Development of Glass Melter Technology for HLLW Vitrification in Japan

2014 ◽  
Author(s):  
Akira Sakai ◽  
Hajime Koikegami ◽  
Nobuyuki Miura ◽  
Eiji Ochi
Keyword(s):  
Noble Metals ◽  
Technology Development ◽  
Process Development ◽  
Scale Up ◽  
Liquid Waste ◽  
Glass Production ◽  
Full Scale ◽  
Acceptance Test ◽  
Radioactive Liquid Waste ◽  
Glass Melter

This paper describes the development of glass melter technology, primarily the liquid fed joule-heated ceramic melter process (LFCM) for the vitrificaton of high-level radioactive liquid waste (HLLW) since 1977 in Japan. In 2013 the active test at the vitrification facility (K-facility) in Rokkasho commercial reprocessing plant was successfully completed for the final acceptance test. During this period many activities on LFCM process development have been carried out in the engineering scale or the full-scale inactive cold tests including the radioactive laboratory scale hot tests. In particular, the design of melter bottom structure and the operating method should be optimized in order to avoid the operational problems caused by accumulation of noble metals (Ru, Rh, Pd), electro-conducive deposits on the melter bottom. Through the operation of inactive and active test facilities in Tokai, the design basis for the Tokai Vitrification Facility (TVF) has been provided. The hot operation of the TVF was started in 1995 to demonstrate the LFCM process including the performance of the melter off-gas clean-up system etc. The TVF has provided the basis of the process design and the operation method for the K-facility melter in Rokkasho. In case of commercial scale vitrification, the glass production rate of the melter should be several times larger than that of the TVF. The K-facility full-scale inactive mock-up melter (KMOC) has been planned to confirm the influence of scale-up factors and the difference between Tokai and Rokkasho wastes. Through the testing operation of the KMOC, which was initially started in 2000, it has been found that the stable formation of a cold cap on a molten glass surface is fundamentally important to avoid the excessive precipitation of noble metals and the yellow phase formation. The active test of the K-facility has been proceeding under the same conditions as the KMOC, and was successfully completed in May, 2013. The advanced glass melter development programs have also commenced from 2009 to ensure a more robust and noble metals are compatible with the LFCM system and also to provide a higher processing rate. The second K-facility full-scale inactive mock-up melter (K2MOC) has been installed in the vitrification technology development facility (X-14) at Rokkasho. Its testing operation has commenced from November, 2013.

Glass Melter Replacement and Melter Technology Development in the Tokai Vitrification Facility

2004 ◽  
Author(s):  
Atsushi Aoshima ◽  
Tetsuo Kozaka ◽  
Kazuhiko Tanaka
Keyword(s):  
Glass Matrix ◽  
Technology Development ◽  
Laser System ◽  
Liquid Waste ◽  
Platinum Group Metal ◽  
Main Process ◽  
Radioactive Liquid Waste ◽  
Metal Compounds ◽  
Effective Discharge ◽  
Glass Melter

Japan Nuclear Cycle Development Institute (JNC) has the vitrification facility (Tokai Vitrification Facility: TVF) at the Tokai Reprocessing Plant (TRP) site (Fig. 1). In the TVF, highly radioactive liquid waste from the main process of the TRP is vitrified into glass matrix. On March of 2002, the damage on one electrode of the 1st melter occurred, so JNC decided to exchange the melter to the new one in two years. The design of the second melter to be replaced is modified to have more effective discharge ability of the platinum group metal compounds which are suspended in the molten glass matrix. The exchange project has four main steps: (1) fabrication of the new melter, (2) removal the failed melter, (3) installation of the new melter in the TVF and (4) dismantling the failed melter. As of April 2004, fabrication of the new melter and its cold operation test have been completed and the in-cell remote installation has been initiated. The installation will be finished until the end of August 2004 and the TVF operation will restart on October. For dismantling of the melter, JNC planned to cut structural materials by the YAG laser system and has progressed the device design and fabrication. The melter dismantling will be started in 2005 and it also includes detail investigation of the failed electrode. In the TVF, JNC have started other new activities for development of future melter technologies such as (1) design study of advanced melter, which has less environmental burden (2) glass volume reduction.

Vitrification Technology Development Plan in Tokai Reprocessing Plant

2006 ◽  
Author(s):  
Atsushi Aoshima ◽  
Kazuhiko Tanaka
Keyword(s):  
Noble Metal ◽  
Technology Development ◽  
Liquid Waste ◽  
Development Plan ◽  
Stable Operation ◽  
Radioactive Liquid Waste ◽  
Basic Strategy ◽  
Long Lifetime ◽  
Reprocessing Plant ◽  
Main Electrode

The Tokai Vitrification Facility (TVF) is the only operating vitrification plant in Japan, constructed and operated by JAEA, to vitrify concentrated high radioactive liquid waste (HALW) in the Tokai Reprocessing Plant (TRP). JAEA started TVF hot operation in 1995 and produced 218 canisters as of March, 2006. An existing melter is the second melter, which was installed from 2002 to 2004 in place of the first melter stopped its operation by damage of a main electrode. JAEA has estimated that the damage was caused by accumulation of noble metal. Therefore, melter bottom structure was improved to get better drain ability of glass containing noble metal. Completing the melter replacement, vitrification operation was restarted in October 2004 and produced 88 canisters successfully until the end of March 2006. Through these experiences, JAEA made basic strategy to achieve stable TVF operation: keeping stable operation of the existing melter preventing adverse effect by noble metal accumulation and developing a new advanced melter with long lifetime preparing for future exchange as the third melter. Based on the basic strategy, JAEA made a decade development plan of necessary key technologies and has started the development since 2005.

New Melter Technology Development in Tokai Vitrification Facility

2008 ◽  
Author(s):  
Atsushi Aoshima ◽  
Tsutomu Ueno ◽  
Masao Shiotsuki
Keyword(s):  
High Performance ◽  
Technology Development ◽  
Liquid Waste ◽  
Life Time ◽  
Stable Operation ◽  
Radioactive Liquid Waste ◽  
Basic Strategy ◽  
Key Points ◽  
Long Lifetime ◽  
Reprocessing Plant

Concentrated high radioactive liquid waste (HALW) containing almost FP and TRU elements is stored temporarily in Tokai Reprocessing Plant (TRP) and then transferred and vitrified in Tokai Vitrification Plant (TVF). TVF entered hot operation in 1995 about twenty years later of the start of hot operation in TRP. In TVF, total 247 canisters have been produced so far and JAEA should vitrify a large amount of HALW stored in TRP hereafter. Through about ten year operation of TVF, JAEA have experienced a failure of the first melter and got a lesson that stable operation of a melter and development of a melter with long life time were key points for high performance operation of TVF. Based on these experiences, JAEA has made a basic strategy to achieve stable TVF operation; keeping stable operation of the existing melter preventing adverse effect by noble metal accumulation and developing a new advanced melter with long lifetime preparing for future exchange as the third melter. According to the basic strategy, JAEA made a decade development plan of necessary key technologies two years ago [1] and has been continuing development. In this paper, present situation of the development is described.

Radiation Effects on Hollandite Ceramics developed for Radioactive Cesium Immobilization

2003 ◽  
Vol 792 ◽  
Author(s):  
V. Aubin ◽  
D. Caurant ◽  
D. Gourier ◽  
N. Baffier ◽  
S. Esnouf ◽  
...  
Keyword(s):  
Radiation Effects ◽  
Liquid Waste ◽  
Fission Products ◽  
Radioactive Cesium ◽  
Radioactive Liquid Waste ◽  
Epr Spectrum ◽  
Paramagnetic Resonance ◽  
Γ Radiation ◽  
The Stability ◽  
High Level

ABSTRACTProgress on separating the long-lived fission products from the high level radioactive liquid waste (HLW) has led to the development of specific host matrices, notably for the immobilization of cesium. Hollandite (nominally BaAl2Ti6O16), one of the main phases constituting Synroc, receives renewed interest as specific Cs-host wasteform. The radioactive cesium isotopes consist of short-lived Cs and Cs of high activities and Cs with long lifetime, all decaying according to Cs+→Ba2++e- (β) + γ. Therefore, Cs-host forms must be both heat and (β,γ)-radiation resistant. The purpose of this study is to estimate the stability of single phase hollandite under external β and γ radiation, simulating the decay of Cs. A hollandite ceramic of simple composition (Ba1.16Al2.32Ti5.68O16) was essentially irradiated by 1 and 2.5 MeV electrons with different fluences to simulate the β particles emitted by cesium. The generation of point defects was then followed by Electron Paramagnetic Resonance (EPR). All these electron irradiations generated defects of the same nature (oxygen centers and Ti3+ ions) but in different proportions varying with electron energy and fluence. The annealing of irradiated samples lead to the disappearance of the latter defects but gave rise to two other types of defects (aggregates of light elements and titanyl ions). It is necessary to heat at relatively high temperature (T=800°C) to recover an EPR spectrum similar to that of the pristine material. The stability of hollandite phase under radioactive cesium irradiation during the waste storage is discussed.

scholarly journals Scaling-up production of plant endophytes in bioreactors: concepts, challenges and perspectives

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Seedhabadee Ganeshan ◽  
Seon Hwa Kim ◽  
Vladimir Vujanovic
Keyword(s):  
Crop Production ◽  
Process Development ◽  
Hazard Analysis ◽  
Scale Up ◽  
Process Technology ◽  
Lack Of Information ◽  
Agriculture Industry ◽  
Start Up ◽  
Plant Growth Promoting ◽  
Agriculture And Food

AbstractThe benefit of microorganisms to humans, animals, insects and plants is increasingly recognized, with intensified microbial endophytes research indicative of this realization. In the agriculture industry, the benefits are tremendous to move towards sustainable crop production and minimize or circumvent the use of chemical fertilizers and pesticides. The research leading to the identification of potential plant endophytes is long and arduous and for many researchers the challenge is ultimately in scale-up production. While many of the larger agriculture and food industries have their own scale-up and manufacturing facilities, for many in academia and start-up companies the next steps towards production have been a stumbling block due to lack of information and understanding of the processes involved in scale-up fermentation. This review provides an overview of the fermentation process from shake flask cultures to scale-up and the manufacturing steps involved such as process development optimization (PDO), process hazard analysis (PHA), pre-, in- and post-production (PIP) challenges and finally the preparation of a technology transfer package (TTP) to transition the PDO to manufacturing. The focus is on submerged liquid fermentation (SLF) and plant endophytes production by providing original examples of fungal and bacterial endophytes, plant growth promoting Penicillium sp. and Streptomyces sp. bioinoculants, respectively. We also discuss the concepts, challenges and future perspectives of the scale-up microbial endophyte process technology based on the industrial and biosafety research platform for advancing a massive production of next-generation biologicals in bioreactors.

Studies on hydrolysis and radiolysis of N,N,N′,N′-tetraoctyl-3-oxapentane-1,5-diamide

2002 ◽  
Vol 90 (3) ◽  
Author(s):  
Y. Sugo ◽  
Y. Sasaki ◽  
S. Tachimori
Keyword(s):  
Gamma Irradiation ◽  
Room Temperature ◽  
Degradation Products ◽  
Liquid Waste ◽  
Amide Bond ◽  
Radioactive Liquid Waste ◽  
Ether Bond ◽  
Nuclear Fuel Reprocessing ◽  
High Level ◽  
Fuel Reprocessing

SummaryHydrolytic and radiolytic stabilities of a promising extractant, N,N,N′,N′-tetraoctyl-3-oxapentane-1,5-diamide (TODGA), for actinides in high-level radioactive liquid waste from nuclear fuel reprocessing were investigated in air at room temperature. Hydrolysis by nitric acid was not observed, whereas radiolysis by gamma irradiation was notably observed. The radiolysis study showed that an amide-bond, an ether-bond, and a bond adjacent to the ether-bond tended to be broken by gamma irradiation, and dioctylamine and various N,N-dioctylmonoamides were identified as the main degradation products by GC/MS and NMR analyses. The

Benchmarking of Truss Spar Vortex Induced Motions Derived From CFD With Experiments

2005 ◽  
Author(s):  
John Halkyard ◽  
Senu Sirnivas ◽  
Samuel Holmes ◽  
Yiannis Constantinides ◽  
Owen H. Oakley ◽  
...  
Keyword(s):  
Scale Up ◽  
Vertical Cylinder ◽  
Reynolds Numbers ◽  
Full Scale ◽  
Scale Model ◽  
Current Direction ◽  
Test Results ◽  
Helical Strakes ◽  
Truss Spar ◽  
Scale Data

Floating spar platforms are widely used in the Gulf of Mexico for oil production. The spar is a bluff, vertical cylinder which is subject to Vortex Induced Motions (VIM) when current velocities exceed a few knots. All spars to date have been constructed with helical strakes to mitigate VIM in order to reduce the loads on the risers and moorings. Model tests have indicated that the effectiveness of these strakes is influenced greatly by details of their design, by appurtenances placed on the outside of the hull and by current direction. At this time there is limited full scale data to validate the model test results and little understanding of the mechanisms at work in strake performance. The authors have been investigating the use of CFD as a means for predicting full scale VIM performance and for facilitating the design of spars for reduced VIM. This paper reports on the results of a study to benchmark the CFD results for a truss spar with a set of model experiments carried out in a towing tank. The focus is on the effect of current direction, reduced velocity and strake pitch on the VIM response. The tests were carried out on a 1:40 scale model of an actual truss spar design, and all computations were carried out at model scale. Future study will consider the effect of external appurtenances on the hull and scale-up to full scale Reynolds’ numbers on the results.

Model-based evaluation of a new upgrading concept for N-removal

2002 ◽  
Vol 45 (6) ◽  
pp. 169-176 ◽  
Author(s):  
S. Salem ◽  
D. Berends ◽  
J.J. Heijnen ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Mathematical Modelling ◽  
Scale Up ◽  
Treatment Plant ◽  
Ammonia Concentration ◽  
Pilot Scale ◽  
Full Scale ◽  
Model Based ◽  
N Removal ◽  
Quantitative Basis ◽  
Treatment Concepts

Mathematical modelling is considered a time and cost-saving tool for evaluation of new wastewater treatment concepts. Modelling can help to bridge the gap between lab and full-scale application. Bio-augmentation can be used to obtain nitrification in activated sludge systems with a limited aerobic sludge retention time. In the present study the potential for augmenting the endogenous nitrifying population is evaluated. Implementing a nitrification reactor in the sludge return line fed with sludge liquor with a high ammonia concentration leads to augmentation of the native nitrifying population. Since the behaviour of nitrifiers is relatively well known, a choice was made to evaluate this new concept mainly based on mathematical modelling. As an example an existing treatment plant (wwtp Walcheren, The Netherlands) that needed to be upgraded was used. A mathematical model, based on the TUDP model and implemented in AQUASIM was developed and used to evaluate the potential of this bioaugmentation in the return sludge line. A comparison was made between bio-augmentation and extending the existing aeration basins and anoxic tanks. The results of both modified systems were compared to give a quantitative basis for evaluation of benefits gained from such a system. If the plant is upgraded by conventional extension it needs an increase in volume of about 225%; using a bioaugmentation in the return sludge line the total volume of the tanks needs to be expanded by only 75% (including the side stream tanks). Based on the modelling results a decision was made to implement the bioaugmentation concept at full scale without further pilot scale testing, thereby strongly decreasing the scale-up period for this process.

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