Program decisions are key stages, constructed on the integrated data accumulated during previous years of Project implementation. Program decisions are accepted for definition of SIP complex realization ways and are the indication for transition to the following stage of the task solution.
Decisions are made by the Customer and are agreed by the European Bank for Reconstruction and Development (EBRD) on behalf of Donors Assembly at the technical expertise executed by the International Advisory Group (IAG) and by an Independent Expert Team of Ukraine.
Program decision P1. Stabilization and Shielding Strategy.
Program decision P2. Decision on roof stabilization, supports and constructions Strategy.
Decisions P1 and P2 in a complex determine necessary and sufficient scope of measures on Shelter object stabilization for the term of 10-15 years. Decision P1 determines the contents of SO current condition stabilization (short-term and long-term measures and unstable constructions dismantling) taking into account New Safe Confinement Concept. According to this Concept, the controllable barrier will be created between sources of radiological contamination inside SO and environment, ensuring realization of Fuel Containing Materials (FCM) removal and Radioactive Waste Management Strategy.
Decision P2 confirms necessity and specifies scope of stabilization measures on a roof and other decisions accepted in P1. These decisions are the indication to transition to the designing and construction stage with the purpose of practical SO collapse risk reduction up to time and during New Safe Confinement construction.
According to these decisions it is anticipated to perform 8 stabilization measures including deaerator stack, "Mammoth" beam support, Western wall of "Shelter" stabilization.
Program decision P3. The report on a building construction condition and the monitoring system of building construction condition.
The current status of "Shelter" is linked to the certain risk of partial constructions collapse and radioactive dust release that will have negative influence on the personnel and an environment. Decision P3 is a basic point in SIP Task 6 realization on creation of initial monitoring system of constructions status (MS CS) in real time and proves necessity of such monitoring implementation.
MS CS at interaction with other monitoring systems which creation is stipulated by SIP, will provide implementation of the complex monitoring of SO constructions integrity and a condition during all stages of stabilization measures, dismantling measures and New Confinement construction.
The decision on MS CS creation maid by the operating organization, is based on Shelter object investigation, on results of the works executed during SIP realization, on results of existing SO monitoring systems operation. This decision is the important part at transition to the stage of Shelter transformation into ecologically safe system.
MS CS will carry out automated collection and transformation of the information from the monitoring detectors in physical values parameters, and to carry out their comparison with control and critical levels. Monitoring detectors will fix vibrations, linear deformations and displacement, inclinations tilting and other parameters of a constructions condition. MS CS also will monitor of environment parameters: temperature, speed and a direction of a wind, etc.
The system will work in free running mode, and will be connected by information channels to Integrated Monitoring System (IMS). Using information support of IMS and MS CS SO personnel will make a decision on these or those situations.
Program Decision P4 Desosion on Seismic Monitoring System.
Program Decision P4 confirms necessity of Seismic Monitoring System creation in ChNPP site area. Such system is necessary for data collection on seismic characteristics of area of ChNPP location, more exact assessment insurance of dismantling methods and seismic event consequences, timely notification of ChNPP operational personnel on seismic events with the purpose of the analysis, monitoring, check and other operative actions performance.
Five seismic monitoring stations should be installed in ChNPP local zone (0-40 kms), one of which directly (less than 1 km) near "Shelter" should be installed for data obtaining on an earth basis and the Shelter object foundation interaction. Five stations is the minimal desirable quantity necessary for unique decisions calculations on location, depth and time of a signal receipt. The seismic stations data will be transferred on the telemetric channel to completed monitoring data system.
Program decision P5. Criticality and Nuclear Safety.
In the decision all subsequent measures connected to criticality monitoring necessity will be determined. These measures will affect determination of processes concerning criticality condition limitation proceeding passively or actively, and also on preconceptual designing of stages or systems, used for the criticality monitoring when it is necessary. Acceptance of the given decision will be influenced by expenses factor for its implementation, and also objectives in view of nuclear and industrial safety, personnel and environment safety increasing.
Program decision P6. Shelter object Water Management.
P6 should solve the Water Management problem inside the object: water inflow source, their location and characteristics, available capacities of premises with ChNPP equipment for water treatment and storage.
The contained in SO water promotes reduction of constructions durability so, collapse risk increases. This destruction mechanism is revealed in reduction of concrete durability, damaged as a result of accident, in corrosion of reinforcing steel and metal constructions. To reduce such risk, the water management system should collect water before its ingress inside SO. The previous attempts of Shelter object hermetization were linked to high doses rates and have not completely eliminated a possibility of their ingress inside SO. There is a many ways of water ingress in object, and high dose rates at roof significantly eliminate time for revealing and hermetization of all found looses.
It is possible to divide contaminated water flows, considered in SIP on internal and external. Waters inside the Shelter are internal. These waters have various radio-activity levels, in some premises they are highly radioactive and contain organic substances, used for dust suppression. External waters flow down from external Shelter surfaces and ingress in a local zone.
For the period prior to the New Confinement construction beginning the decision will consist in waters removal from SO premises, creation of unit for the preliminary treatment for radio-activity decrease up to the required by ChNPP norms. The subsequent treatment will be carried out on the available at ChNPP equipment. Besides the opportunity of local improvement of temperature conditions and humidity level inside the Shelter will be considered to reduce a condensation level in premises and in areas where water presence results in building constructions deterioration and to risks of industrial safety increase. As to full-scale Shelter roof hermetization, its implementation is recognized inexpedient, taking into account significant dose rates and that fact, that New Confinement will be constructed in 5 years. It is noted, that it is necessary to analyse more in details "expense - benefit" of local hermetisation for water ingress reduction in SO.
Program decision P7. Fuel Containing Materials (FCM) removal and Radioactive Waste (RAW) Management Strategy.
This decision determines the subsequent measures implementation, realization of which is stipulated outside SIP frameworks (except for determined in Scope Plan) and is the important step confirming SIP actions compatibility with preparation for final Shelter transformation into ecologically safe system. In SIP frameworks Decision P7 is preliminary and should be confirmed by final Decision P8 on FCM removal and RAW management Strategies.
Basically strategy provides:
• FCM removal during New Confinement life time (100 years).
• The removal duration estimated on the preliminary data, makes 40-50 years.
• Advantage is given to Radioactive Waste, low and medium active, and highly active, transportation from Shelter directly to Final Disposal (Geological Disposal or other created within the framework of the National Program of RAW Management). That will exclude expenses for Long-term Storage Facility construction outside New Confinement only for FCM.
• Selective FCM removal after unstable constructions dismantling and FCM removal technology test completion.
• Steam removal will begin after solution of removed FCM storage questions.
• Implementation of completion works on Shelter transformation into ecologically safe system after FCM removal.
• To use existing practice for Wastes Management generating during SIP realization.
Program decision P8. FCM removal Strategy investigation and development.
This is final decision on definition of optimum time and strategy of FCM removal. It will determine the final program recommendation on use of FCM removal and disposal methodology and terms. The decision and the recommendation will be based on FCM characterization results, FCM removal and RAW Management Program, and on FCM removal demonstration results and other factors. Performance of this decision will give clear conception on FCM removal, management and packing possibilities inside the Shelter within determined terms.
This decision represents the formal agreement concerning determination of FCM removal terms and techniques. Performance of the decision will consist in corresponding document signing in which completion of FCM removal and RAW Management Program and also Researches Program will be submitted.
Program Decision P9. FCM removal prototype.
Decision P9 determines necessity of development and implementation of FCM removal technology prototype tests, FCM removal demonstration in real Shelter object conditions, its structure, doses and cost estimation.
Demonstration of FCM removal and RAW Management at SO site should confirm main provisions of P7 Decision. That will considerably reduce the existing uncertainty linked to cost and doses estimations.
Uniqueness of such works, absence of their realization experience and necessity of FCM removal Strategy predesign development confirmation cause necessity of FCM removal demonstration. The following step will be designing a complex of operations of FCM removal technological chain (technology development).
Decision P9 proposes a specific zone in SO for demonstration experiment realization (a premise on the bottom levels) and specific FCM congestion. The general scheme of tests carrying out will consist of operations on access creation, a mechanical fragmentation of the chosen congestion, and transportation to the equipped interim storage.
Program Decision P10. New Safe Confinement Strategy (NSC).
Decision P10 determines strategy of Safe Confinement creation as a complex of constructions, systems, sites and equipment. During implementation of activity on Shelter object transformation Safe Confinement should restrict radiation influence on personnel, population and environment by the established borders under normal SO operation condition and at infringements of normal operation, emergencies and accidents, including accidents during unstable constructions dismantling and FCM and RAW Management. Safe Confinement as multifunctional facility with life time 100 and more years allows to carry out the third stage of Shelter object transformation Strategy (approved by the Decision ¹5 of Governmental Commission on complex solution of ChNPP problems, dated April 18, 1997), namely – Fuel Containing Materials removal, their conditioning with the subsequent safe storage.
The carried out researches confirmed necessity of New Safe Confinement construction. The stabilization measures within SIP frameworks will allow safe operation of facility only during 15 years. Therefore with the purpose of probable collapse risk reduction some constructions will be dismantled after New Safe Confinement construction.
Results of the researches connected to FCM removal and RAW Management strategy also confirm necessity of additional barrier creation which will reduce to a minimum distribution of radioactive substances in an environment during implementation of future operations on FCM removal and RAW Management.
ARCH type construction is accepted in Decision P10 on which are conducted designing works.
SIP Creation became the culmination of efforts applied during last years by Ukraine and the international community with the purpose of development economically and ecologically acceptable approach to Shelter of ChNPP Unit 4 problems solution.
1992.
International competition of projects and technical solutions for Shelter object transformation into ecologically safe system was announced, that became a first step to the international cooperation. According to results of this competition the stage-by-stage Concept of Shelter object transformation into ecologically safe system was accepted by the Decision of Jury, dated June 17. Seven stages have been put in a basis of the Concept:
1. Investigation of the Shelter object condition and monitoring of an environment.
2. Public informing on the Shelter object and its industrial site condition.
3. Stabilization of the Shelter object condition.
4. New protective structure construction around the Shelter object ("Shelter - 2").
5. Construction of near surface Radioactive Wastes (RAW) storage.
6. Creation of RAW sorting and processing technological site.
7. Removal, conditioning and storage of radioactive materials being in "Shelter - 2".
1994.
European Community Commission announced the tender on Feasibility Study development for the first stages of the Concept of Shelter object transformation in ecologically safe system – stabilization of existing Shelter condition and "Shelter - 2" construction. Consortium "Alliance" led by the French company “Campenon Bernard SGE ” became the winner of the tender.
1995.
Feasibility Study development on object transformation is completed and Consortium "Alliance" submitted report, which is topical up to the date. Its fundamental conclusions:
1. Existing Shelter is unstable and it isn’t earthquake-proof. Urgent measures are necessary, an option “don’t undertake any measures, that is to do nothing is not acceptable”.
2. In view of high radiation level and a real condition of existing constructions long-term stabilization of "Shelter" considered as impracticable. Constructions of existing "Shelter" don’t ensure possibility of Radioactive Waste removal, lifetime of which makes tens thousand years.
3. Construction of a new protective encasement, allowing Unit four dismantling is necessary.
4. Designing and construction of the second shelter is extremely difficult, multipronged problem, covers both initial site clearing and Radioactive Wastes removal. Prior to the "Shelter - 2" construction beginning it is necessary to organize wastes processing and storage.
5. Ukraine cannot independently provide such project financing. This question needs to be considered critical. International community should demonstrate the desire to assist Ukraine to solve the problems connected to Chornobyl accident. A real choice today is establishment and support of political will, financial guarantees for all period of the project realization.
On September 11, 1995
European Commission Session was held in Brussels at participation of Ukrainian delegation for definition and coordination of the subsequent actions on the basis of Consortium "Alliance" study. Result of this meeting became the agreement, signed by European Commission with a consortium "Alliance" and “Trischler und Partner GmbH” company on short- and long-term measures development. According to the Decision of the Cabinet of Ministers of Ukraine (¹696-p, dated 14.11.95) functions of the works Customer on Shelter transformation into ecologically safe system are transferred to Gosatom and DS ChNPP.
According to signed in December, 1995 Memorandum of Understanding between Government of Ukraine, G7 countries Governments and European Commission on Chornobyl NPP shutdown” within the framework of TACIS Project “Chornobyl Unit 4, Short- and long-term measures – Measures 2+4” the Recommended Course of Actions was developed in which potential short- and long-term measures have been determined and the complex of urgent measures, consisted of the following phases was proposed:
Phase 1. Stabilization and other short-term measures.
Phase 2. Preparation for transformation into ecologically safe system.
Phase 3. Transformation into ecologically safe system.
The stabilization stage, necessity of which was considered by the Ukrainian side earlier has been emphasized in the project. The purpose of a stabilization stage is potential risks reduction, protection of an environment against the most probable event – construction destructions and connected to it intense radioactive dust release.
June, 1997.
"Shelter Implementation Plan” (SIP), developed sequential to the project “Chornobyl Unit 4, Short- and long-term Measures – Measures 2+4 ” in cooperation with European Commission (EC), Ukraine, USA and team of international experts was accepted at G7 meeting. This plan defined the basic concept, including a number of steps aimed on Shelter object transformation into ecologically safe condition. Two fundamental tasks were posed during plan development:
- ensuring detailed works plan development according to earlier suggested recommendations;
- development of a preliminary cost estimation, including necessary annual expenses.
Three stages have been determined in “Shelter Implementation Plan” for Project Management and its subsequent realization as key decisions:
- confirmation of decisions on stabilization, determination of a level of earlier suggested stabilization works performance, that includes necessary access ensuring to works performance areas and personnel protection during these works performance inside the Shelter object;
- decision on Fuel containing Materials (FCM) strategy, determining an optimum way and term of removal, expenses and feasibility level;
- decision on the strategy of an optimum localizing encasement creation, determining its functions.
Conceptual Design, confirming the decision on stabilization, protection and necessity of a localizing encasement will be developed on the basis of this decision and FCM removal strategy.
On November 20, 1997 Pledging Conference of donors-countries taken obligations on funds allocation for this plan implementation in specially established Chornobyl Shelter Fund (CSF) was held in New York. Fund administration was entrusted to the European Bank for Reconstruction and Development (EBRD). Agreement between Ukraine and European Bank for Reconstruction and Development on Fund activity (“Framework Agreement”) also has been signed at the Conference.
On February 4, 1998 Verkhovna Rada of Ukraine ratified “Framework Agreement between Ukraine and European Bank for Reconstruction and Development on Chornobyl Shelter Fund activity”.
On April 20, 1998 the Contract with the tender winner on SIP Project Management Unit (PMU) Consultant was signed. That was Consortium including companies Bechtel (USA), Battelle (USA) and EDF (France).
Since May till November, 1998 tender procedures were completed and Contracts between “Energoatom” Company and tenders winners on Early Biddable SIP Projects were awarded.