It’s raining in Fukushima.
Since radioactive contamination from the crippled nuclear power plant is spread mainly by introduced water, even a routine weather bulletin has more-than-usual significance. The annual tsuyu, or rainy season, is in full swing in Japan. Fukushima prefecture normally receives 250 millimetres of rain in June-July, and every drop adds to the burden of the disaster.
More than three years after the Great East Japan Earthquake and tsunami, it is difficult to form a reliable overview of how the nuclear accident is unfolding, its long-term effects on public health, and progress in making the site and surrounding areas safe. Information is released piecemeal fashion from various sources: Tokyo Electric Power Company (TEPCO); national government agencies; separate local authorities; regulators; and non-government monitors. There is no single, unbiased source plotting progress comprehensively against consistent terms of reference and using plain language. The mainstream media also seem incapable of addressing the information gaps and unanswered questions. What follows, therefore, is necessarily a partial impression.
For all intents and purposes, the decontamination and decommissioning of the four damaged nuclear reactors at Fukushima has yet to begin. Despite heroic efforts, the task has actually increased in size and complexity, rather than reduced, since March 2011. Debris may have been removed, cooling systems stabilised, structures reinforced and plans drawn up for the 30-40 year decommissioning process, but one critical factor remains out of control. By the end of next March, the amount of contaminated water being held on site, much of it highly radioactive, will have reached 800,000 tonnes––not counting leakages from storage tanks and containment vessels that continue to bedevil operations.
Materials failure at inaccessible points is a constant threat. In one case, a leak of up to 1.5 tonnes of water per hour from the containment vessel of a reactor (which must be kept topped up for cooling purposes), detected last November, was only recently traced to its source with the aid of a robotic camera. The scale of the problem defies a simple solution. For instance, a new leak was found some days ago in a rainwater storage tank that had not been patrolled for three months. There are hundreds of such tanks.
TEPCO’s latest strategy for reducing one of the main sources of new contamination––rain run-off and groundwater movement––is to install metal rods driven 30 metres into the ground to create a frozen perimeter around the plant 1.5 kilometres in circumference. The project, begun recently, will take six months and cost the public purse US$330 million. If it works––and nothing on this scale has been tried before––the big freeze will be maintained until at least fiscal 2020. Some commentators, however, fear it may exacerbate a subsidence problem said to be posing a separate risk to the reactor buildings.
TEPCO, working with a variety of Japanese and foreign firms, continues to deploy newly developed robotic devices in parts of the facility where radioactivity levels are impossibly high for human activity. While technically impressive, the robots’ real rate of progress in performing tasks of assessing damage and sucking up radioactive dust is not clear from the TEPCO press releases.
An operation that seems to be going well is the much-discussed one to remove and secure spent fuel rods from inside Reactor No. 4, which was off-line at the time of the accident. The delicate procedure began last November, and as of 9 June a total of 1,034 of the 1,533 fuel rods had been lifted out and transported to a ‘common pool’ storage facility nearby. Because of damage to the fuel rod assemblies, the task of removal, also being undertaken by remotely-control grabbing and lifting devices, is slow and arduous. Exposure of any one of the four-metre long rods to the air could have catastrophic results. It’s assumed that the most severely damaged assemblies have yet to be dealt with.
Another enormous challenge is the removal of radioactive isotopes from the 400 tonnes of contaminated water accumulating each day on the site. A primary system is being used to extract the Cesium-134 and 137, but a secondary system, needed to remove Strontium-90, has been plagued by problems since its installation in October 2012. The radioactive water eats away the treatment system’s Teflon gaskets.
Outside the nuclear plant, 81,000 people in 10 municipalities are still directly affected by evacuation orders. How long it will take to make these ‘no-go’ areas habitable again is uncertain (indeed 40% of former residents say they have no intention of ever returning). Since last October, special decontamination efforts have been focused on seven places inside the evacuation zone: washing roads and buildings, removing vegetation and topsoil, etcetera. As a result, considerable reduction in radioactivity was observed, but the average level remained ten times higher than acceptable for human health.
The huge volume of soil and other radioactive waste dug up since 2011 is much more than authorities have been able to store away from population centres. In some cases, large bags of contaminated material remain in people’s backyards, with no indication when, if ever, they’ll be collected.
The various health consequences associated with the disaster––from stress-related deaths to high-level contamination of workers involved in the cleanup––are difficult to fully assess. Time will reveal more. The national government insists that Fukushima is not a health risk, and it recently gave approval for rice production to resume in the prefecture (though only 2% of the pre-disaster acreage was planted this year).
Fishing is still banned in waters off Fukushima due to the presence of elevated levels of radioactive isotopes. Cesium levels in the sea near the plant rose to calamitous levels in the immediate aftermath of the accident. Although they soon fell to a level close to the standard considered safe by Japanese authorities, they have stabilised there rather than fallen further, indicating that radioactive material continues to enter the Pacific Ocean from the site. While Cesium exists as a soluble salt and does not accumulate in bio-systems, Strontium-90 does, by displacing calcium in bones, and is of greater concern to some marine scientists.
Local governments in affected areas continue to test children for possible thyroid damage. Certain findings point to an elevated incidence of thyroid disease. In one town, follow-up checks have been prescribed for about a quarter of the children on the basis of an initial screening.
The World Health Organisation has not updated its February 2013 Health Risk Assessment from the Fukushima accident. Based on recorded exposures, the WHO report concluded that any disease effects would remain ‘below detectable levels’ in the general population. It predicted a ‘relative high increase’ (up to 70%) in the lifetime risk of thyroid cancer among females in the vicinity of the nuclear plant exposed as infants. For all solid cancers a maximum relative increase of 4% was estimated for the population living near the plant. Among the hundreds of workers engaged in the emergency response, the WHO report estimated a 20% increased risk of thyroid cancer for the youngest team-members.
Though the Ministry of Health releases regular ‘all-clear’ bulletins on the results of testing of foodstuffs and drinking water, this information is mainly in the form of raw data and can be difficult for a layperson to interpret.
No deaths directly attributable to radiation exposure have been verified. On the other hand, according to a survey published in March by the Asahi newspaper, Fukushima prefecture had recorded more deaths (1,660) due to ‘physical and psychological fatigue’ since the accident than were directly caused by the earthquake and tsunami––with more than 80% of the deaths occurring among residents forced out of the evacuation zone. In the absence of a legal standard for attributing such fatalities to the disaster, compensation claims are heading into the courts.
Japan’s national television news programs have given up regular daily, even weekly coverage, of the problems associated with the disaster. As a story, it has slipped into the background of public consciousness except for those living in the most affected areas.
But any of us can look at a weather map. And it’s still raining in Fukushima.
Walter Hamilton is currently in Tokyo.