Small Modular Reactors: Will they change anything? | S.G.Vombatkere

In her 2024 Union Budget speech, the Finance Minister said, "Nuclear energy is expected to form a very significant part of the energy mix of Viksit Bharat. Towards that pursuit, our government will partner with private firms for setting up of Bharat Small Reactors, conduct research and development on Bharat Small Modular Reactor and newer technologies for nuclear energy". [1] Funding for R&D in Small Modular Reactor (SMR) technology is budgeted at ₹1-trillion. [2]

India already has 22 operating nuclear reactors in seven nuclear power plants (NPPs), with a total installed capacity of 6,780-MWe. In addition, eight new reactors with 6,000-MWe capacity are under construction. [3] Nuclear power capacity is expected to reach 22,480-MWe by 2031. SMRs can contribute towards this target.

SMRs

SMRs typically have a power capacity of less than 300-MWt per unit. SMR technology allows factory-based production of modules, which can be assembled at site, to save time and costs.

SMRs claim other advantages, although these are not demonstrated. [4] They are, simplicity of design, a high level of passive or inherent safety in event of malfunction, providing resistance to attack by emplacement below ground level, and stand-alone installation and operation.

As of 2023, only China and Russia have successfully built operational SMRs. The U.S Department of Energy had estimated the first SMR would be completed around 2030 by NuScale Power, but this deal has reportedly fallen through because customers backed out due to rising costs. [5]

Notwithstanding the unproven claims of SMRs, fabrication and integration of the modules calls for greater quality control and quality assurance, for materials and processes. It also demands very strict regulatory oversight at every stage of production of each module, and later, when assembling the modules at site, and commissioning operation.

Nuclear installations, Public Health and Public Safety

Public health and public safety [Ref.6] with respect to nuclear radiation from NPPs and nuclear fuel cycle installations, are matters of national security and larger public interest.

The International Atomic Energy Agency (IAEA) safety standards implicitly express finite threats and risks to public health and environment, and danger to life and property from nuclear radiation. The safety standards also reveal that, “There is no threshold dose below which there is no effect†. [6] The double negative means that every radiation dose affects biological systems, with cumulative damage.

These threats and risks arise from nuclear installations that create or release radionuclides as part of their functioning.

All aspects of NPPs and ancillary nuclear installations are under the scientific, technical and administrative control of the Atomic Energy Commission (AEC) and the Department of Atomic Energy (DAE) under the authority of the Atomic Energy Act, 1962.

The Atomic Energy Regulatory Board (AERB) is India’s national nuclear regulatory body. AERB’s mission [7] is ensuring that the use of ionising radiation and nuclear energy does not cause undue risk to the health of people and the environment [emphasis supplied]†.

AERB’s mandate is to conduct regulatory checks on NPPs and nuclear fuel cycle installations operated by DAE, and in DAE‘s industrial and research facilities. The checks are in line with IAEA safety standards, and limits set by the International Commission on Radiological Protection (ICRP).

AERB specifies the limits in terms of quantity and activity content of radioactive waste that can be disposed, to protect public health and safety. Thus, AERB oversees all DAE functions, concerning public health and safety.

The mass production of SMRs will call for hugely magnified need for regulatory oversight and control, for adherence to production and safety standards, at all stages of production and module assembly, and subsequently for starting-up and operation.

Regulatory oversight

Regulatory oversight of nuclear installations is essential, because:

• The presence or intensity of nuclear radiation cannot be detected by human senses, but only by specialized scientific instruments,
• Nuclear installations routinely or accidentally release solid, liquid and gaseous radioactive materials (including nuclides) into the environment, and every radiation dose affects biological systems,
• Nuclear installations generate hazardous wastes. Wastes like used fuel rods, are highly radioactive, and require continuous under-water cooling for several years. Reprocessing used nuclear fuel generates high-level nuclear residual wastes. Less radioactive solid wastes like machinery, instruments and tools, suits, masks, gloves, are disposed by burial.
• Nuclides contaminate the environment, and remain biologically dangerous for periods ranging from weeks to tens of thousands of years, depending upon their half-life period,
• Large-scale nuclear releases as in an accident, are serious health and safety hazards to populations for hundreds of kilometres around,
• Decommissioned nuclear installations present radiation hazards for hundreds of years,
• Pilfered or unaccounted fissionable or radioactive materials, can be misused to fabricate “dirty bombs†.

Can AERB regulate effectively?

AERB’s regulatory effectiveness depends upon its independence from the operator, namely, DAE. However, since AERB functions under AEC, its independence is not assured.

AERB is not an effective regulator, because it is not empowered to independently frame rules, and enforce compliance and penalties. This is stated in Para 6 of Chapter I of the Public Accounts Committee Report, concerning “Grant of independent status to AERB†[8]. It appears that ensuring regulation in keeping with international practice, by establishing an independent Nuclear Safety Regulatory Authority (NSRA), is not a priority for the AEC.

The inadequacy of AERB’s regulatory regime, explained by none other than an AERB Chairman, can only be reduced by establishment of NSRA. [9]

Lack of independent regulatory oversight heightens the risk to public health due to emissions from NPPs and other installations. However, effective implementation of nuclear safety regulations by an independent regulator, can only reduce risks or mitigate severity of "events" on the INES (International Nuclear Events Scale), but not eliminate them. [10]

AERB’s independence will be tested, when it is required to officially notify nuclear “incidents†for compensation payable for public safety and environmental damage, according to the Civil Liability for Nuclear Damage Act, 2010.

Carbon footprint of nuclear installations

NPPs are dependent upon nuclear fuel cycle ancillary installations, for materials essential for their operation. These include uranium mining, uranium refinement, uranium enrichment, fuel pellet fabrication and assembling, used fuel reprocessing, heavy water manufacture, nuclear waste disposal, etc. These installations will need up-scaling to operationalize SMRs.

NPPs, SMRs, and ancillary installations depend upon fossil fuel energy systems for their core operations, and also for every other activity. A holistic and comprehensive institutional energy audit – starting from uranium mining to refinement, fuel manufacture, plant assembly, and physical road or rail transportation between stages, and including handling and disposal of nuclear waste, etc. – will reveal the high degree of dependence of nuclear power generation on fossil fuels.

A NPP’s carbon footprint is not visible at the NPP site, but its carbon footprint occurs in its back-end use of fossil fuels. The nuclear industry’s misleading claim and selling point, is that nuclear power is “clean and green†, because NPPs do not emit smoke, but glosses over routine releases of radiation, claiming it is “below the level of natural radiation†.

Unpredictability of nuclear accidents

The nuclear lobby seeks to placate public fears by arguing that, given the strict control and technical vigilance enforced in nuclear installations, the probability of a nuclear disaster-level (INES-7) accident is extremely small.

Following the 2011 Fukushima disaster, nuclear scientist and AEC Chairman, stated that the probability of accidents at NPPs is “1-in-infinity†. In layman terms, “1-in-infinity†is zero, but mathematically it means infinitesimally small, but not zero. One wonders whether the scientist-Chairman calculated the precise probability. [11]

The “1-in-infinity†assurance is no consolation, because, howsoever small the calculated probability, it cannot predict the time or magnitude of accident – it can happen after 10-years or happen tomorrow. Thus, howsoever rigorous the control and technical vigilance and regulatory oversight, nuclear disaster cannot be prevented.

The ‘1-in-infinity’ conundrum

The location, time of occurrence and intensity of an earthquake, cannot be predicted. A structure can be designed to be collapse-resistant to a certain intensity of earthquake, and still suffer irreparable damage, but no structure can be designed to be earthquake-proof. When a high-intensity earthquake strikes a NPP or SMR, it can trigger INES-7 disaster.

The 2011 Fukushima accident occurred despite the “infinitesimally small†probability of an earthquake-initiated tsunami, which caused reactor cooling system failure. The 1986 Chernobyl accident occurred because an on-duty engineer attempted a reactor test that went out of control. The cause for the 1979 Three Mile Island accident was cooling malfunction in one of the reactors. The 1957 Windscale accident was triggered when routine heating of graphite control elements went out of control. These four global-scale nuclear disasters occurred due to four different unpredictable reasons.

A INES-7 event may have “1-in-infinity†probability, but accidental releases of nuclides from NPPs, lower down in the INES, have greater probability of occurrence.

How does a scientist, who offers “1-in-infinity†assurance of no nuclear accident, explain the four global-scale disasters, or the dozens of lesser scale “events†?

The ‘SMR-factor’

Every nuclear reactor is susceptible to nuclear accident, and is a potential public health and public safety hazard, even with competent engineers and well-trained technicians. The INES-scale severity of the event, or time and place of occurrence, are unpredictable.

India’s high density population requiring infrastructure for emergency evacuation-relocation and/or sheltering, in case of nuclear accident, makes these matters extremely significant.

Greater numbers of reactors, increases the locations at which nuclear “events†can occur. Adopting SMR technology will result in geographical spread of reactors, with accompanying spread of public health and public safety risks connected with NPPs and ancillary installations.

From public health, public safety and environmental perspectives, adopting SMR technology magnifies existing concerns and problems, connected with the nuclear industry.

Government will do well to boost solar PV generation instead of SMRs.

In any case, considered holistically, the nuclear option for power generation, is a dubious short-term asset carrying an unconditional long-term liability