In and of itself, the planned renovation carries the risk that the technologically obsolete and decrepit reactor will become vulnerable to serious accidents. This risk will only increase during subsequent operation, after the reactor’s design is further reworked to accommodate modifications that have not even received proper approval in accordance with state requirements for environmental impact assessments.

In a statement made at a press conference on November 20th 2008 and cited by the Russian news agency Interfax Severo-Zapad, Vadim Ryabov, general director of the engineering and construction concern Titan-2 – the subcontractor hired by the LNPP to perform the repairs on its Reactor Block 4 – said the nuclear power plant has scheduled the start of the renovation for next May.

“The planned time period for the shutdown of Reactor Block 4 is May 2009, and the contract should be fully executed in 2010,” said Ryabov, who is also board chairman of the holding Titan-2, the subcontractor company’s parent structure. The reactor will be taken offline for more than six months. Ryabov’s statement did not include any information on the costs of repair works or modifications planned to prolong the reactor’s engineered lifespan.

Some of these modifications include installing automatic cooling and automatic shutdown systems, as well as upgrading the control systems, which will then be expected to allow the reactor to remain in safe operation for another fifteen years.

Meanwhile, the very notion that it is possible to operate safely the morally and physically outdated reactors of the type RBMK-1000 – the same that was used at the Chernobyl Nuclear Power Plant that on April 26th, 1986 became the ground zero of the worst nuclear catastrophe known to the world to date – is cause for doubt both among nuclear experts and environmentalists.

Yet, the obsolete RBMK-1000s still used in the LNPP's Reactor Blocks 1 and 2 have already been approved for continued operation beyond their engineered life spans. Extensions on their licenses have been issued in absence of any state environmental risk assessments by Rostekhnadzor, the federal supervision entity charged with overseeing industrial safety standards and practices, including those adopted in the nuclear industry.

A reactor hall of the Leningrad NPP, one of ten nuclear power plants managed by Concern Rosenergoatom, state-owned nuclear energy monopoly. The RBMK-1000 is located below the floor level.

Rosenergoatom

Of the most concern is the condition of the reactors’ graphite stacks and fuel assembly channels, as well as of the piping systems. Under the capital repairs planned by the plant, partial replacement of the fuel channels is a viable possibility, however, renovating the graphite stacks will be a challenging task because of the reactor’s huge dimensions and extremely high radiation levels.

While designing the reactor, engineers put the performance resource of the whole system and each of its part to intense scrutiny, and for the plant, deciding to continue operating the old machinery today seems an unjustified choice. Furthermore, it is quite possible that this decision was not at all the result of having an absolute faith in the reactor systems’ reliability – how reliable, really, can a Chernobyl-type reactor be? – but stemmed from a lack of safe technological procedures and funds that would allow shutting the reactor down.

Reliability-wise, RBMK-1000 reactors have more than proven how accident-prone they can be. At the LNPP, the most serious accident to date took place on November 30th, 1975, when fuel assemblies in Reactor Block 1 suffered significant physical damage leading to a substantial leak of radionuclides into the atmosphere, which resulted in radioactive exposure for the population. In the 24 hours after the accident, engineers were blasting nitrogen through the reactor and radioactive discharges were being released outside through air ducts. Estimates say that up to 50,000 terabecquerel’s worth of radiation was altogether blown out into the atmosphere around the plant – 100 times the whole plant’s yearly output under normal operation mode.

The public was not notified of the accident. No evacuation or mass-scale iodine treatment measures – a preventive policy to offset lasting effects of radiation on the population’s health – were ever undertaken. The authorities still keep all information on the accident classified.

As for the LNPP's Reactor Block 4, its performance has recently been plagued with regular glitches. This was possibly one of the reasons why the plant decided to halt its operation and start a major overhaul of its systems. This year alone has already seen two incidents involving activation of the reactor’s emergency response system, in August and September. According to Rostekhnadzor’s statements, on August 17th, “a reduction in the reactor’s load occurred as a result of a response from the emergency shutdown system,” and on September 19th, “Reactor Block 4 of the Leningrad NPP was 50% unloaded because of a response from the emergency shutdown system.” Such responses are quite a serious matter as they are frequently the indication that an accident scenario is unfolding.

It is no surprise that the population still has no trust in any information that is issued with the intention to assure people that everything is proceeding according to plan at the LNPP. Most concerning are statements that notify of a sudden scram or “planned repair works.” As one example, last spring information of exactly that kind triggered a wave of disturbing rumours which, luckily, did not morph into a tsunami of mass panic. The reaction that followed then on the part of Rosatom – the Federal Agency for Atomic Energy, which is Russia’s top nuclear authority – was clearly at odds with what the situation at hand warranted: Rosatom representatives turned around to lay accusations on environmental organisations and even attempted to look for a specific culprit. Yet, no measures were undertaken to make public what information there was on the real problems that the plant was going through. Even today, Rosenergoatom’s official website features stories on anything from a corporate futsal tournament at the Kalinin NPP to “My Smolensk NPP-My Family” Contest – a competition which encouraged the school kids of the town of Desnogorsk, where the Smolensk site is located, to send in their poetry, drawings, and other projects in the run-up to The Power Engineer Day celebrations – but offers no information about what implications should be expected in the course of a planned reactor renovation or what one ought to do in case of a nuclear accident.

Another of the LNPP's predicaments is the depleting capacities of the plant’s radioactive waste and spent nuclear fuel (SNF) storage facilities. The underlying problem is that SNF from RBMK-1000s was never meant to ever undergo reprocessing, which is why all of the nuclear waste the plant has been generating since it came online in the 1960s has since been collected in the cooling pools on the reactor grounds and in the temporary “wet storage” facility at the LNPP's production site.

Furthermore, in addition to taking care of its own waste, the LNPP is using its storage facilities to keep analogous, RBMK-1000-origin waste that had been generated at Chernobyl and transported to Sosnovy Bor, LNPP's home town, after the 1986 disaster.

In 2004, Bellona published an eye-opening report by Sergei Kharitonov, a former LNPP employee turned whistleblower, who, besides exposing the many safety and security violations at the plant, laid bare the alarming condition that the LNPP’s storage facilities are in. The report says that the SNF storage sites were overfilled as long ago as in 1995. The congestion could easily lead to accidents, so the plant’s management decided that storage capacities could be enhanced simply by placing two spent fuel assemblies for storage in a spot meant for one. This so-called “densified storage” approach is still a routine practice at the LNPP, which, in experts’ opinion, poses a safety threat and could cause serious accidents.

Yet, the situation is still the same as it was. According to Rostekhnadzor: “Of the unsolved issues related to the storage of spent nuclear fuel, the following remain: At the Leningrad NPP, a high degree of filling the capacities of the SNF storage facilities and cooling pools.” (See the (Yearly Activities Report of the Federal Service for Environmental, Technological and Atomic Supervision in 2007, Page 42, in Russian.)

Even while functioning in a normal, accident-free mode, the LNPP releases dangerous radionuclides into the surrounding environment on a regular basis. It is such “allowed” discharges which, in all probability, lead to what was recently discovered in a German study to be the effect of an increased rate of cancer cases – especially, incidence of childhood leukaemia – in the populations residing within a distance of 50 kilometres to an operating NPP, most significantly, sites that operate reactors employing the “boiling water” principle, the same on which RBMK-1000s run.

It is through these chimneys that the LNPP releases its discharges of radioactive iodine, cobalt, and caesium isotopes.

Rosenergoatom

The LNPP is unfortunately afforded the wide latitude to discharge a whole bouquet of radionuclides into the surrounding atmosphere. Experts point out that levels of harmful substances present in these discharges increase not only during an accident, but also in the course of repair works – which would compel the residents of Sosnovy Bor and neighbouring areas to exercise additional caution after May 2009, when the renovation is slated to start.

According to Rostekhnadzor’s official data, in 2007, LNPP’s discharges amounted to: 369 terabecquerel in radioactive noble gases; 1.7 terabecquerel in Iodine-131; 125 megabecquerel in Cobalt-60; and 153 megabecquerel in Caesium-137. (See the (Yearly Activities Report of the Federal Service for Environmental, Technological and Atomic Supervision in 2007, Page 38, in Russian.) By contrast, the statistics compiled by Rostekhnadzor for the Kola NPP in 2007 showed the following differences in that plant’s discharge levels as compared to those of the LNPP: 3,690 times as low for radioactive noble gases and 17,000 as low for Iodine-131. That said, the Kola NPP is not up for any safety prize any time soon, it is just that the LNPP’s RBMK-1000 reactors are, for all intents and purposes, much “dirtier.”

Renovation projects are a fomenting ground for potential dangerous incidents or full-blown accidents. In 2007, for instance, employees working at the LNPP's Reactor Block 2 were deft enough to drop a heavy screw onto a piece of electric equipment which was a vital part of a system responsible for the plant’s safe operation. This is a description of the incident as outlined by Rostekhnadzor “Leningrad NPP. An activation of the closing actuator of the 2PEN5 feeding pump discharge valve occurred due to a metallic item (screw) falling onto its contacts while performing works by the operating crew of Reactor Block 2 of the Leningrad NPP. This led to a shutdown of the reactor block. (See the (Yearly Activities Report of the Federal Service for Environmental, Technological and Atomic Supervision in 2007, Page 35, in Russian.)

Repairs works at a nuclear power plant. Sometimes, accidents take place precisely on account of ongoing renovations.

Rosenergoatom

In August 2002, as Reactor Block 3 was undergoing major planned repairs, 241 used – and thus practically defective – ball-type flow meters were installed on the fuel assembly channels instead of new ones. According to Kharitonov’s report, “to conceal the fact that these flow meters had already been used, they were put through decontamination and electro-chemical polishing in the LNPP’s chemical service shop. These operations rendered the sensitive devices unsuitable for use. The documentation accompanying 231 out of the overall number of the used flow meters was tempered with before the meters were installed on the fuel assembly channels. On August 5th, 2002, after the repairs, while bringing the reactor block to an increased capacity, the defective meters started to fail. This resulted in a loss of control over the flow of water through the reactor’s fuel assembly channels in which the used meters had been installed.” Fortunately, the reactor was shut down in time and a serious accident was averted. To be sure, the actual shutdown operation is not a completely safe procedure, either. One should bear in mind that the worst radiation catastrophe known to humankind to date – the Chernobyl disaster – occurred exactly when the plant’s Reactor Block 4 was being shut down for planned repairs. RBMK-1000s’ unreliable design makes such transitional processes as decreasing the reactor’s capacity or taking it offline altogether precarious enough that they can lead to loss of control over the reactor and, by extension, an accident with far-reaching consequences.

Altogether in 2007, four incidents involving failures of various kinds took place in the plant’s operation; in 2006, there were seven such incidents. “Most of the disturbances in the LNPP's operation in 2007 were prompted by such fundamental causes as defects in management, defects in the organisation of the plant’s operation, as well as designing defects,” says the Rostekhnadzor report. It is unclear how these underlying causes can be removed at all, even if the plant undertakes major, long-term repairs. It is likewise unclear why an obsolete reactor needs to be put through a stressful, costly renovation. It all begs the question of whether it might be more prudent to channel all the funds involved in such a risky, expensive endeavour into preparing the plant for being taken offline altogether.

By way of background information

Reactor Block 4 of the Leningrad NPP was put into operation in February 1981; its design-basis operational lifetime is to run out in February 2011. In all, four RBMK-1000 reactors are in operation at the LNPP. Reactors 1 and 2 have already been licensed to continue operating beyond their designed life spans. That was done in circumvention of the procedures of state environmental risk evaluation.

The thermal power capacity of Reactor 4 is 3,200 megawatt; its electric power capacity is 1,000 megawatt; and its performance coefficient is 31%. The reactor is a cylinder-shaped graphite stack 11.8 metres in diameter and 7 metres high. Around 1,700 vertical fuel assembly channels run through the stack which contain fuel assemblies and through which water is pumped. The reactor does not have an outer casing, so replacing fuel assemblies is done while the reactor is running.

The main problem reactors of this type pose is the positive reactivity coefficient both in terms of temperature and the density of the coolant, which, in this case, is steam. This drawback cannot be removed through renovations alone, which only strengthens the argument that the likelihood of a Chernobyl-scale catastrophe near St. Petersburg is quite tangible.