Expert System and Seismic Adequacy Assessment Procedure (GIP-VVER)
This procedure and expert system was reported firstly in Sankt Peterburg in 1995, and then also on the SMiRT 14 Post Conference Seminar 16 in Vienna in 1997. In 1997 the first version of the corresponding report was handed over to IAEA. Further comprehensive report describing the GIP-VVER procedure was prepared for IAEA technical meeting “Procedures for Seismic Qualification of Equipment and Components”, held in 2000. On the SMiRT 16 Conference held in Washington D.C. in 2001 the procedure as a whole was reported as well as the experience gained during its using at VVER-type NPPs in Czech Republic, Slovakia, Hungary and Russia. GIP-VVER procedure became widely used in named countries and accepted by IAEA as the indirect method for evaluation of seismic adequacy for equipment installed on VVER-type nuclear power plants, and, in 2003 it became one of the practices recommended by IAEA TECDOC-1333, publicly available document.
GIP-VVER, Generic Implementation Procedure for VVER-type nuclear power plants, is an indirect experience based method for seismic adequacy evaluation of equipment installed in VVER-type nuclear power plants. Under the name GIP-VVER, a variant of SQUG-GIP was prepared by Rizzo Associates Czech (formerly Stevenson and Associates Office in Czech Republic) under the guidance of Dr. John D. Stevenson within the framework of the recent IAEA sponsored “Benchmark Study for the Seismic Analysis and Testing of WWER-Type Nuclear Power Plants.” The company Stevenson and Associates (S&A), and Dr. Stevenson namely was one of the creative developers of SQUG-GIP procedure.
The GIP-VVER procedure, however, does not use any SQUG proprietary data and it is based on experience obtained during a number of seismic tests, walkdowns and evaluations performed by companies Stevenson and Associates Office in Czech Republic, Office in Romania and Office in Russia and also personally by Dr. Stevenson for VVER-type NPPs located in Czech Republic, Slovakia, Hungary, Bulgaria, Armenia and Russia. Dr. Stevenson properly trained the Stevenson and Associates offices personnel during several formal courses including field walkdowns.
GIP-VVER as well as SQUG-GIP is primarily a screening and walkdown procedure.
The scope of equipment covered by the current version of the GIP-VVER procedure includes, similarly as the SQUG-GIP, the following twenty classes of mechanical and electrical equipment:
- Motor Control Centers (MCC);
- Low Voltage Switchgears (LVS);
- Medium Voltage Switchgears (MVS);
- Transformers (TRN);
- Horizontal Pumps (HP);
- Vertical Pumps (VP);
- Fluid-Operated Valves (FOV);
- Motor-Operated and Solenoid-Operated Valves (MOV, SOV);
- Fans (FAN);
- Air Handlers (AH);
- Chillers (CH);
- Air Compressors (AC);
- Motor Generators (MG);
- Engine Generators (EG);
- Distribution Panels (DP);
- Batteries on Racks (BAT);
- Battery Chargers and Inverters (BCI);
- Instruments on Racks (IR);
- Temperature Sensors (TS);
- I&C Panels and Cabinets (I&C).
VVER-type relays, switches, transmitters and cable penetrations are significantly different from those included into the original SQUG-GIP databases. These two classes of equipment (21 and 22) are not included into the GIP-VVER procedure and their seismic verification shall be based on seismic testing. In addition to twenty classes listed above, the GIP-VVER procedure also includes guidelines for simplified analytical seismic evaluation of the following classes of equipment:
- Cable Supporting Structures;
- Tanks, Heat Exchanger, Filters;
- Pipelines and HVAC Ducts.
GIP-VVER also includes two special guidelines for verification of adequacy of equipment anchorage to civil structures; for verification of seismic adequacy of non-bearing masonry walls; and for non-calculation verification of seismic adequacy of pipelines.
GIP-VVER as well as SQUG-GIP is primarily a screening and walkdown procedure. The characteristics and parameters specific for each equipment item are checked in course of a field walkdown and also from its specific documentation (drawings, passports etc.). If screened equipment item does not meet the criteria of the procedure it becomes an outlier. However, if an equipment item is classified as an outlier, rigorous approaches as testing on shaking table, deep study of input data, sophisticated analysis etc. may be used to verify its seismic adequacy.