What approach should Japan use to discharge waste water from the Fukushima Daiichi site? 

Executive Summary

Following the Fukushima nuclear incident a large quantity of contaminated water has been collected and stored at the site.  The capacity for storing this water will be reached this year and the ongoing storage presents a number of risks.  As such, there is a need to determine and implement a solution to manage the water.  A policy document setting out the approach was published in 2021, which sets out an approach to discharging the water into the ocean at ultra-low concentrations over a period of thirty years. The long timescale for implementation raises questions as to whether the policy is sustainable and sufficiently robust to endure.  In this analysis the status quo policy is compared with alternative options for management of the water, by reference to a serious of goals for a successful outcome and impact categories.  The analysis brings out the importance of timescale, the relatively low importance of safety (given that all options are safe) and the dominance of political feasibility in determining next steps.  This paper recommends continuing with the recently published status quo policy, but with the introduction of a review period given the clear benefits of a faster discharge strategy with higher concentration discharges.

Introduction

On the 11th of March 2011 Japan suffered a major tsunami event caused by a massive offshore earthquake.  The earthquake triggered the automated shut-down of the nuclear reactors at the Fukushima Daiichi power plant.  Unfortunately, the earthquake and tsunami also severely damaged the alternative power supplies required to cool the reactors after shutdown, which in turn, led to a major nuclear incident. Despite various efforts to cool the reactors, three had largely melted within a matter of days (WNA, 2023).

Efforts to cool the reactors at the time of the incident included dowsing them with huge amounts of seawater which became radioactively contaminated and water continues to be used for this purpose (IAEA, 2023).  Contaminated rainwater and groundwater also contribute to the issue (despite significant effort to reduce ingress of both).  Contaminated water is recovered and stored in over 1000 tanks on the site, with a capacity of 1.37 million m3.  The storage capacity is expected to be full this year (WNN, 2022).

Symptoms

As noted above, the Fukushima site will reach capacity for waste water storage during 2023, and as such determining a safe and sustainable long term solution to managing the water is extremely urgent. Despite recent efforts to reduce the amount of contaminated water generated at the site (METI, 2023, p. 4) contaminated water will continue to be generated for many years to come (currently, the site is generating 130 m3/day (METI, 2023)).

There are no options available to cease generating the water and it is recognised that there are a number of other negative impacts associated with the tanks (METI, 2021a):

• The area taken up by the tanks compromises decommissioning work

• The risk of natural events damaging the tanks is a concern (an earthquake in 2021 caused minor damage to some tanks, although containment was maintained)

• Adverse impacts on reputation

• The need for ongoing maintenance

Whilst the physical impact of the tanks is only manifest within the site, reputational impacts are seen at local to international levels.  It is difficult to separate out the contaminated water from other reputational impacts associated with the Fukushima incident, however, any development at the site has the potential to raise concern amongst a broad range of stakeholders.

A key area of interest is the impacts on the fishing industry around the Fukushima site, which has suffered greatly since the accident and has so far only recovered to 17% of its size before the incident (METI, 2021a, p. 11).

Status Quo

In 2021 the Japanese Government published its policy for the management of the contaminated water (METI, 2021a), which is to discharge the water into the ocean after treatment through a filtration system that will remove the majority of contamination from the water. The filtration system will not however recover tritium, which means that additional steps are required. Tritium is a radioactive isotope of hydrogen and is therefore very difficult to separate out from water. The policy proposes to discharge the tritium contaminated water into the Pacific ocean.  Discharges will be capped at an annual amount of 22 TBq[1] of tritium, which was the permitted discharge level during operations. The policy also requires extensive dilution (500 fold) to meet drinking water standards. The dilution will be achieved by pumping seawater onto site, to mix with the contaminated water prior to discharge back into the ocean.

The operating company for the Fukushima site, TEPCO, will implement the policy and it is estimated that this will take approximately 30 years to complete (METI, 2020, p. 28).

In addition to the technical management of discharges, the Basic Policy puts significant emphasis on efforts to what it refers to as “managing reputation”.  In practice, this provides significant ongoing support to the communities and industries affected by the Fukushima accident.  A recent budget document indicates expenditure of over £1.1Bn (METI, 2021b) (this does not include any of the costs associated with the process of storing, treating and discharging the water) and includes:

• Environmental monitoring

• Various public relations activities

• Support to fisheries industry

• Support to other industries (onshore)

• Measures for tourism and increasing visitors

The Japanese government have also secured external independent overview of policy implementation by the International Atomic Energy Authority, with the intention that this provides confidence to stakeholders.

( [1] A Terra-Becquerel (TBq) is a quantitative measure for an amount of radioactive material)

Framing

The Basic Policy defines a path forward for addressing the issue.  However, the long timescale for implementation raises questions as to whether the policy is sustainable and sufficiently robust to endure. It is noted that other options were analysed technically (METI, 2020) and these deserve further investigation through the Policy Analysis lens to determine whether a different course of action would be more appropriate.

Whilst it is clear that Japan has given significant priority to safety, the thirty year timescale for implementation leads to a number of concerns:

• Japan endures the highest concentration of earthquakes in the world (JMA, 2023) and as such sustained storage of contaminated water presents a risk. Whilst this is relatively low, unintended discharge would be problematic, not least for reputation.

• Resources used for the treatment and discharge of the contaminated water (finance, energy, man power, etc) could be deployed in addressing more hazardous aspects of the site, furthering progress and reducing the time at risk presented by more significant hazards on site.

• Whilst the policy has been determined to address stakeholder concerns as best as possible, there is a risk that the discharge remains a concern irrespective of the level of the discharges.  As such, “blight” associated with the discharges could continue throughout the implementation period, with chronic reputational damage and the need for continuing financial support to local communities and industries. This will be costly and there is a risk that it will lead to issues of dependency on state handouts.

The Japanese government have taken a very conservative approach in their published policy.  There are very much higher discharges of tritium elsewhere in the world that have been demonstrated to be safe for people and the environment (METI, 2021a, p. 25), however the Japanese Government have retained the site discharge limit from before to the incident.

In adopting a conservative policy, the Japanese government has responded to the reasoning failures of the general public with respect to perception of hazard associated with radioactive discharges. In a modern setting like Japan, which has a nuclear industry with a long history, the level of risk and harm to people associated with normal operation of nuclear facilities is incredibly low, usually below measurable levels.  However, the cultural history around nuclear power and radioactive waste means that the public’s perception of the risk is much higher than it is in practice. In this area, beliefs depart greatly from the accepted science. It is interesting to note that the policy suggests alignment with the reasoning failure, as opposed to attempting to mitigate the effects of it.

Concern about the potential hazard from radioactivity is likely to be particularly heightened due to the scale and relatively recent occurrence of the Fukushima incident, increasing its “availability” in people’s minds. It is also noted that the Japanese government has been subjected to intense lobbying from anti-nuclear organisations since the Fukushima nuclear incident, and whilst nuclear remains part of the energy mix in Japan, being seen to do the right thing is likely to have affected policy development in this area. 

Goals

For this Policy Analysis, options for addressing the contaminated water issue will be assessed against important goals that a successful policy will address.  Further definition is provided by impact categories that are illustrative of the performance of an option.  These are described in Table 1, including an brief explanation of the relevance of the category to the decision.

Policy Options

Table 2 sets out options for management of the contaminated water. Option 1 is the “status quo”, which is the recently published policy position for discharging the contaminated water (METI, 2021a).  Option 2 is a variation on Option 1, however, it takes less than a third of the time to implement compared to the status quo and is therefore substantially different and warrants consideration.  Option 3 is a deferral option of ongoing storage, that has been proposed by some commentators (Greenpeace, 2020) and is worth consideration as a different approach.

Impact Analysis

A detailed analysis of the performance of the options against the Impact Categories is included in Appendix A. Table 3 below provides a high level summary, highlighting the main arguments and points of learning from the analysis.

A few important themes are illustrated by the analysis of the options:

• The duration of the implementation phase significantly affects performance across many of the impact categories.  Notable areas include resource use, worker safety, progressing the wider decommissioning mission and intergenerational equity.  The thirty year implementation period of Option 1 is a significant weakness.

• From a technical perspective the doses to the public from all of the options are extremely low, presenting  an unmeasurably small impact on the public.  As a result, public safety does not differentiate between the options when considered purely technically.  However, the public’s actual response to nuclear issues is not proportional to the technical risk.  This is illustrated where the analysis considers the potential for blight on local industries and the affect this has as the government endeavours to protect those industries.

• The goal of Political Feasibility, particularly the Reputation impact category, deserves a very high weighting in this assessment.  The policy document setting out the way forward was only published in April 2021 and implementation is yet to commence. Given how recently the policy was established, switching to an alternative approach at this time would be very difficult.  It is notable that the policy performs poorly in a number of areas, suggesting that minimising discharges in response to public opinion was an overriding factor in determining the policy. However, this analysis suggests that discharges may have been minimised so far that the policy is suboptimal when wider implications are considered.

Recommendation

The recommendation from this policy analysis is to retain the current policy position, recognising that moving away from a recently published policy would be incredibly difficult, especially given the commitments that have been made to communities, both locally and internationally.  However, it is also recommended that a review period is introduced and if monitoring of the discharges over an initial period (for example 5 years) demonstrates an over-abundance of caution through showing very low, or indeed no impacts, then the annual discharge limit should be increased to take advantage of the benefits identified for Option 2.

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