Foreign Relations of the United States, 1981–1988, Volume V, Soviet Union, March 1985–October 1986

220. Intelligence Report Prepared in the Central Intelligence Agency¹

Washington, April 29, 1986

SPOT COMMENTARY: Soviet Nuclear Accident

DAMAGE ASSESSMENT: The Soviet nuclear accident announced by Moscow yesterday possibly occurred last Friday or at the latest early Saturday.² [less than 1 line not declassified] the Chernobyl Power Plant [less than 1 line not declassified] extensive damage, indicating a large explosion occurred in the hall of the fourth reactor building.³ The event probably was initiated by some kind of loss-of-coolant-accident, which caused fuel melting. We believe that the associated high temperatures produced hydrogen and methane which caused the explosion.

[3½ lines not declassified] The continuing graphite fire will be a major problem for rescuers and plant personnel trying to contain radioactive release. The fire will continue to spread radioactive fallout as long as it burns. Firefighting efforts will be extremely difficult, however, since the radiation level in the reactor hall certainly is above lethal levels. A further concern is the possibility that water used to extinguish the fire could cause another nuclear reaction.

Principal damage from the releases will be caused by radioactive iodine, which concentrates in the thyroid. The Soviets could be expected to divert milk supplies, since radioiodine concentrates heavily in dairy products. Other major health threats are direct damage to lungs and contamination of water supplies, especially since the reactor is located near the main reservoir for the city of Kiev. The Swedish Meteorological and Hydrological Institute reports that the region where the accident occurred is experiencing only light winds, exposing the population there to greater radioactivity.

SOVIET AND EAST EUROPEAN REACTION: The Soviets delayed admission of the disaster and continue to minimize domestic media coverage, with no local announcement that the government has established a commission to investigate the disaster. Media management of the accident appears to be a critical test of Gorbachev’s year-long push for openness and publicity.

The enormity of the accident is reflected in Moscow’s request for assistance from Sweden and West Germany and the Soviet Foreign Ministry’s warning against travel to Kiev.

[1 paragraph (2½ lines) not declassified]

So far we have heard only from Poland and Hungary of Moscow’s Warsaw Pact allies. Polish radio has admitted that a radioactive cloud passed over Poland “at a great height,” but Warsaw apparently is seeking to minimize any possible health concerns. Nevertheless, the government has established a special commission to track the effects and has set up two hundred additional monitoring stations. Hungarian radio has indicated only that there were injuries during the disaster and has admitted that Kiev’s water supply possibly was affected.

The Chernobyl disaster already has put Moscow on the defensive regarding its advocacy of civilian nuclear power programs, and Moscow is seeking to deflect criticism of its reactor program by unfavorable comparisons to nuclear accidents in the West. The Soviets are also trying to gain a propaganda advantage by stressing the “terrible consequences” of accidents involving military weapons or weapons production, whose abolition Gorbachev demanded early this year. Meanwhile, the disaster represents a significant setback to Moscow’s efforts to increase its reliance on nuclear power, may affect Soviet electricity deliveries to Eastern Europe, and probably has impacted on agricultural production in one of the country’s major grain-producing areas.

WESTERN EUROPE: Scandinavian countries have expressed considerable anger with the Soviets. Sweden in particular has protested Moscow’s failure to notify its neighbors. Stockholm claims its original inquiries in the USSR received no response.⁴ Only after high radiation levels were detected in Scandinavia and inquiries were made at the IAEA in Vienna did Moscow admit to the accident, [less than 1 line not declassified]. Stockholm has directed its Ambassador in Moscow to protest the incident. Denmark and Norway have also expressed concern over Soviet hesitancy to inform neighboring countries.

Meanwhile, the West Germans have detected two to three times the normal radiation levels in their northernmost state, Schleswig-Holstein. This still remains below those levels being measured in Scandinavia—four to five times above normal in Sweden, and 60 above normal in Norway. Bonn has offered to assist the Soviets.

Over the long term, we do not see the accident changing West European views on security issues such as a nuclear weapons-free zone, largely because both sides will use the accident to support their own arguments. Proponents will argue that such steps are now more necessary than ever, while opponents will point out that the radiation came from outside any zone currently being proposed. Opponents are also likely to use Moscow’s slow reaction to raise new questions about Soviet credibility. Western Europe’s nuclear industry is likely to suffer a blow, at least initially as ecologists use this accident to highlight the dangers accompanying nuclear energy. Political groups, like the West German Greens, may benefit from a heightened public sensitivity to the issue.

1. Source: Reagan Library, Jack Matlock Files, USSR Subject File, 1981–1986, USSR: Nuclear Accident: Chernobyl April 29, 1986. Secret; [handling restriction not declassified]. Prepared in the Directorate of Intelligence. A note in an unknown hand attached to the report indicates that it was sent to Thompson for Poindexter, Pearson, and Bush. Shultz was traveling with the President to the ASEAN meeting in Indonesia, the G–7 Economic Summit in Tokyo, and meetings in South Korea and the Philippines from April 29 to May 9. Shultz wrote in his memoir: “The president and the first lady left Washington on April 25, 1986, for a thirteen-day trip to Indonesia and Japan. We made our way slowly westward. As we were leaving Honolulu for Bali, Indonesia, on April 28, distressing news reached Air Force One. Abnormally high levels of radioactivity had been reported by Sweden, Finland, and Denmark, all downwind from the Soviet Union. Experts in these Scandinavian countries first checked their own reactors and found no problems. Sweden demanded information from the Soviets.” (Shultz, Turmoil and Triumph, p. 714)
2. Friday, April 25.
3. The USSR Council of Ministers released the following brief statement on April 28: “An accident has occurred at the Chernobyl Atomic Power Station; one of the nuclear reactors has been damaged. Measures are being taken to eliminate the consequences of the accident. Aid is being given to the victims. A government commission has been established.” (Current Digest of the Soviet Press, vol. XXXVIII, no. 16 (May 21, 1986), p. 1)
4. In telegram 3296 from Stockholm, April 29, the Embassy reported: “The Swedish Ambassador in Moscow will be using a pre-scheduled meeting at the Soviet Foreign Ministry on April 27 to demand clarification and details on the nuclear accident at the Chernobyl reactor in the Ukraine and to complain over the Soviet delay in notifying Sweden of the accident. Airborne nuclear debris from the accident was first registered by ‘automatic’ measuring stations in Sweden on April 26 but not read until opening of business the following day. A cloud of nuclear materials is now over most of the Scandinavian peninsula but poses no serious radiation threat and is expected to disperse shortly. Swedish authorities now speculate that the Chernobyl accident could have occurred early on Saturday, April 25, and that it has resulted in serious damage to the reactor’s core and possibly a core melt.” (Department of State, Central Foreign Policy File, Electronic Telegrams, D860328–0229)