Seismic Capacity Test of Nuclear Piping System using Multi-platform Shake Table

Abstract

In this study, dynamic characteristics and seismic capacity of the nuclear power plant piping system are evaluated by model test results using multi-platform shake table. The model is 21.2 m long and consists of straight pipes, elbows, and reducers. The stainless steel pipe diameters are 60.3 mm (2 in.) and 88.9 mm (3 in.) and the system was assembled in accordance with ASME code criteria. The dynamic characteristics such as natural frequency, damping and acceleration responses of the piping system were estimated using the measured acceleration, displacement and strain data. The natural frequencies of the specimen were not changed significantly before and after the testing and the failure and leakage of the piping system was not observed until the final excitation. The damping ratio was estimated in the range of 3.13 ~ 4.98 % and it is found that the allowable stress(345 MPa) according to ASME criteria is 2.5 times larger than the measured maximum stress (138 MPa) of the piping system even under the maximum excitation level of this test.

Seismic Fragility Evaluation of Main Steam Piping of Isolated APR1400 NPP Considering the Actual Failure Mode

“…β C in Equation ( 4), can be expressed as the square root of the sum of squares of the logarithmic standard deviation β R of the probability variable considering randomness and the algebraic standard deviation β R , which means uncertainty, as shown in Equation (5).…”

“…Research on the safety of crossover piping systems has been conducted. Shaking table tests [5] and seismic response analyses were performed to evaluate the seismic safety of the crossover piping system. They confirmed that the crossover piping system has a significantly larger relative displacement compared to the case of a general piping system.…”

Seismic Performance of Piping Systems of Isolated Nuclear Power Plants Determined by Numerical Considerations

“…Under this background, a study was carried out to evaluate the seismic safety of the crossover-piping of a seismic isolated nuclear power plant [15]. In addition, finite element analysis was performed to evaluate the seismic safety of the pipe system of the nuclear power plant [16,17].…”

A Study on the Seismic Protection Performance of Press Fittings for Light Gauge Stainless Steel Pipes

“…배관 내부는 물을 가득채운 후 2.0 MPa의 수압을 가한다. ASME (4) 의 경우 원자력발전소의 Class I 배관에 대한 Level D Service Loading 조건의 응력기준은 다음 식과 같 으며 허용응력의 3배 이하로 응력기준을 두고 있다.                 ≤   허용응력이를 근거로 정진환 등(5) 은 원자력발전소 배관계통의 내 진성능실험에서 실험된 배관의 파괴에는 설계기준작용력 과 비교하여 3배 이상의 하중이 요구되었다고 하였다.배관에서 지진에 취약한 부분은 엘보(6) 이다. 따라서 본 논문에서도 허용응력의 3배 이하의 응력이 배관에 걸리는 지 여부를 엘보에서의 이상 여부로 프레스식 관이음쇠를 지진분리이음으로 사용가능 여부를 판단하고자 한다.3.3 실험 장치프레스식 관이음쇠의 실험체 가진을 위해 지진방재연구 센터(Seismic Simulation Test Center, SESTEC)의 정하중 250 kN Actuator (미국, MTS Systems Corporation)를 이용하였 다.…”