HTGR Knowledge Base

Conference Article: Design and safety consideration in the high-temperature engineering test reactor (HTTR)

Saito, Shinzo; Tanaka, Toshiyuki; Sudo, Yukio; Baba, Osamu; Shiozawa, Shusaku; Okubo, Minoru (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

Abstract

The budget for construction of the High-Temperature Engineering Test Reactor (HTTR) was recently committed by the Government in Japan. The HTTR is a test reactor with thermal output of 30 MW and reactor outlet coolant temperature of 950’ C at high temperature test operation. The HTTR plant uses a pin-in-block design core and will be used as an experience leading to high temperature applications. Several major important safety considerations are adopted in the design of the HTTR. These are as follows. 1) A coated particle fuel must not be failed during a normal reactor operation and an anticipated operational occurrence. 2) Two independent and diverse reactor shut-down systems are provided in order to shut down the reactor safely and .reliably in any condition. 3) Back-up reactor cooling systems which are safety ones are provided in order to remove redidual heat of reactor in any condition. 4) Multiple barriers and countermeasures are provided to contain fission products such as a containment, pressure gradient between the primary and secondary cooling circuit and so on though coated particle fuels contain fission products with high reliability. 5) The functions of materials used in the primary cooling circuit are separated to be pressure-resisting and heat-resisting in order to resolve material problems and maintain high reliability. The detailed design of the HTTR was completed with extensive accumulation of material data and component tests.

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key words: coolants; httr reactor; power range 10-100 mw; reactor cooling systems; reactor safety; research programs; specifications; testing; very high temperature
Reference:
Technical committee meeting on gas-cooled reactor technology safety and siting Dimitrovgrad (Russian Federation) 21-23 Jun 1989
International Atomic Energy Agency, Vienna (Austria)
IAEA-TC--389.26, pp:368-388