Licensees are required to protect critical digital assets (CDAs) in nuclear facilities against cyber-attacks, up to and including design basis threat (DBT), according to「ACT ON PHYSICAL PROTECTION AND RADIOLOGICAL EMERGENCY」. However, CDAs may be excluded from cyber security regulations at nuclear power plant decommissioning, and this may lead to severe consequences if the excluded CDAs contain sensitive information such as the number and location of nuclear fuels and information on security officers. In that case, that information could be leaked to the adversary without adequately removing the information before discarding the CDAs. It can be potentially abused to threaten nuclear facilities inducing radiological sabotage and nuclear material theft. So, controls of sensitive information are needed. This study aims to derive regulatory improvements related to discarding CDAs that have sensitive information by analyzing foreign cases such as IAEA and U.S. NRC. The sensitive information in the IAEA guide is the following: (1) details of physical protection systems and any other security measures in place for nuclear material, other radioactive material, associated facilities, and activities; (2) information relating to the quantity and form of nuclear material or other radioactive material in use or storage; (3) information relating to the quantity and form of nuclear material or other radioactive material in transport; (4) details of computer systems; (5) contingency and response plans for nuclear security events; (6) personal information; (7) threat assessments and security alerting information; (8) details of sensitive technology; (9) details of vulnerabilities or weaknesses that relate to the above topics; (10) historical information on any of the above topics. In the case of the U.S. NRC, they categorize sensitive information into three groups: (1) classified information, (2) safeguard information (SGI), (3) sensitive unclassified non-safeguards information (SUNSI). Classified information is information whose compromise would cause damage to national security or assist in manufacturing nuclear weapons. The SGI concerns the physical protection of operating power reactors, spent fuel shipments, strategic special nuclear material, or other radioactive material. Finally, SUNSI is generally not publicly available information such as personnel privacy, attorney-client privilege, and a confidential source. IAEA recommends protecting the above sensitive information in accordance with NSS No.23-G (Security of Nuclear Information), and NRC protects classified information, SGI, and SUNSI under relative laws. In the case of ROK, if security control measures are enhanced CDAs that possess sensitive information, the risk of information leakage will be decreased when those CDAs are discarded.

Nuclear Safety and Security Commission (NSSC) and KINAC review a Cyber Security Plan (CSP) by「ACT ON PHYSICAL PROTECTION AND RADIOLOGICAL EMERGENCY」. The CSP contains cyber security implementation plans for the licensee’s nuclear power plant, and it shall meet the requirements of KINAC/RS-015, a regulatory standard. The KINAC/RS-015 provides more detailed information on the legal requirements, so if licensees implement cyber security under the approved CSP, they can meet the law. To protect nuclear facilities from cyber-attacks, licensees should identify their essential digital assets, so-called “Critical Digital Assets” (CDAs). Then, they apply cyber security controls (countermeasures for cyber-attacks) on CDAs consisting of technical, operational, and management security controls. However, it is hard to apply cyber security controls on CDAs because of the large amounts of CDAs and security controls in contrast to the shortage of human resources. So, licensees in the USA developed a methodology to solve this problem and documented it by NEI 13-10, and US NRC endorsed this document. The main idea of this methodology is, by classifying CDAs according to their importance, applying small amounts of security controls on less important CDAs, so-called non-direct CDAs. In the case of non-direct CDAs, only basic cyber security controls are applied, that is, baseline cyber security controls. The baseline cyber security controls are a minimum set of cyber security controls; they consist of control a) from control g) a total of 7 controls. Although non-direct CDAs are less critical than other CDAs (direct CDAs), they are still essential to protect them from cyber-attacks. This paper aims to suggest a cyber security enhancement method for non-direct CDAs by analyzing the baseline cyber security controls. In this paper, baseline cyber security controls were analyzed respectively and relatively and then concluded how to apply small amounts of cyber security controls on non-direct CDAs rather than direct CDAs without scarifying cyber security.

Using whole cell current- and voltage-clamp recording we investigated the characteristics and pharmacology of group I metabotropic glutamate receptor (mGluR)-mediated responses in rat medial vestibular nucleus (MVN) neurons. In current clamp conditions, activation of mGluR I by application of the group I mGluR agonist (R,S)-3,5-dihydroxyphenylglycine (DHPG) induced a direct excitation of MVN neurons that is characterized by depolarization and increased spontaneous firing frequency. To identify which of mGluR subtypes are responsible for the various actions of DHPG in MVN, we used two subtype-selective antagonists. (S)-(+)- alpha-amino-a-methylbenzeneacetic acid (LY367385) is a potent competitive antagonist that is selective for mGluR1, whereas 2-methyl-6-(phenylethynyl)-pyridine (MPEP) is a potent noncompetitive antagonist that is selective for mGluR5. In voltage clamp conditions, DHPG application increased the frequency of spontaneous and miniature inhibitory postsynaptic currents (IPSCs) but had no effect on amplitude distributions. Antagonism of the DHPG-induced increase of miniature IPSCs required the blockade of both mGluR1 and mGluR5. DHPG application induced an inward current, which can be enhanced under depolarized conditions. DHPG-induced current was blocked by LY367385, but not by MPEP. Both LY367385 and MPEP antagonized the DHPG-induced suppression of the calcium activated potassium current (IAHP). These data suggest that mGluR1 and mGluR5 have similar roles in the regulation of the excitability of MVN neurons, and show a little distinct. Furthermore, mGluR I, via pre- and postsynaptic actions, have the potential to modulate the functions of the MVN.

Salinity stress severely affects plant growth and development causing crop loss worldwide. Suaeda asparagoides is a salt-marsh euhalophyte widely distributed in southwestern foreshore of Korea. To isolate salt tolerance genes from S. asparagoides, we constructed a cDNA library from leaf tissues of S. asparagoides that was treated with 200 mM NaCl. A total of 1,056 clones were randomly selected for EST sequencing, and 932 of them produced readable sequence. By sequence analysis, we identified 538 unigenes and registered each in National Center for Biotechnology Information. The 80 salt stress related genes were selected to study their differential expression. Reverse Transcriptase-PCR and Northern blot analysis revealed that 23 genes were differentially expressed under the high salinity stress conditions in S. asparagoides. They are functionally diverse including transport, signal transduction, transcription factor, metabolism and stress associated protein, and unknown function. Among them dehydrin (SaDhn) and RNA binding protein (SaRBP1) were examined for their abiotic stress tolerance in yeast (Saccharomyces cerevisiae). Yeast overexpressing SaDhn and SaRBP1 showed enhanced tolerance to osmotic, freezing and heat shock stresses. This study provides the evidence that SaRBP1 and SaDhn from S.asparagoides exert abiotic stress tolerance in yeast. Information of salt stress related genes from S. asparagoides will contribute for the accumulating genetic resources to improve osmotic tolerance in plants.