Core Dynamics Analysis of Control Rod Withdrawal Test and Nuclear Characteristics in HTTR: Reactor Power 30-60%

Accession number;06A0511422
Title;Core Dynamics Analysis of Control Rod Withdrawal Test and Nuclear Characteristics in HTTR: Reactor Power 30-60%
Author; TAKAMATSU KUNIYOSHI (Nihongenshiryokukenkyukaihatsukiko) NAKAGAWA SHIGEAKI (Nihongenshiryokukenkyukaihatsukiko) TAKEDA TETSUAKI (Nihongenshiryokukenkyukaihatsukiko)
Journal Title;Transactions of the Atomic Energy Society of Japan
Journal Code:L4596A
ISSN:1347-2879
VOL.5;NO.2;PAGE.81-95(2006)
Figure&Table&Reference;FIG.37, TBL.4, REF.14
Pub. Country;Japan
Language;Japanese
Abstract;The HTTR (High Temperature Engineering Test Reactor), which has thermal output of 30 MW, coolant inlet temperature of 395.DEG.C. and coolant outlet temperature of 850.DEG.C./950.DEG.C., is a first high temperature gas-cooled reactor (HTGR) in Japan. The HTGR has a high inherent safety potential to accident. Safety demonstration tests using the HTTR are underway in order to demonstrate such excellent inherent safety features of the HTGR. The reactivity insertion test demonstrates that rapid increase of reactor power during withdrawal of the control rod is restrained by only the negative reactivity feedback effect without operation of the reactor power control system, and the temperature transient of the reactor is slow. A one-point core dynamics approximation with one fuel channel, one fuel temperature coefficient and one moderator coefficient could not simulate accurately the reactor power behavior. On the other hand, an original new method using some temperature coefficients for regions in the core was very effective. It is crucial to evaluate this method precisely to simulate a performance of HTGR with showing excellent inherent safety features under the reactivity initiated incident by control rod withdrawal error. Moreover, all experimental data of reactivity insertion tests and analytical results are released. (author abst.)