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Tochio, Daisuke; Nakagawa, Shigeaki
JAERI-Tech 2005-041, 109 Pages, 2005/08
JAERI-Tech-2005-041.pdf:4.48MB
In High Temperature Engineering Test Reactor (HTTR) of 30MW, the generated heat at reactor core is finally dissipated at the air-cooler by way of the heat exchangers of the primary pressurized water cooler and the intermediate heat exchanger. To remove generated heat at reactor core and to hold reactor inlet coolant temperature to specified temperature, heat exchangers in main cooling system of HTTR should have designed heat exchange performance. In this report, heat exchange performance for ACL in main cooling system is evaluated with previous operation data, and evaluated values are compared with designed value. Moreover, heat exchange performance at full power operation is estimated for the air temperature. As the result, ACL has heat exchange performance removing generated heat at reactor core under the designe ACL inlet air temperature of 33
C.
Tochio, Daisuke; Nakagawa, Shigeaki; Takada, Eiji*; Sakaba, Nariaki; Takamatsu, Kuniyoshi
JAERI-Tech 2003-097, 55 Pages, 2004/01
JAERI-Tech-2003-097.pdf:3.34MB
In high temperature engineering test reactor (HTTR) of 30 MW, the generated heat at reactor core is finally dissipated at the air-cooler (ACL) by way of the heat exchangers of the primary pressurized water cooler (PPWC) and the intermediate heat exchanger (IHX). Therefore, air temperature (secondary-side condition at ACL) is important factor for the heat removal capability of the reactor. Coping with the air temperature, stable reactor inlet temperature control is achieved by adjusting of ACL coolant temperature with coolant (pressurized water and air) flow rate. ACL heat removal characteristic was based on the previous operation data in rise-to-power test and in-service operation at HTTR. And evaluate heat removal capability at summertime air temperature as the most severe condition was estimated. As the result, it was confirmed that the rated power of 30 MW can be removed at the condition of summertime air-temperature.
*; *; Uno, Tetsuro*
PNC TN9410 86-029, 68 Pages, 1986/02
A new test facility "Air-Cooling Thermal Transient Test Facility" (ATTF) was constructed at O-arai Engineering Center. This test facility is utilized, in the first place, for evaluating the strength of outlet tube-sheets of steam generators of FBR Plants. The objectives of the tube-sheet model tests are as follows. The first is to investigate and evaluate the strain concentration in the plastic region. The second is to confirm the adequacy of the design criteria for the prototype reactor MONJU. The third is to confirm the safety margin for failure incorporated in the design evaluation methods. ATTF can impose severe thermal loadings (only cold shock) on the test specimens. The facility produces compressed air (Max. 35kg/cm
G) by two large-sized compressors, and stores it in a storage tank (about 60m
). After a test specimen is heated up to the aimed temperature the compressed air passes through the test specimens quickly by opening the valve to apply cold shock and is released in the atmosphere. Each main loop pipe is 8 inches in diameter and the flow rate is max. 10kg/s in compressed air. The most severe down thermal transient condition is from 550C to 150C (for tube-sheet model) in about 4 min. The test section can be modified for various kinds of structures, which should be air-tight and have the maximum pressure of 8kg/cmG. The facility is operated automatically by two sequencer controllers. One of the main features of ATTF is the adoption of compressed air instead of sodium as coolant. By using compressed air, various kinds of sensors which can not be used in the sodium environment can be used in ATTF; particularly strain gages can be used effectively to obtain strain distribution for thermal transient condition, and the location as well as the mode of failure of test specimens can be recognized easily through the detection of crack initiation and the observation of crack growth. ATTF is expected to be a powerful ...
Okano, Yasushi; Yamano, Hidemasa; Takata, Takashi; Nishino, Hiroyuki; Kurisaka, Kenichi
no journal, ,
External hazard related to meteorological phenomena may impact on decay heat removal system using ambient air as an ultimate heat sink such as in sodium-cooled fast reactor system. This study identify the combination of external hazards to be considered and the items to be quantified for probabilistic risk assessment from the view point of strength and affecting duration of the hazard in case that secondary external hazard which has predicted appearance frequency overlaps after an primary external hazard which is very rare but high consequence.