Commission on Questions of the Chernobyl Catastrophe, Supreme Soviet of the Ukrainian SSR, 'On Some Problems in the Elimination of the Consequences of the Accident at the Chernobyl Atomic Energy Station'

Secret [crossed out and “Not secret 242-3442 20.08.(obscured)” handwritten in Ukrainian]

22 January [19]91

Supreme Soviet of the Ukrainian SSR

[Handwritten: No. 18]

Commission on Chernobyl Catastrophe Issues

To Comrade V.A. Yavorivskiy

On some issues in the elimination of the consequences of the accident at Chernobyl AES

The Committee on State Security [KGB] has received information about several unresolved problems arising in the course of work to overcome the consequences of the accident at the Chernobyl AES and to ensure its safe operation.

Unresolved questions connected to design defects in RBMK reactors continue to raise concerns among specialists, as does the forthcoming decommissioning of Chernobyl AES. According to the conclusion of monitoring organs, the power units, especially Nos. 1 and 2, do not meet modern requirements for the safe operation of atomic power facilities, most of all because of the impossibility of creating protective shells for accident localization systems. The technical condition of the station’s equipment also raises concerns among specialists, first and foremost the reliability of the reactors themselves. Monitoring of the technological channels shows that their dimensions are close to the maximum allowable and further operation of the power units could lead to emergency situations arising.^[1] For instance, from 1989-1990, there were 5 cases in which spent fuel assemblies jammed as they were being unloaded from the core.

The USSR Ministry of the Atomic Power and Industry has yet to find solutions to issues connected with the end of the service life of reactor control and protection systems, of main circulation pumps and of other equipment. As tests which have been conducted demonstrate, the emergency cooling system in the RBMK reactors in the first stage^[2] are essentially non-serviceable because their technical parameters do not meet established norms.

The measures mentioned in accordance with USSR Council of Ministers Decision No. 722 from 21 July 1987 on the reconstruction and modernization of the station were planned to be achieved in 1993-1994. Should these measures be implemented, the plan to replace equipment will coincide with the deadlines to decommission the power units. In connection with this, AES specialists have expressed concern about the fact that during the period of preparation to dismantle the equipment and close the station, which according to preliminary calculations will take no less than 5-7 years, a further deterioration in the level of safety at the station will take place.

One of the most important issues is that of ensuring the safety of the “Ukrytiye”^[3] facility. Despite information obtained by scientists from the integrated expedition of the Kurchatov Institute of Atomic Energy about the deep sub-criticality of fuel masses in the collapsed reactor, the USSR State Committee for Oversight of Industrial and Atomic Safety determined it to be a nuclear hazard. Up to the present time the facility’s status, as well as documentary justification of its nuclear and general safety, has been lacking.

Research data obtained in 1990 attests to the intense destruction of the concrete structures, the transformation of the fuel-containing mass from a vitreous into a pulverized state, and about the threat of the collapse of the reactor’s upper cover, which would lead to the ejection of radioactive dust into the environment. Under these conditions, the task of primary importance is to ensure constant oversight over the condition of the core, the walls and foundation of the destroyed power unit, and the reliability of the functioning of dust suppression systems in case of the development of a critical situation.

However, according to specialists’ assessments, the “Shater” [“tent” information diagnostic complex, developed by the Ukr. SSR Academy of Sciences Institute for Nuclear Research to be used for these purposes, does not fully meet the requirements of objectivity, modernity, or completeness of information about the processes occurring within the collapsed reactor and requires modernization. Moreover, the possibility of operational deployment of the dust suppression system in a crisis situation was not envisioned.

The resolution of these and other tasks for the “Ukrytiye” unit and for Chernobyl AES as a whole continues to be constrained by the lack of a scientifically justified concept that takes into account the whole complex of issues, including those connected with the forthcoming decommissioning of the station. Its development has been unjustifiably delayed by the USSR Ministry of Atomic Power and Industry.

One of the most important aspects of the elimination of the medical and biological consequences of the Chernobyl catastrophe is identifying the pattern of formation of radiation doses, the development of a radiation situation forecast, and the dose load for the population. Taking these indicators into account, a concept for residing in contaminated areas will be formulated, and the population determined which will be subject to resettlement and continuous medical monitoring.

The existing approach of the National Commission for Radiation Protection under the USSR Ministry of Health to determine doses is based on a calculation of irradiation of the thyroid gland with iodine-131, and of the whole body to cesium-137, and externally from gamma radiation.

However, research results obtained recently by a group of scientists from the Institute for Epidemiological and Preventive Treatment of Radiation Damage at the USSR Academy of Medical Science All-Union Scientific Center for Radiation Medicine demonstrate that such a method does not address all factors of radiation damage. In their opinion, due to the Chernobyl catastrophe, people were subjected to the simultaneous sustained effects of several types of external and internal radiation from radionuclides with a high biological hazard, including strontium, transuranic alpha-irradiators and others, the impact of which were not considered earlier in the formulation of doses and impact on health.

Because of this, the scientists presume, the population that was irradiated, the doses they received, and the scale of radiation contamination are significantly underestimated and do not conform to the actual situation after the catastrophe. According to calculations by this group of scientists, the zone of dangerous contamination after the catastrophe is up to 450-500 km, and the critically dangerous area is up to 120-130 km. More than 4.5 million inhabitants of Ukraine, Belarus, and Russia could have been subjected to internal and external radiation higher than the permissible emergency standards.

The general evaluation of the Chernobyl catastrophe laid out above has had a mixed reception in Kiev’s scientific circles, since it contradicts the concept accepted and provided by the Soviet and global community, according to which the scale of the accident was less significant. For instance, a number of scientists from the Ukr. SSR Academy of Sciences expressed their support of this approach to determination of doses. At the same time, the majority of scientists specializing in dosimetrics at the USSR Academy of Medical Sciences’ All-Union Scientific Center for Radiation Medicine think that such a method is in need of profound scientific reworking.

In consideration of the fact that at the present time there is a lack of a unified scientific approach to the problem laid out above, an opinion has been floated about the expedience of creating an inter-agency commission composed of scientists and specialists with a background in physics and radiobiology to provide expert review of newly received material. This is necessary for a subsequent forecast of the actual changes in the health status of the population, and a more objective approach to the development of concept for people to live safely in the areas subjected to radioactive contamination.

Under the circumstances of the complications in the ecological conditions caused by the accident, the work to create new selective sorbents plays an important role. These sorbents prevent the accumulation of radioactive and toxic substances and enable them to be excreted from the body. The level of scientific research by Ukrainian scientists in this area is demonstrated by the efforts by representatives from Western firms to obtain information about the technological process, which they value as “know-how,” or to obtain patents for these inventions abroad. (The Republic Committee communicated to the Supreme Soviet and Council of Ministers of the Ukr. SSR in December 1990 about some problems in their development in Ukraine).

In 1990 the “Ekosorb” state consortium was created by a Decision of the Republic’s government, which united around 20 organizations and enterprises. The decision also created in January of this year the Urk. SSR Academy of Sciences Institute for Sorption and Problems of Endoecology, whose efforts should be directed toward launching the production of all types of sorbents. In order for their activities to achieve a significant social and ecological effect, according to specialists, it is necessary to consider targeted financing from budget funds directed to the elimination of the consequences of the accident.

The Committee on State Security [i.e. KGB] of Ukraine as part of its duties is continuing work to support the Republic program to determine the consequences of the Chernobyl catastrophe with classified foreign scientific and technical materials and documentation. Specific measures are being conducted taking into account the exceptional significance and are considered priority intelligence-gathering tasks. In addition to the documentation sent earlier to interested ministries and agencies, at the present time more than 100 additional documents are being prepared for transmittal to the newly-created Ukr. SSR State Committee on Protection of the Population from the Consequences of the Accident at the Chernobyl AES. These materials address issues of radiation medicine, biology, decontamination, and AES safety

This information will be communicated in due order.

Committee Chair N. Golushko

[Handwritten: “Verified: Sr. O.(perative)/ P.(lenipotentiary) 3^rd dept. 6^th Directorate of the Ukr. SSR KGB M(ajo)r (Signature) 22.01.91”]

^[1] This is an issue caused by radiation-induced swelling of the graphite blocks through which the channels are placed. Graphite is the moderator for RBMKs.

^[2] The first stage of the station refers to Units One and Two. Stage Two would comprise Units Three and Four.

^[3] The “Shelter” facility is the structure built to encase the destroyed Unit Four reactor.