The first stage of ACE (accident consequences elimination) was completed since Chornobyl NPP transition to a non-rotation based work.

The main objectives of work performance of ACE 2nd stage at Chornobyl NPP were:
- Prevention of radionuclide spreading from radioactive contamination area;
- Re-disposal of solid RAW;
- Creation of conditions within contamination area for radiation-safe vital activity of population;
- Preparation of the Exclusion Zone and resettled territories of strict control zone to the return to national economy;
- Preparation to Chornobyl NPP decommissioning.

Complexity of ACE 2nd stage performance was a practical absence of sufficient economic and ecologically clean technologies and technical means on decontamination of large territories, equipment, as well as metal, wood and other materials. Change of approach to decontamination methods, creation of new, mobile technical means for decontamination of forest areas, agricultural land, water bodies, main transport routes and settlements, creation of facilities for radioactive waste treatment for their secure disposal were required under these conditions. During the meeting held on August 8-10, 1989, in Chornobyl town, Mr. Doguzhyev, Deputy Chairman of USSR Council of Ministers, has committed USSR Ministry of Atomic Energy Industry to review issue on improving organizational structure of work management within Chornobyl NPP area.

After review, USSR Ministry of Atomic Energy Industry has decided on following:
- Separate Chornobyl NPP from PE “Kombinat” as independent enterprise performing Employer’s functions on construction and operation of Slavutich town and auxiliary facilities.
- Close down PE “Kombinat” starting from 01.01.90.
- As agreed with Ukrainian SSR Council of Ministers, to establish scientific-production association (SPA) “Pripiat” in Chornobyl town, Kiev Region, on the basis of PE “Kombinat”.

Primary tasks and forms of scientific research organization associated with ChNPP accident consequences elimination have been laid down by the Decree of USSR Council of Ministers dated 01.11.86. This Decree envisaged development of research on Comprehensive Program during 1986-1990, including six priority scientific directions determining head authorities and scientific-research organizations responsible for execution and development of these directions:
- Impact of radioactive contamination on flora and fauna objects (ecology) – USSR Academy of Sciences, Severtsov Institute of Development Morphology and Animal Ecology of USSR AS (research supervisor is Academician V. Sokolov);
- Control for radioactive contamination level of environmental objects and study of process of transferring fission products and transuranium elements (control and forecast of radioactive contaminations) – USSR State Committee for Hydrometeorology, Fedorov Institute of Practical Geophysics of USSR SCHM (research supervisor is corresponding member of USSR AS Yu. Israel);
- Study of biological factors and late effects of radiation exposure to population and development of measures on reducing negative impact of this exposure (radiation medicine) – USSR Ministry of Health, All-Union Scientific Center of Radiation Medicine of USSR Academy of Medical Sciences (research supervisor is USSR AMS Academician L. Iliin);
- Study of radioactive contamination impact on agricultural products, development of measures on reducing this impact and on disposal of food contaminated with radionuclides (agricultural radiology) – USSR State Agricultural Industry, All-Union Scientific-Research Institute for Agricultural Radiology of USSR SAI (research supervisor is Professor N. Korneev);
- Development of methods and means of decontamination of environmental objects, economic and domestic buildings and constructions, equipment and vehicles (decontamination) – USSR Ministry of Medium Engineering, All-Union SRI for Non-Organic Materials of USSR MME (research supervisor is corresponding member of USSR AS A. Nikiforov);
- Development of technologies, systems and equipment, including remotely operated devices and equipment required for ensuring safe conditions on performing works on accident elimination (equipment and technology) – USSR AS, Blagonravov Institute of Machine Science of USSR AS (research supervisor is Academician K. Frolov).

To perform general management and coordination of this research, including preparation of the most Comprehensive Program of scientific research, control for work performance progress by scientific-research institutions of different ministries and authorities, generalization of results of research being conducted and preparation of recommendations for their implementation, the Interdepartmental Steering Council for scientific problems related to ChNPP accident consequences elimination was established under USSR AS Presidium.

It is comprised of A. Aleksandrov, Academician, Director of Kurchatov Atomic Energy Institute (AEI) of USSR MME (Chairman); V. Legasov, Academician, First Deputy Director of Kurchatov AEI (First Deputy Chairman) and other central figures of science and technique. As time passed, personal line-up of the Council has been changed. At the end of 1989, Academician S. Beliaev became its Chairman. Creation of corresponding data bank at AEI was provided for information support of the Steering Council activity.