The problem of amount and condition of nuclear fuel in the destroyed Unit 4 of Chornobyl NPP is one of key one during determining the condition of nuclear, radiation and ecological safety of the Shelter. Nowadays, one can consider specified that more than 95% of fuel remains inside the Unit from initial loading.

According to scientists’ estimates, total amount of nuclear fission materials is about 200 tons. However, the researchers did not succeeded in obtaining the reliable information regarding many places within the Shelter where detectable amounts of fuel could be.

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Declaration on the ecological consequences of the planned activity

Statement of intent of the construction of the New Safe Confinement above the Object 'Shelter' of the Chornobyl Nuclear Power Plant

Statement on ecological consequences of the planned activities under Project “Reconstruction of ChNPP Stage II (Power Units 3,4) Main Building with Reinforcement and Sealing of structures, which perform NSC enclosing perimeter functions”

NSC CS-1 CONCEPT DESIGN SAFETY DOCUMENT

“SHELTER” OBJECT SAFETY STATUS REPORT. 2008

Clarifications to classification of systems, structures and components (SSC) of the New Safe Confinement Commissioning Stage-1 depending on their impact on nuclear and radiation safety

Technical requirements clarification for NSC auxiliary systems and facilities

Technical decision on OS Physical Protection System regarding interface with future foundations of NSC

Structure and requirements to contents of the NSC CS-1 concept design safety document

Explanations to submission the information on safety in design packages at early stages of SC-1 NSC designing

Explanation of structure and contents of environmental impact assessment for new safe confinement

Explanation of structure and contents of safety analysis report on new safe confinement

Explanation for the new safe confinement sanitary compliance report structure and contents

Conceptual technical decision on liquid RAW management during Shelter Object transformation into an ecologically safe system

“SHELTER” OBJECT SAFETY STATUS REPORT. Volume 1.

“SHELTER” OBJECT SAFETY STATUS REPORT. Volume 2.

“SHELTER” OBJECT SAFETY STATUS REPORT. Volume 3.

“SHELTER” OBJECT SAFETY STATUS REPORT. Volume 4.

Before start to work on stabilization of engineering structures and construction of New Safe Confinement, during 2001-2004 the infrastructure was created necessary for achieving the main objectives of the second phase of SIP implementation

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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 #3В, it was decided to reinforce them by means of installing pillars at mark 16,40.
EDRvalues:
- 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 8.5х15 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.
EDRvalues:
- 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. Theareaoflightroofis1405 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.

"SO Temporary  Emergency Preparedness Plan" (General contractor - NUTECO) has been developed within SIP and approved by regulatory body. Radiating Protection Program (Contractor – Slavutich Laboratory of International Researches and Technologies (SLIRT)) has been developed and approved regulatory body.

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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.