Chernobyl NPP decommissioning assistance project

Background

An explosion hit reactor No. 4 at the ChNPP in Ukraine in April 1986. The explosion destroyed the reactor and spread radioactive material into the surroundings. After the disaster, unit 4 could no longer be used and the entire plant was closed in December 2000. The decommissioning of unit No. 1, 2 and 3 at the plant is now being prepared.

Decommissioning safely the intact three reactors will be a long-term technological and organisational challenge because of the complexity of the plant, the need for transferring knowledge to the next generations, and the contamination. The overall time schedule for the decommissioning indicates that the final shutdown and preservation will take about 10 years from now. Then the safe enclosure is set to take 100 years, followed by the final dismantling taking 8-10 years. The state of the final plant site will be a “grey spot”. That is, when all systems are removed from the buildings, the radioactivity of the constructions is lowered to free-release level.

When planning, training, and performing the dismantling, the need for information about the actual design and the current state of the plant is of highest importance for the staff, the authorities, and the public, in order to perform the work safely, efficiently and with acceptable economically costs. Therefore dismantling a NPP requires highly detailed documentation. Unfortunately a large quantity of the documentation at ChNPP has been lost and must be reconstructed, and if documentation exists it may be contaminated. Another problem is the loss of skills among the personnel, because the equipment has not been used for a long time meaning that the personnel is unfamiliar with it or the experienced staff have left the plant. Careful analysing and planning for the dismantling tasks is important in addition to training the personnel, both theoretical and in practice.

In 2006, the Norwegian authorities decided to fund a project at ChNPP establishing the Chernobyl Decommissioning Visualisation Centre (CDVC) using VR technology in the decommissioning of the three intact units. A first version of CDVC was established in 2007 with visualisation of a 3D virtual environment, features for dismantling procedure development and documentation, in addition to basic features for radiation visualisation. The CDVC as it stands today is a pilot version. The software developed supports the most basic functionality for making dismantling procedures.

Continuation of the project 2008-2010

In April 2008, the Norwegian authorities approved the plan for continuing the Norwegian funded projects increasing safety at nuclear power plants in Russia in the period 2008-2012. The plan states that the decommissioning of ChNPP must be looked at as a unique knowledge base when the Leningrad NPP (LNPP) starts decommissioning planning. Therefore the continuation of the CDVC project is part of the Norwegian plan with close connection to the Norwegian funded project at LNPP.

The Chernobyl Decommissioning Visualisation Centre

When finished the CDVC will enable a group of engineers to test out plans and procedures for various work tasks involved in dismantling a nuclear facility. The VR technology will also be a valuable tool to support the making of the needed documentation and for training the dismantling phase. Intensive training before the real dismantling process may be effective for reducing radiation exposure dose, workload and for enhancing safety. In addition, CDVC will provide the decommissioning project team with an effective medium in presentations to the public as well as for communicating with the management and the licensing authorities.

When planning, training, and performing the decommissioning of a NPP, the need for information about the actual design and the current state of the plant is of highest importance for the staff, the authorities, and the public, in order to perform the work safely, efficiently and with acceptable economically costs. Therefore dismantling a NPP requires highly detailed documentation. Unfortunately a large quantity of the documentation at ChNPP has been lost and must be reconstructed, and if documentation exists it may be contaminated. Another problem is the loss of skills among the personnel, because the equipment has not been used for a long time meaning that the personnel is unfamiliar with it or the experienced staff have left the plant. Careful analysing and planning for the dismantling tasks is important in addition to training the personnel, both theoretical and in practice.

The aim is that the CDVC will be a powerful tool based on Virtual Reality (VR) technology to support planning and training decommissioning procedures in addition to presenting the decommissioning process to the public and authorities. A VR software application for nuclear decommissioning can enable a group of ChNPP specialists to test out plans and procedures for various work tasks involved in dismantling a nuclear facility. VR can also be a valuable tool for making documentation and for train-ing the dismantling phase. Intensive training using VR before the real dismantling process may be an effective way of reducing radiation exposure dose, workload and for enhancing safety.

Overall goals of the project 2008-2010

CDVC should be a tool for ChNPP in optimising the decommissioning plans and in the organisation of the work tasks. This includes the development of dismantling procedures and in radioactive waste management.
CDVC should be a pedagogical means for the ChNPP personnel in training the dismantling procedures. Thereby CDVC should support ChNPP in preserving the decommissioning expertise and knowledge at the plant in a long term perspective.
CDVC should also provide the decommissioning project team with an effective medium in presentations to the public as well as for communicating with the management and the licensing authorities. The overall goals for the project are:

1) To enhance CDVC for better planning and training the safe use of personnel resources when working in a radioactive environment. That is:

• CDVC should be able to visualise the radiation in an area based on measured data and to do occupational dose calculation for estimating the dose to be received by personnel when entering the real area. The visualisation of radiation and the dose calculation may help minimise the personal risks and optimise the usage of personnel.
• CDVC should be usable for training work tasks as part of the dismantling phase. Intensive training before the real dismantling process may be effective for reducing radiation exposure dose, workload and for enhancing safety.
• CDVC should enable ChNPP to make plans and procedures for various work tasks involved in dismantling a nuclear facility. That is, the software application should have functions for dismantling procedure development and documentation creation. It should support the making of the belonging documentation.

2) To transfer knowledge in the area of VR technology from IFE to ChNPP’s specialists through the teamwork between the parties so that after the realisation of the project ChNPP can use CDVC for planning and training new decommissioning scenarios.

3) To have a decommissioning workshop at IFE in Halden. The workshop took place 18-19 August 2009 with the title “Use of Virtual Reality (VR) in decommissioning planning and training”. More than 40 delegates participted coming from Leningrad NPP, Chernobyl NPP, Smolensk NPP, Kursk NPP, Kola NPP, the Norwegian Radiation Protection Authorities, the NMFA and IFE.

The status of the project as for April 2011 is that IFE and ChNPP are preparing the purchasing of hardware (PCs etc.) for ChNPP. When the equipment is in place at ChNPP the software will be installed and ChNPP will start using the CDVC.