International Atomic Energy Agency defines the term “Poison” as a substance used to reduce reactivity, by virtue of its high neutron absorption cross-section, in IAEA glossary. Poison material is generally used in the reactor core, but it is also used in dry storage systems to maintain the subcriticality of spent fuel. Most neutron poison materials for dry storage systems are boron-based materials such as Al-B Carbide Cermet (e.g., Boral®), Al-B Carbide MMC (e.g., METAMIC), Borated Stainless Steel, Borated Al alloy. These materials help maintain subcriticality as a part of the basket. U.S.NRC report NUREG-2214 provides a general assessment of aging mechanisms that may impair the ability of SSCs of dry storage systems to perform their safety functions during longterm storage periods. Boron depletion is an aging mechanism of neutron poison evaluated in that report. Although that report concludes that boron depletion is not considered to be a credible aging mechanism, the report says analysis of boron depletion is needed in original design bases for providing long-term safety of DSS. Therefore, this study aimed to simulate the composition change of neutron poison material in the KORAD-21 system during cooling time considering spent fuel that can be stored. The neutron source term of spent fuel was calculated by ORIGEN-ARP. Using that source term, neutron transport calculation for counting neutrons that reach neutron poison material was carried out by MCNP®-6.2. Then, the composition change of neutron poison material by neutron-induced reaction was simulated by FISPACT-II. The boron-10 concentration change of neutron poison material was analyzed at the end. This study is expected to be the preliminary study for the aging analysis of neutron poison material about boron depletion.

Corporate social responsibility (CSR) has become an important pillar in business practice. Luxury brands are no exception to this trend and have invested deeply in different types of CSR, and this is evident with companies such as Prada and LVMH. However, empirical research has demonstrated the paradox between CSR and luxury and has identified certain undesirable effects. The reason for this inconsistency in the results to date, is the lack of a comprehensive CSR categorization system. To be more specific, we integrated two dimensions - visibility and relevance - and have proposed a novel CSR type in four types, which is external-embedded, external-peripheral, internal-embedded and internal-peripheral. We can easily classify the CSR initiatives into this category, which means the source of undesirable effects can be clearly shown for luxury brands.

The toxicity and toxin composition between blue mussel, Mytilus edulis and oyster, Crassostrea gigas collected at Woepori in Koˇ je island in South Coast of Korea in 1996 and 1997 were compared. The highest toxicity score was about 10 times higher in blue mussel than oyster (blue mussel, 8,670 ㎍; oyster, 860 ㎍ in 1996, blue mussel, 5,657 ㎍; oyster, 531 ㎍/100 g in 1997). The blue mussel also retained its toxicity for slightly longer period than oyster. In the both shellfish, PSP was composed almost exclusively of C toxins (C 1 and C2, 2065%) and gonyautoxins (GTX1, 2, 3 and 4, 38-78%). In the early period of toxin accumulation, the ratio of 11(3-epimer toxins (C2, GTX4) whose amount was 2556 mole% (5th March to 12th April in 1996) and 2580 mole% (18th March to 7th April in 1997), were higher than that of llα-epimer toxins (C1, GTX2) in both shellfish. As the lapse of intoxification time, however, the ratio of 11-epimer toxins (C1, GTX2) whose amount was 41-57 mole% (27th May to 3rd June in 1996) and 25-56 mole% (29th April to 12th May in 1997), became higher than that of 11-epimer toxins. The toxin compositions in the both samples changed on a daily basis, presumably owing to metabolism of the toxins in the bivalves.

Paralytic shellfish poison (PSP) occurrence and variation in the different bivalve species including oyster, Crassostrea gigas and mussel, Mytilus edulis in Jinhae bay Korea from January to December in 1997 were surveyed. And also compositional characteristics of PSP ingredients in the different bivalve species were investigated. PSP in shellfish was detected from late February and increased continuously until the middle of April in Jinhae bay. And after April PSP level had been decreased gradually and the toxicity was not detected by mouse bioassay in the early of June. Of the examined bivalve species, PSP content in the mussel exhibited the highest value and the PSP content in the mussel in the middle of April, PSP high season in Jinhae bay, was 6 times higher than that in the oyster. Gonyautoxin (GTX)1-4 group occupied 59.0-78.8% of whole PSP contents and identified as dominant ingredient in the examined bivalves except oyster. And it is also identified that the PSP toxicity in the tested species were derived from the GTX group. And the dominant ingredient of PSP in the oyster was carbamoyl-N-sulfo-llα- hydroxysaxitoxin sulfate(C1)(37.9%) and neosaxitoxin(neoSTX)(26.2%). But the toxicity of C1 in the tested oyster could be ignorable and most toxicity (80.0%) was derived from saxitoxin (STX) group.

Paralytic shellfish poison threatens public health most seriously from April to early May every year and gives adverse effects on export of these products. Major shellfish products exported were canned oyster, Crassostrea gigas and blue mussel, Mytilus edulis. Toxicities of canned shellfishes with toxin of low levels were mostly inactivated during the processing; in contrast, residual toxicity was of great concern with canned products from highly toxic shellfishes. This study was to provide basic data to establish food safety measure by evaluating the changes of toxicity during 2 year storage of canned products with toxic blue mussel and oyster. Any significant difference was not observed between two samples. Boiled can and smoked can showed inactivation of toxicity to some extent, whereas acidified can did not show reduction of toxicity even after 2 year storage. In case the initial toxicity of shellfish was high long term storage could not inactivate the toxicity of the canned product.

마비성패류독(Paralytic shellfish poison, PSP)에 의하여 독화된 패류의 유효이용에 대한 자료를 제공하고자 독화된 진주담치의 중장선 균질육, 0.1N HCl로 추출한 조독소 용액, 중장선으로부터 정제한 gonyautoxin(GTX) group과 saxitoxin(STX) group 등 4가지 형태의 PSP 독소에 대한 내열성을 조사하였다. 독화된 진주담치의 중장선육 균질액, 산추출 조독소액, GTX group, STX group 등 4 종류의 반응속도상수는 120℃에서 3.28×10^(-2), 1.20×10^(-2), 5.88×10^(-2), 2.58×10^(-2)이었으며 4 종류의 독소 중 0.1 N HCl 추출한 조독소용액의 D-value가 가장 높았다. 반응속도상수를 이용한 살균온도 산정에 있어서, 초 독력이 200 /100g인 독화된 진주담치육의 경우, 독력을 마비성패류독 규제치인 80 ㎍/100g으로 감소시키는데에는 90℃에서는 약 129분, 100℃에서는 약 82분, 110℃에서는 약 48분, 120℃에서는 약 28분이 걸렸다. 이러한 결과는 최초 독력이 200 ㎍/100g인 패류의 경우, 통조림 살균공정 후 잔존 독력이 규제치인 80㎍/100g이하로 감소시키는데에는 현재의 살균조건(115℃, 70분)으로는 충분하다는 것을 입증한다