Response to an accident in theory and in practice

Environment International, Vol. 14, pp. 185-200, 1988

0160-4120/88 $3.00 + .00 Copyright © 1988 Pergamon Press plc

Printed in the USA. All rights reserved.

RESPONSE TO AN ACCIDENT IN THEORY AND IN PRACTICE Anneli Saloa and James Daglish International Atomic Energy Agency, P.O. Box 100, A 1400 Vienna, Austria

(Received 4 November 1987; Accepted I0 May 1988) Although numerical upper and lower levels of dose for countermeasures applicable in the early and intermediate phases after an accident had been identified at the time of the Chernobyl accident, there were no internationally agreed values for derived intervention levels. Emergency plans, including some criteria and procedures for intervention in the event of an accident affecting nuclear installations within national boundaries, had been developed generally as a part of licensing procedures. However, countries were ill-prepared to deal with the effects of transboundary radionuclide releases originating in other countries. At the Chernobyl site, a number of workers suffered whole-body doses which produced various forms of acute radiation syndrome. Although no member of the public was exposed to such a high dose, it soon became apparent that the lower intervention level for evacuation adopted in the USSR (250 mSv whole-body dose) could be exceeded, and eventually even the upper intervention level of 750 mSv if the population remained in the immediate vicinity of the accident site. In some areas within the western part of the USSR, it was therefore rtee.aessaryto implement the full range of possible countermeasures. In other European countries, the dose ¢~uivalents committed from the first year of exposure and intake ranged between a few/xSv and abom I mSv~ :being in the order of p.Sv or tens of p.Sv outside ~Europe in the Northern Hemisphere. In this article, we review the reactions of national authorities to the accident; and, in the second part, we consider informally the response of world news media to the accident, and its influence on public perceptiort.

Introduction

duce countermeasures should be based on a balance of the detriment which it carries and the reduction in the exposure which it can achieve. The magnitude of the detriment of countermeasures will vary with their nature and with the circumstances in which they are applied, for example, with the size of the population involved. Their effectiveness, on the other hand, will depend on the speed with which they can be introduced. For these reasons it is not possible to fix generally applicable intervention levels above which intervention will always be required. However, it might be possible to set levels below which intervention would not generally be considered to be justifred. Intervention levels depend on the particular circumstances of each case and can therefore give only general guidance."

Current radiation protection practices worldwide are based on the recommendations of the International Commission on Radiological Protection (ICRP) (ICRP, 1977; ICRP, 1984). The system of dose limitation recommended by ICRP applies to exposures resulting from controlled radiation sources under normal operating conditions. In an accident the source of exposure is, by definition, not under control and the exposure of members of the public can only be limited, ~f at all, by some form of action or intervention which willdisrupt normal living. ing. The ICRP (1977) has given the following general guidance:

The protective measures available in the event of a nuclear accident or radiological emergency include sheltering, administration of stable iodine, evacuation, respiratory protection, use of personal protective clothing, personal decontamination, relocation, control of access, food and water controls, and decontamination of land and property. In those countries which have major nuclear facilities such as nuclear power plants, the normal practice is to have detailed plans for accident response. These plans or related regulations include levels of dose or other criteria on which to base decisions on intervention in the event of an accident.

"The form of intervention suitable for limiting an abnormal exposure to members of the public will depend on the circumstances. All the countermeasures that can be applied to reduce the exposure of members of the public after an accidental release of radioactive materials carry some detriment to the people concerned, whether it is a risk to health or some social disruption. The ,decision to introapresent address: Finnish Center for Radiation & Nuclear Saf~ty~ Surveillance Dept., P.O. Box 268 SF-00101 Helsinki, Finland. 185

186 The lack of a consistent approach by various states to the implementation of protective measures can result in confusion and mistrust in the arrangements for the protection of the public. Such a situation was clearly demonstrated after the Chernobyl accident, which occurred on April 26, 1986, in some neighboring countries because of the very different responses to the large transboundary release of radioactive material from USSR. This paper discusses the international guidance on intervention levels for protective measures which was available at the time of the Chernobyl accident with examples of national preparedness to implement this guidance. The paper will also discuss protective measures taken and intervention levels used after the Chernobyl accident both in the USSR and other states, together with the problems stemming from the basic philosophy of intervention and other factors. In the second part of the paper we discuss informally the activity of the mass media, and its influence on public perception of the accident. 2. Guidance on Intervention at the Time of the Chernobyl Accident

2.1 International guidance The commission of the European Communities (CEC) was the first international body to publish guidance to its Member States on reference levels of radiation dose as guidance for national authorities in setting intervention levels for nuclear installations in 1982 (CEC, 1982). Similar guidance was published by the ICRP (1984), World Health Organization (WHO, 1984) and the International Atomic Energy Agency (IAEA, 1985). The guidance given by these four organizations is similar in essence. The WHO guidance is less quantitative: the reference dose levels for sheltering; distribution of stable iodine tablets and evacuation set forth by CEC differ slightly from those given by ICRP and IAEA; and the CEC did not give any values for control of foodstuffs. The ICRP and IAEA gave almost identical advice. The basic principles given by ICRP for planning intervention for accident situations and setting intervention levels are the following: 1. Serious nonstochastic effects should be avoided by the introduction of countermeasures to limit individual dose to levels below the thresholds for these effects; 2. The risk from stochastic effects should be limited by introducing countermeasures which achieve a positive net benefit to the individuals involved; 3. The overall incidence of stochastic effects should be limited, as far as resonably practicable, by reducing the collective dose equivalent.

A. Salo and J. Daglish When giving detailed guidance on the implementation of the above principles three different phases after an accident have been distinguished: (a) the early phase, the period during which there is the threat of a significant release up to the first few hours after the beginning of a release; (b) the intermediate phase, starting a few hours after the commencement of the release, and possibly extending over several days or even weeks; and (c) the late phase (also referred to as the recovery phase), which may extend from some weeks to several years after the accident. It was internationally recognized that both the spectrum of accident situations is wide, and that difficulties in implementing protective measures after an accident vary widely from country to country and even from place to place within a country. Therefore, it was not considered possible to set one generally applicable intervention level at which a particular action would always be required. On the other hand, it was recognized that introduction of protective measures would be almost certain if the projected radiation dose is such that serious nonstochastic effects or high probability of stochastic effects are expected. It was also considered that it would be possible, on radiation protection grounds, to define a level of radiation dose for each countermeasure below which introduction of the countermeasure is not likely to be warranted. Such recommended upper dose levels (ICRP, 1984; IEAE, 1985), above which introduction of the countermeasure is almost certain and lower dose levels, below which introduction of the countermeasure is not warranted are present in Fig. 1 for whole body irradiation, and in Fig. 2 if individual organs are preferentially irradiated. Between the recommended upper and lower levels site-specific intervention levels were expected to be set by national authorities. The figures cover both early and intermediate phases. For the late phase no such values were recommended, since it was considered that the main questions facing the decision-maker would be whether and when normal living could be resumed, and the situations would vary too widely to give any generic numbers for that purpose. Therefore, only a procedure was recommended for the determination of the optimum dose level for withdrawal of protective measures. All the recommended intervention levels were specified in terms of radiation dose. In practice, however, the results of measurements will be expressed in activity concentrations, dose rates, etc. (e.g., Bq m -3, Bq m -2, Gy.h-l). To enable the intervention levels of dose to be more readily compared with the results of measurements, it has been urged that derived intervention levels (DILs) be determined for a range of radionuclides of potential radiological importance that could be released from a nuclear facility to various environmental compartments and foodstuffs.

Response to an accident

187

log Y~k roSy T 5000 - ~ ,

7 ~_-_-3: : ~ : _ - ~

~-

~

~

~----~Ir4TRODUCTION --------~MEASURES

---~-------: .

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

OF P R O T E C T i V E ~

ALMOST

CERTAIN

500

50

5

i

,¢, 1 Ro,ooot,oo

Evacoat,oo

I

[

EARLY PHASE (1)

INTERMEDIATEPHASE (2)

administration i

RECOVERY PHASE ,,¢,.~9,,~2J,&2

Fig. 1. Dose-equivalentlevels to wholebodyfor early and intermediatephase protective measures:(1) Projected doses to be received in the short term; (2) Projected dose-equivalentin the first year.

These derived intervention levels (DILs) which are sometimes referred to as derived emergency reference levels (DERLs), represent the practical expression of the intervention levels of dose. In the early phase such derived intervention levels were recommended (IAEA, 1985) to be derived for: time integrated air concentrations (Bq's'm-3); ground deposition density (Bq m-2); dose rate above contaminated surfaces (Gy.h -1) and in the intermediate phase for peak concentration of radioiodine in milk (Bq-L-~); initial deposition density on pasture (Bq.m-Z); initial concentration in green vegetables (Bq.kg-1); initial concentration in drinking water (Bq.L-1). The relationship between these derived intervention levels and the intervention dose level will depend on many factors such as the dietary and living habits of the exposed people, the physical and chemical forms

of the released radionuclides, agricultural practices, food preparation and processing, etc. The wide variation in these factors makes the calculation of globally applicable derived intervention levels impossible. To summarize the situation regarding international guidance on intervention levels at the time of the Chernobyl accident guidance on emergency planning and preparedness including guidance how to set intervention levels was available. Numerical upper and lower levels of dose for countermeasures applicable in the early and intermediate phases had been identified. No internationally agreed values for derived intervention levels existed. However, the measurements or materials to which derived levels should be applied were specified, together with the units to be used. The setting of intervention levels for particular circumstances was considered to be the responsibility of appropriate national authorities. 2.2 Implementation at national level

Emergency plans, including some criteria and pro-

188

A. Salo and J. Daglish

log Y~k mSv ~INTRODUCTION 5000

OF- PROTECTIVE MEASURES ALMOST CERTAIN

500

Not" a n f i c l p a t ' e d 50

Sheltering

dministrotion ~of s t a b l e qodlne

EARLY

PHASE

tt

-_-vacua io

(I)

Control of foodstuffs and water

Relocation

INTERMEDIATE

PHASE

(2)

RECOVERY

PHASE

Fig. 2. Dose equivalent levels to individual organs for early and intermediate phase protective measures.

cedures for the provisions of intervention in the event of an accident, are generally developed as part of the licencing procedure in countries with major nuclear installations, such as nuclear power plants. It is not common to have intervention levels fixed in legislation. To illustrate the different types of national emergency reference levels or intervention levels adopted in various countries one can mention: Belgium. Legislation did not impose an automatic coupling between numerical values of evaluated doses and any countermeasure; it was planned to make use of reference levels published by CEC in the decision making process (van den Damme et al., 1986). United Kingdom. In 1981 the National Radiological Protection Board specified criteria in the form of Emergency Reference Levels (ERLs), which were limits to ranges of projected individual doses within which planned intervention levels for introduction of countermeasures were expected to be set for the early phase. In 1985 the NRPB adopted the guidance given

by ICRP (1984) as bases for the planning for later phases of accidents. The ERLs for evacuation were for example 100 mSv (whole-body) as lower level and 500 mSv (whole-body) as an upper level; for sheltering 5 mSv (whole-body) as a lower level, and 25 mSv (whole-body) as an upper level; and for the distribution of stable iodine tablets, 50 mSv (thyroid) as a lower level and 250 mSv (thyroid) as an upper level. The NRPB had also evaluated derived emergency reference levels (DERLs) for all the radionuclides and pathways which were likely to be important in terms of radiation dose in the early and intermediate phases after an accident for UK conditions (Linsley et al. (1986). These UK DERLs proved to be very useful reference material outside UK as well after the Chernobyl accident. Finland. The nuclear regulatory authority had published for the early phase of an accident preset compulsory action levels for evacuation of 0.1 Gy (wholebody), 0.5 Gy (skin), or 0.2 Gy (child's thyroid). As derived intervention levels for iodine-131 in milk, 2600

Response to an accident Bq L -~ as a compulsory rejection limit and 37 Bq L -1 as nonaction level were set (Blomqvist et al., 1986). Hungary. In line with the recommendations by W H O (1984) and ICRP (1984) temporary e m e r g e n c y reference levels were established before commissioning of the first nuclear p o w e r plant for the early phase of an accident. The lower and upper dose levels were set for sheltering at 0.01 and 0.1 Gy (whole-body) or 0.1 and 1 Gy (thyroid or any single organ); for administration of stable iodine at 0.5 and 5 Gy (adult thyroid) or 0.3 and 3 Gy (child's thyroid); and for evacuation at 0.1 and 1 Gy (whole-body) or 1 and 10 Gy (thyroid or any single organ), respectively. No intervention levels were predetermined for the protective measures to be taken in the intermediate and late phases after an accident (Sztanyik, 1986). Czechoslovakia. T w o action levels were defined as preestablished exposure levels which, if exceeded, would trigger introduction of protective actions. The first level corresponds to annual dose limits for individuals of the public under normal operating conditions (5 mSv to the whole-body and 50 mSv to the thyroid of a child). Action level two is established to protect the most endangered individuals against the nonstochastic effects of radiation (250 mSv to the whole-body and 2500 mSv to the thyroid of a child) (Kriz, 1986). United States o f America. The Environmental Protection Agency (EPA) is responsible for providing guidance and criteria for determining whether protective actions are needed and at what level of dose. Separate Protective Action Guides (PAGs) have been developed for various phases after an accident. For example, for the early phase (called in the USA the emergency phase) the PAGs range from 10 mSv to 50 mSv (whole-body) or from 50 mSv to 250 mSv (thyroid dose). The lower value is used if there are no major local constraints in providing protection at that level, especially to sensitive populations. The upper value should not, however, be e x c e e d e d when determining the need for protective action. PAGs dealing with food were published in 1982, on the basis that protective action should be taken w h e n e v e r the projected dose to the thyroid reached 15 mSv or that to the whole-body, bone marrow or any critical organ 5 mSv (US Food and Drug Administration, 1982). Union o f Soviet Socialist Republics. In 1983 criteria had been approved for taking decisions on measures to protect the population in the event of a reactor accident. Two intervention levels - - A and B - - had been established. If exposure or contamination do not exceed level A there is no need to take e m e r g e n c y measures, while exceeding the level B e m e r g e n c y measures were r e c o m m e n d e d to be taken. Between levels A and B measures should be taken on the basis of the actual situation and local conditions. For external gamma radiation level A was 250 mGy and B 750 mGy, for

189 thyroid exposure due to intake of radioiodine level A 250--300 mGy and level B 2500 mGy, respectively. Also some derived intervention levels for ~31Iwere included. F o r implementation at the national level, only the early and intermediate phases after an accident were considered, and in terms of area only limited area around the accident site. In cases where nuclear p o w e r plants were situated close to the boundaries of neighboring countries (e.g., Sweden-Denmark, Czechoslovakia-Austria) or within economical regions (e.g., CEC, 1986, CMEA, 1984) provisions were made for situations in which accidental transboundary releases of radioactive material might occur. H o w e v e r , in situations such as the Chernobyl acciden~t, in which easily measurable amounts of radionuclides were spread all over Europe and detectable amounts even over the Northern H e m i s p h e r e were not usually taken into account in e m e r g e n c y planning.

3. Protective Measures Taken After the Chernobyl Accident 3.1 Consequences and measures taken in USSR The first urgent measures needed after the accident at the Chernobyl nuclear p o w e r plant to prevent further damage were fire fighting and short term operations to stabilize the plant. During these actions the personnel were exposed to high levels of radiation. The measures taken at the plant and later in the area around it kept the radiation doses to the population below the dose thresholds above which various forms of acute radiation syndrome may occur (INSAG, 1986; II'yin and Pavlovsky, 1987; K o r n e e v et al., 1987). 3.1.1 Radiation injuries to plant personnel and emergency teams Some groups of operating personnel of the reactor and electricity generating plant on April 26, 1986, emergency squads and to the largest extent the fire brigades fighting the extensive early fires on the site were exposed to radiation at the Chernobyl power station to such an extent that resulting whole-body doses produced various forms of acute radiation syndrome. In such cases the absorbed doses in for example, bone marrow, alimentary tract, etc., were in the range from about 2 Gy up to about 16 Gy. Acute radiation syndrome of varying clinical severity developed in about 200 patients as a result mostly of external irradiation with gamma and beta rays. The external beta irradiation, partially from aerosols deposited on the surface of the skin and clothes, led to the development of severe skin burns in 48 persons, covering in some cases up to 90% of the body surface. In most cases of acute radiation syndrome with lethal outcomes (29 cases) the burns had a strong effect on the ultimate fates of the

190 victims. No further deaths from radiation syndromes have been reported after the 96th day following the accident. None of the victims were in critical condition, in the hospital in spring 1987. Some of the persons who suffered from radiation sickness had already started to work. Five patients who suffered badly from burns underwent repeated plastic surgery. The victims are called to hospital for checks and special (scientific) investigations from time to time.

3.1.2 Radiation doses to the population and measures taken The complex meteorological conditions, the local artificial dispersion of rainclouds and the varying characteristics of the release led to a very complex pattern of atmospheric transport and deposition of radioactive releases on the ground, both within the Soviet Union and in other countries. To prevent the accumulation of radioisotopes of iodine (mostly '3'1) from the plume in the thyroid glands of members of the public, potassium iodide tablets were distributed to the population in the surrounding area. This was done by employing volunteers to hand the tablets directly to individual residents on a door-to-door basis, starting on the morning of April 26. Late in the night of April 26, radiation levels in Pripyat started to rise, reaching a value to the order of 10 mSv h - ' on April 27. It soon became apparent that the lower intervention level for evacuation applied in the USSR, 250 mSv whole-body dose, could be exceeded and eventually even the upper intervention level of 750 mSv whole-body dose if the population remained in their homes and no other countermeasures were taken. The evacuation of Pripyat started on the morning of April 27. Immediately after the accident, derived intervention levels were established for the concentration of ,3q in milk and milk products (cheese, cream and butter) and leaf vegetables. The levels were based on the principle that the dose to the thyroid of a child should not exceed 300 mSv per year. If the contamination exceeded the intervention level, milk was processed into butter, cheese and so on, in other words into suitable forms in which the products could be stored while the radioiodine decayed. Derived intervention levels were also introduced for the ':"I in meat, poultry, eggs and berries. At a later stage, when caesium and other longer lived radionuclides became dominant, derived intervention levels of these radionuclides in a wide range of foods were established based on the principle that the effective dose to an individual should not exceed 50 mSv in the first year. Doses incurred by the population evacuated from the 30 km zone around the Chernobyl power station did not reach the threshold level for clinically manifest signs of acute radiation syndrome, and not a single case was diagnosed among the 135,000 evacuees. They were examined promptly after the accident. Most

A. Salo and J. Daglish doses from external radiation to the 135,000 people who were evacuated were less than 100 mGy; doses to the vast majority of the population of Pripyat were 15-50 mGy for gamma radiation although people in the most contaminated areas may have received doses as high as 300-400 mGy. Doses to the thyroids of individuals from inhalation (and possibly ingestion of contaminated foods) were estimated to be mostly below 300 mGy, although some children may have received thyroid doses as high as 2200 mGy. In other regions of the Soviet Union doses to individuals from external irradiation and from intake of radioactive iodine were very much lower. Doses to individuals in various regions of the European part of the Soviet Union and doses to the whole population of these regions were calculated. Estimated (in summer 1986) individual doses from external irradiation ranged from 0.03 mSv to 10 mSv. Committed doses from intakes of '37Cs via foodstuffs were calculated at that time to be of the order of 30 mSv for individuals in the Poles'ye region of Byelorussia and the Ukraine. However, measurements of caesium levels in people already showed that 50% of them would receive a dose of about 3 mSv or less, and only 3% would receive a dose of 30 mSv or more. '37Cs is the main contributor to the internal radiation dose to the whole body. More recent measurements and calculations have lshown that the '37Cs levels in man are ten to twenty times lower than expected on the basis of the first measurements in May 1986. Also, the external radiation doses are likely to be one and a half to two times lower than initially forecasted. The average individual dose in USSR for the first year has been estimated to be 0.36 mSv and for the next 50 years in total 1.2 mSv (II'yin and Povlovsky, 1987). A revised report on the radiation doses to the population was presented in September 1987; together with information from other countries, it was submitted to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) as an input to their overall evaluations of the radiological consequences of the Chernobyl accident.

3.1.3 Decontamination and other actions taken after the early phase and the early intermediate phase of the accident After necessary decontamination and tests Unit 1 was restarted in October 1986 and Unit 2 in November 1986. Unit 3, which is adjacent to the damaged Unit 4, was decontaminated and, after examinations and tests, was expected to be returned to operation during the second half of 1987. The damaged Unit 4 has been sealed off by a concrete structure, for which 300,000 cubic meters of concrete and 6,000 tons of metal were required. This sarcophagus is a complicated technical construction with

Response to an accident

191

repotted to l A B • Stationsin USSR reporting dally to IAEA since 9 May lg86

Ireland 3 May\

L~i~r~ Denmark

27 April a

Netherlands

2 May B-

~

Chernobyl

Poland 27 April

2 May

•rest

France

Switzerland

USSR

• Vilnius

• Spain

~ e Oster

• Kishinev Romania 130 April )

•

Turkey

30 April.

Fig. 3. Dates of first observations on elevated radionuclide levels reported to I A E A .

control and monitoring instrumentation. It also has systems for heat exchange, ventilation and air purification in order to prevent any radionuclide releases into the environment. All physical and chemical processes taking place in the sarcophagus are monitored and studied in depth in order to avoid any unpleasant surprises because of the migration of radionuclides, or of the effects of radiation on the materials used. Measurements are being made on radiation levels inside and outside the sarcophagus, and on concentrations of radionuclides before and after filtration; seismic measurements to control the stability of the construction, and environmental sampling for radioactivity measurments. In the Ukrainian part of the 30 km zone some 24 population centers have been decontaminated and in two of them people returned by the end of January 1987. In Byelorussia people have returned to ten villages. A wall was built in the ground close to the reactor, and 130 dams filled with material to absorb the radionuclides during the spring flood of 1987, which was expected to be higher than 1986. Icebreakers and

teams with explosives were ready to break possible ice barriers. All these measures were costly but considered necessary to protect the water bodies, and they proved to be successful. In areas with high contents of radionuclides in soil, agricultural practices have been altered. Land improvement operations have been carried out to reduce uptake of radionuclides from the soil into the plants. Such operations include liming, special soil cultivation, and fertilization. The livestock feeding patterns have also been changed. 3.2 Consequences and countermeasures in other countries

The radioactive releases were transported by the airmasses all over Europe, and eventually to the USA and Canada in the West and China and Japan the East. The first radioactive clouds already reached Poland, Sweden, and Finland on April 27. Another set of countries, Hungary, Yugoslavia, northern Italy, Austria, FRG, GDR and Norway were reached on April 29, and in subsequent days the contamination reached the rest of the European countries. The unusually variable

192 meteorological situation, characterized by frequent and localized heavy precipitation, contributed to the very uneven distribution of contamination on the ground and later in the food chain. From the data reported by the various countries it can be concluded that the dose equivalents committed from the first year of exposure and intake range between a few microsieverts to about one millisievert. (Annual effective dose equivalent from natural background is in normal background areas 2 mSv, and can be several times, even a hundred times higher in high background areas.) The average thyroid dose equivalent ranges between a few microsieverts and three millisieverts. The maximum doses reported were less than ten times higher than the average doses. In countries outside Europe the corresponding doses have been much lower, in the order of microsieverts or tens of microsieverts. The reactions of national authorities in the countries affected have been very varied, ranging from a simple reinforcement of the normal environmetnal monitoring programmes without any countermeasures, to banning of the consumption of some foodstuffs or to distribu- " tion of stable iodine. Movement of contaminated food in international trade became a special area of concern. The differences between countries with respect to countermeasures cannot be explained by differences in contamination levels nor by estimates of radiological consequences, nor local differences in living or food habits; many other factors seem to have influenced the decisions. The most important seem to be political factors such as proximity of elections, and compensation required for agricultural products, and so on. Another group of factors was certainly the misinterpretation of international guidance - - for example, confusing the rationale behind intervention levels on the one hand, and dose limits on the other. (National reports to IAEA, 1986-87; NEA, 1987; ECE, 1987; WHO, 1986.)

3.2.1 Monitoring and Assessment When the Chernobyl accident became known practically all European countries intensified environmental monitoring and in particular the monitoring of foodstuffs in order to assess the radiation situation. Other countries in the northern hemisphere followed suit. Later on, the monitoring of food moving in international trade was also considered necessary beyond the areas affected by direct deposition. Monitoring in Europe in particular was also commonly performed for people and vehicles travelling from potentially contaminated areas. Fishing boats in the Black Sea and the Baltic Sea were monitored at the beginning of May by some countries (TR, DK). The dates of the first observations of elevated

A. Salo and J. Daglish radionuclide levels reported to the IAEA and other international organizations are presented in Fig. 3. 3.2.2 Information to the Public Authorities in the countries affected established means for issuing information to the public, by news releases, telephone hot lines, tourist information, etc. The problems in relation to information distribution are discussed in Section 4. For codes see Table 1. 3.2.3 Advice to Avoid Contamination and Doses Advice was given on a variety of measures intended to help in minimizing population exposures. Advice was given, for example, to stay out of the rain, to prevent children playing in puddles and sandboxes, to avoid playing ball games outdoors, and to wash hands and clean shoes when coming in. In some extreme cases pregnant women and infants were requested to stay indoors (A, Y). A number of countries requested the cleaning of transport vehicles at borders (A, DK, SF, D, NL, TR) and advised their nationals not to travel to potentially contaminated countries or areas (A, SF, D, GB, IRL, L, NL, N, E, S, USA). Rainwater was advised not to be used as drinking water (A, CND, SF, D, GB, GR, I, J, L, NL, N, S, CH, TR, USA, Y) or for watering cows (A, SF, TR, Y). Also, advice was given not to use rainwater for greenhouses (NL) or in the sauna (SF). With respect to food production and preparation, advice was given to keep cattle from grazing outdoors (B, BG, SF, D, GR, H, S, TR, CS, Y) (in some countries it was even prohibited, A, BG, DK, I, L, NL, PL, TR). It was relatively common to advise people to wash fresh vegetables (A, B, DK, D, GR, H, IRL, I, J, L, NL, S, CH, PL, CS, TR). In some cases it was advised not to eat fresh leafy vegetables (A, BG, D, GR, I, NL, S, CH, TR, Y). In one case it was recommended to delay planting of early vegetables (SF). Advice was given in some countries to avoid consumption of cow milk and dairy products (A, NL, CH, Y), milk from sheep and goats (A, GR, N, CH, TR) and not to market fresh goat cheese (CH, TR). Advice on how to prepare wild plants and mushrooms (A, SF, D, NL, S) and how often to eat freshwater fish (SF, NL, S), and not to hunt certain game (IRL, NL, E, S, Y) nor market game (NL, SF) were recommended in some countries. Advice was also given on special procedures when changing filters in industrial air conditioning installations (A, B, SF, D, GR, I, L, NL, S, CH). In some countries advice was given specifically not to take iodine pills (A, CND, SF, F, D, GR, L, NL, E, S, CH, TR, USA) although in one country (PL) outside USSR stable iodine was distributed to 10.5 million children up to the age of 16 years.

Response to an accident

193

Table 1. Derived intervention levels for t3~l in Bq/L or Bq/kg. Drink Water

Milk Dairy P.

Vegetables

Meat

Albania Australia Austria (A)

2000

Belgium (B)

500

1000

2000A 500C 10; 40 1000

200

2000

70

70

370(l

Bulgaria (BG)

74

Canada (CND)

10

Czechoslovakia (CS) Denmark (DK) Finland (SF) France (C) GDR (DDR) FRG (D) Greece (Gr)

2000

Hungary (H) Iceland (IS) Ireland (IRL) Israel (IL)

Norway (N) Philippines Poland (PL)

500 500 500

1000 250 350

500

350

110

560

220 500

7400 250

500

1000

1000

1000

Portugal (P)

500

350

Romania (R)

1000A 185C

Switzerland (CH) Turkey (TR)

1000

560

10000(1 5000 (2

Sweden (S)

air 11 Bq/m 3 70 (fruit)

2000

1000 (child)

Singapore Spain (E)

30

500

2000

560

no values fixed (121.5.86 replaced by 185 2.5.86 initial values; lowered later 5.5.86 general activity cf. Table 2 May 86 (all but water) May 1986 no values fixed 2.5.86 no values fixed May 1986

2.5.86 replaced by 125 and 250 respect. 23.5.86 1000

90

350

300 5000(1

Date of Adopt. Comments

6.5.86 recommendation replaced by CEC values later general values no values fixed no values fixed for import 250 Bq/kg /3, 3' and 25 Bq/kg c~ attention level; emerg, level 10× higher; adopted 1971

2000

Italy (I)

Japan (J) Luxembourg (L) Malaysia The Netherlands (NL)

185

Other

300

(ltotal/3 until 15.5 (2since 16.5. 6.5.86 recommendation replaced by CEC values later general values

6.5.86 recommendation replaced by CEC values later 2.5.86 "import limit 2-15.5.86 no values fixed no values fixed; 31.5.86 CEC values

(Continued on next page)

194

A. Salo a n d J. D a g l i s h

T a b l e . 1. ( C o n t i n u e d ) Drink Water

U n i t e d K i n g d o m (GB)

11000

USA

1.5

2000

Vegetables

110000

(~esh milk) 560

Meat

Other

Date of Adopt. Comments

160000

M a r c h 86

1850

(forage)

USSR (SU) Yugoslavia (Y)

Milk D a i r y P.

3700

(2

,~

air ~1

'~ > 200 CEC

125 ( ~

90' ~

90 r-',3

(peak concentr.) NRPB-DL10 1982 (milk, forage) based on 300 mSv/a child thyroid (1values not known; ~2inSlovenia only for processing 26.5.86 ~'250/16.5; 500/6.5 ('q75/16.5; 350/6.5

(:~fruit A = adult C = child

3.2.4 Restrictions and Prohibitions

Restrictions on marketing and consumption of cow milk and dairy products (A, BG, SF, D, GR, I, NL, N, R, PL, S, TR, CS, Y) and milk from sheep and goats (A, BG, I, NL, CS), sheep and goat cheese (N, S) were implemented, coupled in some cases with the prohibition of marketing and consumption of sheep and goat cheese (A, GR, I, NL, TR) and of consumption of goat milk (BG) because of elevated iodine-131 levels. Restrictions and prohibitions on imports of milk and dairy products were introduced in the West European countries initially because of uncertainty on actual levels of contamination. Restrictions (D, NL, PL, S) and prohibition (A, BG, F, I, L, NL, N, PL) on domestic marketing and consumption were implemented together with restrictions (OECD-countries) and prohibitions (S, TR, CECcountries) on imports of vegetables, fruit and grains. The sale of plants used for medical purposes exceeding 2000 Bq kg-Vdry weight was prohibited (BG). In the case of meat, restrictions were set on domestic marketing of lamb and sheep (A, GB, GR, NL, N, S, CH), of beef and horse meat (A, N), of reindeer (N, S) and of game (S). Advice alone was considered adequate with respect to the marketing of reindeer in one case (SF). Import of meat was restricted (OECDcountries) or even prohibited (S, TR, CEC-countries). A prohibition on the marketing of freshwater fish was enforced in some areas (N, CH). The derived intervention levels for banning of food used in various countries are summarized for iodine131 in Table 1, and for caesium-134 and 137 in Table 2.

3.3 International guidance after the Chernobyl accident In December 1986, the IAEA published a document (IAEA, 1986) which presents a methodology for obtaining numerical values for derived intervention levels. This document was in preparation at the time of the Chernobyl accident, but the draft was modified after the accident in order to take into account some of the lessons learned from the accident. As derived, intervention levels should always relate closely to the local situation, the document shows how the numerical values for derived intervention levels should be modified in the light of specific situations. After the Chernobyl accident all the aforementioned international organizations have started to review the existing international guidance and to develop it further in order to achieve better international harmonization and better coverage of different types of situations. The ICRP will review and expand its basic guidance on intervention. The IAEA is concentrating on revising and elaborating its basic guidance (IAEA, 1985; IAEA, 1986) on the methodology to set i n t e r vention levels of dose and derived intervention levels. The existing basic guidance has been considered so far to be basically sound for the early and intermediate phases, and when applied to the immediate surroundings of an accident site - - the purpose for which it was developed. Additional guidance is needed primarily for the late phase and remote areas. The WHO is developing guideline values below which the introduction of control measures would not be justified on grounds of prevention adverse health effects. The Food and Ag-

R e s p o n s e to an accident

195

Table 2. Derived intervention levels for ~34Cs and x37Cs in Bq/L or Bq/kg. Drink Water Albania Australia Austria

Milk Dairy P,

Vegetables

Meat

100 185(1; 300

100 110tl; 175

370 370 .~ 740 (3

600 200 ~1 125 (3

50; 100

300

300

370 1000

600

600 1000 (1

France GDR FRG Greece Hungary Iceland Ireland Israel

370 300 370 370

600 300 600 600

600 300 600 600

370

600

600

Italy

250; 370

Belgium Bulgaria

Canada

1.5 I'~

50

Czechoslovakia Denmark Finland

Japan Kuwait

Luxembourg Malaysia The Netherlands Norway

Philippines

100 18YL-"; 370:1 300 '2 600 `3 600 2000 (2 740 ('~

Other

100

370 (4

300 cl

1000 ~2

600' i 370 (z 250 (3 25 (~

3.7

18.5

370 180

370 370 fl

15; 33; 22

250; 600

250; 600

93

93

600 324 600 600 (~

600 540 600 600 (1 6000 f2

22

6

93" 279 (z

252" 370'3

5.6; 8

Date of Adopt. Comments

May 1986 ~lonly 13rCs ~2for pork and poultry "~other 31.5.86 (CEC) gen. activity; cf. also Table 1 (19.5.86 (27.5.86 (314.6.86 14children's food M a y 86 (except water) "fruit 31.5.86 (CEC) 22.5.86; " b e e f and pork (2grain and cereals 31.5.86 (CEC) only l'~rCs CEC ? 31,5.86 (CEC) cf. Table 1 31.5.86 (CEC) " i m p o r t e d from W-Europe; 'Zbaby food from W - E u r o p e ; (3~ and y on all food from E-Europe '4c~ in all food from E-Europe 1971 attention levels; cf. Table 1 31,5.86 (CEC) (1grain ~Zfodder "~TCs equivalent 31.5.86 (CEC) (~cereals 31.5.86 (CEC) 20.6,86; (1original value 300; '~reindeer and game 20.11.86; (~infant food detailed for various food item

(Continued on next page)

196

A. Salo and J. Daglish

Table 2. (Continued) Drink Water

Poland Portugal Romania Singapore

Milk Dairy P.

Vegetables

370

600

600

zero

zero

zero

370 300 ~

Spain Sweden

Meat

600 3 0 0 ~'

Other

zero

600 300 ~l

300 t3

600

600

10000 ~2

Switzerland

Turkey United Kingdom

51000

370

600

370 3600;

600 190000;

370"

USA

90 ~

60ff ~

8880

600 1000;

280000

600 ~j

370 (z

USSR

Yugoslavia

CEC

370

riculture Organization of the U N is concentrating on the guideline values for food moving in international trade (FAO, 1986). Guideline values for food moving in international trade are e x p e c t e d eventually to be agreed upon within the f r a m e w o r k o f Codex Alimentarius C o m m i s s i o n , of which F A O and W H O are the parent organizations.

4. Mass Media Activity and its Influence on the Reaction of the Public In this section o f the p a p e r we adopt a less formal a p p r o a c h to discuss the media r e s p o n s e to the Chernobyl accident. A detailed, quantitative and qualitative analysis will take some time. The accident was unique in two respects. First, it was the m o s t serious accident to have occurred in the history of the use of nuclear p o w e r for electricity generation. Secondly, it was unique b e c a u s e in the initial stages journalists were starved for information, and there was a great deal of misreporting.

600

600

370 ~

Date of Adopt. Comments

no values fixed 31.5.86 (CEC) cf. Table 1 < detection limit 10 Bq/kg 31.5.86 (CEC) 15.5.86; Cqnitially (2.5.86) 1000; ~Zimport limit; ~3game marketing limit 31.5.86 CEC; values used for notification only 31.5.86 CEC March 86 (DERLs) based on peak conc. except meat; ~31.5.86 (CEC) 1982 (milk) ~for Chernobyl ~z1.11.86 based on 50mSv effect.dose for the l.year numerical values approved not known 31.5.86 import/export ~qnfant food

There were m a n y reasons for this. High a m o n g them was the fact that the western press corps in the U S S R is c o n c e n t r a t e d in M o s c o w , and journalists there operate under tight restrictions: they k n e w what they were told, which was very little during the first few days, and for the rest they relied on hearsay - - m u c h of it inaccurate. E v e n if Western journalists had been allowed access to the site, they would not necessarily have been able to learn any m o r e than they could by relying on official s p o k e s m a n . There are limits to what can be discovered a b o u t a reactor accident by the naked eye; and conditions in the area must have been chaotic. A further point must be made immediately. The Soviet authorities were severely critcized for "failing to report the a c c i d e n t " until sometime on the M o n d a y evening. But in all charity some allowance should be made for the very real c o m m u n i c a t i o n difficulties within the Soviet Union itself, and the confusion during the first hours a b o u t what had actually happened. We r e m e m b e r clearly something said at a press con-

R e s p o n s e to an accident

ference some months after the accident, at the PostAccident Review meeting organized by the I A E A in Vienna. Academician Valery Legasov, tackled on this question, said bitterly, " t h e y [the local authorities] were telling us that the reactor was under control, when there was no reactor left." Hindsight is a bad teacher. Perhaps, at another time, in another country, or even in the Soviet Union itself the situation would have been handled differently. ~ But the accident did o c c u r in the Ukrainian Soviet Socialist Republic, at a plant in a rural area. The response to the accident was handled during the first few hours by local officials, and only later from Moscow. The accident occurred in the early hours of a Saturday morning. H o w many readers have tried to contact their masters with bad news at 2 a.m. on a Saturday? H o w many have tried to do so while attempting to cope with what was patently a very severe accident, but whose gravity took time to appreciate? Only those who were there at the time experienced the stress they were under. It must also be noted that experts from the world nuclear community concluded later that the emergency response actions initiated immediately after the accident were appropriate and timely. It may have been possible to do more to inform the news media. Indeed, Mr G o r b a c h e v ' s vaunted policy of glanost (openness) would seem to require it. But there were the practical difficulties to which we have referred. Reports of measurements in the west of enhanced environmental contamination began to trickle in from Sweden on Monday, April 28. _The first alarms were sounded at the Forsmark nuclear power station, on the east coast of Sweden north of Stockholm, at about 0900 h on that day, when a worker whose shoes had b e c o m e lightly contaminated passed through a portal monitor. At first, the Swedish authorities thought there must have been an escape of radioactive materials from the F o r s m a r k plant itself; then, that the contamination might be coming across the Baltic, from a plant in Finland. By noon on that Monday, Swedish experts had drawn a map of observed radiation levels, correlated this with wind directions, and concluded that an accident had occurred somewhere in the Soviet Union. The Swedish science attach6 in Moscow, Per Olof Sjostedt, immediately contacted the Soviet State Committee on the Utilization of Atomic Energy, but was told that no information was available. At about 1500 h, the Swedish Ambassador to the USSR, Torsten Orn, repeated the inquiry at the Foreign Ministry with a similar lack of success.

~Others, such as the Windscale fire of 1957 and the accident at Three Mile Island in 1979, caused severe plant damage but there were no prompt fatalities, and in the case of the TMI accident there was only a very small escape of radioactive materials from the plant.

197

The I A E A received its first intimation that something had happened at the Chernobyl plant during the afternoon of Monday, April 28 and our first inquiries from the media in the evening. At about the same time, TASS issued the first official public statement concerning the accident. It read: '+An accident has taken place at the Chernobyl power station, and one of the reactors was damaged. Measures are being taken to eliminate the consequences o f the accident. Those affected by it are being given assistance. A G o v e r n m e n t Commission has been set u p . " The T A S S statement, though notable for its economy, was wholly accurate. Could the Soviet authorities have said more at that time? More than a week after the accident, Boris Shcherbina, the deputy Prime Minister who had on Saturday, April 26 been named head of the G o v e r n m e n t Commission of Inquiry, said at a press c o n f e r e n c e in Moscow: '+There were many unknown features and a very complex situation. The first information we obtained was not correct. On the ground, local experts and officials did not have a true assessment of the e v e n t . " Here, it is important to note that at the time of the accident the IAEA had no locus standi. The Agency had no responsibility to notify anyone of anything, nor was any country obliged to report anything to us. (We note later that the situation is now different.) Having said that, scientists in our Member States maintain close contacts. The agency has the statutory role of promoting the international exchange of information; it fulfills this role by arranging meetings, at which scientists can compare notes, and disseminating a very wide range of scientific and technical publications. The Agency counts as the largest nuclear science publishing house in the world. It was therefore natural that when the world scientific community sought information, they should approach the Agency. To a certain extent, the media were in the same boat. What had happened? Where was Chernobyl? H o w many people had been killed? What was an R B M K reactor? Was it safe to leave the house? Should children be permitted to play outside? Could they drink milk? The list of questions seemed endless. After a slow start, experts in the I A E A Divisions of Nuclear Safety, and of Public Information were besieged with telephone calls. One of us (JD) was on duty as a press officer for the IAEA throughout the critical period. We were helped immeasurably by briefings from diplomatic staff attached to the Mission of the USSR to the international organizations in Vienna. Almost e v e r y morning they reported to us the latest news from the site; and they showed themselves very ready to discuss and explain developments. If we had questions, they tried at least to get answers. So far as the I A E A was concerned, there were two main lines o f inquiry from the media. First, what had happened? H o w many people had been killed? (We

198 will return to this point.) Was the situation under control? Secondly, the media wished to k n o w what people in E u r o p e (and later in other parts of the world) should do to protect themselves. On the first point, we were able to pass on information which we had obtained from the Soviet Union. We did so, conscious that we were representing the interests of just one of our 113 M e m b e r States; conscious, too, that we might be seen as attempting a w h i t e w a s h for the Soviet authorities. We strove, h o w e v e r , to restrict ourselves to factual information. Until early May, when the Director General of the I A E A , Dr. H a n s Blix, and two senior colleagues visited M o s c o w and the Chernobyl site, we had no opportunity to verify independently any o f the information we were given. H o w e v e r , we found we had no reason to go b a c k on any of the briefings we gave about the reported situation at the accident site and its environs. We were satisfied that the information we were receiving was as accurate as it could be: it was both internally consistent, and consistent with the laws of physics. T h a t is not to say that we had all the information we could have wished for, but we did have engineering design detail of the r e a c t o r itself; and, so far as anyone k n e w in the first few days a b o u t what had h a p p e n e d to precipitate the accident, we k n e w perhaps as m u c h as a n y o n e else. We were at least able to explain some features of reactor physics to inquirers: there are not m a y journalists who have a b a c k g r o u n d in reactor engineering, yet it was journalists without such a b a c k g r o u n d who had the j o b of communicating with their readers or viewers. On the second line o f inquiry - - what people should do to protect t h e m s e l v e s - - we were in a rather different situation. We k n e w what levels o f radioactive contamination were being reported from various parts of various countries throughout E u r o p e (and later in other parts of the world). Decisions on intervention levels were, h o w e v e r , uniquely the responsibility of national authorities. W h a t e v e r our personal views of the a p p r o p r i a t e n e s s o f the actions that were taken, we had to leave j u d g m e n t to the national authorities confusing as this m a y have been to individual m e m b e r s of the public. All of this is b a c k g r o u n d to the m o s t notable feature o f the way in which the accident was reported: that m u c h o f the reporting, for several weeks or even months, was hysterical. It m a y be worth repeating here what information we did have in the west within the first few days after the accident. We k n e w the r e a c t o r type, and had a considerable a m o u n t of information a b o u t its actual design. We k n e w that there had been a violent p o w e r excursion, p r o b a b l y a c c o m p a n i e d by a s t e a m explosion (or two). We k n e w quite quickly that the accident had o c c u r r e d at a time when the o p e r a t o r s were conducting a test associated with the need to p r o v e the station's

A. Salo and J. Daglish ability to withstand the effects of a loss of off-site power. We could conjecture about the m e c h a n i s m s which might have led to initiation of the accident sequence. We had been told, and had no way of disproving, that two operators had been killed in the course of the accident, and that m a n y others (in the end, between 200 and 300) had been hospitalized; a total of 31 died. We knew that substantial radioactive contamination was being m e a s u r e d in a n u m b e r of countries. We k n e w within days that residents of neighboring communities were being evacuated. We k n e w that medical checks were being carried out not only on these people, but on residents of K i e v and on tourists who had been in the area at the time o f the accident. Did the Soviet authorities know any m o r e ? Did they understand what had h a p p e n e d m o r e quickly than the rest o f the world? O f course they did; they c a m e to Vienna for the Post-Accident R e v i e w meeting in August a r m e d with a very full scientific analysis of the accident sequence and of its immediate consequences. At that meeting, experts from all o v e r the world reviewed the data and came to the consensus that the Soviet authorities were, m o s t probably, entirely correct in their conclusions. But the question remains to be asked: did the Soviet authorities know (in the sense o f comprehending the actual accident sequence) any m o r e quickly than the rest of the scientific c o m m u n i t y ? A c a d e m i c i a n Legasov said later (International Nuclear Safety Advisory Group, 1986): " W e got the information about the disaster immediately. But it contained m a n y strange and contradictory things. Believe me, it was impossible to c o m p r e h e n d exactly what had happened, and to realize the scale of the accident. F o r example, the information we had spoke of radiation, but one of the dead had succumbed not to radiation but to chemical burns. I will not try to hide it from you. I did not realise the scale of the disaster was as great as it proved to be. And it was only when we approached to town of Pripyat [on the Saturday evening - - JD] and saw the red glow in the sky that I began to appreciate the character of what had happened there. It was impossible to evaluate what was happening while sitting in M o s c o w . " If it was impossible for a scientific expert and a Russian s p e a k e r to evaluate what was happening, how in the world could Western - - or even Soviet - journalists have been e x p e c t e d to do better? As it was, they did considerably worse. S o m e sought information from us, in Vienna. Others, faced with what they saw as a lack of information, invented stories. Consider the following paragraphs: From Chernobyl: Russia, comes news of a radioactive, 6-foot-tall monster chicken, a pathetic victim of the world's worst nuclear disaster. Trevor Holloway, a freelance journalist who covers the Soviet Union for a British newspaper, says: "The chicken is taller than most men and it must weigh close to 250 pounds.

R e s p o n s e to an accident

"'It is believed to have belonged to a f a r m e r who a b a n d o n e d the area following the C h e r n o b y l m i s h a p . . . " , . . h u n t e r s were finally able to catch the e n o r m o u s bird by baiting it into a 10-foot-deep pit filled with piles of chicken feed. " , . . My s o u r c e s say they were horrified to learn the creature is still growing. T h e y are c o n c e r n e d it could break out o f its cage and attack helpless lab workers. " T h e y are attempting to keep the gigantic bird pacified with m a s s i v e d o s e s of tranquilizers while t h e y c o n d u c t an e x t e n s i v e battery of e x p e r i m e n t s u p o n this disfigured bird."

We quote this, without apology, from the National Inquirer, a mass circulation newspaper published in the United States. When the article was published does not matter; it belongs in the trash can, not in the history books. If that story causes amusement, how should we view the equally inaccurate and tendentious reporting within the first few days of the accident that thousands of victims had been buried in mass graves? This seems to have originated in a fit o f enthusiasm on the part of a Moscow-based UPI reporter, L u t h e r Whitington, on T u e s d a y , April 29. N e w s p a p e r legend has it that he talked to a contact in Kiev who told him that local hospitals had been warned to prepare for many casualties - - perhaps as many as 2000 dead and dying. In itself, this might have been a reasonable precaution, and could have been reported as such. However, Whitington did not himself write the story. He passed it on to a senior colleague who stressed that the report was unconfirmed, but gave the 2000 figure nonetheless. UPI is a respected news agency; the media used the story. T h e y did so, despite the fact that some more careful journalists urged caution on their news editors. Julia Watson, for example, reports from M o s c o w for the L o n d o n Daily Mail. She told her newsdesk that if they used the story it should be heavily qualified as a unconfirmed rumour. The Daily Mail, instead, halffilled their front page with the words "2000 D E A D " - - and put her by-line on it. That was bad enough, but the next day, the New York Post managed to outdo them: their front page screamed the words " M A S S G R A V E . " The paper claimed that 15,000 bodies had been bulldozed into nuclear waste pits. It would be possible to give many other examples of extreme, biased, or tendentious reporting which occurred during the first hectic weeks after the accident. Some newspapers (such as the New York Times) continue even now for example to print worst-case estimates of the potential number of premature cancer deaths which may result from the accident; others (such as the L o n d o n Financial Times) report more responsibly that a long-term epidemiological study is only now being embarked upon. This study may yield data, showing on analysis, that there is some excess of premature cancer deaths which may be attributable to

199

the accident at Chernobyl. But the newspapers will have to wait a while before they can print the outcome of this study; the timespan of interest extends over almost two generations - - 50 or 60 years. Were the public well served by the media? The only honest answer to this is that some were, some were not. Those who read the more responsible newspapers and magazines acquired a very good understanding of the mechanism of the accident, and of its consequences. T h o s e who read the " p o p u l a r " tabloids did not. It must be acknowledged that the complications surrounding the reporting of the accident came close to destroying the credibility even of some of the most experienced reporters. First, this was an accident in an u n c o m m o n (in the west) type of reactor, whose physics are complicated. Secondly, the accident occurred at a site in the Ukraine: there were communications difficulties. Thirdly, any reactor accident is qualitatively d i f f e r e n t - at least in the public perception - - from an accident in a chemical plant or other major industrial accidents. The public are accustomed to accidents in which people are killed, but they have no gut feeling for accidents in which people may or may not be killed at some time during the next 50 years as a result of a single catastrophic event. The public at large has no understanding at all for stochastic risk. It is arguable, therefore, that the fact that this particular accident occurred in the Soviet Union is wholly irrelevant. It would have been equally difficult to report had it occurred anywhere else.

5. Exchange of Information During the First Several Days at the International Level and other Forms of International Response We have already referred to the approaches to the USSR authorities by the Swedish Ambassador to Moscow. Immediately after the issuance of the TASS statement on the evening of Monday, April 28, Yevgeny R y m k o , Deputy Head of the department of the U S S R Foreign Ministry which deals with northern Europe, told Lars Ake Nilsson, the Swedish Deputy Ambassador, that he had nothing to add to it. However, the U S S R authorities were quickly in contact with scientists in a n u m b e r of other countries, including the Federal Republic of Germany. T h e y asked, for example, for advice on how to fight a graphite fire. It was the fact that such questions were being asked that alerted many in the scientific community to the true nature of the emergency. During the last few days of April and the first days of May, the Ambassadors of the United Kingdom, Finland, and the Netherlands, and the Charg6s d'Affaires of France and Austria (and others) went to the Soviet Foreign Ministry seeking further information. On May 4, the Soviet authorities invited Dr. Hans Blix, Di-

200

rector General of the International Atomic Energy Agency, and two senior colleagues to visit Moscow; and on May 8 they flew over the area in a helicopter. On their return to Vienna they were able to give western journalists the first eye-witness account. However, the information available to other governments during the first few days after the accident remained partial, contradictory and confusing. Intelligence-gathering satellites in Earth orbit were used to acquire photogaphs which some analysts thought showed that a second reactor at the Chernobyl site had also been damaged. This false conclusion was faithfully reported. And so it continued, until in August 1986 the Soviet authorities presented their detailed analysis. Immediately after the accident, the 1AEA established informal contacts with radiation protection authorities in most European, and a number of nonEuropean countries in order to build up a more complete picture of what was happening. Since May 9 it also transmitted daily to Member States information about contamination levels which were being measured at six monitoring stations along the western border of the Soviet Union, and one close to the Chernobyl site. Already on May 6, the WHO Regional Office for Europe in Copenhagen convened a meeting of experts to provide immediate advice to health authorities on public health aspects. This was the first of what proved to be a long series of meetings. The most significant of these, in the long term, may prove to have been that of a group of governmental experts from 62 Member States of the Agency and of representatives of 10 international organizations, who met in Vienna from July 21 to August 15, 1986. These experts drafted the texts of two international conventions in the field of nuclear safety: one providing for the early notification of accidental releases of radioactive substances with potential trans-boundary consequences; and the other for the provision of emergency assistance. Following consideration by the IAEA Board of Governors, these two Conventions were adopted by unanimous resolution of a Special Session of the IAEA General Conference in September 1986. Both are now in force, and the Agency is working out arrangements for their practical implementation in the event of another accident. References Blomqvist, L., H~nninen, R. and Vuorinen, A. P. (1986)Emergency Planning by the Public Authorities in Finland. Proceedings of a Symposium, Emergency Planning and Preparedness for Nuclear Facilities, Rome, IAEA, Vienna. Commission of the European Communities (1982) Radiological protection criteria for controlling doses to the public in the event of accidental releases of radioactive material. Employment, Social Affairs and Education, Health and Safety Directorate of CEC, Luxembourg. Commission of the European Communities (1986) Aims and practices of transfrontier emergency planning within the EC coun-

A. Salo and J. Daglish

tries in case of an accident in a nuclear installation. Employment, Social Affairs and Education, Health and Safety Directorate of CEC, Luxembourg. Commission of the European Communities (1987) Proposal for a council regulation (EEC), Brussels. Council for Mutual Economic Assistance (1984) Criteria for radioactive releases from nuclear power plants requiring other countries to be informed Radiation Protection. Series No. 18, CMEA, Moscow (in Russian). Food and Agriculture Organization of ihe United Nations (1986) Expert Consultation on Recommended Limits for Radionuelide Contamination ofk))ods, 1-5 December •986, Rome. ll'yin, L. A. and Pavlovsky, O. A. (1987) The Chernobyl Accident: Radiological Consequences for the USSR and Countermeasures Taken. Paper presented at the International Conference on Nuclear Power Performance and Safety, Vienna, 1987. International Atomic Energy Agency (1985) Principles for establishing intervention levels for the protection of the public in the event of a nuclear accident or radiological emergency. Safety Series No. 72, I A E A Safety Guides, Vienna. International Atomic Energy Agency (1986) Derived intervention levels for application in controlling radiation doses to the public in the event of a nuclear accident or radiological emergency. Safety Series No. 81, IAEA Procedures and Data, Vienna. International Commission on Radiological Protection (1977) Recommendations of the international commission on radiological protection. ICRP, Publication 26, Pergamon Press. International Commission on Radiological Protection (1984) Protection of the public in the event of major radiation accidents: Principles for planning. ICRP, Publication 40, Pergamon Press. International Nuclear Safety Advisory Group (1986) Summary report on the post-accident review meeting on the Chernobyl accident. IAEA, Safety Series No. 75-INSAG-I, Vienna. Korneev, N. A. et al. (1987) The Agro-lndustrial Production Sector: Radiation Consequences of an Aceident and Main Safety Measares. Paper presented at the International Conference on Nuclear Power Performance and Safety, Vienna. Kriz, Z. (1986) Emergency Planning fi~r Nuclear Power Plants in Czechoslovakia. Proceedings of a Symposium, Emergency Planning and Preparedness for Nuclear Facilities, Rome, IAEA, Vienna. Linsley, G. S., Crick, M. J., Simmonds, J. R., and Haywood, S. M. (1986) Derived emergency reference levels for the introduction of contermeasures in the early to intermediate phases of emergencies involving the release of radioactive materials to the atmosphere. National Radiological Protection Board, Rep. NRPB-DL 10. Her Majesty's Stationary Office, London. Morrey, M., et al. (1987) A preliminary assessment of the radiological impact of the Chernobyl reactor accident on the population of the European Community, Health and Safety Directorate, CEC, Luxemburg. National reports on Chernobyl contamination submitted to IAEA, 1986-87. Nuclear Energy Agency of the OECD (1987) The Radiological Impact of the Chernobyl Accident in the OECD Countries, NEA/OECD, Paris. Sztanyik, L. B. (1986) Involvement o f the Public" Health Authority in Emergency Planning and Preparedness fi)r Nuclear Facilities in Hungary. Proceedings of a Symposium, Emergency Planning and Preparedness for Nuclear Facilities, Rome, IAEA, Vienna. US Food and Drug Administration (1982) Accidental Radioactive Contamination of Human Food and Animal Feeds; Recommendations for State and Local Agencies. U,S. Federal Register 45(205):47073-47083. van den Damme, R., Beckers, R. and Moureau, J. C. (1986)Nuclear Facilities Emergency Planning in Belgium. Proceedings of a Symposium, Emergency Planning and Preparedness for Nuclear Facilities, Rome, IAEA, Vienna. World Health Organization/Regional Office for Europe (1984) Nuclear Power: Accidental Releases - - Principles of Public Health Action, WHO Regional Publications, European Series No. 16, Copenhagen. World Health Organization/Regional Office for Europe (1986) Updated Background Information on the Nuclear Reactor Accident in Chernobyl, USSR, Summary Review of Measurement Results relevant for Dose Assessment, 12 June 1986.