In order to dispose of spent nuclear fuel (SNF) in deep geological repository, source term evaluation considering its specification, enrichment, burnup, cooling time should be performed. In this study, the measured values of Takahama-3 pressurized water reactor SNF (WH 17×17) samples were analyzed with SCALE 6.1/ORIGEN-S and TRITON code calculation results for validation. Unlike the ORIGENS code, TRITON code calculations differed from two-dimensional neutron flux distribution by using the multi-group cross-section library. Both calculation results from ORIGEN-S and TRITON code showed higher errors in 234U, 239Pu, and 241Pu compared to other actinide nuclides. In the case of axial locations of fuel rods in fuel assembly, fuel rods located at the edge of the fuel assembly presented increased errors due to nuclear reaction cross-section. Overall, the ORIGEN-S predictions informed more accurate agreement with the measured results compared with TRITON results. Especially to 235U, 239Pu, and 240Pu radionuclides, ORIGEN-S errors were denoted more than twice as low as the TRITON results. Comparing the calculation results with experimental results implied that the ORIGENS code was more accurate code than the TRITON code for source term evaluation.

The management before disposal of spent nuclear fuel is an essential process for safe management. It is important to determine the amount of nuclide inventory in order to ensure the integrity of spent nuclear fuel, as radiation generated from the nuclides is generated along with residual heat in the spent nuclear fuel. Based on the data on the characteristics of spent nuclear fuel generated in Korea, the correlation equation between burnup and enrichment was derived by referring to overseas cases (Sweden). Source term analysis was performed using the SCALE ORIGEN ARP code by securing the burnup history of nuclear fuel. Calculation was performed by inputting the combustion history of the fuel WH14×14 and WH17×17 as a reference for CE16×16 spent fuel. Through this study, the relationship was identified using the burnup, enrichment, and cooling time factors that influence the characteristics of spent nuclear fuel. In addition, the total source and spectrum data from neutrons and gamma sources were used to find out the characteristics of fuel.

Source term analysis should be carried out to prepare the decommissioning of the nuclear power plant. In the planning phase of decommissioning, the classification of decommissioning wastes and the cost evaluation are performed based on the results of source term analysis. In this study, the verification of MCNP/ORIGEN-2 model is carried out for preliminary source term calculation for Wolsung Unit 1. The inventories of actinide nuclides and fission products in fuel bundles with different burn-up were obtained by the depletion calculation of MCNPX code modelling the single channel. Two factors affecting the accuracy of source terms were investigated. First, the neutron spectrum effect on neutron induced activation calculation was reflected in one-group microscopic cross-sections of relevant radio-isotopes using the results of MCNP simulation, and the activation source terms calculated by ORIGEN-2 using the neutron spectrum corrected library were compared with the results of the original ORIGEN-2 library (CANDUNAU.LIB) in ORIGEN-2 code package. Second, operation history effect on activation calculation was also investigated. The source terms on both pressure tubes and calandria tubes replaced in 2010 and calandria tank were evaluated using MCNP/ORIGEN-2 with the neutron spectrum corrected library if the decommissioning wastes can be classified as a low level waste.

The purpose of this thesis is focussed on the explanation of the meaning of Origen’s prayer theology, the valuation of his contributions, and the comparision with Jesus’s understanding of the prayer. Opponents against the prayer argued that there is no need to pray, because God knows what the human wants and needs. In addition, God loved the creation and led them to salvation without prayer. Not only the divine will and providence can not be changed by the human prayer, but also human free will is opposed to God’s providence. In relation to that arguments Origen asserted that human prayer means that God’s providence and human free will work together. The human is cooperating with God through the prayer as an expression of man’s free will. According to Origen, “euché” has two meanings, namely “vow” and “petition”, but “proseuché” “petition or ask”. However, in the Gospels, Jesus say “proseuché” for the “petition”. Therefore, Origen see, that the criticism raised by opponents are easily refutable, if we understand “euché” to mean “vow”. And in relation of the personal egoism or self-centeredness in the korean church the meaning of “vows” ist more necessary and demanded than the of “petition or ask”. And everywhere in our society there is people, who are still facing problems, as well as food, clothing, and the right to live dignified, and violations of human rights and being happy. if the social, economic, and political conditions are in a relatively relaxed situation, petition praying is more suitable than “vow praying”. Thus, Jesus asked to pray his disciples and people gathered around him in the meaning of “petition”, because they were living in that socio-economic and political isolation and discrimination. Anyway, Origen’s rediscovery of the meaning of “euch” as vow would have been the best counter-weapon against his opponents. In that sense, it is suitable of us to vow in a relatively relaxed situation, but in a desperate situation, to ask or petition.

The well-known ecological theologian H. Paul Santmire points out that divine caring for nature we can see in early christian Fathers such as Irenaeus is totally missing in Origen’s anthropocentric view of nature. Origen, according to Santmire, shaped the biblical belief in the resurrection of the body to fit into the hierarchical, spiritualizing conceptuality. Then the material world will presumably fall back into nothingness, from whence it came, at the very end. Santmire concludes that the otherworldly view of salvation and the radical depreciation of the world of nature started from Origen, and this is due to the Platonic and Stoic influence upon him. Origen indeed employed Platonic and Stoic languages and speculations on human being and the created world. However, the fundamental sources and inspirations came from the scriptures and the tradition of the church. Origen, like other early christian Fathers, expressed the unity of creation by describing the functioning of different parts of creation as though they were limbs of a single body. It is difficult to pin Origen down to a specific statement that there will be restoration of the non-rational elements of the universe. He writes that if the heavens are to be changed like a vestment, then they are not to be destroyed, and if the fashion of the world passes away, it is by no means an annihilation or destruction of their material substance, but a kind of change of quality and transformation of appearance. It is primarily of physical human bodies that he is writing, but it is hard to exclude other material bodies from his meaning. Origen’s conception of ‘apokatastasis’, that is, the ‘restoration of all things’ could refer not only to humans but also to their physical environment, a restoration of Paradise. During the series of restorations through which more and more rational beings will have returned to God, successive restorations also of the physical universe will be necessary. When all have returned, at the point when God is all in all, the whole creation will also have returned to a permanent state of aethereal purity. Origen never shut his eyes to the beauty of the world created by God. We should now reevaluate Origen’s view of nature and change the negative thought on him.