Activity for improvement of reprocessing plant quality assurance system; Transition to decommissioning stage, complying with new regulatory requirements for new inspection program, giving up ISO 9001 certification; Operations report FY 2012-2019

Yoshinaka, Kazuyuki; Shimizu, Kazuyuki; Sugiyama, Takayuki

JAEA-Review 2021-008, 112 Pages, 2021/07

JAEA-Review-2021-008.pdf:5.99MB

We had drastically been improving quality assurance system for Tokai Reprocessing Plant (TRP), through applying new regulatory requirements, giving up ISO certification from FY2012 to 2019. In revising QA system, it is obviously necessary to satisfy the regulatory requirements, but it is important to continuously improve the QA system considering effectiveness to safety performance based on earlier experiences. In this report, the background of QA system revision, interpretation and thinking way of conformation and application to new regulation and "Application Guide to Quality Assurance Code for Safety in Nuclear Power Plants (JEAC 4111)" to TRP, issues considered. And matters that require attention for future QA activities are described. Key points are "in work processes planning, relationship with other sections and responsibility boundaries should be clearly defined with such as flow chart", "to manage decision-making processes is important, including input information, judgment criteria and so on", "concerning process monitoring and measurement, not only focusing on scheduling but also viewpoints toward conditions of facilities/systems, conformance to regulatory requirements and process improvement are necessary", and "in documentation, matching for existing system, clear relation to other fundamental documents are necessary".

Waste Technical Standards Working Group annual report 2016

Waste Technical Standards Working Group

JAEA-Review 2017-017, 112 Pages, 2017/11

JAEA-Review-2017-017.pdf:2.87MB

In Japan Atomic Energy Agency, JAEA, a Waste Technical Standards Working Group has established since FY2015. The Working Group is composed of the members from waste management sections in each site in JAEA and from Radioactive Waste Management and Disposal Project Department. In this Working Group, we discussed quality management on conditioning waste packages, methodologies to evaluate the radioactivity concentration and measures for dismantling waste. This annual report summarizes the results of discussion in FY2016.

Visit to Japan Chemical Analysis Center

Usuda, Shigekazu

Isotope News, (617), p.20 - 24, 2005/09

no abstracts in English

Practical gamma-ray spectrometry

Yonezawa, Chushiro; Matsue, Hideaki; Miyamoto, Yutaka; Suzuki, Daisuke; Yasuda, Kenichiro; Inagawa, Jun; Saito, Yoko

Jitsuyo Gamma-sen Sokutei Handobukku, 366 Pages, 2002/06

no abstracts in English

Safety administration division business report; The first quarter of 2001

Kanamori, Masashi

JNC TN8440 2001-015, 100 Pages, 2001/09

JNC-TN8440-2001-015.pdf:3.79MB

As a consequence of this reorganization, the business of the Safety Administration Division became a wide range such as the management of a labor safety health, the crisis management, the security and the management of an entrance, the business of the sanction concerning the Tokai Works, the protection of nuclear materials, the nuclear material safeguards, the transport of nuclear materials and the business of a quality assurance. In the respect of the purpose of summarizing these businesses and utilizing the data concerning the businesses, the report about a business achievement was determined to make.

Present status of the JAERI photocathode microtron

Kando, Masaki; Kotaki, Hideyuki; Kondo, Shuji; Kanazawa, Shuhei; Masuda, Shinichi; Yokoyama, Takashi*; Matoba, Toru; Nakajima, Kazuhisa

Proceedings of 26th Linear Accelerator Meeting in Japan, p.132 - 134, 2001/08

no abstracts in English

Present status of dosimetry for radiation application

Kojima, Takuji

Hoshasen To Sangyo, (89), p.4 - 7, 2001/01

http://ci.nii.ac.jp/naid/40004433181

This paper describes the present status of dosimetry as one of the useful technique for the process/quality control in radiation application and radiation research/testing. It introduces (a)activities in dose standardization of International Organization for Standardization(ISO) and International Atomic Energy Agency(IAEA) on publication of standards and organization of workshops, (b)recent efforts for consistency check in dose evaluation of electrons having energies above 4MeV, and (c)development status of dosimeter systems relevant to new requirements in dosimetry. It also comments on importance of planning for succession of high-dose dosimetry technology and education/training of dosimetry workers/researchers.

Study of the quality of vipac oxide fuel obtained by pyro-processing

Kakehi, Isao;

JNC TN9400 2000-054, 84 Pages, 2000/04

JNC-TN9400-2000-054.pdf:7.15MB

This report describes accomplishment of the study on the quality of vipac (vibro-packed) oxide fuel obtained by pyrochemical processing (molten salt electrolytic processing). This study is intended to contribute to the design study of the pyro-reprocessing-vipac fuel recycling system of oxide fuel. In this study, vibro-packing experiment has been conducted using granular U0 obtained by molten salt electrolytic processing (cold experiment). The oxide pyro process developed by Research lnstitute of Atomic Reactors (RIAR) is the method in which the sintered oxide is electrically deposited on the cathode at approximately 600C. 0xide granules for vipac fuel are obtained by crushing the oxide deposited on the cathode. This process is also developed as recycle process because it is capable of FP separation. Also in Japan, this process is studied as one of the new FBR fuel recycling systems. ln this study, we made an effort to clarify the mechanisms of vibro-packing of the electrically obtained granules, which influence on the effective parameters of vibro-packing density and fuel particles size distribution in the fuel cladding in case of non-sphere particles of the granules. As a result of the study, smear density of 75% and almost uniform distribution of U0 particles have been taken in the experiment, and much knowledge for the improvement of the vibro-packing quality has been found. And the possibility of the smear density over 80% and the uniform distribution of U0 particles has been suggested in this study.

A Study on design methods for overpack welds; Acquisition of basic data to quantify welding quality

*; *; *; *; Sago, Hiromi*; *; *

JNC TJ8400 2000-049, 161 Pages, 2000/02

JNC-TJ8400-2000-049.pdf:9.56MB

In this study basic data on welds of overpack structures for HLW were acquired and a predictive destruction analysis was performed usig the data acquired, in order to examine the viability of weld design methods. The results are summarized as follows: (1)Investigation of Design and Welding Condition for Welded Joint Models. Three welding methods--EBW, TIG and MAG--were selected, and welding conditions were determined so that the welding quality almost equivalent to that of an actual over-pack was ensured. (2)Fabrication of Welded Joint Models. Three welded joint models, one for each of EBW, TIG and MAG, were fabricated. It was confirmed that these models satisfied the quality requirements for Class I specified in JIS Z3104. (3)Sampling and Machining of Strength Test Specimens. Test specimens were taken from each welded joint model, and models for corrosion tests were delivered to the Japan Nuclear Cycle Development Institute (JNC). (4)Strength Test and Micro/macro Structure observation. Tensile tests were conducted at room temperature and at 150C, and fracture toughness tests at 0C and 150C, in order to obtain stress-strain curves, J-R curves and Vickers hardness. In addition, an observation of micro and macro structures was performed. (5)Evaluation. Using the data on the welds obtained from the tests, a fracture prediction analysis and an evaluation of unstable fracture due to weld flaws were performed on the over-pack design described in the second progress report. The following conclusions were obtained: (a)For the overpack design examined, the effects of welds (material property and residual stress) and fabrication tolerance on fracture loading are negligible. (b)In addition, it was decided that even in a design with reduced wall thickness, welds have an insignificant effect on fracture loading because fracture initiates in the center of the shell of the overpack. (c)The size of flaws leading to unstable fracture is on ...

Certification of reliability of nuclide migration data

Ueta, Shinzo*; *; *; *

JNC TJ8400 2000-002, 364 Pages, 2000/02

JNC-TJ8400-2000-002.pdf:16.99MB

Japan Nuclear Cycle Development Institute (JNC) have been setting migration parameters and developing its database for the 2nd Progress Report of HLW Geological Disposal (H12 Report). In this study, experimentswere carried out to certify the reliability of parameters and scenario, and examination was carried out to survey procedures of quality management. The main contents are as follows. (1)Data acquisition for certification of migration parameters. The effect of NH complex of Pd on distribution coefficients (Kd) of Pd on both bentonite and rocks, and the effect of sulfate and carbonate complexes of Am on Kds of Am on bentonite are investigated. Kds of Pd depended on NH concentration in aqueous. The dependence varied with pH. Effects of sulfate and carbonate complexes on Kds of Am were not remarkable. Apparent diffusivities of Cs in bentonite saturated by saline water were measured. It was confirmed that the apparent diffusivities of Cs in saline water were similar to those in pure water. (2)Evaluation of colloidal effect on nuclide migration. An evaluation of validity of analytical model (Hwang's model) for nuclide migration under existence of colloids and investigation of characterization of colloids in groundwater were carried out. As the results, it was indicated that the Hwang's model was appropriate, and it was found that samplingtechnique influenced concentration and size distribution of colloids. (3)Influence of organic substances on solubility. Solubility of Th was measured under the condition with humic acid and carbonate. It increased roughly in proportion to the concentration of humic acid. And it was remarkably high under the condition with carbonate. It was confirmed that Th solubility data set in H12 report was conservative, even though humic acid existed in groundwater. (4)Use of Mechanistic Models for Safety Assessment. The integrated sorption/diffusion model has been used to calculate K, D and D values ...