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Netherlands: serious failure in Petten HFR

Nuclear Monitor Issue: 

(October 4, 2002) A Dutch TV documentary on the High Flux Reactor (HFR) in Petten, owned by the European Commission's Joint Research Center, revealed a serious failure within the cooling system.

(574.5443) Laka Foundation - At the beginning of this year the 45MW research reactor was closed temporarily for safety inspections, because of little cracks in the reactor vessel (see WISE/NIRS Nuclear Monitor 563.5377, "Petten HFR to be closed temporarily"). This safety problem was highlighted by whistleblower Paul Schaap, an operator at the HFR.

As a consequence of this, researchers from the TV program KRO Reporter examined the safety measurements and revealed an undisclosed file, the so-called "Veldman scenario". Paul Schaap didn't name this scenario earlier this year and doesn't want to talk about it, because of his ongoing lawsuit against his dismissal.

The "Veldman scenario" is a discovery made in 1985 by operator Theo Veldman who was working at the HFR from 1964 until 1995. He revealed a serious failure inside the cooling system: in the case of a crack at the lowest spot the water will discharge very quickly, causing a meltdown.


A Dutch Court on Administrative Law ruled on 25 September that the Borssele nuclear reactor does not have to close as of 31 December 2003. The Dutch government had started the court case as it claimed that it had reached agreement in 1994 with owner EPZ to close the plant by that date (see WISE News Communique 551.5190: "Netherlands: court case on closure date Borssele NPP"). The judge recognized that a deal was made but that it had not been laid down in a legal contract. So, Borssele can stay open after 2003. In reaction to the judgement, anti-nuclear activists in Groningen occupied for a short time Essent's office in Groningen (Essent is presently owner of Borssele).
WISE has intensified its campaign against Essent and has sought close cooperation with green electricity supplier Echte Energie. Both will organize a "national switch-over day" on 22 November. On that day, customers of Essent will change to supplier Echte Energie in protest against Essent's nuclear activities. , 25 September 2002; WISE Nieuwsbrief Atoomstroom, September 2002

A retired co-worker remembers that the response of the board was laconic and dismissive. Until 26 November 1987 all co-workers of the HFR kept silent about the Veldman scenario. This changed when an explosion took place during the night of 26 / 27 November: a capsule exploded very close to the reactor vessel. Former co-worker F. Besanger, currently living in Australia, says he was indignant and angry that the reactor was already restarted just after 11 minutes: "a highly irresponsible decision. Everything had to be inspected first." While everybody was shocked about the explosion, the board members remained laconic. After four days the European Commission, the owner of the HFR, was informed and a majority of the Commission voted to keep the reactor open. Independent nuclear physicist Cees Andriesse called this highly irresponsible. According to him the costs of improving the system are relatively low.

Afterwards it appeared that the explosion was not mentioned to the Dutch Nuclear Physics Authority (KFD), because of fears that the license could be withdrawn. The KFD confirmed in writing that they weren't informed. According to a former operator, the Veldman scenario could turn into reality if the explosion had taken place within the core.

In 1992 a labor dispute arose, because of financial cutbacks. Critical articles on safety appeared in the newspapers. Operator H. Slieker went into a discussion with the then director Mr Van den Kroonenberg. He was shocked about his story of the Veldman scenario and decided to investigate the findings of Veldman. When the internal report appeared on 30 November 1992 it concluded that if the Veldman scenario occurs, the core would be uncovered in only 90 seconds. Right up until today, the design fault has not been repaired, because of the board's opinion that the chance of the Veldman scenario occurring is very small. Paul Schaap regrets that he and his colleague operators didn't stand firm to demand safety inspections after the 1992 internal report.

By fall 1994, things were getting worse after some light earthquakes in the area of Petten, which were apparently caused by natural gas extraction in the area. According to Slieker the cooling system was thrown a few centimeters off its balance. "Already in '86 the KFD reported a subsidence of the ventilation building. This was later followed by a new subsidence of the foundations of the reactor building." Andriesse emphasizes that the possible consequences of the Veldman scenario are much worse than was calculated by Veldman. He says he is quite sure that such a scenario would end in a nuclear explosion, a disaster with the magnitude of the Hiroshima nuclear bomb.

The board of Petten HFR, the Nuclear Research Group (NRG) regrets the negative news coverage. It emphasizes that the safety of the HFR is evaluated constantly and is OK: "This is confirmed by the authorities. The conclusions of recent inspections by the KFD and the IAEA show no safety risks."


  • KRO Reporter, 26 September
  • NRG press release, 25 September 2002

Contact: Laka Foundation, Ketelhuisplein 43, 1054 RD Amsterdam, Netherlands
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