German Nuclear Plant Fire Raises Safety Fears

The Telegraph (UK) ^ | 7-6-2007 | Harry de Quetteville

[blam]

German nuclear plant fire raises safety fears

By Harry de Quetteville in Berlin
Last Updated: 12:01am BST 06/07/2007

A row has erupted in Germany after the extent of an accident at a nuclear power station was allegedly concealed, opening bitter political divisions in Europe's most energy-conscious nation.

Initial news flashes a week ago seemed alarming. An ageing nuclear reactor near the northern German city of Hamburg was on fire. But fears were quickly calmed by reassurances that the blaze was limited to an electricity substation, and had not spread to the reactor.

In fact, the reactor was affected. The fire started when coolant was ignited by a short circuit. Afterwards, investigators found that crucial pumps supplying water to the reactor had failed, while two safety valves had opened unexpectedly, causing pressure to drop fast. Bruno Thomauske, the chief of the energy group Vatenfall, which runs the Kruemmel plant, insisted that safety had been maintained.

"At no point was the public at risk," he said.

But while emergency measures may have prevented any radiation leak, Germans have detected a cover-up and the nuclear industry fears exposure to a public relations disaster. The issue is acutely sensitive in Germany, where all nuclear power stations are due to be phased out by 2020.

That is in distinct contrast to the UK where Labour is a staunch backer of nuclear power and seems certain to commission several new plants to replace ageing facilities.

"The final decision to go nuclear should be made by the end of the year," said Stephen Tarlton, from Nuclear Engineering magazine, "but Labour is strongly in favour."

Among those expected to bid for contracts to build Britain's new generation of nuclear power stations are Germany's E.ON and RWE, the latter of which has a nuclear management subsidiary known, alarmingly, as NUKEM.

It was E.ON however, which was at the heart of a second nuclear scare last week, where a power station suffered an emergency short circuit minutes before the blaze broke out at Kruemmel.

The plant at Brunsbüttel, also in northern Germany, had to be shut down.

While Brunsbüttel has subsequently been reactivated, it remains unclear whether Kruemmel, which was built in 1983 and is one of the oldest of Germany's 17 reactors, will be able to return to service.

[kinoxi]

In fact, the reactor was affected. The fire started when coolant was ignited by a short circuit. Afterwards, investigators found that crucial pumps supplying water to the reactor had failed, while two safety valves had opened unexpectedly, causing pressure to drop fast.

Why does that make me think of Chernobyl?

[Robert A Cook PE]

The (incompetently-written) article implies that the reactor “coolant” was burning (instead of the transformer coolant - which does burn), and that the loss of the reactor coolant pumps was the same accident as the transformer fire.

Linked, but NOT the same system, not same fluid, and not even in the same building! Transformer fires do happen (several every year, in power plants from hydro, coal, gas turbine, and steam turbine. And, every now and then, in a steam turbine nuclear plant.

Losing two reactor coolant pumps after the transformer fire is possible if (when) the main power circuits are de-energized as the transformer is de-denergized. The plant expects this, which is why different reactor coolant pumps are powered from different main power circuits (each has several backups) in different places. A single power loss doesn’t affect all of the pumps.