004核

FABRICATION AND TEST OF HYDRAULIC JACKS FOR THE APPLICATION TO DIVERTOR SUPPORT SYSTEM OF FUSION EXPERIMENTAL REACTOR H. Fukushima, K. Itoh, J. Ohmori, N. Miki, N. Tachikawa Heavy Apparatus Engng. Lab., Toshiba Corporation, 2-4 Suehiro, Tsurumi, Yokohama, 230 Japan S. Nishio, K. Koizumi, T. Okazaki, K. Shimizu, FER Team, Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Naka-machi, Naka-gun, Ibaraki, 311-01 Japan Abstract Two different types of hydraulic jacks consisting of hydraulic piston and bellows were developed for an application to locking and lifting systems for divertor segments f o r Fusion Experimental Reactor. For the lifting system where a minimum stroke of 170 nun was required, the telescopic-type hydraulic jack with a length of 300 nun was fabricated and tested under an operation pressure of 1 MPa. For the locking system, the hydraulic jack with the conical cotter was developed that worked at 6 . 5 MPa under a radial offset of 2 nun. These jacks satisfied their specifications without any leakage, failure and abrasion. Performance of several hard facing materials for the cotter was also examined including alumina and metal alloys. The colmonoy #5 o r stellite alloy #6 was found to be excellent as a hard facing material for the cotter. Introduction To remotely replace the damaged divertor, attaching locks systems are required for the divertor of Fusion Experimental Reactor (FER/ITER)[l]. These systems must be strong enough to withstand electromagnetic and gravity forces and must be cooled effectively against nuclear heating. Because of the limited space for installation and because of difficulties in obtaining good compatibility with a remote handling system, several concepts for attaching the divertor segments have been proposed. However, some important problems are still open which include reliability and fatigue life. The system with a hydraulic jack is one of the lock systems currently proposed for Fusion Experimental Reactor (FER/ITER) (see Fig. 1). This system has the attractive feature that it can provide a sufficiently long stroke, simple assembly/disassembly procedure of the divertor segments and better neutron shield. However, since this system includes mechanically movable part such as bellows and piston, its mechanical reliability should be demonstrated under the simulated loading scenario. The paper presents results of loadidng tests of two different types of hydraulic jacks. One is the compact telescopic-type jacks with large stroke for lifting, and the other is the jack with the conical cotter for locking. Results are also presented of performance several hard facing materials with or without solid lubricants. Design of Hydraulic Jacks and Cotter Hydraulic Jacks
of the single-stage jack. For this reason, the twostage telescopic-type jack was developed in the study.
400
-
Driving shoft
t"
300 -
c
0 : Stroke 170mm
A : Stroke l5Omm 0 :Stroke 130mm N Life time (cycle)
170(85x2)
1st: 250 2ndm) 263 300 Welded bellows Welded bel lows Vacuum seal 1000 1000 Lifetime (cycles) Thickness:0.5mm not used Hard facing
I
I Locking jack I Lifting jack 1
Single-stage Type 6 Pushing force (ton) owater pressure ( m a ) 6.5 30 Stroke ("1 o0.D. of piston (mm) 110 Telescopic
1 1
91CH3035-3$03.000 1992 IEEE
Long stroke and compactness rather than large pushing force are required in the lifting jack. Fig. 5 shows the life-stroke diagram to determine the number of convolutions and the total length of the singlestage jack. It may be shown that the total length is required to be about 420 mm for a stroke of 170 mm and for a life of 2000 cycles. The two-stage telescopic jack can be also designed having a total length of about 300 mm. This is about 100 mm shorter than that
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The major specifications for the hydraulic jacks for lifting and locking systems are summarized in Table 1. The jacks designed here consist of piston with two pressure rings, chromium plated cylinder and welded bellows. High strength brass and nickel based superalloy were used as materials for the pressure ring and the bellows, respectively. For the lifting jack with large stroke, the two-stage telescopic-type jack was selected. Figs. 2 and 3 show the bird-eye-views of the locking and lifting jacks, respectively.