Balancing the needs

In this situation, where on the one hand HFR could not meet the highest (and usual) safety requirements and, on the other hand, a considerable societal interest was at stake, the decision as to whether or not to allow the HFR to restart and under which conditions had to be taken at the highest political level and not by the nuclear regulatory body.

On 12 February 2009, after comprehensive discussions concerning the balance between nuclear safety and patient care, the government decided to allow temporary operation of the HFR with additional and precautionary safety measures in order to allow the production of medical isotopes. Operation was allowed for a strictly limited period of time, until 1 March 2010. Seven ministers signed the special permission document including the extra requirements, which should be met. Two weeks later an IAEA review mission confirmed KFD’s assessment, supporting the governmental decision.

4. FOLLOW-UP

Following this decision and the restart of the HFR, the reactor has been operating under strict safety precautions and conditions for almost a year.

The HFR operates in cycles: after having operated for four weeks, the reactor is put out of service for a week to allow for change of the targets and inspection. According to the requirements of the special permission, each cycle must be explicitly authorized by KFD. Before each cycle, KFD assesses whether the safety conditions for operating the reactor are fulfilled and the Ministry of Health determines whether, from a medical point of view, the need for the production of medical isotopes at HFR still exists. If, and only if, both the KFD confirms the possibility of safe operation, and the Ministry of Health confirms the necessity of isotope production, KFD authorizes the following cycle at the HFR.

So far, no leakage has been detected. However, in-service inspections show that degradation is progressing unmistakably.

Meanwhile, NRG has been preparing for the repair activities at the beginning of 2010. A mock-up bottom plug liner (Fig. 6) embedded in concrete has been built for testing and practising purposes and documents concerning detailed engineering and (nuclear) safety aspects of the repair plan were finalized by NRG.

FIG. 6. Mock-up of the bottom plug liner in concrete.

By the end of 2009, KFD completed its assessment of all NRG documents.

KFD’s assessment, together with the NRG documents, was reviewed by an IAEA team in the middle of January 2010. The review confirmed KFD’s assessment.

According to the planning, the reactor will be put out of service before 1 March 2010 and repair will take six months. Postponement of the repair in order to continue production of medical isotopes for a longer period is not considered.

5. LESSONS LEARNED

The ageing of the research reactors for production of medical radioisotopes may in the future again lead to situations where there is a need to combine nuclear safety and healthcare. Although the Petten case has not yet come to an end (the repair work has not been done yet), the process so far has provided several useful lessons for nuclear regulation in the Netherlands:

—Decision making procedure and clear role of government and authorities.

In the Petten case, a decision making process was developed for the govern-mental decision, whether to allow the HFR to restart or to prohibit this and to require immediate repair. A decision was made to ensure both nuclear safety and the supply of medical radioisotopes.

The different steps in the process clearly identified and respected the role and responsibilities of the different authorities involved: the responsibility (independence) of the nuclear regulator to assess and to ensure nuclear safety, the responsibility of the medical authorities to ensure medical care and the responsibility of the government as a whole to balance the needs.

—Communication.

From the very beginning it was felt that all steps in this exceptional process should be publicly communicated on governmental websites and in press releases. In the Petten case, the website of the Ministry of Housing Spatial Planning and the Environment (www.vrom.nl) was extensively used. Press releases were announced before and issued after each governmental decision. The Petten population was invited to an information meeting.

The experience from the HFR-case clearly shows that providing the public with clear information enables people to understand what is happening and increases confidence in the authorities. The open communication during the process contributed to a broad acceptance of the governmental decision.

—Transparency.

No international guidelines exist to deal with exceptional situations like this. Also, no definition exists of what, in such circumstances, could be considered ‘safe enough’. However, it is doubtful whether developing inter-national guidelines and definitions to deal with exceptional situations would be of any use at all, since each exceptional situation is unique and needs a unique approach and a unique decision making.

The experience from the HFR case clearly shows that in exceptional situations it is very important to follow two basic (golden) rules:

(1) All considerations, calculations and assessments should be completely transparent and publicly available; and

(2) They should be subjected to reviews of international experts.

—Facts and figures for health care.

While developing the decision making process and preparing the special governmental decision on the restart of the HFR, describing the need for medical radioisotopes in objective facts and figures became vitally important.

It appeared that the existence of objective facts and figures, which are the basis for the assessment of nuclear safety, requires similar objective information for assessing other societal interests to be taken into account.

—Ageing of research reactors.

All over the world, awareness is growing that alternatives have to be developed to fill the gaps in the supply of medical isotopes, especially when the Chalk River and Petten reactors are out of service. In Vienna, in September 2009, both OECD/NEA² and IAEA³ presented many initiatives in this area.

2 DUNN LEE, J.D., NEA Activities on Medical Radioisotope Supply Issues; Panel Briefing and Discussion on Reliability of Supplies of medical Isotopes Produced in Research Reactors — Issues for Regulators; 53rd IAEA General Conference, Vienna (2009).

3 RAMAMOORTHY, N., The IAEA Support to Enhancing Reliability of Mo-99 Production and Supplies; Panel Briefing and Discussion on Reliability of Supplies of medical Isotopes Produced in Research Reactors, Issues for Regulators; 53rd IAEA General Conference, Vienna (2009).

Following an initiative of Poland, discussions have started with NRG and the Dutch regulator on the possible use of the Maria Reactor in Warsaw for the production of medical radioisotopes. Moreover, more countries are willing to modify their research reactor to irradiate uranium targets for molybdenum production. Very recently, the Delft Technical University issued a press release showing their willingness to contribute to the production of medical isotopes.

6. EPILOGUE

The Petten case was discussed in the Dutch Parliament several times. In spite of the critical attitude of the Parliament towards nuclear energy, during these discussions a very broad political support was shown towards the use of nuclear research reactors for medical use. Following these discussions and considering the fragility of the supply of medical radioisotopes and the present role of Petten, the Government sent a letter to the Parliament in October 2009 manifesting its positive attitude and the willingness to favourably consider the NRG initiative to build a new reactor (Pallas) to replace the HFR.

ACKNOWLEDGEMENTS

The authors thank T. Klomberg, Directorate of Environmental Safety &

Risk Management, and M. Vogels and R. Jansen, Kernfysische Dienst, for their fruitful contributions to this paper.