Measurement and evaluation of the irradiation test parameters for a specimen in a HANARO material irradiation capsule
A material capsule system has been developed for irradiation tests of nuclear materials in the core region of the High-flux Advanced Neutron Application Reactor (HANARO) and has been actively utilized for the various material irradiation tests requested by numerous users. For an irradiation test in the reactor, nuclear characteristics and irradiation temperature of the capsule parts are basically necessary for the safety analysis of the capsule and capsule detail design. The irradiation temperature and neutron fluence of the specimens are key parameters required by a user to analyze any neutron irradiation damage effects. Based on a basic design of a capsule, the reactivity effect, neutron flux/fluence, and gamma heating of specimens are calculated by the MCNP code. To compare the calculated neutron fluence of the specimens, thermal and fast fluence monitors (F/Ms) are installed in a capsule. After an irradiation, the F/Ms are dismantled and analyzed to obtain a neutron spectrum. The obtained fast neutrons (E>1.0MeV) by using the SANDII code are located within about a 20% error range of the theoretical values calculated by the MCNP code. The irradiation temperature of the specimens is analyzed preliminary by using the GENGTC or ANSYS codes based on the basic design of a capsule and gamma heating. During an irradiation test, the temperatures of the specimens in a capsule are measured and monitored by thermocouples. The DPA (Displacement Per Atom) and activation of the irradiated specimens are also evaluated by using the SPECTOR and ORIGEN2 codes, respectively, at HANARO.
Contribution of HANARO Irradiation Facilities to National Nuclear R & D 5
HANARO is an open pool type multipurpose research reactor operated by the Korea Atomic Energy Research Institute (KAERI). Since the commencement of its operation in 1995, various neutron irradiation facilities, such as rabbit irradiation facilities, fuel test loop (FTL) facilities and capsule irradiation facilities for irradiation tests of nuclear fuels and materials have been developed. The irradiation facilities have been actively utilized for the various nuclear fuel and material irradiation tests requested by users from research institutes, universities, and industries. Most of the irradiation tests were related to the R&D relevant to the ageing managements and safety evaluations of the present nuclear power reactors. HANARO has also been applied in several commercial-based irradiation tests relevant to the lifetime extension of the 1st Korean nuclear power reactor Kori-1, and developing of new alloy and fuel in cooperation with Doosan Heavy Industry Company and KEPCO Nuclear Fuel Company. Based on the accumulated experiences regarding commercial nuclear power reactor as well as the sophisticated requirements of users, HANARO has recently started new R&D supports relevant to new nuclear systems including research reactor and System-integrated Modular Advanced Reactor (SMART) and future nuclear systems such as very high temperature reactor system (VHTR) and sodium cooled fast reactor system (SFR). The SMART system, which the KAERI has recently obtained national approval of standard design, is one of the most advanced small and medium-sized reactors (SMRs) in the world. To effectively support the R&D for the new nuclear systems, the advanced irradiation technologies concerning irradiation temperature and instrumentation is being preferentially developed at HANARO. In this paper, not only the status of HANARO irradiation devices but also the contribution of the irradiation facilities to national nuclear R&D is described.
Influence of details of reactor history on microstructural development during neutron irradiation
Abstract Microstructurally-oriented irradiation experiments are shown in this paper to be strongly dependent on details of reactor history that frequently are not brought to the experimenter's attention. In some cases, these details can dominate the experiment so as to produce very misleading results. To aid in the design and interpretation of microstructurally-oriented experiments, a number of studies are reviewed to highlight history effects and then guidelines are presented to minimize the impact of reactor history in new experiments.