Analysis of the features of retrieving of fuel-containing materials (FCM) and associated radioactive waste generated during the accident at Unit 4 of the Chernobyl NPP, from the lower levels of the «Ukryttya» object was carried out. It is shown that, unlike the process of extracting FCM from the top levels of the «Ukryttya» object based on the «top access top-down» method using the New Safe Confinement (NSC) main crane system, to organize the work on retrieving FCM from the lower levels, a more promising option is to use method of "horizontal access". The expediency of this approach is based on the absence of the need to disassemble the block overlaps, to organize access to FCM accumulations at levels 9,000; 6,000; 3,000 and 0,000, which, taking into account the technical characteristics of the NSC cranes and their working mechanisms, is a difficult and long-term task. Conceptual proposals for the creation of a transport scheme for access to the lower levels, consisting of an external closed trestle with a lifting mechanism and a vertical freight elevator for the delivery/retrieval of cargoes, are given. A general sequence of work and possible ways of access to the main FCM accumulations at the lower levels of the «Ukryttya» object has been developed. Basic technological solutions are presented proving the possibility of the device of horizontal penetrations and delivery to the lower levels of remotely controlled units required for the extraction and transportation of packages with FCM for subsequent circulation within the NSC. It is concluded that the proposed option based on the method of "horizontal access" will solve the problem of FCM extracting from the lower levels of the «Ukryttya» object, both in the short term (during the life cycle of the NSC) and postponed extraction, after the NSC is decommissioned.
Keywords: Chernobyl nuclear power plant, «Ukryttya» object, new safe confinement, fuel-containing materials, radioactive waste, extraction, remotely controlled units, block of "hot" chambers.
1. Report on the safety status of the Shelter object. - Chornobyl NPP, 2008. - 436 p. (Rus)
2. Prospects of extraction of fuel-containing materials from the Shelter object using the systems of the new safe confinement / V. G. Batiy, S. S. Podbereznyi, V. M. Rudko et al. // Problemy bezpeky atomnykh electrostantsiy i Chornobylya (Problems of Nuclear Power Plants' Safety and of Chornobyl). - 2007. - Iss. 7. - P. 76 - 84. (Rus)
3. Batiy V. G. Model experiment on the extraction of fuel-containing materials from the Shelter object / V. G. Batiy, A. I. Stoyanov, A. V. Shchulepnikova // Collaboration to solve the waste problem, Proceedings of the VI International Conference, Kharkov, April 8 - 9, 2009. – Kharkov, 2009. - P. 38 - 40. (Rus)
4. Problems of extraction of fuel-containing materials of the "Shelter" object / V. G. Batiy, A. S. Lagunenko, S. S. Podberezniy, A. V. Shchulepnikova // Materily of the International Science and Technology Conference "Problems of management with Radioactive Inputs in Ukraine", Kyiv, 22 - 23 November 2010. – Kyiv, 2010. - P. 23 - 28. (Rus)
5. Tokarevskiy V. V. The strategy of fuel-containing materials extracting from the Shelter object / V. V. Tokarevskiy // Nuclear and radіation safety. - 2012. - Т. 55. - Iss. 3. - - P. 43 - 47. (Rus)
6. Tokarevskiy V. V. Technologies of extraction of fuel-containing materials from the Shelter object / V. V. Tokarevskiy // Nuclear and radіation safety. – 2012. - Vol. 4 (56). - P. 48 - 52. (Rus)
7. Batiy V. G. Analysis of possible ways of management of fuel-containing materials after the completion of the construction of a new safe confinement / V. G. Batiy, V. N. Shcherbin, A. V. Shchulepnikova // Problemy bezpeky atomnykh electrostantsiy i Chornobylya (Problems of Nuclear Power Plants' Safety and of Chornobyl). - 2014. - Vol. 23. - P. 32 - 44. (Rus)
8. Principles of technological solutions for extraction of fuel materials from the upper levels of the Shelter object / O. V. Balan, V. G. Batiy, S. І Glebkin et al. // Problemy bezpeky atomnykh electrostantsiy i Chornobylya (Problems of Nuclear Power Plants' Safety and of Chornobyl). - 2015. - Iss. 25. - P. 83 - 93. (Ukr)
9. The license package 6 (LP-6). Project "Protective construction with technological life support systems and the necessary infrastructure". Report on compliance with the requirements of sanitary legislation, SIP-N-LI-22- E002-SCR-002-01 / LCO-NKA-NSC-017-1-EN. (Rus)
10. Radiation situation and description of building structures in the surveyed premises of Block B of the Shelter object / Passport-Directory. Vol. 1. - Arch. № 3273. - ISTC "Shelter" of the NAS of Ukraine. - 1995 - 367 p. (Rus)
11. FCM atlas, classification, 2D models / FCM atlas, classification, 2-D models. SIP-EBPD-R-0093 (Issue № 1).
12. Analysis of the current safety of the Shelter object and projected assessments of the situation : Report on R&D ISTC Shelter. - Arch. No. 3836. - Chornobyl, 2001. - 337 p. (Rus)
13. Development of scientific and technical bases and substantiation of the principal technological decisions regarding the removal of FCM from the «Ukryttya» object with the use of future safe confinement and the creation of an appropriate infrastructure for their further management : (SRW Report, final) / ISP NPP of the National Academy of Sciences of Ukraine. - Arch. No. 4018. - Chornobyl, 2015. - 443 p. (Ukr)