Emergency shutdown at Balakovo
Balakovo NPP, in Saratov Region, about 900 kilometres south-east of Moscow, operates four VVER-1000 reactors. According to a report by the Crisis Management Centre of the Russian State Nuclear Corporation Rosatom, a turbogenerator was tripped at Reactor No. 3 last Sunday:
“On June 19, 2011, at 10:53 pm, as the unit was operating at 1,035 megawatts capacity, Turbogenerator TG-3 was disconnected from the grid by the actuation of the process protection system. On June 20, 2011, at 00:49 am, Turbogenerator TG-3 was plugged back into the grid.”
According to media reports, however, Rosatom plans to initiate experiments on operating Reactor Units 3 and 4 of Balakovo NPP at 104 percent of nominal capacity – part of a broader plan to increase power output from Russia’s NPPs. On May 24, the Russian Federal Service for Supervision of Natural Resource Usage issued an environmental impact assessment report that put an approval stamp on the planned experiment at Reactor 4.
Three months of repairs – and whole three days of uninterrupted operation
The same experiment – increasing reactor capacity by seven percent, in this case – is envisioned for Reactor 4 of Kola NPP, a four-unit station on Russia’s far northern Kola Peninsula. Meanwhile, Kola’s Reactor Unit 3 was plugged back into the grid on June 15, 2011, at 14:18 pm after the completion of scheduled maintenance, Kola NPP’s public information centre said.
That scheduled maintenance – or rather, planned overhaul – had continued for over three months, since March 11. And one the primary goals with conducting such extensive maintenance was to prepare the aging equipment to operation beyond the 30 years given to it by engineers as its expected useful life term. That term expired around the time that the unit was put into repairs – on March 23, 2011 – but the reactor had not been prepared for decommissioning. Instead, the Russian nuclear industry oversight agency, the Federal Service for Technological, Environmental, and Nuclear Supervision (Rostekhnadzor) extended the unit’s operational licence on April 2 – in contravention of the law, which requires that a reactor first undergo a state environmental impact assessment.
The thirty-year-old reactor was re-launched – and then shut down for almost 24 hours following yet another incident. It had only been in operation three days.
“On June 18, at 20:30 pm, electrical protection systems disconnected Reactor Unit 3 of Kola NPP from the grid while in operation with Turbogenerators Nos. 5, 6. Cause: Fault of Turbogenerator TG-5’s disconnect switch,” Kola NPP’s public information centre said in a statement.
Electrical protection or emergency scram?
However, Rosatom’s Crisis Management Centre reports the incident in a slightly different way:
“1. Emergency situations:
1.1 Kola NPP (Director: [Vasily] Omelchuk), Reactor Unit 3, Polyarniye Zori, Murmansk Region: Reactor shutdown.
1.2 On June 18, 2011, at 20:30, as the unit was operating at a capacity of 430 megawatts, the reactor plant was shut down by the emergency automatic protection system due to a failure of TG-5 generator switch.”
Where Kola NPP was reporting an actuation of “electrical protection systems,” Rosatom’s agency refers to the incident unequivocally as one involving “emergency protection.” It may have been that Kola officials were trying to avoid mentioning emergency scramming altogether in connection with their old and dangerous reactors, thus the “electrical protection.”
A representative of Kola NPP’s press service, Andrei Veryovkin, agreed to talk to Bellona Web about the June 18 incident, but was hard pressed to find an answer to Bellona Web’s question about the difference in the language of the two reports with respect to the cause of the shutdown.
Veryovkin suggested that the discrepancy may have had to do with the different rules of reporting information about operational events – Kola NPP is managed in Moscow by its operator company, Concern Rosenergoatom, and the station’s information and press statements appear on the latter’s website; though both Rosenergoatom and the Crisis Management Centre are part of Rosatom, the two structures remain different organisations – and promised to consult specialists to clarify the matter.
A more detailed comment was later made available to Bellona by Kola NPP’s director Vasily Omelchuk:
“There is no contradiction in the two statements, since the reactor unit was disconnected from the grid by the actuation of electrical protection systems, as a result of which the reactor plant was shut down by the emergency protection system in accordance with design-basis procedure.”
Kola’s reactor back in operation – churning out unneeded energy
The defect was repaired, and on June 19, at 19:17 pm, Turbogenerator TG-6 at Reactor Unit 3 was plugged back into the grid.
“At present, Reactor Units 2, 3, and 4 are in operation at Kola NPP, bearing a cumulative load of 883 megawatts as per the dispatch schedule,” Kola NPP’s press statement on Rosenergoatom’s website said.
The three units, out of the four functioning reactors at the station, are currently in operation at 833 megawatts in total power load, but this is roughly the combined capacity of just two Kola units: The plant operates four VVER-440s, with each, as the name of the reactor series suggests, having an installed capacity of 440 megawatts. The total capacity of three such reactors would add up to 1,320 megawatts – so why are they not operating at full load?
“The reactor units are not working at maximum capacity,” Veryovkin from Kola NPP’s press service confirmed for Bellona Web. “There are dispatch limitations. Which is why [the units] are operating at restricted load.”
This is in line with the unique situation that has formed on the Kola Peninsula. The region is in effect receiving much more electric power than it needs. With the current energy saturation levels, the offer is far ahead of the demand, and the combined production output of just two reactors is well enough to meet local energy needs. The specific industry lingo refers to this situation as “dispatch restrictions” – but what it means is that nuclear reactors at Kola NPP almost always have to operate at decreased capacity, all the while generating spent nuclear fuel, radioactive waste, and so-called “sanctioned” discharges of radioactive gases into the surrounding environment.
Excess power output evidently no reason not to experiment with stretching the reactors’ limit
Strange as it may seem, the situation where Kola NPP’s reactors produce more power than its consumers need appears to be no impediment to the dangerous experiments planned for the station. Besides extending the operation of Kola reactors beyond the design-basis licence period, Rosatom is envisioning capacity increases at the plant – “boosting” a reactor to force it to work at increased load in order to enhance output.
To sum up, the first-generation reactors at Units 1 and 2 are already being operated beyond their engineered life spans, a renewed licence has just been given to Reactor Unit 3, whose design-basis life span expired in March, and an experimental seven-percent thermal capacity increase is planned for Reactor Unit 4.
This is not just a situation fraught with likely risks of more reactor scrams – this amounts to waiting for an accident to happen. Vitaly Servetnik from the Murmansk-based environmental NGO Priroda i Molodyozh (Nature and Youth) believes this is unacceptable.
“Reactor 3 of Kola NPP exhausted its design-basis operational term and, in accordance with the requirements of the Russian legislation, was to undergo a state ecological evaluation, including an environmental impact assessment and a public hearing. None of this was done, despite our appeal to the prosecutors and our protests. Giving the extension on the operational life span of the old unit was especially cynical in light of the tragedy at Fukushima,” Servetnik said, referring to the still ongoing nuclear and radioactive catastrophe at Japan’s Fukushima Daiichi Nuclear Power Plant. “All the experiments at Kola NPP, including extending the operational licence and [allowing further as-per-usual operation of] the old Reactor Unit 3, are unacceptable before the state ecological evaluation has been done.”
Servetnik also said Kola NPP must undergo stress-testing in accordance with testing standards recently introduced by the European Union, which initiated such tests for its commercial nuclear reactors after the disaster broke out at Fukushima. “All else is trickery and PR,” Servetnik concluded.