XA030061 8

SEISMIC QUALIFICATION TEST ON CRDL OF QINSHAN II NPP

GIJO Jianhu Nuclear Power Institute of China, China

WORKSHOP ON "SEISMIC DESIGN ASSESSMENT BY EXPERIMENTAL METHODS"

NUCLEAR POWER INSTITUTE OF CHINA (NPIC) CHENGDU, CHINA,, 10-14 SEPTEMBER 2001

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Seismic qualification Test on CRDL of Qinshan II NPP

Guo jianhu (Nuclear Power Institute of China, P.O. Box 622-207 Chengdu, Sichuan 610041, P. R. China)

Abstract: Control rod drop verification experiment of PWR under seismic load is performed to confirm the insertion function of control rods into the core and the integrity of the parts of CRD3L. A fuel assembly, a control rod assembly, a guide tube and other associated structure are immersed in a water tank, and shaken by four hydraulic actuators. The scram time of control rods under seismic excitation was measured, and confirmed to meet the scram function. Moreover, the vibration responses of parts of CRIDL were measured to confirm the integrity of the parts of CRIDL under seismic condition. Key words: CRDL, control rod assembly, seismic qualification, scram time

1 Introduction The CRDL (control rod driving line) consists of a CRDM, a control rod assembly, thermal sleeve, guide tube, and thimbles of fuel assemble. CRDL is supported at the lid of vessel, upper support plate, upper core plate and lower core plate. So if there is a earthquake, CRDL will be excited at those four points. The purpose of this verification test is to confirm the insertion function of control rods, and the integrity of the parts of CRDL by multi-point seismic exciting.

Fig the test rig 2 test The test rig is shown in Fig 1. It consists of a prototype CRDM, a thermal sleeve, control rods, a guide tube, a fuel assembly, a water tank four and electro-hydraulic actuators as well as its control system (S-59 and L-cat). The test rig was installed in a pit (15m deep). The excitation was applied simultaneously by means of electro- hydraulic actuators at following four locations: --tthe lid of vessel --tthe upper support plate --tthe upper core plate --tthe lower core plate.

3 Seismic excitation The seismic excitations to be imposed were calculated by the seismic response analysis of the reactor structure. The displacement response time histories at above four locations were used to excite the CRDL in order to control easily.

4 main results The control rods can be inserted automatically into the bottom of reactor core even under a earthquake load larger than SSE, and scram time was less than required value of reactor shut-down for SSE. The parts of CRDL under an earthquake have a good integrity.