WRITTEN QUESTION E-0456/02

by Erik Meijer (GUE/NGL) to the Commission

(22 February 2002)

Subject: Temporary shutdown of the High Flux Reactor in Petten, the Netherlands, on account of safety problems and damage to the reactor wall

1. Was the Commission aware before 4 February 2002 that the following problems existed with the 45 megawatt High Flux Reactor (HFR) of the European Community's Joint Research Centre near the village of Petten in the Netherlands, where:

(a) a hairline crack in the reactor wall caused by a welding error in 1984 is continuing to grow;

(b) the reactor vessel was not designed to withstand strong explosions, yet after an explosion followed by a pressure wave had occurred in 1987, the reactor was immediately restarted without a thorough inspection;

(c) in April 2001, due to an oversight, the irradiation of highly enriched fuel elements for the production of isotopes was started without any coolant;

(d) written operating rules have been overridden where duty managers have seen fit;

(e) while working at night, staff were forced to sign a declaration of loyalty, forbidding them to disclose facts;

(f) instructions from the Nuclear Energy Service were not carried out;

(g) until 4 February, there was a risk that planned inspections by the Nuclear Energy Service would be postponed until a planned close-down in the summer of 2002; and

(h) there are general serious criticisms about attitudes to safety?

2. Why did the Commission only this week decide to endorse the wish of the Netherlands Government to close down the Petten reactor, although serious problems as referred to in question 1 had already existed for some time?

3. What is to be investigated while the reactor is closed down? What possible solutions will the investigations be concerned with? Are the results of the investigations to be published, and will Members of the European Parliament at least be informed of them?

Answer given by Mr Busquin on behalf of the Commission

(30 April 2002)

1. (a) The welding anomaly was detected in 1984 during a pre-service inspection. The Dutch licensing authority (Kernfysische Dienst, (KFD))

agreed to put the vessel in operation on condition that the vessel was inspected every three years. During the periodic inspections, which were made before 2001, no changes in the welding anomaly were measured. The last periodic inspection took place in the summer of 2001. That inspection which was done with different (ultrasonic) techniques gave different results from the earlier inspections, which might have suggested that the welding anomaly had grown. It was agreed between KFD and Joint Research Center (JRC) that during the stop of the reactor that took place on 18 February 2002, a new inspection of the welding anomaly would be performed. The results of this inspection showed that the welding anomaly had not grown in size since the summer of 2001. SERCO Assurance, a company specialised in structural assessment, indicated in its report assessing the inspection results that application of more conventional sizing methods to inspection data generated throughout plant life showed little or no variation in the measured size.

(b) No explosion ever occurred in the vessel itself. The question probably refers to a capsule loaded with Tellurium oxide (used for the fabrication of Iodine-131, an isotope of iodine used in medicine) which exploded on 28 November 1987 as a result of an unexpected reaction. By construction, the HFR reactor vessel is immersed in a water pool. The upper surface of the water pool is open to the air, inside the containment building. In this pool, next to the reactor vessel, is the so-called pool-side facility, which is used as a supporting device for experiments. The irradiation of this capsule took place in the pool-side facility and not in the reactor vessel itself. After the explosion in the pool-side facility the reactor was immediately shut down. An inspection was performed and the only damage that was observed was on the tellurium oxide capsule and capsule holders in the pool-side facility and no damage on the reactor itself. The subsequent decision to re-start the reactor was based upon the fact that all systems to shut down the reactor had worked properly, the origin of the explosion was clearly the tellurium oxide capsule located in the pool-side facility and not an experiment in the reactor core. In the two weeks following the incident it was discussed thoroughly by the reactor safety committee. In 1988 an inspection of the reactor vessel was performed and no problem was detected. Furthermore, it was decided not to irradiate tellurium oxide in the future and to introduce acceptance procedures for irradiation of isotopes. As a result, the reporting criteria to KFD were strengthened.

(c) Isotopes are not produced from Highly Enriched Uranium (HEU) fuel elements, but by irradiation of targets made with HEU and inserted in capsules. On 30 March 2001 during handling, a capsule loaded with highly enriched uranium pellets for isotope production was inadvertently considered to be empty (hence, cooled less than normally foreseen for a loaded capsule) and an empty capsule was inadvertently considered to be loaded (hence, cooled more than normally foreseen for an empty capsule). During the check procedures before irradiation, this situation was detected and corrected. Therefore, no irradiation occurred without proper cooling. An analysis was made in order to investigate what would have happened in case the check had failed. The result of the investigation was that in the worst case safety systems would have been activated, including if necessary shutdown of the reactor or isolation of the reactor containment building.

(d) The operating instructions have been followed by the operator of the reactor Nuclear Research and Consultancy Group (NRG) as confirmed also by a KFD inspection. These operating instructions provided in some instances the possibility for the operator of the reactor to deviate from them and this according to well-described procedures. In order to remove any ambiguity, it has been agreed between KFD and JRC in February 2002 to remove this possibility for the operator of the reactor to deviate from the operating instructions.

(e) On 25 October 2001 there were reports in the local press that safety rules had been breached by NRG at the HFR. JRC Petten, as licence holder, immediately contacted the management of the NRG, the operator of the reactor, to ask for explanations. The management of NRG reacted by presenting a declaration signed by nine out of the ten Heads and Deputy Heads of the operator's shifts. This declaration stated that they had respected the rules and procedures in force and had reported all deviations and incidents according to those rules and would continue to do so in the future. The Head and Deputy Head of the evening and night shift on duty signed this declaration during the night of 24 to 25 October 2001. The other Heads and Deputy Heads (except one who was on holidays) signed the declaration during the morning of 25 October 2001.

The NRG operator claims that the involved staff were not forced to sign this declaration, but the JRC, together with the KFD, is of the opinion that the fact that some of the operators were asked to sign the declaration during the night could be considered as putting pressure on them.

As a result, JRC Petten also immediately contacted the KFD, who performed inspections on these matters on 31 October 2001, 6 November 2001 and 12 November 2001. The Dutch authorities came to the conclusion that there were no indications that the NRG operators of the HFR had been obliged by the NRG management to not mention incidents in the HFR logbook.

Finally, the Commission requested, jointly with the KFD, the International Atomic Energy Agency (IAEA) to review the safety culture of the operator (see question h).

(f) JRC as license holder is not aware of any instances where instructions from KFD have been contravened.

(g) Immediately after the in-service inspection of the summer of 2001 it was agreed between KFD and JRC that the next in-service inspection of the welding anomaly indication would take place in the summer of 2002 and not after three years as is done normally. At the beginning of February 2002 it was agreed between KFD and JRC to advance the in-service inspection to 21 and 22 February 2002.

(h) There have indeed been criticisms with respect to the safety culture regarding the operation of the HFR. The JRC has therefore asked the IAEA to review this very issue, which took place from 3 to 8 March 2002 (a preparatory meeting to the audit took place on 13 and 14 February 2002).

On Friday 8 March 2002, the IAEA presented the principal findings and recommendations to the licence holder (JRC) and KFD. Several elements of the safety management system were highlighted for corrective actions. These actions include improved and more frequent training of personnel, improved communication channels, a tightening of the monitoring and review procedures, and an in depth review of the licence. These are to be implemented by the operator (NRG), in some cases together with JRC. A proposal for the implementation of the above recommendations has now been approved by the KFD. The JRC will monitor closely the progress of implementation by NRG in order to ensure the continued safe operation of the reactor.

2. On receipt of a letter from a parent company of the operator NRG, raising some concerns, the Commission reacted immediately in calling for an inspection of the HFR by the KFD. Subsequently, the Commission announced its intention to shut down the reactor on 8 February 2002. Following contacts with the Dutch Authorities, all parties agreed that the shut down would be postponed until 18 February 2002.

The issues mentioned under question 1 were reported to the KFD according to the reporting procedures in force and the KFD has performed several inspections on them. In the second half of 2001, JRC Petten also launched two audits on the quality management system of the operator of the reactor and specific safety culture issues. The Commission nevertheless decided to take advantage of a routine shut down of the reactor to carry out a safety audit and a re-measurement of the weld anomaly.

3. During the period of shutdown the following happened:

- a renewed inspection of the welding anomaly (see also question 1.a);

- a review of the safety and the safety culture of the HFR operation by the IAEA;

- an independent assessment of the consequences of the welding anomaly indication on the life time of the HFR reactor vessel by Serco Assurance.

As discussed in detail under question 1, KFD and JRC have studied carefully the conclusions and recommendations of the IAEA review regarding the safety culture, and of the Serco Assurance assessment regarding the life time assessment. All actions required to be done before the start-up were judged to be satisfactory by KFD. In agreement with KFD, JRC has given its consent to the restart of the HFR on 22 March 2002 in line with the normal schedule. The JRC will monitor closely the progress of implementation of all necessary actions in order to ensure the continued safe operation of the reactor. Both Serco Assurance and IAEA reports are available on the web pages of the JRC at the following addresses: http://www.jrc.org/download/press/releases/Serco_reports.pdf and http://www.jrc.org/download/press/releases/iaea.pdf.