0
Technical Briefs

# Conceptual Structure Design of High Temperature Isolation Valve for High Temperature Gas Cooled Reactor

[+] Author and Article Information

Small-Sized HTGR Research and Development Division, Nuclear Hydrogen and Heat Application Research Center, Japan Atomic Energy Agency (JAEA), Oarai, Higashi-ibaraki-gun, Ibaraki 311-1393, Japantakada.shoji@jaea.go.jp

Kenji Abe

Frontier System Co. Ltd., Mito-shi, Ibaraki 310, Japan

Yoshiyuki Inagaki

Hydrogen Application Research and Development Division, Nuclear Hydrogen and Heat Application Research Center, JAEA, Oarai, Higashi-ibaraki-gun, Ibaraki 311-1393, Japaninagaki.yoshiyuki@jaea.go.jp

J. Eng. Gas Turbines Power 133(11), 114501 (May 17, 2011) (3 pages) doi:10.1115/1.4003454 History: Received October 26, 2010; Revised December 28, 2010; Published May 17, 2011; Online May 17, 2011

## Abstract

The high temperature isolation valve (HTIV) is a key component to assure the safety of a high temperature gas cooled reactor connected with a hydrogen production system for protections of radioactive material release from the reactor to the hydrogen production system as well as of combustible gas ingress to the reactor at the accident of fracture of an intermediate heat exchanger and the chemical reactor. However, the HTIV has not been made for practical use in the helium condition over $900°C$ yet. The conceptual structure design of an angle type HTIV was carried out. A seat made of Hasteloy-XR is welded inside a valve box. Internal thermal insulation is employed around the seat and a liner because the high temperature helium gas flows inside the valve. The inner diameter of the top of seat was set 445 mm based on fabrication experiences of valve makers. A draft overall structure was proposed based on the diameter of the seat. The numerical analysis was carried out to estimate the temperature distribution and stress of metallic components by using a three-dimensional finite element method code. Numerical results showed that the temperature of the seat was simply decreased from the top around $900°C$ to the root, and the thermal stress locally increased at the root of the seat, which was connected with the valve box. The stress was lowered below the allowable limit 120 MPa by decreasing the thickness of the connecting part and increasing the temperature of the valve box to around $350°C$. The stress also increased at the top of the seat. Creep analysis revealed that the intactness of the HTIV is kept after the assumed operation cycles of the plant life as well as at the depressurization accident.

<>

## Figures

Figure 1

Overall structure of the HTIV

Figure 2

Numerical results of temperature and stress in metallic components: (a) temperature and (b) stress

Figure 3

Time history of cumulative inelastic strain at the top of seat

Figure 4

Time history of stress at the top of seat

## Errata

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections