New Concept of Reactor Decommissioning
Concept Development of Innovation Technology for Decommissioning of Nuclear Power Plants. Calculation, Experimental, Technical and Economic Studies in Justification of the Concept
Tech Area / Field
- FIR-DEC/Decommissioning/Fission Reactors
8 Project completed
Senior Project Manager
Tocheny L V
Federal State Unitary Enterprise Research and Development Institute of Power Engineering named after N.A.Dollezhal, Russia, Moscow
- Nizhegorodsky State Technical University, Russia, N. Novgorod reg., N. Novgorod\nOrgenergostroy, Russia, Moscow
- FRAMATOME, France, Paris La Défense
Project summaryIn world nuclear power the problem of nuclear power plants' (NPPs) decommissioning after completion of their service life becomes increasingly urgent.
At present there are 538 operating and constructing nuclear power units over the world, including 261 units placed at the seaside, including 115 units which should be decommissioned until the year 2010, including 40 units which should be decommissioned until the year 2000.
For example, in Great Britain 35 out of all 35 power units are placed at the seaside; among these units 22 power units are to be decommissioned until the year 2000; in Japan also all 51 power units are placed at the seaside and 21 power units are to be decommissioned until the year 2010; in Germany corresponding numbers are 20, 8, 4; in USA-109, 29, 16.
After the year 2000 a number of power units to be decommissioned will increase at an accelerated pace.
The technologies of NPP decommissioning available at present require large-scale works at its siting and long-duration periods for decontamination of equipment and its disposal (up to 40 years) and reactor compartment (RC) cooling with radiation monitoring (up to 130 years).
The concept of innovation technology for NPP decommissioning, calculation, experimental and technical and economic studies in its justification are proposed in the Project; this technology permits to shorten ultimately duration of the works on nuclear power unit decommissioning, reduce radiation burden on the personnel engaged in these works and in the shortest possible time (2...4 years) return sites of worked-out NPP into economic circulation, into initial positions («green grass-plots» with normal radiation background). It is attained by the fact that RC of decommissioning power unit is taken down from siting as a unit, with whole building and processing equipment, transported to water area and carried by water to single place specially selected at the Earth and remoted from populated regions for further decontamination with minimal detriment for population and territories where worked-out power units of NPP were placed.
The objectives of the project are:
A. To resolve complex of scientific and engineering issues pertaining to development of innovation technology on coastal NPP decommissioning which permits to shorten ultimately duration of the works on nuclear power units decommissioning and reduce radiation burden on the personnel engaged in these works.
B. To help the group of employees (27 persons) having work experience and technology knowledge in the field of nuclear weapon and means of its delivery to reorientate their abilities to peaceful activities pertaining to calculation and experimental studies on suggested innovation technology of NPP decommissioning attractive on its environmental and potential opportunities.
Project fulfillment gives an opportunity to achieve following specific results:
- to develop well-founded, satisfying necessary and sufficient conditions principal scheme of completion stage on NPP decommissioning based on RC removal from the place of NPP siting;
- to develop recommendations for taking into account the geology data by using innovation technology of NPP decommissioning;
- to establish principal criteria of NPP suitability for innovation technology on.the basis of evaluating state of building structures from viewpoint their strength, leakproofness and radiation safety;
- to conduct engineering developments of floating complex with RC of chosen representative NPP designed for wind and wave loads by its transportation over sea routes to specially selected place;
- by the example of representative NPP to fulfill design development of coastal and sea constructions and facilities necessary for RC detachment from foundation, lifting and its transferring to sufficient depth of water area, and for RC transferring from water area, transportation and mounting on the place of long-duration storage;
- to develop the concept of remote equipment cutting with applying the laser by RC preparation to transportation;
- to calculate heat generation and heat removal from in-vessel equipment by RC transportation;
- to determine integral dose to.the materials by transportation and storage;
- to determine radionuclide release from RC into environment by its transportation, emergency submersion at sea and by disposal under sea bed;
- by the example of representative NPP to conduct comparative engineering and economic analysis on completion stage of NPP decommissioning according to conventional and suggested technology;
- to conduct comparative analysis of radiation burden on the personnel at completion stage of NPP decommissioning according to conventional and suggested technology;
- to establish recommendations on designing future NPP with allowance for suggested technology of NPP decommissioning completion stage.
Engineering Approach and Methodology
In 1989 the decision on abandonment of Kryimsky NPP was adopted (it was in prestarting state). In this connection the issue of transferring its main components by sea route to Far East of former USSR for Primorsky NPP with WER-1000 reactors designed at that time was examined. Kryimsky NPP site is placed for a distance of 6 km from Kazantipskiy bay of Azovskoye sea. Sea depth for a distance of 1 km from the coast is 9... 10 m. The elaboration had been shown actual opportunity for delivery of Kryimsky NPP components to Far East by sea route. It has been just this elaboration which is intended to use by developing alternative innovation technology of NPP decommissioning.
It is proposed to use RDIPE - one of leading Russian reactor-building firms -experience on nuclear plants' design, operation and decommissioning for justification of radiation and nuclear safety and also for analysis of emergency situations over whole cycle of the works and, in particular, when transporting by sea route.
By developing building constructions for RC detachment from foundation and lifting, their transfer to water area with sufficient depth, transporting over sea routes and its mounting at foundation for placing in long-duration storage the long-standing experience of ORGENERGOSTROY firm being leading organization in the system of power installation building by floating method. An example of such installation is the Kislogubskaya tide power plant (TPP). The calculations and model tests of floating facilities will be implemented at the NSTU. Over many years of the model testing basin operation a large body of experimental research for various designing, servicing and scientific organizations was carried out, and validity of the results obtained has been confirmed by many times repeated comparative standard tests. At the NSTU there is model testing basin for conducting model tests of transport ship with floating complexes The basin is intended for experiments in floating, submersible and above-water positions. It measures 40 ґ 4,1 ґ 1,8 м and is equipped by wavemaker, wave damping system and production area of model servicing. The tests of floating facilities' models for RC transportation will be fulfilled with using this basin.
State-of-the-art NCNP, MELCOR type software complexes will be used during project performing for neutronic and thermophysical calculations.
Three-dimensional graphic designs and calculations of deflected mode allowing for flexibility and creep will be performed with the help of licensing calculation complex of «Mirage» and «Cosmos» by developing building constructions for RC detachment from foundation and lifting, their transfer to water area with sufficient depth and so on.
Estimation of sea water effect to concrete, metal and other RC materials is presumed to perform on the basis of analyzing the results of long-standing concrete monitoring at marine constructions and facilities of Kislogubskaya TPP.
The values of strength, density and water absorption for various materials used by RC transportation will be determined at the test beds of laboratory complex for research of structural materials.
All works on the project are directed to solution of following principal tasks in the end:
1. Development of well-founded, satisfying necessary and sufficient conditions principal scheme of completion stage on NPP decommissioning according to innovation technology.
2. Data gathering on geology of RC foundations for NPP suitable from viewpoint of using innovation decommissioning technology, their analysis and ranging. Development of recommendations for taking into account of geology data by, using innovation NPP decommissioning technology.
3. Development of principal criteria on NPP suitability for innovation technology on the basis of evaluating building constructions from viewpoint of strength, leakproofness and radiation safety.
4. Design elaboration of coastal and marine constructions and facilities for representative NPP necessary for RC detachment from foundation, its lifting and transferring to sufficient transport depth of water area and also for RC transferring from water area, transportation and mounting on the place of long-duration storage.
5. Making of comparative technical and economic analysis for completion decommissioning stage as applied to selected representative NPP according to conventional and innovation technologies. Development of integrated technical-and-economic indices characterizing suitability of NPP decommissioning according to innovation technology.
6. Analysis of emergency situations by using innovation technology. Analysis of radiation safety.
7. Development of recommendations for designing future NPP with allowance for proposed innovation decommissioning technology.
All specific engineering, design and technological decisions and calculations are performed conformably to selected representative NPP.
The collaboration with all foreign partners is proposed in the form of mutual information exchange, discussions about project results and in various other mutually acceptable forms.
Business trip of Executor representatives to France, USA, Italy and Great Britain with reports about principal project results is planned.
The participation in the reports at ICONE6, ICONE7 international symposium is planned also.
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