The Process Information System Upgrading (PIS)

In association with the company ABB Oy from Finland we performed the replacement of the obsolete process information system with the recent and more advanced one, which brings essential improvements to control and analysis of the technological process.

The PIS consists of three levels. Their main functions are following:

• Level 1 – data acquisition
• Level 2 – data processing, application software and operator interface
• Level 3 – source of data for external applications

Picture: PIS Cabinets

The fundamental purpose of PIS Upgrade can be summarized as follows:

• Obsolescence of PIS Level 2 equipment (DIGITAL VAX/AX Station Computers) leads to the necessity of the replacement with modern equipment (ALPHA, OpenVMS) that is easier and less expensive to maintain in the future.
• As a secondary effect, Gateway computers on PIS Level 1 have been removed and existing Global PCs have been replaced in order to facilitate and support the connectivity with the upgraded PIS Level 2.
• Improvement of overall PIS performance and availability during plant transients.
• Modernization of PIS Level 2 user interface features.
• Expanding the PIS capability to receive and send process parameters to different process computers (expanding existing L1 FEP&MUX with redundant new Level 2 FEP&MUX).
• Adding the availability of PIS Level 2 and 3 user interface features for the office users.
• Upgraded Plant Process Computer System provides capabilities for MCR operators to issue commands (control actions) to other digital control system - external systems that are not part of the Plant Process Computer System.

                                                                                       Project Manager: Božidar Linke, B.Sc.E.E.

Replacement and Upgrade of PW – WT Water Treatment System

Because of increasing demand for clean water, nuclear power plants are searching for more efficient and cost – effective ways to source and select up-to-date water pretreatment technologies. Good example for that kind of improvement is Water pretreatment system modification for Krško Nuclear power plant. The project was implemented in 2005 as turn-key project by the company IONICS, Italba (Italy) in association with Sipro Engineering, Ltd.

Picture 1: 3D image of piping layout

                  Picture 2: Softener's skid                      

Reverse osmosis (RO) is a membrane process in which the salt ions will be excluded while the pure water (permeate) is forced through the membrane.

Picture 3: Reverse Osmosis Membrane 

Electro deionization (EDI) is final stage in producing of demineralized water. It is combined of electro dialysis (ED) and resins ion exchange. The essential components of EDI system are ion exchange membranes, resins and DC electricity. In ED process due to DC current the cations and anions migrate through the membranes. The ED stack contains two flow channels: one for feed and the other for concentrate removal.

Picture 4: Picture: Electro-deionization 

The advantage of this technology is in minor use of chemicals, less waste water release and energy saving. Mentioned upgrade system is releasing very clean demineralized water by means of mechanical filters, reverse osmoses, electro-deionization and degasifying. It is managed and manipulated with Supervisory Control and Data Acquisition (SCADA) and integrated into plant process information systems.

                                                                                   Project Manager: Božidar Linke, B.Sc.E.E.

Conceptual Design for HV substation 220/110/10 kV Dmitrov

We developed conceptual design for electrical installation and electrical equipment for high-voltage substation 220/110/10 kV Dmitrov, Russia for our Contracting Partner Riko d.o.o. Ljubljana.

The scope of the project is:

• complete 220 kV air insulated switchyard with two main systems of bus-bars, with six bays (two line bays, two transformer bays, coupling bay and measuring bay),
• complete 110 kV air insulated switchyard with two main and one subsidiary system of bus-bars, with nine bays (five line bays, two transformer bays, coupling bay and measuring bay),
•  two 220/110/10 kV auto-transformers, with rated power 125/125/63 MVA each.
• two 10/10 kV auto-transformers, with rated power 40 MVA each, two auxiliary transformers 10/0,4 kV, 10 kV switchgear consists of 40 air insulated metal clad cubicles,
• complete auxiliary power supply equipment, cables and overhead connections, control system and control room,
• complete protection system for the whole substation,
• communications and optical connections,
• other auxiliary systems and equipment for the substation.

                     Picture 1: RTP – VN view part                                        Picture 2: RTP before reconstruction    

Project Manager: Franc Katic, M.Sc.E.E.

Pre-investment concept for NPP 2

Considering the vision and strategy of our company we adopted the project called Technical analyses of newer nuclear power plants within the context of pre-investment conceptions for nuclear power plant 2. Direct contracting authority of the chapter in Detail Design Documentation was ELEK d.o.o. Ljubljana and final contracting authority of the pre-investing conception was GEN energija d.o.o., which owns 50 percent of Nuclear power plant Krško.

Picture 1: 3D Cross-section of AP1000, Westinghouse 

Picture 2: 3D Cross-section of EPR, Areva

Picture 3: 3D Cross-section of US-APWR, MHI

From technological point of view this kind of facilities falls within the highest category of planning, maintenance and operation worldwide. In pre-investment conception we have analyzed the main constituents of various types of new nuclear power plants and compared their intrinsic features. Thus we have analyzed the characteristics of reactor vessel, fuel and main pipe-work, as they represent a unique technology for the Slovenian circumstances. Analogically we have focused on other constituents of the main system, like reactor cooler pump, pressurizer and evaporator. The latter enables energy transfer from the main circle to turbine and generator. We have also described the safety systems, their safety electrical supply and the systems of their own electricity use. We have also designed one-line schemes of such charging with juncture as well.

With this project we have presented that in our company we master a wide range of technologies and expertise of various professions. We have also shown that we wish to maintain connections with state-of-the-art technology.

                                                                                  Project Manager: Blaž Zadravec, B.Sc.E.E. 

Services for solving problems on boiler K5

For paper mill VIPAP Videm Krško we prepared design documentation (design for construction permit and as built documentation) and we lead the process for construction and operating permit as well as carried out professional supervision over residues (ashes, dross and slag) from the combustion in boiler K5 transportation, storage, dosage, disposition and dampening system.

The system consists of:

• a silo for the storage of residues from the combustion
• a system for transportation of residues from the combustion from boiler to silo and loading the silo
• a system for unloading and moistening of residues from the combustion
• drives, automation and control system and auxiliary equipment

  Picture: Silo

The capacity of the new silo is 300 cubic meters, net capacity (mass) of silo contents is up to 300 t, gross mass of the metal silo construction with content is approximately 320 t, the height of a metal load-bearing construction is 10.90 m, the surface is approximately 25 square meters, the height of the top of reservoir is 21 m and the height of the elevator for loading with pipeline is 25 m.

The system for transportation of residues of the combustion from boiler to silo and loading the silo consist of screw conveyers, pouring shafts, the elevator and dust removal system. The system for unloading and moistening consists of closing device, dosage equipment, double screw conveyer and moistening device.

The drives are supplied and operated with electricity from boiler K5; visualization on DTS is also performed.

                                                                                           Project Manager: Franc Katič, M.Sc.E.E. 

Aging Management Review (AMR) of NPP Krško (phases I and II)

Nuclear power plant Krško performs Aging Management Review (AMR) project, which should ensure a complete overview of system components and structures (SSC) in power plant and their required functions to assure performing of the required safety functions for which they have been designed.

The first phase of this project (Aging Management Scoping and Screening) has already been performed, where methodology and selection of SSC were established. Final product of phase I of the project is AATS data base, which is used as a tool in the phase of inspection and composition of AMP / AMR.

The starting point of AMR or the entire AMP is NRC regulatory and U.S. strategy of renewal of operating licenses for nuclear power plants (License Renewal Process – LR), which is based on 10 CFR 54. Regarding to U.S. regulatory being frequently used in NPP Krško and nuclear industry in general and regarding to the process being established and frequently used in practice of U.S. nuclear power plants, this method was accepted as the most appropriate for NPP Krško.

General practice in U.S. nuclear power plants is life time extension for a period of 20 years. It needs to be emphasized here that AMR is an integral part of documentation, which is delivered to NRC at the time when the application of renewal is submitted.

AMP is based upon the NRC regulatory, which is the base of renewal of nuclear power plant operating license (License Renewal Process – LR, 10 CFR 54). It includes two spheres:

• Integrated Plant Assessment (IPA)
• Time Limited Aging Analyses (TLAA)

The review process consists of two parts: Scoping & Screening and Review. Systems, structures and components (SSC) are defined within Scoping & Screening project, whereas the examination of aging process and suitable management are performed in the phase of Review Project (AMR). Independent on the examination of SSC, Time Limited Aging Analyses (TLAA) are prepared. SSC, which are managed by AMP are so called »passive, long-lived components«.

Picture: Sipro Team at AMR Project 

In Sipro we perform works on mechanical part of the "Aging Management Review" project, as the subcontractor of Westinghouse Electric Company, who is the holder of the entire project for Nuclear power plant Krško.

                                                                                 Project Manager: Matjaž Pleteršek, B.Sc.M.E.