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JAEA Reports

Change in heat exchange performance of VCS cooler and its recovery works

Hamamoto, Shimpei; Watanabe, Shuji; Oyama, Sunao*; Ota, Yukimaru; Tochio, Daisuke; Fujimoto, Nozomu

JAERI-Tech 2005-035, 35 Pages, 2005/07

JAERI-Tech-2005-035.pdf:2.54MB

The Vessel Cooling System (VCS) is one of the safety engineered features of the HTTR. The VCS removes the decay heat of the reactor core when the forced circulation can not be maintained due to pipe rupture accidents, etc. VCS cools the core by water cooling panels surrounding the reactor pressure vessel. The VCS also keeps the temperature of the concrete of the primary shielding under the design limit during the operation. The temperature of cooling water of the VCS has recently tended to rise gradually, though the amount of heat removal of VCS has been constant. Accompanying with the increase of the cooling water temperature, the temperature of the shielding concrete is also possible to rise and exceed the limit. The heat exchange performance of the VCS cooler was evaluated and the deterioration of the cooler was verified. Therefore, the cleaning of heat transfer tubes was carried out to recover the heat exchange performance. The cleaning recovered the performance of the VCS cooler drastically and the cooling water temperature of the VCS could be reduced sufficiently.

JAEA Reports

Heat transfer characteristics evaluation of heat exchangers of mock-up test facility with full-scale reaction tube for HTTR hydrogen production system (Contract research)

Shimizu, Akira; Ohashi, Hirofumi; Kato, Michio; Hayashi, Koji; Aita, Hideki; Nishihara, Tetsuo; Inaba, Yoshitomo; Takada, Shoji; Morisaki, Norihiro; Sakaki, Akihiro*; et al.

JAERI-Tech 2005-031, 174 Pages, 2005/06

JAERI-Tech-2005-031.pdf:20.71MB

Connection of hydrogen production system by steam reforming of methane to the High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Research Institute (JAERI) has been surveyed until now. Mock-up test facility of this steam reforming system with full-scale reaction tube was constructed in FY 2001, and a lot of operational test data on heat exchanges were obtained in these tests.In this report specifications, structures and heat transfer formulae of steam reformer, steam superheater, steam generator, condenser, helium gas cooler, feed gas heater and feed gas superheater were described. Evaluation codes were newly made to evaluate heat transfer characteristics from measured test data. Overall heat-transfer coefficient obtained from the experimental data were compared and evaluated with the prospective value calculated with heat transfer formulae. As a result, heat transfer performance and thermal efficiency of these heat exchangers were confirmed to be appropriate.

JAEA Reports

Management techniques of the JRR-4 heat exchanger

Horiguchi, Hironori; Oyama, Koji; Ishikuro, Yasuhiro; Hirane, Nobuhiko; Ito, Kazuhiro; Kameyama, Iwao

JAERI-Tech 2005-001, 38 Pages, 2005/02

JAERI-Tech-2005-001.pdf:2.79MB

After JRR-4 heat exchanger was renewed in made of stainless steel from carbon steel, it was examined how to manage the heat exchanger. The main subject is the cleaning technology of the heat exchanger. The recovery of old heat exchanger cooling performance has been by only chemical cleaning. Now we use chemical and dry cleaning as a new technique. It helps prevent of corrosions of secondary pipes and reduce of management costs. This report describes the performance management and cleaning technology of the JRR-4 heat exchanger and the management of the JRR-4 coolant.

Journal Articles