COMMENT: Rosatom plans dangerous thermal capacity increases at Russia’s RBMK reactors of Chernobyl infamy

Страшное лицо «мирного атома». Скульптура на главной улице города Курчатова.
Фото: Андрей Ожаровский

Publish date: March 7, 2011

Written by: Andrey Ozharovsky

Translated by: Maria Kaminskaya

MOSCOW – A new experiment to be conducted at Russian nuclear power plants employing RBMK-type reactors of Chernobyl notoriety is aimed at increasing the thermal power capacity of these reactors – and presumably, beefing up the operator company’s profit – but is likely to contribute to growing radionuclide discharges and a heavier burden on the aged equipment, at the risk of setting it up for malfunctioning and failure

The advent of capitalism in the Russian nuclear industry has not just shown itself in the many transformations the former Ministry of Atomic Energy, later the Federal Agency of Atomic Energy, and finally the State Nuclear Corporation Rosatom has undergone, re-incorporating its many structural entities as joint stock companies in place of former state enterprises.  Capitalism’s first law is that of making profit. This may be what gave rise to a seemingly insane idea that is now gaining force within the Russian nuclear domain: Operating commercial reactors at capacities exceeding design-basis levels.

The frightening insanity is that this dangerous experiment is expected to have a broad enough reach to encompass not just the VVER-type reactors – of which none, thankfully, has blown up to date – but also the RBMK-1000s, the series infamous for the 1986 catastrophe at the nuclear power plant (NPP) in Ukraine’s Chernobyl.

Eleven RBMK-1000s are currently in operation at Russia’s Leningrad, Kursk, and Smolensk Nuclear Power Plants. These reactors were not shut down after 1986. First, as per the International Atomic Energy Agency’s (IAEA) recommendations, their output capacity was decreased. But following a series of upgrades, the reactors were brought back to design-basis capacity – and furthermore, permissions were then applied for and granted to extend their operational life spans beyond the 30 years specified in the original design.

And now Reactor Unit 1 of Kursk NPP, located in the town of Kurchatov in Kursk Region in West European Russia, has been designated as a pilot site to experiment on increasing these reactors’ thermal output capacity.

Rosenergoatom, Rosatom’s structure in charge of operating Russia’s nuclear power plants, is soon expected to apply for a license to operate Kursk’s Reactor 1 at an increased thermal capacity. The application will be filed with Russia’s industrial oversight authority, the Federal Service for Ecological, Technological, and Atomic Supervision (or Rostekhnadzor, in its Russian abbreviation). Bellona has at its disposal documents that were used as the basis for the application. An analysis of these documents shows that a large-scale dangerous experiment has been devised that threatens to create risks of the kind that precipitated the world’s worst nuclear disaster at Chernobyl.

Runaway greed as a precursor to runaway reactors

It would seem logical that as the main objective for Rosenergoatom is producing power at nuclear power plants, maximising output would be one of desired goals. Achieving that goal was what prompted the development of the “Programme for increasing electric power output at generating units of nuclear power plants in operation by Concern Rosenergoatom for 2007 to 2015.”

Increasing output can be done without risks incurred to a nuclear power plant’s safety – for instance, by enhancing a plant’s installed capacity utilisation factor via improving the performance of its non-nuclear components – such as power generators and turbine plants. But the nuclear capitalists are opting for a simpler, if more dangerous, solution: Raising profit by boosting the reactors’ thermal output – in other words, making them operate under loads increased beyond design limits.

It is more or less clear why the eleven RBMK-1000s were not excluded from the output-enhancement programme – all reactors are supposed to participate in this race for profit, including reactors that have proved, in practical experience, just how capricious and dangerous they can be.

In 2007, Rosenergoatom adopted a “Sub-programme for implementing five-percent increases in thermal output at generating units of RBMK-running nuclear power plants in operation by Concern Rosenergoatom for 2007 to 2015.” There are also plans to further boost the RBMK reactors’ capacity by 10 percent. Kursk NPP has been selected to pioneer these efforts.

Public discussion

In late January, a public hearing was held in Kursk NPP’s satellite city, Kurchatov, to discuss the plan to operate the station’s Reactor Unit 1 at above-nominal capacity. The plant’s management chose not to post the documents they had presented at the hearing for open access on the Internet.

“The materials are stored in a library here, in the town of Kurchatov – you’re welcome to come and read,” Kursk NPP’s public information service told the author of this comment. I came, I read, I found a lot of interesting and curious information: The plant’s reactors are already operating at increased capacity; the engineering proposals on which this capacity boost is based are dubious; the NPP’s radioactive discharges are bound for a significant increase, while safety levels will likely go down – but, as per usual, those behind this experiment are confident the Chernobyl tragedy will not repeat itself.

Reactors boosted already 

At the hearing, Kursk NPP’s chief engineer Alexander Uvakin said the thermal capacity increase programme was already in full swing at the plant. Back in March and April in 2009, Reactor Unit 1 at Kursk NPP already underwent a “Comprehensive programme for gradual (phase-by-phase) elevation of thermal output of Reactor Unit 1 of Kursk NPP by 5 percent above nominal.”

Documents presented at the public hearing show that compared to the nominal capacity of 4,000 megawatts, the actual combined operating load at the station was usually in excess of 4,150 megawatts; a maximum of 4,204 megawatts was reached on February 4, 2010. Power output levels of individual generating units frequently went above 1,060 megawatts – or 106 percent of nominal values. Maximum electric power output was reached on Reactor Unit 2 twice, on January 20 and February 1, 2010, when output amounted to 1,070 megawatts (7 percent above nominal load).

The danger of this experiment is both in increased radionuclide discharges through the ventilation system and in an increased burden on the reactor components, as well as in the changing operating modes – all of which could lead to an increased risk of accidents.

Increasing radiation doses

The documents that Kursk NPP presented at the hearing demonstrate that with Reactor Unit 1 operating at 110 percent capacity, the combined radionuclide discharges from the station grow – in the worse-case scenario – by 1.2 times in inert radioactive gasses and by 1.5 times in iodine-131.

Yearly acceptable discharges, as per the existing Sanitary Rules for Designing and Operating Nuclear Power Plants, will not be exceeded, but the danger of significant increases of radioactivity discharges is evident. And if the experiment is deemed successful and all four of the station’s power units begin to operate at above-nominal capacity, then discharges of inert radioactive gasses should rise by 80 percent, while discharges of radioactive iodine, which causes thyroid cancer, will be three times as current levels!

It is not too difficult to understand why it is the discharges of radioactive iodine specifically that will grow as output capacity increases by what seems like a fairly insignificant percentage.

With a reactor of the RBMK type – a channel-type reactor – total thermal capacity only increases if thermal capacity is increased in each of the fuel channels. Radioactive iodine is generated in fuel rods as a product of nuclear fission. As long as fuel rods remain sealed, radioactive iodine presents no threat. However, with load increases, the likelihood of loss of seal increases accordingly, and so does the thermal load on those fuel rods where loss of seal has already occurred. Fission products, such as radioactive iodine, end up in the coolant flow much faster; part of them is held back by filters, but that part that has passed through is released via ventilation pipes into the surrounding environment, leading to increased radioactive discharges.

Expert estimates say a ten-percent increase in the average output of a non-hermetic fuel rod doubles iodine-131’s radioactivity levels in the water passing through the coolant circuit and augments its concentration in a nuclear power plant’s discharges by 1.5 times.

Kursk NPP, however, believes the experiment to be safe: “Discharges of [inert radioactive gasses], iodine, and radioactive aerosols into the surrounding environment are possible as a result of increasing capacity of Reactor 1 of Kursk NPP, however this will not lead to statistically discernible changes in environmental contamination levels or radiation exposure experienced by the population residing in the vicinity of [Kursk] NPP.”  

The documents used to substantiate Kursk’s application for Rostekhnadzor’s license to run Reactor 1 at an increased thermal capacity also say: “With three reactors of Kursk NPP operating at nominal capacity and Reactor Unit 1 operating at an increased capacity, an increase in the radiation exposure burden on the population at the perimeter of the [sanitary protective zone] (1.7 kilometres) and in the town of Kurchatov will be observed, in the amount of 0.03 [microsieverts], or 18 percent, above current levels.” 

One can expect, therefore, that if the remaining three reactors are also brought to output levels beyond nominal, the combined radiation exposure burden on the population living in the vicinity of the plant will increase by 72 percent – or by 0.12 microsieverts per year. That would already constitute a serious problem, since what is at issue here is not external exposure, but radiation doses received internally, exposing the thyroid to the harmful impact of radioactive iodine. 

The threat of abnormal iodine discharges is, unfortunately, quite real. It was precisely that sort of radioactive iodine release – during a November 1975 accident on an RBMK-1000 reactor at Leningrad Nuclear Power Plant – that accounted for a spike in newborns diagnosed with chromosomal abnormalities (Down Syndrome) in Leningrad NPP’s hometown of Sosnovy Bor, near St. Petersburg, the following year. The little nuclear town had zero Down Syndrome statistics prior to the accident.

Radioactive discharges reach as far as Kursk

It has long been no secret that the tall ventilation stacks are needed at nuclear power plants to ensure emissions of dangerous artificial radionuclides into the surrounding atmosphere – to release radioactive products such as resulting from both accidental leaks and as part of so-called “sanctioned discharges,” or discharges implemented under normal operating conditions.

It was not for nothing that Kurchatov, the satellite town of Kursk NPP, made it into a report entitled “On the condition of the environment and on environmental protection in the Russian Federation in 2009” and prepared by the Ministry of Natural Resources and Ecology. This is what the report had to say about Kursk NPP:

bodytextimage_KuAES2.jpg Photo:

“Increased, as compared to background [radiation] levels, radioactivity concentrations of [caesium-137], as averaged per month, were registered in 2009 in Kurchatov […] in April, at 42* 10–7 [becquerels per cubic metre]. Increased, as compared to background levels, by 6.5 times, radioactivity concentrations of [caesium-137], as averaged per year, were registered […] in Kurchatov, at 15* 10–7 [becquerels per cubic metre] […]. Furthermore, in 2009, as in previous years, several instances were registered of detection in the atmosphere in the cities of Kursk and Kurchatov […] of certain products of nuclear fission and neutron activation.”

The ministry continues in its report: “The appearance of traces of these radionuclides in the atmosphere of these cities is directly linked with the operation of the nearby Kursk NPP.”

That the radiation from Kursk NPP, located some forty kilometres west of the regional centre of Kursk, was established to reach that far – albeit in small quantities – speaks plenty about the seriousness of the problem.

And according to Rostekhnadzor, in 2009, Kursk NPP discharged into the surrounding environment 297.3 terabecquerels’ worth of inert radioactive gasses, 1.32 terabecquerels of iodine-131, 0.333 terabecquerels of cobalt-60, and 50.7 megabecquerels of caesium-137. And this is not the complete list of artificial radionuclides released by nuclear power plants through their ventilation stacks into the surrounding atmosphere. For instance, discharges of tritium – radioactive hydrogen – are not even monitored at all…

By trial and error

Curiously, the proponents of the risky experiment with boosting the RBMKs’ thermal output are themselves no strangers to understanding that the equipment is not ready to withstand such increases and that the associated additional burden may turn out to be just the straw that broke the camel’s back.

This, for instance, is how experts with the federal Scientific and Technological Centre for Nuclear and Radiation Safety, an entity of Rostekhnadzor’s, expect the separator drum – a device that separates steam needed to turn the turbine from water – to behave in reaction to such an experiment: “As the power unit’s capacity is increased to 110 percent of nominal levels, the steam humidity burden is increased on the evaporation surface in the [separator drum] […] Moreover, there is, in the existing design of the steam drum internals, the threat of steam getting caught in the downcomer, which can lead to a cut-out of the [main circulation pump] as the emergency protection system is activated at nominal capacity. Steam drum internals of existing designs, furthermore, do not provide for even distribution of steam across the width of the submerged perforated plate or reliable operation of hydroseals at water outlet from the plate.” 

But the experimentators will not be stopped. They have taken it upon themselves to modernise the steam drum design, substituting a non-standard variation for the machinery previously in use: “The steam drum internals of the existing project design have been replaced at Reactor 1 of [Kursk NPP] with a system of collector distribution of the water-steam mixture inside the steam drum.”

There is no certainty that the innovation will work, so tests are needed: “The Applicant plans, while increasing capacity to 110 percent, to conduct steam separation tests at each incremental capacity increase of 2÷3 percent owing to the separation drum’s limited capability to provide for regulated steam humidity and the existing [inflexible] separating characteristic. In the Applicant’s opinion, the results of the tests on the reactor unit will help find the limit to which increasing the reactor installation’s capacity is possible, as well as identify the exact emergency protection setpoints with regard to changing water levels in the separators.”

So basically, Kursk personnel will have to go through nearly every NPP component, working by trial and error, adjustments and improvements, just to get it right and force the reactors to work at increased capacity.

The deaerators, too, seem to need retrofitting, inserting an additional valve that was not provided for in the original design: “Because, during the unit’s operation at increased capacity, the flow of “hot” feedwater into the deaerator will increase as well, an adjustment is needed in the deaerator’s excess pressure protection system, i.e. inserting into the scheme a backup safety valve.”

Just how substantiated and thought through these innovations, improvements, adjustments, etc are, introduced as they are on the go, only practice will show – experimental, in this case. But it wouldn’t hurt sparing a thought as to what kind of accidents might occur on a Chernobyl-type reactor once it is “boosted” beyond the tried and tested limits.

Rusty old wrecks…

Two facts can serve as confirmation that Rosenergoatom’s plan to boost RBMKs’ capacity is a dangerous venture.


One is the accident at Lithuania’s Ignalina NPP, where the cooling circuit of the shut-down Reactor Unit 1 – Lithuania had to close down the aged Soviet-built station, complying with a European Union condition as it was ascending the union – failed to withstand the impact of a decontaminating solution, as it was being flushed through the systems, and leaked some 300 cubic metres of radioactive sludge onto the floor of the main operations hall. Even though Ignalina’s Reactor 1 – of the upgraded RBMK-1500 series – was in operation less than the 30 years of its design-basis lifetime, the equipment was evidently in a deplorable enough condition – even though the plant’s owner had no inkling of how worn-out the systems were until the leak occurred. 

The second is the information from a yearly report by Rostekhnadzor, publicised in 2010, which says that Rosenergoatom simply does not have reliable data on the state of many reactor components that are critical to the safety of the NPPs in its purview: “As regards the weld seams in the […] austenitic pipelines of RMBK-1000 reactors, the issue of reliability of maintenance control must be differentiated depending on the method of maintenance control and location of the weld seams (some of them are not subject to control). On the whole, the reliability of defect monitoring, as dependent on the method of maintenance control, can be assessed to range between 64% and 90%, which also attests to the urgency of the problem of substantiating assessments of integrity and strength of […] welded austenitic pipelines.”

In plainer language, the danger is there that the pipelines in use at Russian RBMK-running NPPs may burst at any given moment. Whether this is as big a threat as another Chernobyl depends on many factors, but certainly, these are not risks to be dismissed offhand.

So let’s just not pretend that our RBMKs are in a good enough condition and that we know all there is to know about them and their safety. If we just stop pretending, then maybe it will become clearer that experimenting on the aged and unreliable equipment is a stunt of the kind that borders on criminal negligence.

Inadequate analysis of accident scenarios

The issue of whether accidents of Chernobyl magnitude are possible with RBMK reactors as their innards go through retrofitting and adjustments to squeeze more power out of them is being dodged by Rosenergoatom in the simplest way possible – by keeping total silence on the subject. As in, it’s just impossible, and that’s that.

There is, to be sure, some progress, compared to the 1980s: Back then, what was at the time the atomic energy ministry claimed RBMKs were so safe one might as well build one in Red Square. At least now, there is an admission, to a certain point, that there might be certain consequences if an accident occurs – though, Rosenergoatom says, they will not reach farther than 2.6 kilometres in the worst case.

This is not a joke: The documents presented at the hearing in Kurchatov say no measures beyond evacuating and sheltering the population and iodine-based prevention will be required at distances greater than 1.7 kilometres from the plant, while sheltering measures will not be required at any distance greater than 2.6 kilometres. The only other limitation that the documents provide for in case of a beyond-design-basis accident is “necessary measures to limit consumption of contaminated food at distances less than 25 kilometres” from the plant. 


What is meant here is precisely beyond-design-basis accidents – that is to say, accidents developing according to the worst scenario possible, one that cannot be entirely prognosticated, thought through, or taken all necessary precautions against in advance… Does one really need to point out, for the umpteenth time, that one beyond-design-basis accident has already happened once on an RBMK reactor – on April 26, 1986, at Reactor Unit 4 of Chernobyl NPP – and that its impact went far beyond a mere couple of kilometres, poisoning lands as far away as in Western Europe? Limitations on food consumption were introduced then in Germany’s Bavaria, for instance – thousands of kilometres away from ground zero…

Contamination misinformation

In critical remarks written with regard to the documentation presented at the hearing in Kursk, Bellona’s St. Petersburg-based branch, Environmental Rights Centre (ERC) Bellona, said the impact of potentially serious beyond-design-basis accidents was unjustifiably excluded from consideration:

“Only those scenarios for beyond-design-basis accidents are examined [in the documents] that can potentially develop as a result of ‘loss of [cooling] water’ and ‘simultaneous rupture of nine fuel channels.’ Excluded from analysis, absent of any foundation, are other possible scenarios for beyond-design-basis accidents, such as, for instance, destruction of the reactor resulting from external impact – a plane crash involving a passenger plane with a mass of around 100 tonnes and proceeding at a speed of around 800 [kilometres per hour] – or […] internal causes or actions of the personnel (the Chernobyl scenario, or the ‘human factor’).”

“Only the ‘benchmark’ Level 5 beyond-design-basis accident scenario is considered, as described by the INES scale, while more serious accident scenarios, of Levels 6 and 7, are unjustifiably excluded from consideration,” ERC Bellona’s document said, referring to the International Nuclear and Radiological Events Scale, an IAEA tool developed to classify nuclear and radiation incidents and accidents by their degree of severity in order to provide for a uniform public information code. The “benchmark” in this case is the estimated concentration of iodine-131 released as a result of a given accident and serving to classify the accident according to one level or another.

Level 5 on the INES scale describes “Accidents with Wider Consequences” involving “limited release of radioactive        material likely to require implementation of some planned countermeasures; several deaths from radiation,” and, where radiological barriers and control are concerned, “severe damage to reactor core; release of large quantities of radioactive material within an installation with a high probability of significant public exposure,” possibly resulting from “a major criticality accident or fire.” The infamous 1975 accident at Three Mile Island in the US was a Level 5 event.

Accidents of Levels 6 and 7 are classified as “Serious Accidents” and “Major Accidents,” respectively, and involve “significant release of radioactive material likely to require implementation of planned countermeasures,” for Level 6 events, and “major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures,” for Level 7 events. In terms of examples in the history of operation of nuclear facilities worldwide, both levels are represented by accidents that have taken place in the former Soviet Union, with Chernobyl being the world’s severest nuclear accident to date.

In reference to one of the documents, entitled “Environmental protection while increasing capacity of, and operating at above-nominal capacity, Reactor Unit 1 of Kursk NPP,” ERC Bellona continues to say in its critical remarks that as a result of failure to pay due attention to the possibility of more serious accidents than Level 5 events, “the impact of a serious beyond-design-basis accident on the environment and population health was significantly underrated. Erroneous conclusions were made based on underrated data with regard to the significance of population exposure levels following a beyond-design-basis accident and the necessity of evacuation and iodine-based prevention measures for the population at any distance greater than 1.7 kilometres, or protection (sheltering) of the population at any distance greater than 2.6 kilometres, from the reactor.”

ERC Bellona concludes: “This approach may cause both the public and persons responsible for relevant decision-making to be misinformed about the real consequences of a serious beyond-design-basis accident.”

Hostage to the “peaceful atom”

The town of Kurchatov and its 48,000 inhabitants are just 3.5 kilometres away from Kursk Nuclear Power Plant, towering on the banks of an artificial pond where the plant takes water for its cooling circuits. The ventilation stacks on top of the station’s roof are well visible from the top floors of Kurchatov’s buildings and from many other vantage points in the town.

bodytextimage_gorod.JPG Photo: Фото: Андрей Ожаровский

Living in such a close proximity to a nuclear power plant has been proved to be dangerous, especially for children. Studies conducted in Germany in 2007 showed leukaemia incidence in children under five living at distances of less than 5 kilometres from nuclear power plants was double the rate among their peers from regions with no nuclear power plants. Nothing says the same risks cannot be anticipated for populations residing near nuclear power plants in Russia.

Yet Russia, unlike Germany, maintains no federal registry to keep track of cancer cases; the single maternity hospital in the region where Kursk NPP operates is located in Kurchatov, right inside the five-kilometre radius of the plant.

Furthermore, even though the operating license for Kursk’s Reactor Unit 1 expires in December 2016, there are no plans in motion to prepare the reactor for decommissioning. No social support programmes are being developed for the locals, specifically, nuclear specialists, to provide assistance in relocation or re-training or create new production enterprises and new jobs. Rosatom’s idea of social programmes probably amounts to spending the funds the corporation wheedles out of the federal budget for nuclear satellite cities on building new reactors to replace outgoing ones.

Is a nuclear-free future possible for Russia?

On March 1, a visiting session of the Committee for Energy of the Russian parliament, the State Duma, was to take place at Kursk NPP. The parliamentaries were likely in for a long sales pitch on how there was no future without nuclear energy and that all these initiatives at Kursk NPP needed to be approved – from increasing the existing reactors’ capacity to building a second line of construction at the plant.

If the parliamentaries are so naïve and ill-informed that they will believe the usual incantations about the RBMKs’ safety, there might be a tangible risk they will make a new tragedy that much more possible in the future.