The economic and political significance of Russia's RBMK reactors

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The Economic and Political Significance of

Russia’s RBMK Reactors

by

Daniel E. Corney

SUBMITTED TO THE DEPARTMENT OF NUCLEAR SCIENCE AND

ENGINEERING IN PARTIAL FULFILLMENT OF THE

REQUIREMENTS FOR THE DEGREE OF

BACHELOR OF SCIENCE IN NUCLEAR SCIENCE AND

ENGINEERING AT THE

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

JUNE 2017

© 2017 Daniel E. Corney. All rights reserved.

The author hereby grants to MIT permission to reproduce and to distribute publicly paper and electronic copies of this thesis document completely or in part.

Signature of Author:_____________________________________________

Daniel Corney Department of Nuclear Engineering May 18, 2017

Certified by:___________________________________________________

Prof. R. Scott Kemp Assistant Professor of Nuclear Science and Engineering Thesis Supervisor

Accepted by:___________________________________________________

Michael P. Short Assistant Professor of Nuclear Science and Engineering Chairman, Committee for Undergraduate Students

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The Economic and Political Significance of

Russia’s RBMK Reactors

by

Daniel E. Corney

Submitted to the Department of Nuclear Science and Engineering on May 18, 2017 In partial Fulfillment of the Requirements for the Degree of

Bachelor of Science in Nuclear Science and Engineering

ABSTRACT

The safety of continued operations of Russian Raktor Bolshoy Moshchnosti Kanalnyy (RBMK) reactors is often questioned. The original RBMK design was riddled with deficiencies in its shutdown procedures resulting in unsafe operation under certain conditions, most notably resulting in the April 26th Chernobyl disaster. Despite

implementing modifications to correct these problems, almost all countries permanently cancelled existing RBMK reactor operations. The sole exception to the European decommissioning effort was Russia. In Russia, RBMKs make up approximately 35% of the country’s nuclear power, and are a significant source of heat energy and electricity for specific high priority and remote regions. As a result, Russia relies on the RBMK reactors as an important component within a weakened industrial infrastructure. By analyzing the safety concerns of the RBMK reactors in conjunction with the reactors’ economic and political contributions to the country, a conclusion as to whether or not Russia should continue operating the reactors or transition to an alternative technology should be discoverable. Subsequent discussion should address the modern safety and operating issues of RBMKs along with the generic risks of operating nuclear power plants to determine whether the reactors’ are capable of operating safely. Furthermore, this research should help consolidate existing, yet scattered data, pertaining to the significance of RBMKs to create a concise evaluation of their continued operation.

Thesis Supervisor: Prof. R. Scott Kemp

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Acknowledgements

I would like to start by thanking the nuclear department for providing me with a wonderful experience over my time at MIT. Overtime, I may have discovered interests in other fields that have led me to pursue a career elsewhere, but the time I spent as a course 22 will never be forgotten.

I would also like to thank the squad of friends that have been with me since freshmen year. Each of us has had our ups and down, but together we have overcome so much and we are all set to graduate within less than a month. I look forward to seeing where our lives may lead and hope that we can stay just as close in the years to come. Also, Mom and Dad, I could not have done this without you. Since coming to MIT you have had my back, and despite college not always being the easiest experience for me, you have both been supportive and honest. I love both of you, and I am proud to say that I am only the person I am today because of your guidance.

Finally, I would like to thank my siblings, each of whom has had a major impact on my life. Amanda and Brianna, you continue to be an inspiration and amazing mentors to me as I start taking on more responsibilities in the real world. Things have come a long way, and I am excited to watch your new families to continue to grow and be happy. And Michael. I am so proud of you for doing so well in everything you do. You are and always will be the biggest inspiration to me, and I hope that I can continue to be an excellent role model as you continue through your young adult life.

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List of Terms and Abbreviations

IAEA…… International Atomic Energy Agency RBMK….. Reaktor Bolshoy Moshchnosti Kanalnyy WWER…. Water-Water Energetic Reactor (VVER)

USSR…… Union of Soviet Socialist Republics (Soviet Union) EU………. European Union

FSU………Former Soviet Union GDP…….. Gross Domestic Product PWR……. Pressurized Water Reactor NPP…….. Nuclear Power Plant

PSA…….. Probabilistic Safety Assessment TMI…….. Three Mile Island

KGB……. Komitet gosudarstvennoy bezopasnosti ORM…… Operating Reactivity Margin

EPS…….. Emergency Protection System

OSART… Operational Safety and Review Team LCOE….. Levelized Costs of Electricity

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1. Introduction

First introduced in 1954 with the Obninsk AM-1 reactor, the Russian designed Reaktor Bolshoy Moshchnosti Kanalnyy (RBMK), or “High Power Channel Reactor,” was an important breakthrough for Soviet Era nuclear electricity generation [1]. The RBMK adapted the existing Soviet graphite-moderated plutonium production reactor to a water-cooled power reactor. This innovation ultimately led to the construction of 17 more reactor blocks throughout Russia, Lithuania, and the Ukraine [2].

Nine additional RBMK reactors were slated for construction over the course of the late 80’s, but the projects were canceled due to international safety concerns. Ultimately, the operating reactors had many technical issues, which lead to the most devastating reactor malfunction to date: the Chernobyl disaster of April of 1986 [3]. Due to the perceived safety threat and pressures from the European Union, all RBMK reactors outside of Russia were preemptively decommissioned over the course of the next

decades. [4]

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The Soviet industrial complex’s desire for reactor production speed and efficiency over safety is the most likely reason safety considerations were overlooked. The rapid production of the reactors led to a series of design characteristics that were extremely unstable when the reactors were operated outside of their precise specifications. These design flaws did not fully reveal themselves until after the Chernobyl disaster. The most significant defect of the original RBMK reactor was a positive void coefficient that occurred at low power. This created a thermal feedback loop where the reactor heat would induce water evaporation and in turn would fail to correctly moderate reactor heat output [3]. Upon further investigation in years following the incident, a few reports exist from individuals who questioned the safety of constructing and operating RBMKs. Most of these concerns for safety were recorded in personal journals and not addressed

publicly, presumably due to the inherent fear of retribution for criticizing the state-run projects [4].

After Chernobyl, safety concerns and pressure from the European Union prompted the decommissioning of all RBMK reactors outside of Russia [5]. Currently, Russia is the only country that chooses to continue operating its existing RBMK reactors [6]. This is largely due to the improvement of many of the reactors’ issues by retrofitting a number of updates for safety [7]. These enhancements include increased fuel

enrichment, increased number of manual control rods, additional absorbers at low power, decreased rapid shut down (SCRAM) time, and administrative remedies [8]. While Russia has cancelled all plans to construct more RBMK reactors, they plan to operate their current RBMKs until as late as 2030.

While modern Russia continuously acknowledges international concerns by modifying reactor operating standards and technical specifications, many Western countries remain skeptical of whether or not the RBMKs are safe to operate. Russia currently relies heavily on the power generated from their RBMKs, as the collapse of the Soviet Union lead to a ten-year gap in nuclear reactor production. The existing RBMKs significantly contribute to the national energy economy and to regional power generation throughout Russia. Subsequent discussion throughout this paper should address the modern safety and operating issues of RBMKs along with the generic risks of operating

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nuclear power plants to determine whether the reactors’ are capable of operating safely. Furthermore, this research should help consolidate existing, yet scattered data, of the economic and politic significance of RBMKs in order to create a concise evaluation of their continued operation.

2. Historical Background

Russia’s modern nuclear energy industry is intricately intertwined with its Soviet Union predecessor. As such, it is important to review the USSR industry paradigm before discussing Russia’s modern nuclear problems. Three common failures of Soviet industry are especially relevant to the nuclear sector: the rigidity of the command economy, regulatory forbearance, and employee apathy. The first component that existed throughout all soviet industries was the USSR’s use of a command economy, which allows for the repurposing of a nation’s GDP as commanded by the government [9]. While this system was a plus for the Soviet Union in its ability to cause huge booms in a wide range of industries, it also lead to failures when money was repurposed elsewhere, resulting in inconsistent funding and shortcuts during reactor design [9]. The second failure existed with regulatory forbearance, reinforced by the machismo condition of many soviet leaders, leading to officials to hide rather than correcting errors in reactor design or operation in order to save face, causing many accidents due to hidden

knowledge [10]. The third failure of industry in the Soviet Union was lack of employee motivation, furthering the propensity of industrial accidents due to negligence and improper operation of machinery. These three issues laid the groundwork for a flawed system that eventually contributed to the Chernobyl incident, and led to many strains on the nuclear industry following the collapse of the Soviet Union [11].

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2.1 Nuclear Energy in the Soviet Union

Despite public perception that Soviet nuclear technological development was well behind the USA following WWII, the USSR completed construction of “the world’s first nuclear power plant” at Obninsk on June 27th_{, 1954 four years before the US [9]. The} success of the nuclear reactor led to high interest in nuclear power from USSR officials, triggering shifts in the command economy towards greater investment in nuclear energy. This initial investment led to a boom in reactor designs, as the USSR’s State Committee for the Utilization of Atomic Energy determined that the Union could “not rely upon only one type of nuclear power plant,” and instead must focus on a variety of types for

stability in nuclear energy [9]. Realizing the importance of highly researched but varied reactors for proper nuclear stability led to the USSR researching various technologies, though ultimately resource allocation forced the FSU to abandon all projects but the VVER and the RBMK by the late 1960’s [9].

The VVER would go on to be highly successful for the USSR, and remains lucrative for modern Russia. These reactors, which are the Russian analog to the US and Western Europe’s versions of the PWR, are still being constructed and upgraded, and are even exported out of Russia to other countries seeking to invest in nuclear power [9]. The VVER reactors have become the most widely used reactor in Russia following the

collapse of the Soviet Union, producing the highest proportion of nuclear energy in Russia today.

While the VVER was more successful, the RBMK reactor’s design was

specifically unique to the Soviet Union and was the most widely used reactor type in the USSR prior to its collapse. The RBMK design is a pressurized water-cooled reactor with individual fuel channels and using graphite as its moderator, also known as a light water graphite reactor [3]. Interestingly, part of the uniqueness of the RBMK reactors comes from their dual purpose design, as the reactors were intended for both plutonium and power production [3]. This design was highly lauded by Soviet scientists during the reactor’s construction. The reactor’s design purportedly had the capability to obtain high power, while the on-load refueling ability was intended to allow more availability for power production by decreasing maintenance shutdowns [3]. Due to the reactor’s design

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to have many “interchangeable auxiliary systems,” two RBMKs were able to be

constructed simultaneously on site at NPPs, taking the average construction time of one RBMK unit down to about 4 years. Construction efficiencies allowed the RBMKs to be the primary reactor constructed during the Soviet era. By 1980, 11 RBMK reactors were in operation in Russia, producing 68% of the country’s nuclear generated electricity. [3].

2.2 Chernobyl and the Shortcomings of the RBMK

According to a report released to the IAEA prior to the Chernobyl accident, the Soviet Union guaranteed the safety of its reactors through various measures including:

Securing high quality manufacture and installation of components; Checking of components at all stages; Development and realization of effective technical safety measures to prevent accidents, to compensate for possible malfunctions, and to decrease the consequences of possible accidents; Development and realization of ways of localizing radioactivity released in case of an accident; Realization of technical and organizational measures to ensure safety at all stages of construction and operation of nuclear power plants; Regulation of technical and organizational aspects in securing safety; and Introduction of a system of state safety control and regulation [9].

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Various official documents certified and recorded these measures, which were then put into place by government regulators in charge of the nuclear sector. The most notable of these bodies was Gosatomnadzor, the State Nuclear Safety Inspection, which was in charge of defining nuclear safety and assuring all operating reactors in the USSR met “design, construction, and operation” standards [9]. In 1973, Gosatomnadzor, along with other regulatory bodies, released a document entitled “General Regulations to Ensure the Safety of Nuclear Power Plants in Design, Construction, and Operation,” calling for general problems to be solved for all reactors currently operating in the Soviet Union. However, this document only identified the problems that needed to be solved to ensure reactor safety and did not present solutions to solve the issues themselves [9]. This led to ambiguities when operators attempted technical modifications and misunderstanding of safe operating procedures by administrators, and would immeasurably affect the

Chernobyl disaster.

The Chernobyl disaster is significant in the discussion of continued operations of RBMKs in Russia because the incident highlights the key technical flaws and

administrative flaws undermining the USSR’s nuclear program. To begin, it is important to understand the conditions that began the critical failure of the reactor. On April 25, 1986, the Chernobyl reactor was scheduled to be shut down for maintenance [12]. At this point, the operators of the Chernobyl plant wanted to perform a test to determine whether the plant’s electrical back-up generator could use excess steam from the reactor to start the generator faster than the generator’s previously estimated 60-75 second start up time. Part of the urgency for conducting this test was the 60-75 second delay was considered unsafe for general reactor operating conditions. During the start of the test, while the reactor was operating underpowered, a grid operator in Kiev contacted the power plant and refused to allow further shutdown of the reactor [12]. The unexpected delay in the reactor shutdown caused a prolonged testing window, forcing a worker shift change in the middle of testing and might have led to the reactor stabilizing at 200 MWt during testing, rather than the suggested stable level of 700-1000 MWt [12]. Ultimately, these miscommunications and oversights led to unsafe operating conditions of the reactor, allowing steam to build up, explode, and prompting the complete failure of the Chernobyl 4 reactor.

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Initial reports suggested the plant operators were at fault for the disaster, however, further investigation concluded in consensual blame of the reactor’s design. Specifically , two significant shortcomings drove the reactor to critical failure: the positive void

coefficient and the design of the reactor’s control rods [13]. In all reactors cooled with boiling water, steam exists in a certain fraction with liquid water [14]. Steam, in comparison to water, is much less effective at slowing down fast neutrons. In most standard water-cooled reactors, the failure to slow neutrons actually leads to a negative void coefficient due to fast neutrons being less likely to cause fission. However, in

RBMK reactors, which use graphite as their moderator, the failure to slow neutrons in the water actually led to more neutrons being moderated by the graphite moderator, causing more fissions and more heat to be produced. In the RBMK design, this makes the reactors extremely dangerous to operate at low power (such as the 200 MWt at which the

Chernobyl 4 reactor was operating), as more heat creates a positive feedback loop where more power creates more steam which generates more power [13]. The positive void coefficient in the original RBMK design makes this risk unique to the RBMK reactor.

The poor design and operation of the manual control rods in the reactor were crucial in the failure to shut down the reactor once the accident was underway.

Interestingly, these rods achieved their intended purpose when both fully inserted and fully removed from the reactor, yet failed as the operator transitioned the control rods from one state to the other. This was due to a ‘positive scram’ effect, which counter intuitively increased rather than decreased the reactivity of the generator during the rods insertion [13]. This malfunction was due to a defect in the design of the reactor’s control rods [Figure 3]. The rods consist of a graphite displacer and an absorber rod, which is used to slow reactivity, separated by a layer of water. However, the control rods were too short, which led to a gap of water beneath the control rod. With the water gap and the graphite tube, as the rods were inserted, the water beneath the rod was displaced, leading to less neutron absorption at the bottom of the reactor, and locally higher reactivity [13]. This problem may have been non-consequential if the rods were inserted quickly, but the fluid in the control rod channel created a mild damping effect that slowed the rod

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Despite the aforementioned failures of the RBMK design, there remain many issues concerning safe operation of the reactors associated with human fallibility. These risks were analyzed by the IAEA and were categorized as “deficiencies in safety culture” [14]. In the initial IAEA report from 1986, which was based largely on accounts from Soviet scientists and officials rather than an independent comprehensive study of the Chernobyl catastrophe itself, the representatives from the USSR suggested that the lack of safety was at the operator level. However, while the reactor’s operators did often fail to meet certain safety standards, it is more accurate to state that the safety culture was flawed from higher up the administrative system [15].

Operator failure preceding the Chernobyl accident stemmed from a pre-existing trend of disregard for safety standards and practices. For example, the emergency core cooling system, which provides an influx of water to cool the reactor core in states of emergency, had been shut down for the entirety of the reactor test. It is presumed that the events of Chernobyl were likely unaffected by shutting down the ECCS, but such

instance of disregard for safety protocol exemplify how human negligence poses a dire risk to nuclear reactors [14]. The issues of failing to follow proper safety guidelines were

Figure 3: Control rod design for the original RBMK. The presence of a water absorber beneath the graphite displacer leads to spikes in reactivity during the rod’s insertion into the tube. Dimensions are given in centimeters. [13]

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compounded on the day of the test when the plant director approved the test without seeking approval from the Soviet Nuclear Oversight Regulator (the Soviet official in Russia who approves reactor maintenance). This communication lapse was exacerbated when operators decided to proceed with the test without informing proper authorities, despite the reactor not being stabilized at a proper 700-1000 MWt range [14]. Finally, the inability to start the test as scheduled due to the grid operator’s request that the plant remain operating should have resulted in the test’s cancellation, yet the test continued taking place over the course of multiple worker shifts.

While the decisions and mistakes of plant operators may seem injudicious, they stem from the larger issue of mismanaged nuclear oversight in the USSR. An example of questionable Soviet responsibility is illustrated by the reasoning behind an operator’s decision to manually shutdown automatic scram behaviors. When the operator chooses to unjustifiably shutdown the scram sequence, it allows the reactor to appear more reliable, as the year-end safety figures would provide a safer representation of the plant than are actually true. In contrast, if the operator were to shut down the reactor at every scram instance, it would shed light on poor plant maintenance and equipment failures which existed throughout the Soviet nuclear industry [15]. The ability of the reactor operators to control certain safety measures allowed the Soviet Union to hide its maintenance issues and report better safety numbers internationally, all while pressing any mistakes on the operator itself. The flawed culture and mismanaged safety standards from the

administration were specifically concerning for RBMKs, as reports surfaced after the incident that many experts had known of the technical issues with the reactors, yet were quieted in order to promote the quality of Soviet nuclear industry [15].

It is useful to note that the IAEA has published two main reports on the

Chernobyl disaster, one in 1986 immediately following the catastrophe, and one in 1992, after the collapse of the Soviet Union. The first report largely relied on the information provided by administration of the USSR, and placed the fault of the accident largely in the hands of the reactor operators, whereas the second report revised this statement, suggesting that the reactor’s design flaws were more significant contributors [13]. This discrepancy plays a huge element in the international view of Russia’s current energy

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system, as a lack of transparency over Chernobyl has led to a paranoia of high-perceived risk with little technical evidence to quell suspicions over the honesty of the Russian nuclear program.

2.3 Reactor Risk and the Nature of Accidents

After Chernobyl, international fears surrounding continued operation of unsafe nuclear power plants and the potential for future industrial accidents emerged. Many nuclear experts on the global stage expressed concerns directed specifically at the utilization of RBMKs both within and outside of Russia. These trepidations exacerbated the growing public fear of nuclear generated power. However, human perception of risk associated with nuclear reactors is often unfairly overstated, and the public’s ability to influence political representatives unfairly impact funding for research and development. Understanding the reasons supporting the public’s perceived risk compared to the actual risks that exist can provide a better understanding of how reactor risk is analyzed and mitigated. Often industry transparency is dwarfed by media propaganda arousing alarm and lack of consensus amongst industry leaders. At a technical level, an analysis can be accomplished by scrutinizing common causes of reactor failures compared to a

probabilistic safety analysis (PSA); one of the most commonly used safety assessment tools for nuclear reactors.

Studies suggest people reevaluate their opinion of risk as new information becomes available; however, lack of consensus amongst the scientific community regarding the actual risks of operating nuclear reactors makes the release of new information less credible [16]. Major nuclear accidents are relatively infrequent

compared to accidents in other energy sectors, making it hard to accumulate concrete risk analysis data to quell negative public perception [16]. Public doubt due to the absence of scientific consensus and information is aggravated when the media blows minor reactor malfunctions out of proportion and regulator transparency fails to keep people at ease. This creates a cycle of conflict, as too much transparency allows media outlets to attack

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potentially negligible incidents, causing public fear, and too little transparency allows the media to question what is actually occurring at nuclear power plants, leading to public skepticism. The negative perception of risk will be what leads to the downfall of most nuclear industries.

In reality, the main nuclear reactor operating risks can be categorized as technical risk and procedural risk. Technical risks are contributed to flawed reactor design or construction defects. The Chernobyl reactor exemplifies this where the positive void coefficient and the improperly designed control rods led to rapid increase in the reactor’s reactivity, causing the explosions to occur. Additionally, some technical risks can occur due to disparate variables such as geographic location or regional meteorology, as was the case with the Fukushima. In 2008, the plant was discovered to be susceptible to potential tsunami flooding, which ended up being the cause for the complex’s 2011 disaster [17]. Technical risks such as these are hard to identify prior to accidents due to the complex system design which involves many codependent parts to operate properly, and which behave differently from reactor to reactor.

Technical vulnerabilities are usually compounded by procedural risk, or human fallibility, which can be further broken down into administrative risks and operator risks. Most operator risk occurs during reactor emergencies, when a lack of understanding compounded with a technical issue creates a misstep in the operator’s response to the reactor failure. This is highlighted in the Chernobyl investigation where it was discovered the reactor operators did not understand the effects of the manual control rods on

reactivity during the scram procedure. In another example, In the TMI incident, this human-technical interplay occurred due to a steam valve indicator issue. Here a pressured steam valve malfunction and a steam valve indicator on the control board did not

properly indicate the condition of the steam valve. This improper status indicator led to the current operator’s failure in identify the problem with the valve, leading to a rupture [18]. Administrative risk occurs as the result of regulatory forbearance or regulatory capture. Regulatory forbearance transpires when authorities consciously fail to intervene, such as the case of Fukushima where regulators neglected to address the tsunami flood risk. Regulatory capture exists when authorities act to advance personal or political

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agendas instead of promoting public interest, for example KGB hiding documents indicating flaws with the RBMK design resulting in Chernobyl[17][10].

The possible combinations of unresolved or unknown technical issues and the potential for human error are too vast and complex to be analyzed individually, which is why PSAs are commonly employed. The purpose of the PSA is to “provide quantitative results in the form of point estimate and probability distributions that a risk event will occur” [19]. This type of analysis helps to provide intelligible safety issue identification on a plant specific basis, and allows improved resource allocation to resolve the identified problems. PSAs rely on event tree and fault tree analyses in an attempt to uncover the probability of all potential reactor outcomes [19]. This methodology has led to three PSA levels used internationally to evaluate reactor risk:

Level 1: The assessment of plant failures leading to the determination of core damage frequency. (Figure 4)

Level 2: The assessment of containment response leading, together with Level 1 results, to the determination of containment release frequencies. (Figure 5) Level 3: The assessment of off-site consequences leading, together with the results of Level 2 analysis, to estimates of public risks. [20]

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Figure 4: An example logic tree of the level one PSAs [20].

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While PSAs are viewed as good standard of practice, several factors such as new operational procedures, new technological advancements, and new plant research

influence the result of a PSA at any given time. Therefore, the PSA of each power plant should be updated regularly as more factors are identified and updates are made to the plant. Finally, while PSAs have been conducted in western countries since the 1970s, it should be noted that it is a relatively new practice in Russia, only being introduced after the collapse of the Soviet Union.

3. Analysis of Modern RBMK’s in Russia

After Chernobyl, all planned RBMK construction projects in the Soviet Union were cancelled, except for the Smolensk-3 reactor, which was already near completion. In addition, with encouragement from the IAEA and western political powers, five reactors outside of Russia (three at Chernobyl in the Ukraine and two at Ignalia in

Lithuania) have been shut down prior to their scheduled decommissioning. Presently, the Russian Federation is the only country to continue operating RBMK reactors with only the 1000 MWe RBMKs currently active [21].

Due to Russia’s failing economy and questionable political structure following the collapse of the Soviet Union, very few nuclear power plants of any type were constructed from the early 1990s to the mid-2000s. This lack of investment and innovation in the nuclear energy sector fostered the decline of the energy infrastructure in Russia and the potential loss of its nuclear power industry. While the country has vast natural gas reserves available for energy production, it maintains the desire to remain energy diverse through nuclear power [21]. In 2006 Russia’s state atomic energy corporation, Rosatom, requested approval to extend most of the current reactor lifetimes, including the

RBMK’s, by 15 years despite their questionable operating statuses. Rosatom has

expressed it is more economically viable and safer to extend the lifetime of RBMKs than to expedite the commissioning of new reactors. This rational is supported by the

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effective enough to warrant lifetime extensions. Nevertheless, almost all RBMKs are scheduled to be completely decommissioned by the end of 2030, ultimately being

replaced by VVERs [21]. As illustrated in Figure 6 and Figure 7, the VVER reactors will be replacing RBMK reactor generation, not increasing overall industry capacity.

39% 52% 4% 5%

2017

3% 46% 47% 4%

2030

RBMK Pre V-338 Model VVERs Post V-338 VVERs Other

Figure 6: A side-by-side comparison of the current reactor distribution and the project reactor distribution for 2030 [21].

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3.1 Safety

Following Chernobyl, the Russian Federation, with reassurances from their European peers, modified the existing RBMK reactors to improve their safety standards. The key improvements specifically addressed the design deficiencies identified in the Chernobyl investigations and more generally focused on:

 increasing automated safety features to bring the reactors to stable condition when necessary

 decreasing the reactors ability to succumb to run away reactivity levels

 mitigating the potential for human error by restricting the ability of the operator to circumvent certain engineered safety features

 adding radiation containment measures

Several other initiatives have been conducted on an international level to determine whether additional updates would further improve the safety of the RBMK reactors [22]. In conjunction with the technical upgrades to augment reactor safety, Russia has been urged by international groups to update its procedural safety protocol to improve the safety culture of its nuclear industry. While these changes appear to have vastly improved

0 5000 10000 15000 20000 25000 30000 35000 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 Cap acity (MW e)

RBMK Pre V-338 Model VVERs Post V-338 VVERs Other

Figure 7: Total capacity organized by reactor type from now until 2030. Noticeably the RBMK capacity is declining while new generation VVERs are constructed [21].

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the safe operation of RBMKs, Russia’s lack of transparency has made it difficult to manage the perceived risks of the reactors both domestically and abroad [22].

The specific technical safety issues identified during the investigation of

Chernobyl have been meticulously addressed by lowering the positive void coefficient, modifying the “positive scram” control rods, and improving the Emergency Protection System (EPS) [3]. The positive void coefficient, which led to unstable operation

conditions and run away reactivity levels, has been resolved by installing more absorbers, increasing the enrichment of the fuel, and increasing the number of control rods.

Absorbers make it difficult for the reactor to operate at low power so an increase in the number of absorbers prevents the reactor from being able to run at low the 200MWe of power, which contributed to Chernobyl. To counteract the effects of the absorbers lowering the reactivity of the reactor, the enrichment of the uranium used required an increase from 2.0% to 2.8% to remain operational. Conveniently, this level of uranium is easily accessible, as most RBMKs now use recycled uranium from VVER reactors, improving resource efficacy [3]. The addition of more control rods, from 26-30 to 43-48 depending on the reactor, increased the operating reactivity margin (ORM), or the “effective number of control rods in the core,” allowing for better control over the reactor’s activity. The increase in the ORM was supplemented with improvements to the on board computation of the reactor, giving operators a more precise knowledge of current reactor conditions [3].

Another enhancement to manage runaway reactivity was to improve the control rod design. The issues with the original design were twofold. The first had to do with water displacement that occurred in the bottom of the core as the graphite tip was inserted. To mitigate this, the control rods were modified so that there would be no excess water located in the bottom of the control rod tubes [3]. Secondly, the absorbing section of the control rod could be fully removed from the reactor’s core, causing the insertion of graphite to increase reactivity without any absorption offset [3]. This issue was amended by lowering of the height of the control rods, as can be seen in Figure 8.

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The adjustments to the original control rod design also improved the efficiency and response speed of the EPS. The modified control rods allowed for reduced insertion time from 18 to 12s, as the removal of water from the bottom of the control rod channels decreased the damping effect of insertion. This decrease in time improved the speed of the emergency response, mitigating the level of runaway activity. In addition to the benefits of the improved control rod design, a new automatic fast-acting EPS was

implemented, which decreased reactivity by a factor of two in under 2.5 seconds with the quick insertion of 24 extra control rods [3]. The improvement of the EPS created a superior automated safety system to shut down the reactor should an emergency transpire.

Supplementary technical enhancements were conducted at the individual RBMK NPPs; however, a noticeable deficiency included the failure to implement full

containment buildings around the reactors. One goal of the RBMK’s design was to be quick and inexpensive for the Soviet Union to construct and maintain, and the inclusion of a containment building was estimated to double construction cost and time. Russian authorities believed that if the reactors were operated properly, it was impossible for them to fail, and thus the FSU chose to ignore the need for any additional containment [22]. The consequences of the omission of a containment unit in the design plan were stressed

Figure 8: Modified control rod of the RBMK. Absence of a water absorber beneath the graphite displacer removed the spikes of reactivity during the rod’s insertion into the tube. Dimensions are given in centimeters. [13]

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in the aftermath of Chernobyl, as radiation leaks had no way of being contained following the reactor explosion. Subsequently, some RBMK partial containment structures have been added around the fuel-channels of the reactors, yet no full reactor containment buildings have been constructed around any RBMK reactors [22]. While this fact does not affect the safe operation of the reactors themselves, it leads to concerns regarding the capability of meltdown prevention measures.

In response to the IAEA 1992 report, Russia has made considerable

improvements to its safety procedures over the past decades. In the period immediately following the Soviet Union’s collapse, according to data collected between the collapse of the Soviet Union to 2003, RBMKs actually experienced fewer shutdowns per unit of time than the world average [Figure 9][23]. Additionally, according to a report filed by the IAEA Operational Safety and Review Team (OSART) in 2015, which provides “objective assessment[s] of operational safety status for individual reactors,” Russia has implemented suggestions for safety improvements to a greater extent than were actually recommended. The same report, which also evaluates changes to reactor operation on a recommendation, suggestion, and good practice scale, noted that Russia has had fewer recommendations than the international average, as can be seen in Figure 10 [24]. An increased understanding of nuclear power plant safety operations over the last decade has stimulated the Russian focus on RMBK safety issues. In fact, Further investigations, as recent as 2015, have suggested that Russia has continued this trend of strengthened safety [25]. While the aforementioned statistics help enhance the perception of safety in the Russian nuclear industry, there are notable flaws in the legitimacy of the actual safety evaluations of RBMKs. These shortcomings are illustrated by infrequent PSAs conducted at Russian reactors. Level 1 PSAs were performed on various RBMK plants throughout the 90s and into the early 00’s, but since then only VVERs have received extensive PSAs with results shared to the international community. In contrast, either RBMKs have yet to be extensively analyzed or PSA results are inaccessible by the public to be common knowledge [20].

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Figure 9: Performance in terms of scrams/unit time of the RBMK average vs the world average. [23]

Figure 10: Comparison of four individual Russian OSART tests to the world average. Notably, Russian safety recommendations are low compared to the world average, while suggestions and good practices are similar worldwide. [24]

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Lack of transparency is an undermining trend in the Russian nuclear industry, so despite efforts to improve safety measures, the international community and Russian citizens continue to doubt the safe operation of RBMKs. Fueling this skepticism, reports of recent events from anti-nuclear media outlets provoke fear in the Russian public. In 2012, the shutdown of the Leningrad I reactor due to deformations in the reactor’s graphite core generated speculation from news reporters [26]. The reports went on to disclose that though Rosenergoatom, the nuclear power station subsidiary of Rosatom, mentioned maintenance had been planned, many experts believed the repairs only became planned after the malformation was identified. Media outlets criticized

Rosenergoatom’s communications as vague, implying distrust in the Russian state energy corporation and suggesting the reactor’s unexpected shutdown increased public fear of continued RBMK operation [26]. This anecdote highlights how the media's power combined with the lack of government transparency has incited the public-perceived risk of ongoing RBMK use.

The catastrophic nature of nuclear industrial accidents arouses the inherent fear of nuclear fallout, diminishing public perception of reactor safety. However, it is important to compare the performance of nuclear energy with regards to safety to other forms of energy generation. Nuclear engineers and regulators emphasize that “no individual should bear a significant additional risk due to NPP operation and the societal risks of NPP operations should not be a significant addition to other social risks” [27]. Although Chernobyl experienced higher incidents of thyroid cancer in children and increased lifetime radiation dose of its inhabitants, generally, the use of nuclear power (including RBMKs) has led to fewer deaths per amount of energy produced and less loss of life expectancy than almost any other energy source [Figure 11] [27]. This is especially true when considering the entirety of the energy cycle for each nuclear power plant. This information is not cause for stagnating nuclear safety standards, but it does highlight how

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the effects of extreme isolated incidents can skew the public’s perception on the safety of specific technologies.

3.2 Economic Significance

Currently, the Russian economy depends heavily on natural gas, as the state controls the largest natural gas reserves in the world. This significant resource has led the country to rely on natural gas as a critical energy source and a major export to support their GDP [9]. Enterprise in diverse energy segments allows Russia to facilitate

continuous economic production explaining the large investment in nuclear power, with over 16% of all electricity generation coming from NPPs [9]. In a breakdown of the

Figure 11: Comparison of the years of loss life per TWh produced for various technologies. Sources compared are pulverized coal, lignite coal, natural gas, hydroelectric, biomass wind, photovoltaics, and nuclear power plants. [27]

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Russian energy system, thermal plants generate roughly 63% of electricity, while hydropower generates 21% and nuclear generates roughly 16%. Of the 16%, Russian RBMKs, make up approximately 38.3% [28].

The country’s reliance on energy diversity to support its economy is a major reason Russia has not decommissioned its RBMKs. A key economic benefit of nuclear energy generation is that NPPs can operate 24/7 with relatively few required shutdowns per year. This makes nuclear energy a reliable and permanent energy source [9]. For Russia, nuclear production is especially useful, as 80% of the country’s natural energy resources are located in the eastern half of the country, while over 75% of the population lives in the western portion [9]. This disconnect generates significant costs to transport resources such as natural gas across the country for domestic power generation. These costs are exacerbated by Russian industry circumventing traditional cash payment methods by using informal methods such as bartering, which remove company accessible cash flow. Additionally, investment in the country’s own nuclear infrastructure allows for further innovation in the nuclear industry, creating a market for Russia to export its nuclear technology [15].

15%

22%

63%

Nuclear Hydro Thermal

Figure 12: Percent of total electricity generation by power type in the Russian Federation.

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Nuclear power expenses are mostly concentrated in three categories: capital costs, plant operating costs, and external costs. The capital costs include most of the

pre-operation costs of the plant, including planning, preparing, manufacturing, and commissioning costs [28]. Costs such as raw materials for plant operators and

construction worker’s wages are included in this outlay. Plant operating costs includes fuel, operating, maintaining, and decommissioning costs for the plant. These costs include both fixed costs and variable costs, which are independent and dependent on electricity generation, respectively [28]. External costs are the amounts owed to society stemming from plant operation, such as cleanup for environmental impacts and waste disposal. Due to regulations monitoring nuclear power, most of these costs are absorbed by the NPP operating plan. In comparison, other energy production facilities such as natural gas must pay for externalized costs such as greenhouse gas emissions [28]. Therefore, nuclear external costs are typically assumed zero, except in cases of serious accidents resulting in excessive clean up and environmental mitigation expenditures. To compare nuclear power costs to other energy types, costs are normalized to the electricity units capable of being produced through the levelized cost of electricity (LCOE) [28].

Capital costs, also known as investment outlays, are typically the largest expense for NPPs, especially in comparison to thermal plants. This is predominately attributed to the massive scope of NPP construction [28]. These costs include everything from labor to cost of materials, which vary depending on the state in which the reactor is being built. For example, in China, where labor is inexpensive, the capital costs of reactor

construction would be much lower than in Western Europe [28]. Construction completion time also affects capital costs because most projects are funded by bank loans; longer projects and potential delays inherently affect interest rates. Since these expenses only pertain to the construction of new NPPs, Russia is incentivized by the cost savings to keep the plants using RBMK reactors operating [28].

Operating costs include both fixed and variable costs of running NPPs. The fixed costs for nuclear reactors include paying wages, powering facilities at the plant, and the regular planned maintenance and operations of the plants. The variable costs include fuel expenses and expenditures to replace wearable elements in the reactor. For RBMKs, the

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costs of fuel are difficult to compute because their ability to use VVER waste fuel decreases the total investment required for nuclear energy production in Russia [28]. Unfortunately, these savings are offset by frequent unscheduled maintenance and equipment replacement due to the older design of the RBMKs.

The notion that NPPs have zero external costs stems from the rarity of major nuclear accidents. In the case of a catastrophic event, cleanup and reparations are usually paid for by government organizations, as a form of government social responsibility, because private insurers find the risk to be uninsurable and are unwilling to offer coverage. Case in point, the cost to clean up the Chernobyl disaster was estimated to be $235 billion, exceeding the insurance industry’s capacity for indemnification [30]. Therefore, while external costs are low for safely operating NPPs, they have the potential to be exorbitant if the plant fails catastrophically [30].

LCOE for new nuclear power plants compared to other energy sources indicates that nuclear energy is highly competitive on the global stage. This is contributed to the majority of nuclear costs being allocated to pre-operational capital costs, whereas the bulk of carbon intensive energy costs come from fuel and carbon expenses [30]. A study conducted by the World Nuclear Association illustrates how the LCOEs compare for various energy sources across several regions in Figure 13 [30].

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Although Russia is not explicitly analyzed in Figure 13, inferences of their LCOE results can be made through comparisons to the included countries. First, Russia is the number one producer of natural gas in the world, thus its relative resource acquisition for natural gas is lower than that of other countries without access to significant natural gas reserves. For example, Russia has more natural gas than the United States, so it can be presumed that Russia’s natural gas production LCOE would be comparable to that of the United States [31]. In addition, Gazprom, Russia’s primary natural gas producer, is majority owned by the Russia government and therefore resource acquisition should be even less expensive [31]. Without access to costs of Russian resources, it is difficult to make accurate predictions of Russian electricity costs, but it can be assumed that Russia’s most efficient method for generating electricity would come from the nation’s most abundant resource.

Despite the fact that Russia’s LCOE for natural gas should be low compared to the country’s LCOE for new nuclear power plants, existing nuclear power plants tend to

Figure 13: Comparison of the LCOEs for various generation types in different countries. [30]

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be much more effective in terms of LCOE [31]. Once again, this is due to the primary costs of nuclear power plants being the capital costs that are essential to construct the NPPs. With these costs out of the way, as is the case for RBMKs, the only costs that continue to exist are operations and maintenance and fuel costs, both of which are low compared to other energy industries. The production of Uranium fuel for nuclear power is also generally cheaper than the production of fuels for thermal plants, and this factor becomes even more beneficial for RBMKs as they use recycled fuel from VVER plants, further lowering costs [31]. In general, these factors indicate the once reactors have been constructed, they are one of the cheapest sources of energy, if no extraneous external costs, such as incident like Chernobyl, are incurred.

3.2 Political Significance

The political significance of Russia’s RBMKs exist at a regional, national, and international level. Currently, the international significance largely relies on their relation to the Chernobyl incident. As such, these reactors are what led the international nuclear community to begin operating nuclear projects in the Russian country. Due to the nature of the start of the international involvement, many still believe that Russia should stop their RBMK operations, which causes much of the international cooperation to be about the safety of continued operation [15]. These types of international concerns are difficult to address, and largely are caused by both skepticism of politics in Russia in general.

Russia’s other international political quandaries are in relation to their nuclear exports. These exports include nuclear fuel, nuclear operational equipment, and nuclear reactors themselves. While these types of exports are not directly related to the RBMKs in the Russian Federation, RBMK politics do involve the social economic responsibility Russia has maintained in the ex-Soviet states that had possessed these reactors [15]. This has led to Russia’s continued involvement in the Ukraine and Lithuania, the only other countries to possess RBMKs.

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Nationally, Russia’s interest in nuclear politics largely has to do with the

country’s current national nuclear corporation, Rosatom. Despite Rosatom’s relevance to Russia’s energy production and its state operated status, there have been questions over whether or not Russia will continue to use government support for Rosatom’s future projects [21]. This removal of political influence from Russia’s largest nuclear company may cause delays in future reactor production, leading to the continued operation of current reactors such as the RBMKs in order to maintain the country’s current profits [21]. Despite the Russian government’s thoughts on possibly ending state support, the country still seems to be moving forward with nuclear power.

RBMK’s are prominent in Russian nuclear politics due to their regional

significance. Most importantly, each NPP is the largest contributor to the electrical grid in the region in which they operate. According to the Rosenergotaom website, the Smolensk NPP shares 80% of the power production in the Smolensk Oblast, the Kursk NPP shares over 50% in the Black Earth area, and the Leningrad NPP contributes over 50% to the city of St. Petersburg and the rest of the Leningrad Oblast [31]. In addition to these native regional exports, the Leningrad reactor also significantly contributes to the international electrical grids in the Baltic States, while the Kursk power plant contributes to the Ukraine. The Leningrad reactor’s contributions to the country’s energy exports result in ample funding, which partially explains why the RBMKs at the Leningrad plant will be the first to be phased out with the introduction of new VVERs [15].

4. Analysis and Conclusions

Ultimately, while international fears in the wake of Chernobyl continue to pressure the Russian federation to shut down their RBMK reactors, Russia has no incentive to shut down their reactors. For the simplest reason, it appears that despite the fear of another Chernobyl, modern Russia addressed the design and operational concerns of the reactor. The fixing of the positive void coefficient along with the addressing of the flawed control rod issues has made the reactors operationally safe enough to the point where Russia has justified extending the reactors’ lifetimes by 15 years. This, combined

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with addressing human operational errors by editing soviet safety culture from both an operational standpoint and an administrative standpoint seems to have addressed a majority of the concerns from an internal standpoint. To add validity to these

adjustments, Russia’s inclusion of international regulatory bodies such as the IAEA in the country’s nuclear policy seems to reflect the redirection from Soviet era flaws.

Additionally to the safety issues that were addressed, it would be ill advised for Russia to shut down their RBMKs prior to their currently extended decommissioning date from an economic and political standpoint. Had Russia not gone through a period of political and economic turmoil following the collapse of the Soviet Union, it may have been advisable for Russia to not extend their reactors and to update their reactor technology during the 1990s. However, since the disruption forced Russia’s nuclear industry to take a backseat, the gap in technology has forced Russia to maintain its current technology while it undergoes new construction over the next 20 years. If Russia were to shut down RBMKs immediately, they would lose a large amount of power generation in regions that are heavily dependent on the power supplied by the Reactors. For example, such a shutdown would remove over 50% of the generative capacity for Russia’s second largest city, St. Petersburg, without currently having the infrastructure to replace it. These power shutdowns would occur in conjunction with a loss of available power exports, which contribute to regional Russian economies. Furthermore, while the reactors could potentially be replaced with cheap thermal plants that could be constructed and operated cheaply, the continuation of RBMKs is still the preferable option. Despite the continued need to maintain the operating reactors, ultimately their bulk costs are already paid capital costs, meaning continued operation of these plants will always be the cheapest option, except in the case of a catastrophic failure.

While the research suggests that Russia should absolutely continue use of the RBMKs, it also suggests that some policy changes should be undertaken in order to further validate the Russian nuclear sector as a whole. To start, transparency is recommended both nationally and internationally, as it is the only way to remove perceived risk from the RBMK equation. It is understandable that Russia may choose to remain nontransparent if actual risks do exist; however, the advantage of being

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transparent even in these situations is the ability of the international community to address potential concerns as quickly and as efficiently as possible. In conjunction with transparency, Russia should continue to westernize its nuclear policies while working with international bodies to address generic safety issues. The inclusion of the western safety culture has led to positive changes in Russian nuclear industry that should be continued. Additionally, the furthering of PSA conduction in the state would add validity to the safety changes that have been made, and also may help uncover other issues that can be addressed.

4.1 Future Work

As these reports are information sensitive, it is recommended to update these types of reports relatively often as new information becomes available. Additionally, these types of reports can be extended to all types of reactors in Russia, and such studies of the economic and political benefits could be useful in helping to justify the

introduction of the next generation of VVERs for Russian nuclear energy, especially if they are made publicly accessible. Furthermore, in order to make this study more comprehensive, further exploration into the costs of modifications and maintenance of RBMKs vs the costs of thermal plants can be conducted. Such information can be difficult to access, but a more comprehensive study can help validate some of the generalizations made about nuclear economics in this study.

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