis:

• The List of the Equipment Required for the Safe Reactor Shut down in Case of Fire Including Associated Circuits and Their Equipment
• Fire Protection Means for Rooms with the Equipment and/or Cabling Required for Safe Reactor Shutdown in Case of Fire. Fire Compartments and Fire Cell.

The group reached agreement on revisions needed to clarify important information in each of the reports. Energoprojekt analysts will make the revisions and resubmit the reports. Participants also reviewed a third Energoprojekt task report, The List of the Unit Systems and Their Functions to be Used for SSD in Case of Fire, and agreed no further revisions were needed.

The balance of the meeting focused on plans for future work, including the start of the deterministic and probabilistic analysis tasks. The project team agreed to hold the next project review in Ukraine in fall 2000. (Grigory Trosman, DOE, 301-903-3581; Andrew Minister, PNNL, 509-376-4938)

International team reviews South Ukraine probabilistic risk assessment

Members of an international team conducted an early-April review of the Level 1 probabilistic risk assessment (PRA) for internal initiating events of South Ukraine Unit 1. The review was conducted in Kyiv by an international probabilistic safety assessment review team (IPSART), a service provided by the International Atomic Energy Agency (IAEA).

The review was held at the offices of Energorisk, Ltd., the main technical subcontractor for the South Ukraine in-depth safety assessment project. The IPSART consisted of experts from the IAEA, other Soviet-design reactor and support organizations, and the U.S. Nuclear Regulatory Commission. Members of the U.S. team from SCIENTECH, Inc., and Argonne National Laboratory participated primarily as observers and to provide a programmatic perspective for the work under review.

The IPSART reviewed the final PRA report, significant portions of the supporting documentation, and the project archives. The overall evaluation of the PRA was positive; the reviewers identified the following strong points:

• the extensive use of thermal-hydraulic analysis to support success criteria definition and accident sequence timing
• the project quality assurance program
• plant-specific databases and the efforts to develop a very comprehensive and realistic reliability database.

The IPSART mission turned up several key findings:

• the need for a detailed independent peer review (in process of being implemented)
• the omission of certain accident scenarios, e.g., steam line and feedwater-discharge line breaks outside the containment (will be analyzed as part of internal flooding)
• accounting for some dependencies between human actions (needs to be checked)
• some questions with respect to common-cause failures and the unavailability of systems due to corrective maintenance (mostly to be resolved before issue of final report by IPSART).

The successful IPSART mission represents an important milestone for the in-depth safety assessment projects in Ukraine: it provided the first review by a recognized international body of an important aspect of the overall safety assessment for a reactor unit. (Walter Pasedag, DOE, 302-903-3628; Christian Kot, ANL, 630-252-6151)

Participants review South Ukraine safety assessment project

Status of the South Ukraine in-depth safety assessment project was reviewed on April 15 in Kyiv. Representatives of South Ukraine NPP, Energorisk, SCIENTECH, Inc., and Argonne National Laboratory conducted the review. The group determined that for the first phase of the internal/external hazards assessment, which includes hazards identification and data collection, all tasks are essentially complete. Only the internal flooding report still is under review. Work on the design-basis accident analysis is progressing well and is in accord with the revised schedule developed in December 1999.

Possible and planned future activities, including priorities and potential issues, were discussed. These activities included external hazards, internal hazards, limited beyond-design basis analysis, Level 2 PRA, support for emergency operating instructions, a living PRA, and the implementation of peer review. (Walter Pasedag, DOE, 302-903-3628; Christian Kot, ANL, 630-252-6151)