Questions and answers on the situation in Japan and the possible impact on Germany

The situation in Japan

What happened at the Fukushima Daiichi nuclear power plant?
What is the current radiological situation in Japan?

Response in Germany

What new legislation has been introduced in Germany?
What safety reviews have German nuclear power plants been subject to?
What were the results?
Have any specific measures been implemented already?
What is an information notice (WLN)?
Have safety assessments been carried out on other nuclear facilities?

Nuclear power plants in Germany

How are German facilities protected against power cuts or other unlikely hazards?
Could a situation comparable to that in Japan arise in Germany following an earthquake?
How are German nuclear power plants protected against earthquakes?
Do comparable reactor types exist in Germany?
How is the design basis earthquake determined?
Can the possibility be ruled out in Germany that a more severe earthquake than the design basis earthquake might occur - as was the case in Japan?
What measures are in place in Germany for coping with a core meltdown?

Information for the German general public

What impact did the atmospheric transport of radioactive materials from Japan have on Germany?
Should travellers to Japan take a supply of iodine tablets with them?
How are contaminated foods prevented from entering the market?
What level of radiation exposure are travellers likely to encounter in Japan, including the consumption of local products?
Based on the experience gained from the Fukushima accident, are Germany's current emergency response/preparedness plans sufficient?

Information for shipping

Is there a chance that ships, consignments and crews active in the crisis region could be contaminated?
Do shipping recommendations exist concerning the avoidance of certain areas and/or shipping routes and ports?
What basic precautions should shipping companies be taking?

Background information

Can Japan's neighbours expect increased radiation values?
What is the estimated degree of contamination affecting the marine environment off Japan's coastline?
What level of radiation exposure poses a threat to human health?
How and by whom is environmental radiation monitored in Germany?
How dangerous is plutonium?
Has radiation originating from the accident in Fukushima been detected in foods produced in Germany?
How are imports of food from Japan regulated?

The Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH has published a brochure on the situation in Fukushima offering an overview of what took place during the accident at the Fukushima Daiichi nuclear power plant. This brochure can be found at  www.bmu.de/48443 (in German only).

The radioactive substances (radionuclides) released into the atmosphere as a result of the Fukushima reactor accident were carried by the wind and deposited on the earth’s surface at a local, regional and global level. How far the different radioactive substances spread depended largely on the moment of their release and the weather conditions, such as wind and precipitation, which were prevalent at the time. Initially, during the weeks following the accident, people were exposed to radiation both by inhalation and externally, as a result of radioactive substances still contaminating the air; later this exposure was limited to radionuclides deposited on the ground and the consumption of radionuclides through the food chain. Three radioactive substances are of prime importance when considering exposure to radiation: during the initial days and weeks following an accident, radiation exposure is largely caused by the radioactive isotopes of iodine and tellurium. In the longer term (i.e. after several weeks), caesium radionuclides (caesium-134 and caesium-137) are generally responsible for on-going radiation exposure.
Owing to the radionuclide deposits on the ground, dose values (effective dose) in excess of 20 millisieverts (mSv) are to be expected during the first year following the accident, both within the 20-kilometre exclusion zone surrounding the reactor, and in highly contaminated areas to the northwest at a maximum distance of approx. 45 km from the reactor. The population was evacuated from these areas. It is planned to decontaminate the affected regions prior to allowing inhabitants to return. For other areas demonstrating higher levels of contamination in the east of Fukushima prefecture, values between 1 and 10 mSv are expected for the first year (in Fukushima City, for instance); for low contamination areas in the west and south of Fukushima prefecture estimates range between 0.3 and 3 mSv. In the neighbouring prefectures (Miyagi, Ibaraki, Tochigi, Gunma) maximum dose values of 3 mSv are expected for the first year; in most areas, however, the actual level is unlikely to exceed 1 mSv. For Japan’s remaining regions, dose values of under 1 mSv (in a few areas up to 2 millisieverts) can be expected for the first year, with most estimated lower than 0.1 mSv (e.g. in Tokyo under 0.3 mSv). Figure 1 shows a map of caesium-137 ground deposits, produced on the basis of helicopter readings taken at the beginning of November 2011. Ground contamination of 1000 kBq caesium-137 per square metre (yellow area) equates to radiation exposure during the first year of about 25 mSv; this also takes into account the role played by all other radionuclides.
During September 2011 work began on estimating the individual radiation exposure of inhabitants in Fukushima prefecture. Members of the population were questioned on where they had been and how long they had remained there during and after the accident. Initial interim results involving approx. 10,000 inhabitants from the highly contaminated areas revealed that in 99% of cases radiation exposure during the first four months following the accident was below 10 mSv, the highest recorded rate of individual rate of exposure was 23 mSv.
In the years to come annual dose values will drop significantly, specifically as a result of the radioactive decay of radionuclide deposits, their penetration into deeper soil layers, and the weathering of radionuclides from surfaces such as rooftops, streets, etc.
In order to limit radiation exposure through the consumption of contaminated foods, Japan introduced maximum values which were adopted by the EU for imports from Japan. The sale of foods with concentrations of Cs 134/137 in excess of 500 becquerels per kilogram (Bq/kg) and/or iodine-131 over 2000 Bq/kg was banned. Since the accident random tests have been carried out on foods being sold in Japan. Whenever the maximum permitted levels are exceeded, the product in question is withdrawn from the market. By the end of January 2012, some 100,000 radionuclide readings involving over 500 different foods originating from all the prefectures in Japan had been published. At the beginning of the monitoring process, approximately 1% of the samples taken were found to be in excess of the maximum values. The frequency of such transgressions has been dropping for months now. One year on from the reactor accident, very few such cases are being reported. On the basis of readings taken in Fukushima prefecture and assuming typical consumption rates for Japan, it may be estimated that radiation exposure caused by the consumption of radionuclides with food will have been under 1 mSv for the first year following the accident in areas of higher contamination.
As a comparison: In Germany the average radiation exposure caused by radionuclides occurring naturally in the environment is 2.1 mSv per annum.

Germany’s federal government has decided to phase out the use of nuclear energy as soon as possible - a gradual process to be completed by 2022. Among other things, this decision was based on the results of safety reviews carried out on all German nuclear power plants by the Reactor Safety Commission and on the findings of the report by the Ethics Commission for a Safe Energy Supply. To this end the German Parliament passed the 13th Amendment to the Atomic Energy Act on 30th June 2011. The new law came into force on 6th August 2011 and introduced the following principal changes to the Atomic Energy Act:

• The electricity quotas additionally granted with the 11th Amendment to the Atomic Energy Act in December 2010 were deleted from the Act.
• The authorisation to generate electricity in the seven oldest nuclear power plants and the Krümmel plant will expire on the date of entry into force of the amended Atomic Energy Act.
• The power generation license for the three newest facilities will expire by 2022 at the latest; for all other nuclear power plants, expiry will be gradual in compliance with the deadlines 2015/2017/2019/2021.
• The transfer of electricity quotas – taking the relevant expiry dates into account - is still possible.

While conducting its safety reviews on German nuclear power plants in the aftermath of Fukushima, the Reactor Safety Commission (RSK) assessed the robustness of the facilities when confronted with events in excess of the design basis of the plants in question. The results were published in RSK statement no. 437 dated 16.05.2011.

At European level, Germany participated in the European stress test (EU stress test), submitting its final report to the European Commission on 31st December 2011. The stress test examined the three central aspects of external events, power and coolant failure, as well as emergency response.

In summary, the Reactor Safety Commission observed in its initial statement dated 16th May 2011 that as far as the electricity supply and provision against flooding were concerned, German facilities would appear to be better prepared than the Fukushima power plant. Further stress tests revealed that no uniform finding could be established which related either to plant design or age.
In Germany, the EU stress test was conducted - in addition to the RSK’s own safety investigations - during the second half of 2011. It revealed that in terms of the three central aspects (external events, power and coolant failure, emergency response) conservative and tough design requirements had been realised at the time of construction. Indeed the RSK had already established that with reference to specific aspects, the German facilities demonstrated a higher resistance to stress. The EU stress test report as conducted in Germany nevertheless also revealed room for on-going improvements to power plant safety, especially with relation to emergency control - which will need to be pursued by the relevant supervisory authorities of the federal states in question. The Federal Ministry for the Environment has asked the RSK to take into account the results of the EU stress test (published at the end of April 2012) during its on-going discussions concerning possible ways in which to improve the safety of German nuclear power plants.

At the beginning of 2012 and on behalf of the BMU, the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) forwarded an information notice concerning the impact of the Tohoku earthquake on Japan’s Fukushima Dai-ichi (I) and Dai-ni (II) nuclear reactors on 11.03.2011 and of the Niigataken Chuetsu Oki earthquake on Japan’s Kashiwazaki-Kariwa nuclear power plant on 16.07.2007 (PDF, 242 KB) to the nuclear supervisory authorities of the federal states, as well as surveyors, experts, and nuclear power plant manufacturers and operators throughout Germany. Using the findings relating to the facilities affected by these earthquakes at the Japanese nuclear sites, the GRS specified a total of 22 recommendations for nuclear facilities in Germany. These include specific demands for measures to counter power cuts (station blackout/emergency power situation), an additional back-up electricity generator, an additional and separate auxiliary cooling water supply, the option of an offsite reactor cooling water supply, as well as additional measures aimed at cooling fuel element storage pools, preventing the accumulation of hydrogen, and relieving containment pressure in a filtered manner. Precautionary firefighting measures also feature in the recommendations. The risk of earthquakes is to be re-assessed in line with the latest scientific and technological developments.
The Reactor Safety Commission (RSC) completed its comprehensive deliberations of the findings drawn from the Fukushima accident and their impacts on German nuclear power plants by submitting its recommendations of 26/27 September 2012. Based on more in-depth discussion of individual issues, the RSC has also drawn up additional recommendations for robustness. These recommendations include additional requirements on flood protection, internal flooding and dropping of heavy loads. 
Resilience of nuclear power plants against power cuts is also an important aspect to consider.  In the future plants will therefore have to be able to operate without external power for a week rather than 72 hours. Furthermore, the length of time a plant must be able to run safely on batteries alone has been extended from two to ten hours. As an additional safety measure mobile emergency back-up generators which can be used during floods and earthquakes must be purchased
With regard to heat removal from plants, the demand was made to provide for an additional independent possibility for heat removal (e.g. to a well) over and above the regular heat removal, e.g. to a river.

The Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) is commissioned by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) to produce information notices on events in nuclear power plants in Germany and abroad with potential safety implications. The aim of these information notices is to learn from the operative experience of individual nuclear facilities, thus enabling safety to be improved at other sites. Information notices feature a detailed account of the event, findings derived from the root cause analysis, an assessment of safety implications, any measures already implemented or planned by the operator, and most importantly, an assessment of transferability to other nuclear power plants, recommendations concerning reviews and corrective measures for other nuclear power plants where necessary. The GRS forwards these notices on behalf of the BMU to the nuclear supervisory authorities in the federal states, expert organisations, operators, manufacturers and other bodies.
In response to every information notice, the operators are required to submit a statement to the appropriate nuclear regulator specifically addressing the implementation of any recommendations made. The relevant supervisory authorities in the different federal states ensure that these recommendations are implemented and submit corresponding reports to the BMU. The GRS analyses the feedback of experience associated with information notices.
For more information on information notices and how they are drafted, please see the GRS website at  www.grs.de (in German only).

In addition to the safety review of German nuclear power plants, the risk analysis is also to include other nuclear facilities. The relevant state authorities have already finished reviewing all research reactors with a continuous thermal load of over 50 kilowatts and forwarded the results to the Reactor Safety Commission (RSK). The Reactor Safety Commission submitted its opinion on 3 May 2012 entitled "Plant-specific safety review (RSK-SÜ) of German research reactors in the light of the events in Fukushima-1 (Japan)". 
The Nuclear Waste Management Commission (ESK) was commissioned in the summer of 2011 with developing review concepts for facilities - either already commissioned or under construction - intended for the treatment, interim storage, or final disposal of irradiated fuel elements, heat-generating and other types of radioactive waste, as well as for the Gronau uranium enrichment plant and the fuel element production plant in Lingen. These deliberations need to take into account the results of the RSK discussions and the review of the nuclear power plants by the supervisory authorities and their inspectors. The corresponding concept is likely to be presented by the ESK during the first six months of 2012, the results of its reviews at the end of 2012.

Following the Harrisburg and Chernobyl reactor accidents, in 1979 and 1986 respectively, the German government carried out a comprehensive review of the relevant safety requirements. In the process many unlikely scenarios, such as an utter power breakdown involving the failure of the backup diesel generator - known as a station blackout, were factored in. Additional precautions were implemented as a result, such as a second secured emergency power network and/or a link to additional available power sources, capable of being used even in critical situations.

What happened to the nuclear power plants in Japan? Firstly, the facilities were subjected to an earthquake of hitherto unexpected proportions. These facilities were not designed to withstand an earthquake of this scale.

Nevertheless, they stood up to this initial impact: the automatic emergency shutdown procedure (SCRAM) is said to have worked in all the reactors. The second onslaught on facility safety was the failure of the power supply networks: in such circumstances the emergency power supply is meant to kick in. This too is also supposed to have worked initially.

After about an hour, the reactors suffered a third attack on their safety: the tsunami. This caused the failure of those facility systems which were essential to maintaining plant safety such as the emergency power and the coolant supply. With that a scenario emerged for which there was no action plan.

From this point on, staff at the site were required to improvise in order to minimise the impact of the accident as far as possible.

The chain of events in Japan cannot be directly transferred to Germany. A comparable situation to the one in Japan is therefore highly unlikely. The tectonic and geological conditions are completely different and the risk of a tsunami occurring along the German coastline can be assumed to be negligible.

Earthquakes, nevertheless, remain a natural hazard that is also native to Germany. By Japanese standards, the anticipated strength of any tremor, however, can be considered moderate. Flooding, on the other hand, does pose an additional risk in Germany. With the aim of countering both these hazards faced by German nuclear power plants, facilities are designed to cope with earthquakes and flooding, as well as a combination of the two. The risk posed by earthquakes and flooding in Germany is therefore greatly reduced.

All German nuclear power plants are designed to withstand earthquakes. Thanks either to their initial design or a retrofit, the facilities are capable of being shut down safely in the event of an earthquake, while guaranteeing essential on-going cooling. When calculating such scenarios in Germany, an earthquake strength is assumed which might reasonably be expected at the site in question.

The Fukushima nuclear power plant is equipped with boiling water reactors produced by General Electric, Hitachi and Toshiba.
Boiling water reactors also exist in Germany: three older Series 69 facilities (Brunsbüttel, Isar 1, Phillipsburg), a slightly newer Series 69 in Krümmel and two Series 72 facilities (Gundremmingen B and C). The Series 69 facilities have since been permanently shut down. Major differences exist between the Series 72 reactors installed in Germany in particular and the Japanese facilities.

The design basis earthquake is determined using a procedure specified by statutory nuclear regulations. These regulations were reviewed in 2011. They foresee that, taking past events into account, the earthquake with the greatest conceivable seismic impact for the site in question must be used as a basis. It is of equal importance to carry out a probabilistic risk analysis for the nuclear power plant site. For this purpose, an earthquake should be assumed which occurs once every 100,000 years at the site (exceedance probability of 10-5/a).

Certain assumptions must be made when calculating a design basis earthquake. In order to take the inherent degree of uncertainty into account, the statutory nuclear regulations specify ‘safety margins’ when calculating design basis earthquakes, with the aim of preventing the design basis earthquake from being underestimated.

The following measures - depending on the location - are planned:

a. Evacuation of the immediate vicinity (approx. 10 - 25 kilometres)
b. Population remains indoors (approx. 25 - 100 kilometres)
c. Consumption of iodine tablets to protect the thyroid from absorbing radioactive iodine
d. Agricultural measures to avoid contamination (ruminants in barns, covering of crops)

As a result of the Fukushima reactor accident, heightened concentrations of airborne iodine-131 and caesium-134/137 were recorded for about a month in Germany. The concentrations measured were so low, however, that they posed no health risk to the population and the environment in Germany and Europe. Total population radiation exposure as a result was just a few millionths of a millisievert (mSv), which is extremely low when compared with the average radiation exposure to which an individual is exposed by natural radionuclides present in the environment (2.1 mSv p.a.).

Following their release, these - primarily highly volatile – radionuclides were distributed by the air masses throughout the entire Northern Hemisphere. The concentration of radioactive substances in the air naturally and continuously reduced during transport owing to the increase in distance from the site of the accident. The concentration of radioactive substances was also reduced by a proportion of the radionuclides being washed out by precipitation on the way, and also by the natural process of nuclear decay, which particularly applies to the short-lived radionuclides iodine- 131 and tellurium-132, which made up much of the initial dose following the accident in Japan. Owing to this process of dilution, merely very low levels of airborne radioactivity reached Germany which could only be verified through elaborate trace analysis methods.

On 23.03.11 iodine-131 and caesium-134/137 were first detected in air samples taken at trace analysis laboratories in Braunschweig, Potsdam and Offenbach; by the next day similar readings were being picked up at the Schauinsland trace analysis laboratory near Freiburg. The highest concentration of radioactivity was reached approximately one week later; at the four analysis laboratories, these amounted to a few thousandths of a becquerel for iodine-131, and a few ten thousandths of a becquerel for caesium-137, per cubic metre of air. Thereafter the extent of radionuclide activity went on steadily decreasing. By the end of May 2011 all readings had returned to pre-Fukushima reactor disaster levels.

By way of comparison, concentrations of the naturally occurring rare gas radon and its airborne progeny amount to several becquerels per cubic metre of air (Bq/m3) outside, and an average of some 50 Bq/m3 inside buildings. These readings fluctuate depending on the location, since concentrations of radon are influenced by the geological properties of the parent rock and prevailing weather conditions.

No. Were there to be - contrary to expectations - a new release of radioactivity into the atmosphere, it would be up to the Japanese government to provide protection appropriate to the radiological situation for both its own citizens and foreigners currently visiting the country, including the distribution of iodine tablets as necessary. Individuals planning to travel to areas in the direct vicinity of Fukushima can find more information on the German Embassy’s website  www.japan.diplo.de (German).

Further information www.jodblockade.de (German).

Foods imported from Japan are tested for radioactivity by the relevant state food regulatory authorities. These tests are legally on special measures adopted at a European level intended to act as a safety net when importing foods from Japan. These specify that foods from the affected Japanese regions may only be imported into Germany if they have already been tested and certified in Japan. This confirms the non-existence of heightened radioactive contamination. Should, contrary to expectations, contaminated foods be detected at the EU’s external borders, these are to be rejected, thus preventing their distribution on the European market.

The Commission Implementing Regulation (EU) No 297/2011 (PDF, 759KB, external), which took effect on 26th March 2011, has since been regularly modified to take changes in the situation into account. In accordance with Commission Implementing Regulation (EU) No 284/2012 of 29 March 2012, radioactivity levels and sampling frequencies have been reduced and an extension of the validity of the special measures until October 2012 has been set.

Commission Implementing Regulation (EU) No 561/2012 (PDF, 770KB, external) of 27 June 2012 extended the scope of Commission Implementing Regulation (EU) No 284/2012 to include Iwate prefecture.
In October 2012 this Regulation was replaced with the Commission Implementing Regulation (EU) No 996/2012 of 26 October 2012, which is valid until 31 March 2014.

In Germany the risk posed by radioactively contaminated foods imported from Japan is extremely low. Controls prescribed for agricultural products imported from Japan have detected only a handful of cases where contamination was actually measurable. In just 2 of a total of 298 samples did the readings exceed normal background levels.

For more information, particularly on the results of official food monitoring, please see
Federal Ministry of Food, Agriculture and Consumer Protection: Information on the nuclear accident in Japan (German)
Federal Office of Consumer Protection and Food Safety: Radioactivity (German)
Federal Office of Consumer Protection and Food Safety: List of measurement results for radiation in Japanese foodstuffs, as submitted to the European Commission (XLS, 62 KB, external) (German)
General information: www.irs.uni-hannover.de (German)

During a 4-week trip to areas of higher contamination in the east of Fukushima prefecture (e.g. to Fukushima City), individuals are likely to be exposed to approximately 0.1-1 millisieverts (mSv) of radiation from radionuclides deposited on the ground; in the less contaminated areas in the west and south of Fukushima prefecture, this level will drop to some 0.03-0.3 mSv. In the neighbouring prefectures, a maximum 0.3 mSv of radiation exposure is possible, yet in most areas, levels are expected to be well below 0.1 mSv. For the rest of Japan, a 4-week trip is likely to mean radiation exposure of less than 0.1 mSv, and in most cases, of less than 0.01 mSv (in Tokyo, for instance, less than 0.03 mSv). Conservative assumptions form the basis for calculating exposure levels associated with time spent outdoors and time spent indoors.

(Basic assumptions: 8 hours outdoors, 16 hours in buildings with low shielding. Japanische Berechnungen beruhen ebenfalls auf diesen Annahmen (Quelle: Bundesamt für Strahlenschutz))

Based on the readings taken during food radioactivity monitoring activities conducted in Japan since March 2011, it is estimated that those eating foods produced in Japan during a 4-week trip to the country can expect their radiation exposure not to exceed 0.1 mSv for a period of up to one year following the accident.

Contamination in the food sector has significantly reduced (gone down?) with few exceptions for example in certain types of fish. In light of this (Against this backdrop?) the maximum values (thresholds) for food in Japan have been further reduced. The resulting radiation dose in Japan currently lies significantly under 0.1 mSv.

As a comparison: In Germany the average radiation exposure caused by radionuclides occurring naturally in the environment is 2.1 mSv per annum.

In Germany, as in the other European countries, current preparedness plans for nuclear power plant accidents and protective measures for the general public are based on experience gained from the accident at Chernobyl. The course of events in Fukushima was characterised by long-lasting releases. In this respect it differs from the assumptions for measures for incidents with a longer lead time prior to release or a release taking place over a comparatively short period of time. These are emergency response measures (remaining indoors, potassium iodide as a thyroid blocker, temporary or long-term evacuation).

The technical authorities and institutions involved in emergency control of accidents in nuclear power plants (Federal Office for Radiation Protection (BfS), Gesellschaft für Reaktorschutz (GRS), Commission on Radiological Protection (SSK)) are currently engaged in a complicated procedure analysing whether the existing preparedness plan has any weak points and what precisely these may be. In the process they are also assessing whether, by including “Fukushima accident scenarios”, larger areas of application (e.g. larger evacuation areas) need to be taken into account. Based on the experience gained from Fukushima, moreover, there are limits to the application of the ‘remain indoors’ principle when faced with extended periods of release, since (for psychological reasons) this measure should not be applied for longer than two days if possible.

There are currently no specific measures that need to be observed.

Japan’s neighbours (such as Korea, China, Russia, Philippines) have no reason to expect increased radiation values. Even in the regions of Russia directly to the north of Japan, where traces of radioactivity were detected in the air shortly after the accident, no increase in the dose rate could be determined at this time. During food radiation monitoring conducted in Japan’s neighbouring countries, and from among the many thousands of readings taken, only a handful of import samples were found to exceed the maximum permitted values.

(answer provided by the Johann Heinrich von Thünen Institute - an organisation under the auspices of the Federal Ministry of Food, Agriculture and Consumer Protection)
Seawater:
Die hauptsächlich infolge des Reaktorunfalls von Fukushima im Meer nachgewiesenen Radionuklide sind Cäsium (Cs)-137, Cs-134 und in geringerem Maße auch Strontium (Sr)-89 und Sr-90. In den Küstengewässern überwiegt das aus den Reaktoren stammende Cäsium bei weitem das noch vom globalen Kernwaffenfallout im Pazifik vorhandene Cäsium.(The primary radionuclides detected in the sea as a result of the Fukushima reactor accident are caesium (Cs)-137, Cs-134 and, to a lesser extent, strontium (Sr)-89 and Sr-90. In the coastal waters, the level of caesium originating from the reactors greatly exceeds the caesium still found in the Pacific Ocean as a result of global nuclear weapons fallout.) This statement is based on data from four stations very close to the Japanese coast (two of them situated directly at the nuclear power plant’s outflow channels), which TEPCO uses to determine radioactivity concentrations in seawater on a daily basis. According to the samples, by the summer of 2011, Cs-137 concentrations had dropped to below 5 becquerels per litre (Bq/l). Since the end of October, by lowering the detection limit to approx. 1 Bq/l, it has been possible to trace Cs isotopes at levels slightly above 1 Bq/l.
Analysis of the concentration readings revealed a reduction of activity in seawater by the end of April, with an effective half-life of approximately 2-3 days; thereafter the effective half-life increased to some 20-30 days by October 2011, and since winter has appeared to be lengthening again to over 100 days. This pattern indicates a potential input from run-off from the land into the sea.
Unfortunately few readings have to date been taken concerning Sr-isotope activity concentrations in seawater. The following median values (relating to 11th March 2011) were recorded for concentrations of radionuclide activity in the sea off Fukushima:
Sr-89/Sr-90: 12
Sr-90/Cs-137: 0, 04
According to readings taken, plutonium isotopes were not discharged into the sea.
Marine life:
To date the Japanese monitoring programme has gathered over 5600 samples from more than 200 different species of marine biota. These have been mostly fish. Between May 2011 and February 2012, the caesium readings for various species of invertebrates (e.g. mussels, snails, prawns) taken off the coast of Fukushima prefecture dropped from almost 400 Bq/kg to just 10 Bq/kg. South of Fukushima, off the coast of Ibaraki prefecture, the commensurate values were approximately 3 times lower. The gross caesium concentration among fish in the waters off Fukushima prefecture increased to an average of around 200 Bq/kg by last summer. Bottom-dwelling fish (benthic and demersal) such as flatfish, rays, scorpion fish and similar, demonstrated three times the level of Cs activity as those fish living in the open water. This can be attributed to the relevant prey spectrum and the consumption of caesium-contaminated benthic organisms by bottom-dwelling fish. Since then the temporal activity value curve for fish with monthly averages of just under 200 Bq/kg and maximum monthly values of between 2000 and 4000 Bq/kg of gross caesium has yet to reveal a clear trend. The proportion of total fish samples in excess of the threshold value of 500 Bq/kg gross Cs on a monthly basis fluctuates between 5 and 10%. At the same time gross Cs concentrations in saltwater fish decrease to the south as the distance to Fukushima increases (Ibaraki ≤50 Bq/kg and Chiba ≤15 Bq/kg respectively). A ban on commercial fishing is still being enforced in Fukushima province.
The handful of Sr analyses conducted on fish to date have revealed no trace of Sr-90. It is therefore assumed from the above-mentioned Sr-90:Cs-137 ratio that, in fish, compared to caesium isotopes, concentrations of Sr-90 play a minor role.
Up until mid-November, moreover, fish samples were also taken offshore, several hundred to over a thousand kilometres east of Fukushima. In the process maximum gross Cs values of 16 Bq/kg were established (skipjack tuna or stripe-bellied bonito).
Freshwater fish
With reference to fish sampled from the inland waters in Fukushima and neighbouring prefectures, fish from fish farms demonstrated low levels of gross Cs of under 15 Bq/kg. By contrast, considerably higher values with averages ranging from 50 - 200 Bq/kg were established for fish living in the wild. As of summer 2011 Cs concentrations among river fish began dropping steadily to a current level of approximately 50 Bq/kg; lake fish stocks on the other hand have been returning fluctuating monthly readings of around 300 Bq/kg since the late autumn. This distinction was noted in German waters in the aftermath of the Chernobyl reactor disaster and is a result of the low rate of water exchange found in lakes.
Assessment
Were one to eat deep sea fish from the Pacific with an average 10 Bq/kg of Cs-137 and Cs-134 once a week for a whole year, this would equate to radiation exposure of approx. 3 µSv p.a. or some 0.14% of the average natural radiation exposure respectively. For more information see www.vti.bund.de (in German only).

There is no threat of direct radiation damage if the radiation dose does not exceed 100 millisieverts. Nevertheless even low doses can lead to a statistical increase in the risk of contracting cancer.
In the event of a nuclear accident in Germany, the official recommendation is to stay indoors when the potential radiation dose is 10 millisieverts and above, with evacuations being initiated from the immediate vicinity if the potential dose exceeds 100 millisieverts.
As a comparison: under normal circumstances the annual effective dose of natural radiation exposition in Germany is 2.1 millisievert. This is caused by both cosmic radiation and natural radionuclides (cosmogenic and terrestrial radionuclides), which are present everywhere in the environment.
For more information on radiation doses, as well as a summary of the main dose and threshold values, please see the website of the Federal Office for Radiation Protection: www.bfs.de.

The Federal Office for Radiation Protection (BfS), an agency under the auspices of the Federal Ministry for the Environment (BMU), operates an integrated monitoring and information system (IMIS) for the comprehensive monitoring of environmental radiation in Germany. The nationwide system boasts some 1800 around-the-clock monitoring stations. This means a detailed picture of the radiological situation in Germany is available at all times. For specific details about your region see www.bfs.de/ion/imis. Fifty stations also produce readings on airborne radioactive concentrations. Moreover, more than 60 national and federal state-run laboratories regularly conduct analyses on food and feed samples, plant, soil and waste samples.

Plutonium is a by-product of nuclear fission and originates from uranium-238. It is a radioactive substance which emits alpha radiation as it decays. The range of alpha radiation, however, is very limited, meaning that thin layers of air can be enough to effectively protect individuals from the external effects of alpha radiation. The risk only becomes real if plutonium is inhaled with air, as organs are then directly exposed to the local effects of alpha radiation. Like other heavy metals such as lead and mercury, plutonium is also toxic. Consumed with food, it becomes concentrated in the body, especially in the bones and liver, and may lead to cancer.
The existence of plutonium is currently confined to the Fukushima facility. Germany is not at risk.

Owing to our huge distance from Japan and the associated dilution of the radioactive substances released, only a tiny amount actually reached Germany. It was possible to detect minimal traces of iodine and caesium in the atmosphere, but this was undeniably as a result of the extreme sensitivity of the measuring equipment.
Once the radioactive cloud had passed over Germany, the Max Rubner Institute in Kiel (coordinating office for soil, vegetation, feed and foodstuffs of plant and animal origin) conducted detailed analyses on representative environmental media in addition to its routine environmental monitoring activities. Milk and winter leek were tested in order to review different food chains. Traces of iodine-131 were found in a few milk samples during the period between 31.3.2011 and 11.4.2011. Concentrations were between 5 and 12 mBq per litre. After 14.4.2011, milk readings dropped to below the detection threshold of 2 mBq per litre. None of the milk samples was found to contain radioactive caesium. Iodine-131 concentrations between 110 and 550 mBq per kg were measured for winter leek during the period from 31.3.2011 to 26.4.2011. Caesium was only found in two leek samples. At 40 and 60 mBq per kg respectively, these readings only just exceeded the detection threshold.
The readings taken were so low that, even if individuals consumed a lot of milk and vegetables, no health risk could be said to exist.

1.    The first special provisions concerning the import of foods and feed from Japan were introduced with the  Commission Implementation Regulation (EU) 297/2011 (PDF document, 757 KB, external) of 26th March 2011. The maximum permitted levels specified in the Council Regulation (EURATOM) No 3954/1987 (regulation establishing maximum levels; also known as emergency regulation) served as a basis for this special legislation. In Commission Implementing Regulation (EU) No 351/2011, adopted in April 2011, the levels were aligned with the limit values applicable in Japan. This allows authorities to determine whether the placing on the European market of food and feed from Japan is acceptable.
On 25th May 2011 the  Commission Implementation Regulation (EU) No 506/2011 of 23 May 2011 (PDF document, 801 KB, external) came into force. This effectively extended the validity of amended Commission Implementation Regulation (EU) No 297/2011 until September 2011 and widened the obligatory monitoring of foods to include another Japanese province. Commission Implementation Regulation (EU) No 657/2011 of 7 July 2011 amending Regulation (EU) No 297/2011,  its scope was extended to include another Japanese province in which contaminated green tea had been discovered. Two other provinces were struck from the conditions.
Commission Implementation Regulation (EU) No 961/2011 of 27 September 2011 extended the validity of these measures until 31st December 2011. Validity was extended for a further three months and additional modifications introduced with the Commission Implementation Regulation (EU) No 1371/2011 of 21 December 2011. Among other things, the demand for measuring iodine-131 was revoked, since this radionuclide was no longer of any relevance owing to its short half-life.
In March 2012, in response to the radiological situation, it was decided to reduce the reference values for various food groups, to limit food sample readings to caesium isotopes, to reduce the frequency of sampling, and to extend the validity of these special regulations yet again. (Commission Implementation Regulation (EU) No 284/2012 of 29 March 2012).
Commission Implementing Regulation (EU) No 561/2012 of 27 June 2012 extended the scope of Commission Implementing Regulation (EU) No 284/2012 to include Iwate prefecture as shitake mushrooms, fern and fish products were found to be exceeding the maximum threshold.
In October 2012 the above mentioned regulation was replaced with a modified regulation. Commission Implementing Regulation (EU) No 996/2012 of October 26 2012 (PDF; 774KB, external) contains the continuation of monitoring measurements in the Fukushima prefecture in its current scope, stipulations regarding monitoring arrangements in other prefectures affected according to a positive list of food and feed groups, stipulations regarding temporary transitional measures and finally derogation procedures for products intended for personal use. The Regulation is valid until 31 March 2014 and will be reviewed at the end of the current harvesting period in March 2013.
All the above-mentioned implementation regulations were introduced under the main responsibility of the Directorate-General Health & Consumers (DG SANCO) and approved by the Directorate General for Energy (DG ENERGY).
2.    The original regulation on maximum permitted levels, Regulation (EURATOM) No 3954/87, was not used as a basis for an EU implementing regulation. The definition of maximum levels under this regulation was designed for cases of nuclear accidents that could pose a threat to food supply in Europe. The situation at the Fukushima nuclear power plant is no such case.

• Federal Office for Radiation Protection (BfS)
• Gesellschaft für Anlagen- und Reaktorsicherheit (GRS)
• International Atomic Energy Agency (IAEA)