Molten salt reactor (MSR) has a unique characteristic using liquid fuel and/or coolant salt among six type of GEN IV reactors. Liquid fuels and on-site processing are fundamentally different from a solid fuel reactor where separate facilities produce the fresh solid fuel and process the Spent Nuclear Fuel. Because the choice of fuel cycle affects the safeguards and non-proliferation characteristics of the reactor system, different MSR concepts may have different proliferation resistance and physical protection characteristics. For example, MSR design variants that use solid fuel but are cooled with liquid salts such as FHR are very close to the Very High Temperature Reactor design concept. The composition of various fuel salts is a representative factor that makes it difficult to generalize the PRPP evaluation principle of MSR. In addition, the flow of molten salts containing fissile materials is also complex depending on the design of the reactor. The path through which radioactive materials travel not only inside the reactor but also to nuclear fuel cycle facilities can act as a difficult factor in measuring nuclear materials. As a further complication, some of the plants include fuel salt drain tanks intended to provide decay heat removal while others are designed to provide decay heat removal while the salt is maintained within the reactor vessel. Some lessons learned from the prior molten salt breeder reactor program are reflected in all of the new designs. Interior reflectors/shielding are frequently employed to reduce the radiation damage to the reactor vessel, and fuel salt chemistry control is employed to substantially limit oxidizing the container alloy constituents. However, even with the vessel interior shielding, the containment environment around both solid and liquid fueled MSRs during operation is likely to have substantially higher dose rates than at LWRs due to the fission process and fission products in the case of circulating liquid fueled reactors, and the shortlived activation products of fluorine (16N, 20F, and 19O) in the case of FHRs. Consequentially due to insufficient shielding from the coolant and the vessel wall, MSR containments will be remote access only for liquid fueled systems and remote access only during operation for FHRs.

Liquid-fueled Molten Salt Reactors (MSRs) do not contain their fuel in assemblies. It is then not possible to perform traditional item counting and visual accountability of the salt fuel. These facilities are closer to bulk accounting facilities, such as reprocessing plants, and require inventory determinations based on measurements of the actinide content of salts. This can be problematic due to the difficulty of sampling and the destructive analysis of actinide-containing molten salts. Some problems arise from the unique combination of high temperature and high radiation environments present in molten salt fuels. Another challenge is the continuous change in the isotopic concentration of fuel salts due to burn-up, conversion, plating out, and online chemical processing. There is a potential for fuel stocks outside the reactor containment vessel in on-site salt processing. In terms of proliferation resistance of 233U-232Th fuel cycle, the nuclide 232U is an important nuclide in thorium fuel cycle from the standpoint of proliferation resistance, because its daughter Thallium (208Tl) is a strong gamma (2.6 MeV) emitter. The hard gamma ray is not only barrier from to nuclear material theft, but also an effective means of detecting lost fissile material. However, there is a theoretical weakness in obtaining pure 233U at the core of the initial two weeks with a concentration of 232Pu less than 1,000 ppm. Therefore, Pu separation process is one of the most sensitive parts in online reprocessing facility. The decision to use a fertile blanket should also be based on proliferation risk considerations in addition to operational parameters. MSRs can be designed without a separate fertile blanket, which should be considered. In the case of the MSFR, even if fertile blankets are used, the production of 232U is large enough to make difficult the utilization of blankets for proliferation purpose. For the liquid-fueled MSRs without fissile materials separations, many of the observations from the previous section apply, except salt processing is minimized. The reactors will still need some method of estimating total actinide content. These reactor designs reduce proliferation risk for the reactor by not separating any actinides during operation.

Soybean cyst nematode, Heterodera glycines is one of the major plant parasitic nematodes in soybean. Recently, another soybean cyst nematode, H. sojae was recorded from Korea. This study was conducted to determine the geographical distribution of the two soybean cyst nematodes in Gangwon-do and Chungcheongbuk-do, Korea. In Gangwon-do, H. glycines and H. sojae were detected in 12 and 5 of the 53 sites sampled, respectively, while in Chungcheongbuk-do, H. glycines was isolated from 14 of the 46 sites sampled. H. sojae was detected at only one site. Additionally, the two soybean cyst nematodes co-existed in 3 of the 46 sites.

The TMDL (Total Maximum Daily Load) has been used to determine the water quality target. LDC (Load Duration Curve) based on hydrology has been used to support water quality assessments and development of TMDL. Also FDC (Flow Duration Curve) analysis can be used as a general indicator of hydrologic condition. The LDC is developed by multiplying FDC with the numeric water quality target of the factor for the pollutant of concern. Therefore, this study was to create LDC using the stream flow data and numeric water quality target of BOD and T-P in order to evaluate the pollutant load characterization by flow conditions in Heukcheon stream. When it is to be a high-flows condition, BOD and T-P are necessary to manage. BOD and T-P did not satisfy the numeric water quality target for both seasons (spring and summer). In order to meet the numeric water quality target in Heukcheon stream, management of non point source pollutant is much more important than that of point source pollutant control.