The CERTA (Centre for Emergency Response, Training and Analysis) is the working premise of the groups of the HAEA Emergency Response Organization (HAEA ERO). The CERTA is activated only in the case of nuclear or radiological emergencies or exercises and serves exclusively for emergency response. The centre is equipped with the software and hardware tools necessary to perform the emergency related tasks of the HAEA in the case of nuclear or radiological accident situations. The structure and operation of the HAEA ERO is governed by regularly updated documents, which are dealt within the quality management system of HAEA. The nuclear and radiological experts can use various computer codes in their analysis job.
In addition, databases (EPRIMS – Emergency Preparedness and Response Information Management System, TroubleBase -database of pre-calculated accidents and transients, set of plant schemes) and results of pre-calculated severe accident analyses are also available.
The centre is equipped with advanced IT and communication systems.
The radiological and nuclear experts of the HAEA ERO are supported by a number of analysis tools. These software tools include the plant Safety Parameter Display System, the CERTA VITA and the source term estimator InterRAS. Further quick analysis systems are the AMARView as the displayer of radiation data monitoring network and the environmental simulator program SINAC that estimates the potential radiological consequences.
Diagnosis of nuclear conditions
The CERTA VITA (developed by the HAS Centre for Energy Research – HAS CER) maintains an online data link with the units, and collects and displays 500-600 selected parameters from each of the four units of Paks NPP and optionally from the full-scope simulator (that runs the accident scenarios during exercises) with a ten second update frequency. There are four different screens of CERTA VITA to display the measured and derived data. Safety parameter display presents the most important safety related parameters of the units. Trend views are used to display any of the parameters selected by the user. The p-T (pressure-temperature) diagram displays the evolution of the cold leg and hot leg operating-points of the primary circuit. The data can also be visualized in more than 30 plant schemes.
In addition to online data, the Nuclear Group also receives the written status reports of the plant, and maintains the connection via phone with a resident inspector delegated to the Protected Emergency Command Centre of the plant to clarify any potential issues.
The source term contains the following information in the case of an accident entailing radioactive release to the environment:
The source term must be determined in an isotope-specific manner to run the environmental simulator. However, summing up of the isotopes into major isotope groups makes the interpretation of the results easier. A so-called Methodological Procedure supports the Nuclear Group, which contains pre-assessed accident situations. Based on this procedure the Nuclear Group is able to provide an estimation of the source term even if only very limited information is available about the plant state. The Nuclear Group assesses the radiological source term by the InterRAS software developed by the US NRC and adapted by the International Atomic Energy Agency. An advantage of the InterRAS is the very fast running time based on pre-calculated accident phenomena. Consequently, it is to be used during the early phase of the accident. Nevertheless, it has a significant limitation, i.e. it is not able to assess the time available before a significant release. The InterRAS provides the detailed source term, which can serve as input for the SINAC environmental simulator. Additionally, the program is able to estimate the environmental doses.
Evaluation of radiological conditions
During its work, the Radiological Group can rely on the second generation of the SINAC software developed by the HAS CER to estimate the environmental consequences. The input for the SINAC consists of the source term determined by the Nuclear Group and the 36 hours weather forecast provided by the National Meteorology Service.
The dose-rate values measured by the approximately 130 monitoring stations of the national network can be displayed by the AMARView software. The radiation values required for the evaluation is being served by the nuclear emergency centre (NBIÉK) of the MoI National Directorate General for Disaster Management on a continuous basis.
The source term data is also sent to the NBIÉK, where the Java-based RODOS (JRODOS) developed in the frame of an international cooperation is used for calculation of environmental dispersion. In order to provide a higher degree of reliability the Expert Panel of the KKB NVM compares the results of the RODOS with those of the SINAC, and develops recommendations on the necessary protective actions for the public based on their conclusions.
Besides the simulation of environmental dispersion of radioactive materials, it is also important, after a release, to estimate the dose of the public due to the amount of radioactive materials accumulating in the food-chain. For this purpose the predecessor of the National Public Health Centre, the National Institute for Radiobiology and Radiohygiene (OSSKI) developed the WRadFood code which is used in the CERTA.
Communication tools, energy supply
Modern informatics tools at the disposal of each expert in the CERTA. During its operation, the documenting tasks of the CERTA are managed by a IBM Notes based application adapted for the needs of the HAEA ERO. This system directs the management of incoming and outgoing faxes, docketing and the email traffic within the HAEA ERO and in connection with other organizations playing role in emergency response.
A high performance Xerox machine located in the CERTA can carry out the copying jobs, while three network printers are available for printing. All compartment of the centre is air-conditioned, equipped with smoke detectors and motion sensors, the signals of which go to the security service of the building. Uninterrupted power supplies serve for the case of loss of off-site power, while longer power outages can be managed by the diesel generators installed on the parking level of the building.
The CERTA and its training centre also serve for exercise activities. Initial, refreshing and further training of the HAEA employees take place here. The HAEA ERO staff regularly takes part in exercises at various level. There are three types of exercises: alerting exercise, when the activation capability and tasks to be performed subsequent to the activation of the staff are tested; thematic exercise, when only a selected group performs its emergency tasks based on a pre-prepared accident scenario; full-scope exercises, when every role of the HAEA ERO is involved and all tasks are exercised.
The annual training and exercise plan usually schedules three to five alerting drills initiated by the Emergency Inspector on Duty involving the entire staff. During some of the alerting drills only the vigilance of the ERO staff is surveyed, in this case the time necessary to reach the CERTA should be estimated by the staff members; in other cases it is required to come to the centre.
During the thematic exercises the pre-selected portion of the staff of the organization practices the tasks outline in the ERO procedures. In full scope national exercises the MVM Paks NPP emergency response organization also plays together with the HAEA ERO organization. The tasks and circumstances during the full scope national exercises are approached as far as possible to a potential real situation. The accident scenario runs in the Paks NPP simulator, whilst the CERTA VITA system displays the data in the CERTA. During such exercises the HAEA ERO has to prepare all the analyses and reports as required in a real situation.