ENVIRONMENT: Safety Works At Chernobyl-Type Plants ‘Insufficient’

By IPS Correspondents Reprint | | Print |

Senthil Ratnasabapathy

VIENNA, Apr 4 1996 (IPS) - Despite a number of modifications, the safety standards of the so-called Chernobyl type reactors still fail to meet those applied to western nuclear power plants, say experts.

Delegates at the International Forum on One Decade after Chernobyl: Nuclear Safety Aspects, conceded the safety aspects of the 15 reactors of the Chernobyl (RBMK) type have improved over the years, but said there is still to be done.

Adolf Birkhofer, head of the German nuclear safety agency GRS and others at the forum agreed that more safety measures should undertaken at the reactors irrespective of whether the plants are to be shut down or not.

Ukraine is under pressure from the West to close down the Chernobyl plant, scene of the world’s worst nuclear accident in 1986. Kiev demands western compensation for the cost of replacing a plant that it says could have years more safe use left in it.

The forum, which ended Wednesday, was organised by the International Atomic Energy Agency (IAEA) and convened to supply conclusions to a larger international conference to review all aspects of the Chernobyl disaster and its consequences.

It was attended by nuclear officials from countries still running RBMK plants like Lithuania, Russia and Ukraine. Its final conclusions were not released to the public, though closing comments maintained that safety improvements had at last ensured that an accident like the 1986 disaster would not occur again.

Viktor Siderenko, Russian deputy minister for nuclear energy went as far to say: “We now have the right to say such an accident will not happen again.”

A copy of the draft conclusions obtained by IPS said the forum maintained that beyond existing improvements to the RBMK’s core and shut down mechanisms, the three generations of reactor types all need extra strengthening against flood and fire hazards.

However the conclusion were dismissed as inadequate by Helmut Hirsch of the environmental NGO Greenpeace who described all 15 RBMK reactors now in service as “like time-bombs”. Of the fifteen RBMK types still working, eleven are in Russia, two in Lithuania and two at Ukraine’s Chernobyl plant.

Experts consider the Soviet-designed RBMKs and VVER 440-230 types to be the least safe among civilian nuclear reactors. Their main deficiency is that they lack a containment structure to prevent a radioactive release in the event of an accident.

Despite the back-fitting operations to tackle this problem over the past ten years with international help, says Hirsch, the RBMK reactors which are still operating in Lithuania, Russia and Ukraine, remain inherently unsafe.

At present Ukraine’s 14 reactors at five nuclear power plants produce nearly a third of the country’s electricity. To meet its energy needs and lessen dependence on Russian supplies, Ukraine is committed to a nuclear development programme that will increase its output by 50 percent by 2020.

The fourth reactor at Chernobyl, north of Kiev, exploded on the night of Apr. 26, 1986, ripping out the roof of the reactor and sending tonnes of radioactive material high into the atmosphere.

Thirty-one people were killed outright and many more later died from the radiation-related after effects. Large tracts of Ukraine and neighbouring Belarus were contaminated and thousands of people died from radiation-linked diseases. Several west European countries suffered pollution from radioactive fall-out.

But critics point out that even after ten years, there is still no definitive account of how the explosion occurred. “In particular it has proved impossible to establish the exact mechanisms which caused the exceptional level of destruction,” said a Greenpeace report on Chernobyl released here this week.

The draft of the forum acknowledges that three are still “some gaps” relating to details of the accident, but says the knowledge accumulated so far is sufficient to identify the causes and prevent a repetition.

Although in the immediate aftermath of the accident officials blamed human error, it is now known that basic construction and design errors also played a part. A 1991 report by an independent Soviet commission said while the staff did not follow what limited safety regulations were in place, they also did not have manuals and documentation to hand about the plant.

Based on its report, the International Nuclear Safety Advisory Group, an experts group appointed by the IAEA, concluded that the accident was probably caused by errors made by designers and builders and final supervising authorities alike.

Since the accident in Chernobyl, a number of international programmes have been enacted to back fit the more than fifty nuclear reactors, including the RBMKs, no operating in central and eastern Europe.

The result has been an overall improvement in safety and monitoring of the plants’ cores, according to IAEA officials. The forum report found that technology has been improved to enable the reactor to shut down more quickly in an emergency and staff have been better trained to meet more stringent safety standards.

Nevertheless, missions conducted by the IAEA and other international organisations have come up with more recommendations. The IAEA has a list of 59 measures and a consortium of the European Union has come up with no fewer than 300 required changes.

The Greenpeace report also points out a number of other alleged deficiencies. One of them is that key differences exist even between the RBMK reactors of the same generation and thus safety studies need to be tailored to each individual reactor.

This has not been done, says Greenpeace, either by the operators, the IAEA or the EU consortium. The last studied two reactors, the third unit of a plant in Smolensk, Russia and the second unit at Ignalina in Lithuania.

Greenpeace adds that the importing of western technology alone will not improve safety standards to accepted levels. More importantly, Hirsch said, nuclear safety standards and practices countries operating RBMK reactors should be improved.

Better, argued the NGO, for Russia and Ukraine to close the reactors down, as they provide just seven and five percent of their respective national electricity needs.

Lithuania however generates 80 percent of its national power from the two RBMKs at Ignalina, where despite extensive safety improvements at the plant, funded in part by the EU and the European Bank for Reconstruction and Development, a series of accidents at the plant in late 1995 have raised new concerns.

“Despite the complexity of reactor technology, in the Ignalina atomic power plant certain tasks are carried out with very primitive means,” Povilas Vaisnys, director of Lithuania’s atomic energy security inspectorate told IPS in January.

Lithuania has set up a fund for the phased closure and decommissioning of Ignalina by 2010 which it is estimated will cost 600 million dollars.