TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 1 Rev.:  Beneficiary:Rosenergoatom  Contractors:Siemens-KWU  Local Subcontractor: MOKHT  Sector of activities: Design Safety  Sites: VVER 1000  Installations: VVER 1000 (Type 320)  Status: Completed  Budget: €  Duration: 12 months Project General Data

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 2 Rev.: Objectives of the Project  To analyze the Russian Fission Product Retention System (FPR) during discharge of steam-gas mixture from a VVER-1000 –V320 Containment under accidents with rupture of the primary circuit pipe and simultaneous NPP black out  To compare Russian and Western FPR-design  To create an upgraded Russian basic design of a FPR  To review and adapt compliance with current Russian requirements

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 3 Rev.: The project covers the following phases: 1.Creation of a project related Quality Assurance Programme 2.Evaluation of the status in development of Russian FPR systems 3.Evaluation of the status in development of EU-FPR systems 4.Comparison of the 2 FPR systems 5.Determination of respective Emergency scenarios for VVER-1000 Scope of the Project (1)

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 4 Rev.: Scope of the Project (2) 6.Selection of a General concept for a FPR system 7.Development of a Process Diagram of the FPR system 8.Development of the System Description 9.Development of the Design Report of the FPR system 10.Development of Diagrams of the FPR-System Layout 11.Development of the List of Design data

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 5 Rev.: Details on Selected Project Tasks (1) Status of FPR development in the Soviet Union / its basis for upgrade: In 1998 a system has been started to be developed The designer was NIIKhIMMASh in Sverdlovsk (Ekaterinburg) In 1989 a FPR-system has been introduced (sketches, system concept defined) The concept has been tested experimentally on a large scale mock up In 1993 all further works were suspended in Russia

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 6 Rev.: Details on Selected Project Tasks (2) The status of FPR-development in the EU: EU-FPR Systems use dry filters, metal fiber filters in combination with molecular sieve, operating under atmospheric conditions metal fiber filters in combination with molecular sieve, operating under varying pressure conditions Sand filters Scrubber-type retention systems Different Western variations were analysed concerning weight, cost and effectiveness

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 7 Rev.: Details on Selected Project Tasks (3) Comparison criteria, which where generally considered essential: Aerosols retention rate; Elemental iodine retention rate; Organic iodine retention rate; Reverse sublimation; Passivity of the system; Aerosol load capacity; Restrictions in operation; National qualification; International qualification; Dimensions; Potential for general usage for several NPP units.

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 8 Rev.: Details on Selected Project Tasks (4) Criteria, which where considered essentially for design of VVER-1000-FPR: Operational modes for the FPR-system project have been determined taking into consideration the following main parameters: design pressure; mass flow rate through the system; retention rate; residual power density accumulated inside the system; aerosol load capacity; aerosols spectrum; period of passive operation.

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 9 Rev.: Details on Selected Project Tasks (5) Selection of a general concept for a FPR system for VVER-1000 The performed cost-benefit-analysis proved, that the Sliding Pressure Venturi Scrubber has best characteristics among scrubber types because of: Equal retention rates of Aerosols and Iodine This is the only scrubber for which the organic Iodine retention rate is 90%, allowing to omit an additional filter stage Lower weight and dimension Lower cost of installation

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 10 Rev.: Summary (1) The output was the basic design of an upgraded Russian system for trapping fission products (FPR) related to containments of VVER-1000 (Type V-320) based on Sliding Pressure Venturi Scrubber with metal fiber filter stage The major dimensional characteristics and the weight of a new FPR have been determined A future implementation of the FPR will bring the VVER-1000 (V-320) in line with the current safety requirements Detailed design, construction and commissioning can now be performed

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 11 Rev.: Summary (2) The main technical requirements for the FPR System were determined with:  Aerosols retention rate99.9 %  Molecular iodine retention rate99 %  Organic iodine retention rate90 %  Aerosols load capacity200 кг  Residual power density of fission products accumulated  in filter 300 kW  Average mass diameter of aerosol particles 0.5 micro-meter  Flow rate through system kg/s  Period of passive operation24 hours  Pressure at which the system opens 5 bar (functioning up to 6bar)  Temperature of steam-gas mixture180 C (Overheating condition)

TACIS Project: R8.01/98 – TRANSLATION, EDITING AND DIFFUSION OF DOCUMENTS (Result Dissemination) Improvement of the fission product retention system at VVER NPPs under Accidents TACIS R2.08/95 Project Slide 12 Rev.: Summary (3) The required design documentation for implementation can be drawn up based on the results of the present project Russian specialist have gotten inside into the FPR-systems developed by the EU-Contractor (Siemens) by: a walk down of a German FPR-installation and of experimental facilities, where FPR systems are verified for their performance data The work carried out was characterized by a efficient team spirit and good mutual understanding