Sum-up bulletin for the Press on the event occurred at Paks Nuclear Power Plant

1. What did happen?
The presence of radioactive gas was detected by the monitoring systems of the reactor hall of Unit 2 at night-time from Thursday 10 April 2003 to Friday, the origin of which was a cleaning tank. This tank had been temporarily installed in the reactor hall for a few week period, for the cleaning of fuel assemblies in a chemical way. An amount of gas exceeding the normal operational values was discharged into the environment. Apart from the first minutes of the event, the highly sensitive monitoring systems around the power plant have not detected any change in the radiation conditions, which means that there was no detectable variation against the natural background radiation. There has been no danger and no requirement for adopting special emergency procedures in the neighbouring regions around the power plant.
The professionals started disassembling the cleaning tank installed at a depth of 8 m under water of several hundred cubic meter. After the removal of the tank lid, the 30 fuel assemblies in the tank were inspected with the use of an underwater camera and it was stated that they have mechanically damaged and distorted. According to preliminary expert opinions, insufficient cooling of the fuel assemblies within the tank was responsible for the damage, as a consequence of which the fuel assemblies overheated.
The maintenance work of the Unit was terminated. Additional cooling circuits were installed to the tank and new monitoring systems were commissioned to ensure the continuous inspection of the actual conditions. The situation evolved as a consequence of the incident has stabilised and have been firmly controlled. In the middle of the last week the environmental discharge rate dropped back to below the limit, to about the normal operational level. On 16 April, radiation measurements were performed by the representatives of GLOBAL 2000 environmental organisation from Austria, who published even on the same day that the measurement results communicated by the power plant were correct and the environmental conditions were actually corresponding to the normal background radiation values.
The event investigation team commenced its work immediately after the occurrence of the event, and has been analysing the occurrences and their possible reasons, from the design up to the compliance with the operational instructions. The resulting investigation report has to be submitted by 10 May 2003 at latest to the Hungarian Atomic Energy Agency (HAEA), the country’s nuclear regulator.

2. What did not happen?
Many kinds unfounded news bulletins have been issued in relation to the incident in addition to the official information provided by the power plant and the regulatory body. The itemised disclaimer to these rumours are as follows:
- The incident did not occur in the equipment, process systems or the reactor of Unit 2. The items of equipment of the Unit have been intact and ready for operation.
- No nuclear event has happened. The structural damage of the fuel assemblies was due to cooling problems.
- No accident occurred in the power plant. The event was not endangering the environment.
- None of the employees has received any radiation dose exposure higher than the allowable limit. No one had to be homed with reference to such reason.
- The radiation dose exposure received by one of our crane operators was amounting to some 10% of the annual dose limit. A part of his hairs had to be cut because of surface contamination presumably due to incorrect use of his personal protection devices. The worker concerned is working even today as normal. No hospitalisation was required.
- The employees of the power plant have not received any extra payment for their daily work. The majority of them have been working here for several years. They are well qualified and well aware of their duties and responsibilities.

3. Classification to the International Nuclear Event Scale (INES)
On the day of the occurrence, the event was classified, according to the relevant international requirements, to Grade 2 on the event scale used for information of the public, and this rating was approved by the Hungarian Atomic Energy Agency. After opening and visual inspection of the tank inside, the event was re-classified by the power plant to Grade 3 due to the damage of large number of fuel assemblies, and this rating was approved again by the above-mentioned regulatory body. The reason for the re-classification was not a worsening of the situation but the recognition of facts, which became known only after opening the tank lid. The classification to Grade 3 was finally accepted and recorded by the International Atomic Energy Agency. Grade 3 event had not occurred before in Paks Nuclear Power Plant since the introduction of INES in 1992.

4. What can be expected
The continuous cooling and monitoring of the cleaning tank and its neighbouring environment is ensured. A plastic foil ‘greenhouse’ has been built above the pond accommodating the cleaning tank. The air space within the ‘greenhouse’ is subject to continuous analysis and purification. A number of some 40 to 80 people per day perform work in the reactor hall. Depending on their workplace within the hall, most of them are supposed to wear personal protective devices and their working period is limited.
Professional teams involving various trades (reactor physics, hydrodynamics, technical logistics) have been set up for elaborating alternatives for the resolution of the problem. They will choose the safest possible solution. Their work is supported by competent specialists of Hungarian universities and research institutes and German engineers as well. The representatives of the Russian fuel manufacturer has also arrived at Paks this week. The final solution, i.e. the removal of the damaged fuel assemblies, the provision for long term cooling, and the decision on storage will be the outcome of a wide ranging working process. Forecasting the date of the completion of this work would be inappropriate in this phase of the process.

5. Financial losses
The completion of the maintenance work at Unit 2 was planned to 6 May. Every additional day of outage will involve a financial loss of some HUF 50 million. The costs for the liquidation of consequences will also involve an expenditure in addition to this loss of production. Again, the cleaned and damaged 30 fuel assemblies, that can anyway no longer be used, represent a significant value.
Both the cleaning method and the items of equipment required for the implementation were supplied and operated by Framatome ANP, a French–German company. This work had been approved by the regulatory body (HAEA). The contract for the cleaning work was granted within an international tender to the above mentioned company who had performed the cleaning of several hundred fuel assemblies during the past years at Paks with he use of a similar equipment. The above mentioned contract includes a Clause to provide for compensation for damages, which may potentially be enforced only after the completion of the investigation and the confirmation of liabilities.

6. Communication to the Public
The incident occurred at dawn of 11 April was quickly communicated to the public, first of all with the effective co-operation of the press, as soon as the first correct information became available. Special emphasis was laid on the communication to the population of Paks and the regions around the power plant, where all locally available channels have been used for the purpose of communication. The mayors of settlements within a 30 km range of the power plant, were informed via a special SMS system provided for his purpose, to allow them to satisfactorily answer the questions arisen in their respective settlements. Upon availability of new details, countrywide bulletins were issued. According to analyses, the number of press appearances was more than 600 during the period since the time of the occurrence. A great majority of them provided an objective and correct communication to the readers, listeners and viewers. The power plant answers to every enquiry and accepts all interview invitations of the press.
A press conference was held in the reactor hall of Unit 2 on 22 April, and Dr. Béla Túri-Kovács, the Chairman of the Environmental Committee of the Parliament was received on 27 April by the Chief Executive of Paks Nuclear Power Plant Ltd. On the following day, the parliamentary representatives of the region around the power plant, and the members of the FIDESZ parliamentary fraction accepted the invitation for an information meeting. On the same day, the Chief Executive met the mayors of the 13 neighbouring settlements and the representatives of civilian organisation, which was followed by a visit to the reactor hall.
The managers of the company also visited to public hearings of settlements and meetings of local councils and small-region associations.

Paks, 28 April 2003
Balázs Kováts
Head of the Information and Visitor’s Centre


Cleanup work, directed at the recovery of normal operating conditions, has commenced in the twin reactor hall of Paks NPP Unit 1 being under operation and Unit 2 shutdown for annual maintenance. The stainless steel floor, the wall and ceiling surfaces covered by special coating and the different auxiliary equipment are flushed with water and chemicals. The reactor hall cleanup is scheduled to be completed by the middle of the next week. Simultaneously the shaft No. 1 containing the cleaning tank with damaged fuel assemblies is being separated from the Unit 2 process equipment fully intact and ready for operation.

Highly experienced Russian experts selected from the engineers of fuel assembly manufacturer are going to arrive in Hungary on Sunday, 27th April.

Paks, 26th April 2003
Balázs Kováts
Head of the Information and Visitor’s Centre


Sunday morning dr. Béla Turi-Kovács, the chairman of National Assembly Environmental Protection Committee paid a short visit to the Paks Nuclear Power Plant. He met with the plant management and made a site tour to the Unit 2 reactor hall.

The first draft of the Incident Review Commission report has been developed. Additional information acquiring and analysis are going on with the involvement of research institutes. The final investigation report shall be submitted to Hungarian Atomic Energy Authority by 10th May 2003. A simultaneous regulatory investigation is carried on by HAEA. The emergency issues are also being dealt with the French-German FRAMATOME ANP who manufactured, delivered, installed and operated at Paks site the cleaning equipment.

Paks, 27th April 2003
Balázs Kováts
Head of the Information and Visitor’s Centre


Today a mission was started by a six specialist task force the members of which represent the Russian fuel assembly manufacturer and the Kurchatov Institute. The fuel assemblies used at Paks NPP are manufactured in Russia, the nuclear power plants of former Eastern European countries and Finnland cover their need of fresh fuel supply from there. Several hundreds of thousand fuel assemblies have been manufactured in this fuel manufacturing workshop during the past decades gaining huge experience by this. The Kurchatov Institute is a citadel of Russian nuclear energy research an development. The specialists upon their arrival at Paks site got acquainted with the situation in hand, reviewed the related documents and made consultations with their Hungarian and German colleagues.

The mayors of neighbouring 13 settlements paid a visit to the power plant in Monday afternoon, in the company of regional civil organizations’ representatives. Latest information on the incident was briefed by the chief executive officer of the Paks NPP. The visitors were briefed on the inspection role of nuclear regulator by the deputy director general of Hungarian Atomic Energy Authority. Following this the delegation made a site tour to the Unit 2 reactor hall.

The classification of Paks NPP incident into class 3 by INES scale has been acknowledged, accepted and registered in the database of International Atomic Energy Agency seated in Vienna.

Paks, 28th April 2003
Balázs Kováts
Head of the Information and Visitor’s Centre