Four years ago, on March 11, 2011, a powerful earthquake triggered a massive tsunami that struck Japan’s northeastern Fukushima prefecture and led to a nuclear disaster – multiple reactor core meltdowns – at the Fukushima Daichi nuclear power plant. Unsurprisingly, that event prompted numerous national governments to reevaluate existing nuclear power plant safety regulations, with differing results.

Re-examinations of nuclear reactor security were launched in many of the 31 countries around the world, which possess “over 435 [operable] commercial nuclear power reactors (…) with over 375,000 MWe of total capacity [while about] 70 more reactors are under construction,” World Nuclear Association data show. The IEA stressed on the occasion of its January launch of the 2015 edition of the “Technology Roadmap: Nuclear Energy” that nuclear safety is of paramount importance: “Nuclear safety remains the highest priority for the nuclear sector. Regulators have a major role to play to ensure that all operations are carried out with the highest levels of safety. Safety culture must be promoted at all levels in the nuclear sector (operators and industry, including the supply chain, and regulators) and especially in newcomer countries.”

This is even more salient in a climate-constrained world in which 2014 “marked the greatest number of reactors being built in 25 years.” It is in this context that IEA Executive Director Maria van der Hoeven reminded the public that “[n]uclear energy (…) remains the second-largest source of low-carbon electricity worldwide. And indeed if we are to meet our collective climate goals, nuclear energy is critical. In fact, to efficiently meet the target of limiting average global temperature rise to 2 degrees Celsius, global nuclear capacity must more than double by 2050.”

 Source: IEA / NEA

Calls for tougher international safety standards followed in the wake of the Fukushima disaster, which resulted in a push to tighten respective measures by amending the Convention on Nuclear Safety (CNS). The CNS’s explicit aim is to “legally commit participating States operating land-based nuclear power plants to maintain a high level of safety by setting international benchmarks to which States would subscribe.” Most importantly, the “obligations of the Parties are based to a large extent on the principles contained in the IAEA Safety Fundamentals document ‘The Safety of Nuclear Installations’ [covering] siting, design, construction, operation, the availability of adequate financial and human resources, the assessment and verification of safety, quality assurance and emergency preparedness.”

In this respect, it is important to understand that the CNS is an “incentive instrument” with no enforcement mechanism. It is primarily built around the principles and practices of ‘peer review’. That may explain why the US, one of a total of 77 ‘Contracting Parties’, has also ratified this Convention, which entered into force on July 10, 1999.

Eventually, an international diplomatic effort spearheaded by Switzerland to amend the Convention on Nuclear Safety at the Diplomatic Conference 2015 held on February 9, 2015 at the IAEA Headquarters in Vienna (Austria) failed. Bloomberg’s Jonathan Tirone described the Swiss-led European initiative as “intended to make regulators show how they mitigate against radioactive contamination from nuclear accidents like the March 2011 Fukushima Dai-Ichi meltdowns.” He added that strengthening international nuclear safety rules faced both American and Russian opposition from the very beginning because it would have forced costly reactor upgrades. This is especially true for those countries with older reactors. Nevertheless, Tirone writes that “the U.S. has insisted its opposition to the European initiative has nothing to do with cost and that its nuclear-safety controls are adequate.”

Mark Hibbs, Senior Associate Nuclear Policy Program at the Carnegie Endowment for International Peace, also thinks that the ‘upgrade costs for older reactors’ argument particularly applies to the US case. He stated in an article about the CNS: “For many parties, the proposal’s implications for new reactors were, in principle, not problematic. But its potential impact on existing plants led countries operating older reactors—including the United States—to object. They argued that these plants would have to be shut down because equipping them with state-of-the-art features would be prohibitively expensive and in some cases not feasible.” Besides, he cites every country’s ‘darling argument’ in international diplomacy – i.e. violation of one’s sovereignty – as an additional reason for important nuclear power–generating states such as the US or China to reject such an amendment to the Convention.

Most importantly, Mark Hibbs makes a crucial point with regard to the safety of older reactors in general, contrasting two real-world approaches with respect to risk mitigation associated with older nuclear power plants:

“According to calculations of the theoretical probabilities of accident scenarios, older nuclear power plant designs are less safe. But there may be mitigating factors in the real world. At stake in the amendment debate were different philosophies about how to reduce the risk associated with older plants. European countries (…) have for years compelled nuclear power plant owners to continually upgrade their units, at a cost that was not considered prohibitive because electricity markets were highly regulated and monopolistic. In the United States, where market forces reign supreme, a different approach to safety has been followed, resulting in fewer expensive plant design changes and, instead, less intrusive and less costly measures that industry and regulators assert are effective. U.S. experts acknowledge that if the CNS were to compel older units to undergo major surgery, many of the units may have to be closed.”

The US is the world’s largest producer of nuclear power, with 30 per cent of global nuclear power generation capacity, and currently operates 99 nuclear power reactor units (98.7 GW total capacity) – according to data by the World Nuclear Association – with an additional five under construction. As such, it is understandable from a cost perspective what an amendment to the Convention would have meant for the US in particular. Note, the following charts illustrate another key point; namely, that nuclear power plant construction starts peaked throughout the 1970s after having taken off earlier in the late 1960s, which renders a large portion of the global nuclear power plant fleet older than 30 years thereby disproportionately affecting the US nuclear power plant fleet.

Source: IEA / NEA

Source: The World Nuclear Industry Status Report 2014 (Mycle Schneider Consulting)

This status report finds that three-quarters of nuclear power plants globally – out of a total of 388 units at the time of writing – are at least 20 years old. Moreover, a total of 172 are even older having already reached age 30 and over. The report’s authors emphasize that “[a]s of mid-2014, 39 of the world’s operating reactors have exceeded the 40-year mark [and as] the age pyramid illustrates, that number could rapidly increase over the next few years.”

Interestingly, “none of the 120 reactors started up in the past 25 years (since 1989) has been permanently shut down yet,” they add. The mean global nuclear reactor age of 28.5 years does not indicate a danger for the public from an operational standpoint per se given that the typical original lifespan for a nuclear power reactor used to be 40 years of operation. However, the US nuclear industry is in the process of extending those original 40-year licenses via a re-licensing process in which the Nuclear Regulatory Commission (NRC) issues additional 20-year license renewals thereby bringing a typical US nuclear power plant’s lifespan up to 60 years of operation.

According to the EIA, the NRC has granted operating license renewals – i.e. providing a 20-year extension – to a total of 74 of the 99 operating reactors in the US. The EIA notes that “[t]o date, no applications for a second, or subsequent, license renewal, which could extend nuclear plant operating lives to 80 years, have been filed.” However, that is likely to change because new nuclear power plant construction starts are in no way able nor intended to replace retired/decommissioned nuclear power plant capacity in the US. As these plants retire, replacing their considerable share of low-carbon generating capacity – often above 1,000 MW for a single plant – is a massive challenge.

The US approach to extending nuclear reactor lifespans coupled with the ‘cost-oriented’ US (NRC) approach to nuclear reactor safety upgrades to older reactors begs the question whether the US is sacrificing safety in the name of cost. Under US regulations, nuclear power plants do not have to invest in new safety equipment that is deemed too expensive by the NRC based on their cost-benefit analysis system.

There is no question that since 2009 US utilities operating nuclear power plants faced stiff competition from lower US natural gas prices. Historically cheap natural gas prices have exposed nuclear power plant operators to immense cost pressure that has brought the economic viability of operating older plants into question. Indeed, Entergy largely cited economic factors in its decision to decommission the Vermont Yankee Nuclear Power Station in Vernon, Vermont.

Meanwhile, Bloomberg’s Jonathan Tirone cites France – the world’s most nuclear-reliant country with 75 per cent of its energy supplies coming from nuclear power production – as an example for “installing reinforced bunkers, back-up power and emergency cooling systems” in the wake of the Fukushima disaster. By comparison, the US approach is softer on nuclear power plant operators and thus far has not resulted in ‘real’ safety improvements.

Given current regulatory inertia, it unfortunately appears that a nuclear accident on US soil would be required to motivate politicians and regulators to mandate serious safety upgrades to existing nuclear power plants. Admittedly, it is difficult to define what ‘real nuclear safety improvements’ would be and how to determine what constitutes ‘immediately necessary nuclear safety improvement’. So far, with no serious nuclear event in the US since 1979, the nuclear industry and the NRC as regulator have every right to call nuclear safety and control regulation adequate and effective.

However, that good safety track record looks set to be tested further as nuclear power plant license extensions allow many of these facilities to remain online for additional 20-year periods. The domestic US regulatory nuclear safety approach and framework raises the question of whether US nuclear reactors are protected against accidents that have been assessed as highly unlikely, like the disaster that struck Fukushima.

Keep reading Breaking Energy for a follow-up article that will be published as part of our US Nuclear Investigation series. The next article will shed light on the above questions by examining the domestic US NRC operating reactor licensing process and regulations regarding the implementation of ‘Post-Fukushima’ requirements; especially regarding any mandatory implementation of higher safety measures as needed after an initial operating license has been issued. Breaking Energy obtained documents under the Freedom of Information Act (FOIA) that suggest cost sensitivity could be playing a disproportionate role in the assessment of US nuclear plant safety risk.