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    5. Project to transform the Shelter Object

    The objective of stabilization of the Shelter building structures is to decrease the probability of building structures collapse for the period up to 15 years.
    It is achieved by means of stabilizing the unstable building structures.

    Stabilization Project was implemented in four stages:
    Stage 1 – defining a list of stabilization measures
    Stage 2 – conceptual stabilization decisions
    Stage 3 – detail design
    Stage 4 – construction, commissioning

    STAGE 1 started in June 1998 and completed in May 2001.
    Contractor: Consortium ICC(MK)JV consisting of Morrison Knudsen (USA), NIISK, KIEP, ISTC.
    Main tasks of STAGE 1:
    - Defining a number of stabilization measures;
    -     Conceptual decisions on stabilization measures;
    -     Taking decisions about required stabilization of the Shelter building structures.

    Number and scope of stabilization measures to be designed are accepted by the key decision P1 “Strategy of Stabilization and Shielding”, for which 15 stabilization measures are defined, 6 ones of which depended on burdens due to tornado.
    Program decision P2 “Decision on Stabilization Strategy for Roof, Supports and Structures” defines 9 measures for further implementation.

    STAGE 2 started in June 2001 and completed in February 2002.
    Contractor: Consortium ICC(MK)JV consisting of Morrison Knudsen (USA), NIISK, KIEP, ISTC.
    Main tasks of STAGE 2: Pre-design investigations to gather initial data for development of Work Design on stabilization measures.

    STAGE 3 started in September 2001 and completed in August 2003.
    Contractor: Consortium     КСК consisting of NIISK, KIEP and ISTC.
    Main tasks of STAGE 3: Development of Work Design on stabilization measures, specification of a number of stabilization measures, approval of Work Design on stabilization measures.

    STAGE 4 started in May 2004 and completed in August 2008.
    Main tasks of STAGE 4: Implementation of stabilization measures.
    Contractor    : russian-UkrainianConsortium “Stabilization” consistingofCJSC “Atomstroyeksport”, russian(Consortiumleader), JSC “Yuzhteploenergomontazh”, CJSC “RovnoNPPConstructionDepartment” andUDETI “Atomenergostroyproekt”, Ukraine.

    General contract organization JSC YuTEM performed building-assembling works on site involving 7 subcontract organizations.

    Stabilization measures

    Measure #14
    Western support leg of “Mammoth” beam –     completed on 01.11.2005
    Reinforcement of the western support leg of “Mammoth” beam lies in increasing section area of existing cross braces located along edges of dimensional metal support leg. Reinforcement is provided by means of installing and welding of two angles additionally to two same angles forming T-section so that closed hollow quad of two angles is formed in section of each branch of coupling element.

    The exposure dose rate (EDR) near the support leg is 400-1000 mR/h.

     

    Measure #14А
    Eastern support leg of “Mammoth” beam     – completed on 20.12.2005
    Eastern support leg of “Mammoth” beam is constructed as concrete abutment of 9.0 m height with 4.6x4.6 m section and metal head. The support leg basis is debris of building structures filled with concrete located at remaining cover at mark +35.500. The debris top corresponds to mark +43.050. By means of visual natural investigations, it was determined that cavities are detected within support leg basis that could impact on its stability in case of potential seismic activity.

    Reinforcement is performed by embedment of support leg basis with arrangement of fixed block of metal beams secured with existing reinforced concrete columns by means of plate steel loops. Covering the support leg basis with concrete of В25 class is performed in permanent form from northern and eastern side of support leg, from mark +40,100 to mark +44,300. Metal beams of rolled sections are installed at mark 43,050 m at axis 41 between column of row “B” and column of row “Г”, and at row “Г” between column at axis 41 and column at axis 42. The maximum weight of beam is 1.5 t.
    EDR values:
    - near eastern support leg of “Mammoth” beam – within 300-1,200 mR/h;
    - maximum value of EDR (up to 1,200 mR/h) is detected near southern-western basis of support leg between axes “    В” – “Г”;
    - minimum – 300-600 mR/h at axis “    В” near southern support leg basis;
    - the highest values of EDR (up to 1,000 mR/h) are detected near northern side of support leg, and EDR values are increasing westward and northward from support leg.

     

    Measure #3В
    Reinforcement of upper part of deaerator stack frame     – completed on 27.07.2006
    It was decided to reinforce the upper part of reinforced concrete frame by means of installing additional metal braces binding upper part of the column of row “    Б” at mark +33,15 with cover structures at mark +24,270 near row “В”.
    Metal braces are installed along column edges (axes 42-48) and are two-branch grid structure consisting of two channels combined on upper and lower booms by grid of single angles. For convenience of supplying structure elements to premise     Г635/3, each branch of brace was divided into three assembling elements of length up to 6 m and of weight up to 200 kg.
    EDRvalues:
    - in premise Г635/3 it varies from 10 to 100 mR/h, herewith EDR values are increasing towards upper marks and towards new cover of Turbine Hall;
    - local increase of EDR is detected in wall apertures near axis “    Б” over Turbine Hall roof;
    - maximum values of EDR (1800 mR/h) are detected near axis “    Б” during measurement in wall apertures over Turbine Hall roof.

     

    Measure #3С
    Reinforcement of plates for deaerator stack cover at mark 33,70     – completed on 25.05.2005
    Seven plates for deaerator stack (DS) cover at mark 33,70 are under emergency condition. To avoid their collapse and to create safe labor conditions during work performance on measure #3    В, it was decided to reinforce them by means of installing pillars at mark 16,40.
    EDR    values:
    - in premise Г635/3 it varies from 10 up to 100 mR/h, herewith EDR values are increasing towards upper marks and towards new cover of Turbine Hall;
    - local increase of EDR is detected in wall apertures near axis “    Б” over Turbine Hall roof;
    - maximum values of EDR (1800 mR/h) are detected near axis “    Б” during measurement in wall apertures over Turbine Hall roof.

     

    Measure #2
    Reinforcement of western fragment –     completed on 30.05.2008
    The reinforcement of western fragment of Shelter Object is made by constructing dimensional metal reinforcing tower structure (MRS) within local zone near western buttress wall. MRS is designed as two bar support legs sized as 8.5    х15 m, total height 49.2 m, with dimensional consoles outreaching up to 22.8 m eastward. The support legs are installed on reinforced concrete foundations at mark +14.000.
    Stabilization of western area lies in 80% load transmission from Beams     Б1/Б2, own weight of light roof and piped subfloor over Central Hall for new metal reinforcing structures to remove loads from destroyed wall at axis 50. Wall at axis 50 is reinforced by means of installing seven supporting legs at three levels.
    EDRvalues:
    - at height of buttress wall at axis “Л”, EDR is increasing from 20-25 mR/h at the bottom to 150 mR/h;
    - EDR values at internal side of buttress wall at axes “    Е” and “Н”:
    -     maximal – 420-620 mR/h near axes “Е” and “Ж”;
    - minimal – 18-26 mR/h at axes “    К” and “Л” at the bottom at mark +4,000 m.

     

    Measure #5/11
    Combining northern “shields-sticks” with northern buttress wall using fixing anchors     – completed on 28.11.06
    Combining northern “shields-sticks” with northern buttress wallis stipulated by means of installing and fixing “shields-sticks” at supporting traverses, by which the sticks are supported by the top of metal irremovable concrete form of northern buttress wall, specifically produced metal fixing anchors (Stabilization Measure #5), and by subsequent concreting of upper part of northern buttress wall up to designed wall top level (Stabilization Measure #11).Work area – work sites along northern buttress wall supported by its buttresses (mark +53,700 m). Welding works are performed higher the top of metal irremovable concrete form of the mentioned wall (mark +54,600 m).
    EDR values:
    - at mark 42,850 m at the bottom of northern buttress wall (axis “У1”), EDR values range from 6.5 mR/h (axes “47” – “49”) to 50 mR/h at axis “43”;
    - the lowest EDR values are from 180 to 1000 mR/h on northern side of cover at axis “    П”;
    - within cover area limited by axes “    С” – “Т” and “П” – “Р” and axes “41” – “49” (inclined surface of northern “shields-sticks”), EDR values range from 640 up to 2800 mR/h.

     

    Measure #8
    Combining southern “shields-sticks” with southern shields     – completed on 12.12.06
    Stabilization of southern part of Shelter roof is performed by combining southern “shields-sticks” with southern roof shields preventing displacement of “shields-sticks” southward. It was reached using triangulated bracing installation along row “    В” between axes 41-50 at mark +57.500. The triangulated bracing is located parallel to roof surface at the distance, approximately, 500-700 mm from it and is supported by mounting hooks of southern shields and “shields-sticks” overhanging over roof surface.
    Location of work area – southern area of SO cover near axis “    В” between axes “41” – “50” at mark +57,600 m.
    EDR    values:
    - increasing from 200-340 mR/h (axis “41”) to 1500 mR/h (axes “48”–“50”) on cover near adjoining of southern shields to southern “shields-sticks” along axis “В”;
    - EDR has values 200-1000 mR/h along axis “    В” and 340-1500 mR/h along axis “Г” on SO cover between axes “В”–“Г” and axes “41”–“50” at mark +57,600 m.

     

    Measure (withoutnumber)
    Local hermetic sealing (repair) of light roof     – completed on 12.08.2008
    The light roof is located over Central Hall and consists of six packaged units of 36 meters length. The    areaoflightroofis1405 m2. It is made of zinc-plated profiled flooring with 1 mm thickness of a plate. Since construction of Shelter Object, significant destructive impacts on roof took place leading to formation of large areas damaged by corrosion. During investigations it was revealed that along the whole roof area the profiled flooring has sections with corrosion, and in some places significant breakdowns were detected of total area from 120 to 150 m2, joint hermetic sealing is lacking, etc. Opened apertures enabled atmospheric precipitations to come easily inside the object. This resulted in destruction of building structures, influenced on condition of fuel-containing materials inside the Shelter.
    The light roof repair is made by means of local hermetic sealing by stacking new plates of profiled flooring, mounting tray-like battens, recovering hermetic sealing, and arranging regulated discharge outlet.

     

    All activities on stabilization measures were conducted under conditions of high level of radiation exposure.

     

    Stabilization of Shelter Object structures has the importance to assure safety for personnel working today on ChNPP site, and for inhabitants of territories outside of the Exclusion Zone. It is absolutely essential for safe construction of NSC as it would enable existing Shelter to isolate the environment from the impact of fuel-containing materials enclosed inside the “Sarcophagus” until New Safe Confinement is built and accepted for operation. After this, structures of existing Shelter will be dismantled under NSC cover.

    Main SIP objective is transformation of the Shelter object into ecologically safe system from the point of view of personnel protection, radiological safety and environment safety.
    SIP is organized on the basis of five purposes, which is necessary to achieve during its planned realization, and includes 22 tasks grouped according to these purposes.


    MAIN SIP TASKS

    OBJECTIVE 1. Collapse probability reduction (structural stabilization)
    Task 1. Stabilisation and Shielding Design Integration and Mobilisation
    Task 2. Stabilisation and Shielding of Western Section.
    Task 3. Stabilisation and Shielding of Mammoth Beam and Southern Section.
    Task 4. Stabilisation and Shielding of the Eastern and Northern Sections.
    Task 5. Stabilisation of the Roof, Roof Supports, and Covering.
    Task 6. Structural Investigation and Monitoring.
    Task 7. Geotechnical Investigation.
    Task 8. Seismic Characterisation and Monitoring.

    OBJECTIVE 2. Collapse Consequences Reduction
    Task 9. Emergency Preparedness.
    Task 10. Dust Management.
    Task 11. Emergency Dust Suppression System.

    OBJECTIVE 3. Nuclear Safety Improvement
    Task 12. Criticality Control and Nuclear Safety.
    Task 13. Contained Water Management.
    Task 14. Fuel Containing Material (FCM) Characterisation.

    OBJECTIVE 4. Worker and Environmental Safety Improvement
    Task 15. Radiological Protection Program.
    Task 16. Industrial Safety, Fire Protection, Infrastructure and Access Control.
    Task 17. Integrated Monitoring System.
    Task 18. Integrated Database (Configuration Management).

    OBJECTIVE 5. Long Term Strategy and Study for SO Conversion to an Environmentally Safe Site
    Task 19. FCM Removal and Waste Management Strategy and Study.
    Task 20. FCM Removal Technology Development.
    Task 21. Safe Confinement Strategy.
    Task 22. Implementation of a Safe Confinement to Support Deconstruction and FCM Removal.

    Realization of all project tasks is interconnected. The course of works on one task determines a course of works on another. There are three types of the basic SIP stages with the purpose of the necessary information obtaining for works progress and for the project status definition:
    - program – important decisions acceptance, influencing works progress or the beginning of new. 10 basic program decisions was defined, among them there are three key for successful SIP Project completion: P1 – Decision on stabilization, P8 – Decision on FCM removal strategy, P10 – Decision on New Confinement Strategy.
    - regulatory – Ukrainian Regulatory Bodies permission obtaining. It was defined 18 basic regulatory stages.
    - basic stages of tasks completion – stages specifying work, task completion, or completion of key activity within the task framework. It was defined 28 stages.

    PROJECT IMPLEMENTATION PHASES

    Phase 1: 1998 – middle of 2000 – Early Biddable Projects Stage (strategy and programs development, conceptual designing), preparatory works for Phase 2, including – implementation 2 of 5 urgent stabilization measures.
    Transition period: middle 2000 – beginning of 2001 – Early Biddable Projects closeout and decision-making on the basic program stages.
    Phase 2: beginning of 2001 – 2007 – equipment designing and procurement, facilities and systems construction and commissioning. This phase is characterized by Project transition to the stage of first phase results real implementation. There are, first of all, the works connected to building constructions stabilization, installation and commissioning of monitoring systems and the integrated database, FCM removal technology development and testing, water and dust management technical solutions realization, New Safe Confinement (NSC) erection and unstable constructions dismantling under its encasement. Solution of the specified tasks is supported by the Radiological Protection Program, Technical and Fire Safety ensuring, access control.

    PROJECT ORGANIZATIONAL STRUCTURE

    According to Memorandum of Understanding between G7 countries, European Commission and Government of Ukraine on Chornobyl NPP shutdown the special fund has been established – Chornobyl Shelter Fund (CSF) intended for assistance provision to Ukraine in existing "sarcophagus" transformation in safe and ecologically stable system by realization of the Shelter Implementation (SIP). G7 addressed to the Governments of the interested countries and to other donors to join the initiative for complete plan realization.
    European Bank for Reconstruction and Development (EBRD) became the Administrator of Grants funds allocated by Chornobyl Shelter Fund’s Contributors and Donors. Ukraine and the European Bank for Reconstruction and Development signed the Framework Agreement on CSF activity in Ukraine, ratified by Verkhovna Rada of Ukraine on February 4, 1998. Taking into account Grant intended for Regulatory Bodies financing, the total cost of project’s works makes 768 million US dollars. 28 Donors countries and European Commission accumulate these funds in CSF.

    Ukraine has taken obligation to allocate 50 million US dollars to Fund in form of property, works and otherwise.
    European Bank for Reconstruction and Development manages Fund Activity on behalf and under supervision of Assembly.

    Assembly:
    • authorizes Fund Grants allocation;
    • determines basic directions of activity, financed or are subject to financing from the Fund, carries out the general supervision of their realization by Bank;
    • traces pledged funds payments in Fund and provision of Ukrainian financing supplying Grants for SIP;
    • examines efficiency of activity, financed from Fund’s means;
    • approves Fund’s Annual Budget and Financial Reports; organizes regular annual meetings in process of which Fund’s Financial Reports for the last fiscal year are submitted for approval. Assembly can hold meetings at any time when it is necessary or expedient.

    Every Fund Contributor has the right to be presented in Assembly by the plenipotentiary representative without any compensation from Fund.

    The main responsibility for financial and program management of Project realization is entrusted on European Bank for Reconstruction and Development.

    The control and the organization of operational safety management pertain exclusively to Chornobyl NPP. Chornobyl NPP with the Consultant support manages the Project regarding to key programs and technical designs implementation.

    SIP Project Management Unit (PMU), established from SSE ChNPP personnel and the personnel of the Consultant (consortium of companies Bechtel (USA), Battelle (USA), EDF (France)), manages the Time Schedule, Scope of works, project budget, project changes, Civil work and carries out administrative contracts management.

    Phase 1 (1998 – 2000) is a phase of the information collection, investigations implementation, conceptual designs development, program decisions acceptances on their basis. These tasks performance was necessary for design and construction works deployment in Phase 2.

    The main achievements of Phase 1


    •  Project Management Unit establishment.
    Western and Ukrainian experts appointment, office creation and equipping.

    •  Nuclear Indemnification Program development, Project insurance, taxes exemption.

    •  Project planning, control and reporting means development. Integrated Base Time Schedule and Procurement Plan are the main control means. The information on SIP Procurement Plan can be obtained at an official EBRD Web- site http://www.ebrd.com/

    •  Evaluation of proposals, contracts awarding and Early Biddable Projects management. Early Biddable Projects packages (EBP) cover planning, development and project works according to main SIP tasks. Early Biddable Projects packages have been incorporated into 4 groups (A, B, C, D) for Terms of References similarity and included 17 of 22 SIP tasks. Such grouping has provided controlled packages quantity for tendering, contracts awarding and its subsequent management.

    Early Biddable Projects scopes:
    EBP À – Civil Construction (geotechnical investigations, building constructions monitoring system and infrastructures for stabilization measures designing, stabilization works determination, Decision on New Safe Confinement Strategy).
    EBP B     – operation and monitoring (industrial and fire safety, integrated monitoring system and database, seismic monitoring, radiological protection program).
    EBP C – emergency systems (Emergency Plans development, Safety related Emergency Systems, dust and water monitoring).
    EBP D – FCM removal strategy (Fuel Containing Materials Characterization, Decision on FCM removal prototype, RAW removal and Management Strategy).

    More than 30 companies from the different countries has been involved in works on Early Biddable Projects implementation, among which Morrison Knudsen Ltd (USA), BNFL Engineering Ltd (Great Britain), NUKEM (Germany), SGN (France), JGC Corporation (Japan), RSC “Kurchatov institute" (Russia), and Ukrainian Scientific Research Institutes – SRI of Building Constructions, Kiev Scientific Research Project Institute "Energoproject", Interbranch Scientific and Technical Center "Shelter" NASU and others.
    For all listed tasks deliverables were developed and approved, key program decisions have been accepted on their basis.

    •  two urgent stabilization measures performance

    Ventilation Stack of ChNPP Units 3 and 4 foundation and strengthening repair – in 1998.
    The total cost of the Project was US $ 2249966. Project financing was carried from tripartite payment: USA and Canada payment has made US $ 1800000, Ukraine – US $ 449966.
    "Ukrenergobud" Company was executor of works.
    This repair became the first international project provided direct improvement of Shelter object physical characteristics and safety increasing. Explosion of ChNPP Unit 4 in 1986 has seriously damaged ventilating stack supports system and its foundation. Investigation and analysis, carried out in 1996, have allowed to conclude, that the constructions are in emergency condition and its collapse probability is high enough. As a result of the stack collapse probability of the subsequent lethal dose obtaining by several thousand persons worked at ChNPP and adjacent territories was not excluded.
    Ukraine provided the personnel for works performance, radiation protection, radiation monitoring of construction and the necessary information. Shelter Object personnel managed works implementation and was fully responsible for works performance.
    USA and Canada experts provided the technical assistance and consultations, carried out general supervision on project performance, and evaluated works progress, conformity of the project realization to the objective. Quality and safety assurance was supervised together with the Ukrainian side.
    Average value of an external irradiation doze of the personnel, implemented these works, has made less than 1 cZv. Exceeding of individual irradiation dozes control levels – 4 cZv wasn’t fixed.

    B1 and B2 Beams support strengthening – 1999.
    The total project cost made US $ 2844079.
    “Ukrenergobud” company was executor of works.
    B1 and B2 Beams are one of main elements of Shelter object’s Central Hall and Deaerator stack covering.  As support for beams was ventilation shafts and wall on the axes 50 considerably damaged as a result of accident. In turn, on B2 beams blocks leans pipe covering above the Central Hall and covering plates are installed on B1 Beams. Beams are designed for vertical loading from their weight, weight of radiation protective concrete layer and loading from snow.
    Installation of beams was carried out in extreme conditions of the high radiation hazard in the absence of the reliable data about the level of supporting constructions damage. As a result of the subsequent surveys, calculations and expert assessments, works on B1 and B2 Beams supports strengthening have been included in the list of urgent stabilisation measures which should be immediately implemented, their failure could lead to a collapse of a considerable part of a covering with a total area about 3,5 thousand m2.
    Works inside object on high levels in the extreme conditions connected to the wide temperatures drops and high radiation fields became main peculiarity of the project. All operations on bioprotection and attached implements installation, shuttering manufacturing for concreting and welding works implementation were previously perfected on specially created mockup - simulator in Chornobyl.
    Average value of the external irradiation of personnel involved in works according dosimetric orders, made 1,31 cZv. Control level of individual irradiation dozes exceeding – 2 cZv – wasn’t fixed.

    Besides within the framework of the first project phase a number of works, promoting Shelter object safety and infrastructure improvement has been implemented:
    - the prototype of neutron monitoring system "Pilot" has been installed;
    - works on Shelter roof hermetization are executed. 5 stages of this task have reduced water penetration inside SO through roof thinnesses;
    - roads for radioactive wastes and building construction transportation are built;
    - operation testing of Shelter object Fuel Containing Materials database is started;
    - removal and disposal of the top ground layer, fencing, electrosupply, cold warehouses block construction at the small construction site, intended for stabilization measures was executed;
    - internal power supplies networks of Unit 4 are reconstructed, the fireproof covering of cable lines is executed;
    - site preparation for clothes change facility for 1430 persons and other works are started.

    Thus, during the period of Phase 1 realization significant progress in all basic areas, determined by SIP plan strategy and the works schedule has been achieved.

    The Shelter Object was constructed within 206 days. The accelerated time of its construction led to appearance of design flaws, in particular:
    1. The bearing structures of the supporting walls (survived constructions of the Power Unit 4) and their junctions were significantly damaged, overloaded with the weight of the building structures that were dropped on them, and materials used during the accident elimination
    2. Exposed reinforcing bars of the reinforced concrete structures and metal structures are corroded
    3. The structures constructed after the accident are freely supported on the bearing structures without a physical connection and are retained without welded or bolted connections

    Basic information Accident and its Elimination

    The international competition of designs and technical solutions was announced in 1992 to transform the Shelter Object into an environmentally safe system, which was the first step towards the international cooperation.

    Shelter Object’s design defects were described in 1995 in the report of the Alliance company and it contains the following conclusions:

    1. The operating Shelter is unstable and seismically isn’t resistant. Urgent measures should be undertaken to stabilize it and delay is unacceptable
    2. Due to the high radiation level and the actual state of existing structures long-term stabilization of the Shelter Object was considered as impossible. The state of the Shelter does not allow retrieving the radioactive materials
    3. New protective encasement should be constructed to allow Unit 4 dismantling
    4. The facility should be constructed for radioactive waste storage and management
    5. Ukraine isn’t capable to provide financing for such a project without outside help

    In June 1997, the G7 meeting accepted the "Shelter Implementation Plan" (hereinafter: SIP), developed under the assistance of the European Commission, Ukraine, United States and a team of international experts. This plan defined the basic concept, including a number of steps aimed at bringing the Shelter Object to an environmentally safe state.

    Objectives of the Shelter Implementation Plan:

    1. Reduce the Shelter Object collapse probability
    2. Reduction of consequences in case of the collapse
    3. Nuclear safety improvement
    4. Improve the personnel and the environment safety
    5. Develop a long-term strategy and investigate ways to transform the Shelter Object into an environmentally safe system

    The Donor countries pledging conference took place November 20, 1997 in New York. These countries committed to allocate funds for this Plan implementation in a specially established Chornobyl Shelter Fund. The Fund administration was entrusted to the European Bank for Reconstruction and Development.

    The Shelter Object transformation into an environmentally safe system is carried out in 3 stages::
    1. Stabilization. Stabilization of the existing facility state and increase of its operational reliability
    2. Preparation for transformation. Creation of additional protective barriers, in particular New Safe Confinement. This will provide the necessary conditions for the subsequent stages of transformation, as well as will protect the personnel, general public and environment. In addition, at this stage preparatory work is planned to develop a technology for Fuel Containing Masses retrieval from the Shelter Object and to create infrastructure for Radioactive Waste Management
    3. Transformation. Fuel Containing Masses and Radioactive Waste retrieval from the Shelter object and their disposal. Shelter object decommissioning

    SIP stabilization stage was implemented within 2004-2008.

    The urgent stabilization measures were implemented during 4 years, which allowed strengthening the main most vulnerable Shelter Object's elements. At this stage the Shelter western wall was strengthened, the emergency slabs were stabilized, the Shelter northern zone, the southern zone roof and the western and eastern Mammoth Beam supports construction were reinforced, the light roof of the Shelter Object and the Ventilation stack of Units 3 and 4 were repaired.

    These works allowed extending the Shelter Object lifetime for another 15 years.

    The stage of preparation for the transformation stipulated the construction New Safe Confinement (hereinafter: NSC) — a protective structure, which includes a complex of technological equipment for FCM retrieval from the damaged 4th Power Unit, radioactive waste management and the safety assurance for the personnel, the general public and the environment.

    Preparatory works for the NSC construction were started in 2005. In 2010 the site for the confinement construction was prepared.

    Basic information: The project "New Safe Confinement Construction"

    November 29, 2016 — the NSC Arch was installed in the design position above the Shelter Object.


    © Video from YouTube channel PRIPYAT-film. See the video here.

    In 2016, the Chornobyl NPP obtained a permission to operate the Shelter Object's Integrated Automated Monitoring System (IAMS).

    The system is designed to perform automated monitoring of the Shelter Object's condition and improve the nuclear, radiation and general technical safety of this facility, including increase of emergency preparedness. The IAMS consists of a Nuclear Safety Monitoring System, Radiation monitoring system, system for building structures condition monitoring and seismic monitoring system.

    Within the third stage of the transformation it is planned to retrieve the Fuel Containing Masses from the Shelter Object, to transfer them to the controlled state by storing them inside the protective barriers or by disposal in geological repositories for radioactive waste. The goal of this stage is to transfer the facility into an environmentally safe state.

    The available level of knowledge is insufficient to identify the timeframe for the Stage 3 implementation. Priorities for the nearest future are the NSC commissioning and transition to dismantling of Shelter Object's unstable structures by 2023 — the final service life of the Shelter Object stabilized structures.

    1. Program decisions
    2. History

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