Regarding Requirements to Load Combinations in Case of Evaluation of SSC Seismic Resistance by Indirect Methods


load combinations, seismic resistance, thermomechanical equipment, GIP-WWER, steel structures, operating basis earthquake, safe shutdown earthquake

How to Cite

Shugaylo, O.- r, Ryzhov, D., Sakhno, O., Pavliv, Y., & Khamrovska, L. (2020). Regarding Requirements to Load Combinations in Case of Evaluation of SSC Seismic Resistance by Indirect Methods. Nuclear and Radiation Safety, (1(85), 56-61.


Extension of the list of load combinations that should be analyzed during the nuclear power plant (NPP) components seismic resistance justification is one of the important new regulatory requirements.

The paper deals with the thermomechanical equipment for which seismic resistance assessment is performed using operating experience method, in particular the methodology of indirect assessment using the GIP (Generic Implementation Procedure) for the WWER reactors (GIP-WWER procedure).

Review of GIP-WWER procedure has been performed. The paper presents the analysis of seismic screening evaluation work sheet based on the example of motor-operated valve. The disadvantages of the GIP-WWER procedure in terms of ensuring compliance with current regulatory requirements for combinations of operating and seismic loads have been identified and the ways of eliminating the revealed disadvantages have been offered.

The supporting structures of the equipment in most cases are the metal structures. Impact of different NPP operating modes to the steel supporting structures of the equipment has been considered and the provisions of building codes governing the calculation of steel support structures have been analyzed. A minimum listing of operating and seismic loads combinations has been established, which should be considered in the justification of the seismic strength of steel support structures referred to the first and second seismic categories.

The paper is a part of a series of publications devoted to consideration of regulatory requirements to combinations of operational and seismic loads in assessing the seismic resistance of NPP components.


1. NP 306.2.208-2016. Requirements for seismic resistance design and for evaluation of seismic safety of Ukrainian NPPs. Approved by SNRIU Order No. 175 dated 17 October 2016 registered in the Ministry of Justice of Ukraine on 11 July 2016 under No. 1449/29579.

2. PNAE G-5-006-87. (1989). Standards for design of seismic-resistant nuclear power plants. Мoscow, Energoatomizdat, 29.

3. Ryzhov, D., Shugailo, O., Shugaylo, Ol-r, Kendzera, O., Maryenkov, M., Shenderovich, V., Buryak, R. (2017). About modern requirements for seismic resistance design and for evaluation of seismic safety of Ukrainian NPP units. Nuclear and Radiation Safety, 2(74), 9–13.

4. Organizational and technical measures of Energoatom for implementation of NP 306.2.208-2016 “Requirements for seismic design and seismic safety assessment of NPPs”. Kyiv, Energoatom, 2017.

5. Shugaylo, Ol-r, Ryzhov, D., Mustafin, M., Pidhaietskyi, T., Letkova, N. (2019). Some aspects of practical application of regulatory requirements related to operating and seismic load combinations for thermomechanical equipment and piping. Nuclear and Radiation safety, 4(84), 5–11.

6. DITI 300/376-RU/R.2. (2009). Methodology of seismic assessment for qualification of equipment for seismic impacts. UJV Rez.

7. DOE/EH-0545. (1997). Seismic Evaluation Procedure for Equipment in U.S. Department of Energy Facilities. U.S. DOE (U.S. Department of Energy), Washington D.C.

8. Comprehensive (Integrated) Safety Improvement Program for Ukrainian NPPs. Approved by the Resolution of the Cabinet of Ministers of Ukraine No. 1270 dated 07 December 2011.

9. DBN V.2.6-198:2014. (2014). Steel Structures. Design Standards. Kyiv, Ukrarkhbudinform, 199.

10. PNAE G-7-002-86. (1989). Standards for strength calculations of equipment and piping of nuclear power installations. Moscow, Energoatomizdat, 454.

11. Comparative analysis of the calculated load combinations for building structures, several groups of equipment according to requirements of PNAE G-5-006-87 and NP 306.2.208- 2016. Kyiv, Energoatom, 2018.