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International Conference on the Safety of Radioactive Waste Management (RWM) Session 4: Post-Accident Waste Management – Lessons Learned and Preparedness Poster Presentation / 3 Posters
Transcript of International Conference on the Safety of Radioactive ... Documents... · International Conference...
International Conference on the Safety of
Radioactive Waste Management (RWM)
Session 4: Post-Accident Waste Management –
Lessons Learned and Preparedness
Poster Presentation / 3 Posters
IAEA International Conference on the Safety of Radioactive Waste Management, Vienna, Austria, 21–25 November 2016
Srinivasa Reddy Mallampati,a* Yoshiharu Mitoma,b Cristian Simionc
Potential Nano-Fe/Ca/CaO Composite Enabled Environmental Remediation Technologies for Radioactive Waste
aDepartment of Civil and Environmental Engineering, University of Ulsan, Ulsan, Republic of Korea bDepartment of Environmental Sciences, Prefectural University of Hiroshima, Shobara, Japan cPolitehnica University of Bucharest, Department of Organic Chemistry, Bucharest, Romania
*Corresponding Author: Phone/Fax:+82-52259-1412/2629; Email address: [email protected]
Environmental Nanotechnology
& Waste Treatment Laboratory
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Conta
m inated
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soil/w
aste*
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In Japan, the major environmental concern on the radioactive cesium (137Cs) deposition and its
contamination due to the emission from the Fukushima Daiichi Nuclear Power Plant showed up after a
massive quake on March 11, 2011. Many fallout of radioactive Cs generated a large amount of various
wastes (soil, water, ash, sediment/wide range of concentration), therefore we should develop various
methods and devices adapted to all polluted situations. Fukushima prefecture exceed the government’s
safe limit of 2500 Bq/kg of cesium137 in soil. According to the Japan science ministry about 8 percent of
the country’s land has been contaminated with levels higher than 10,000 Bq/m2 of cesium137 a threshold
that Japan’s science ministry defines as affected by a nuclear accident. By the end of March 2012, ash
containing 100,000 to 140,000 becquerels per kilogram (Bq kg−1) of (137Cs) was recorded. High levels of 134Cs and 137Cs are also present in incineration ash from normal garbage. Temporary disposal sites for
incinerated ash containing 137Cs are rapidly filling up. No alternative landfills are available. During and
after the 30 years it takes for 137Cs to decay by half, each time it rains, 137Cs deposited will be washed
down to where people live. Therefore, the cesium fixation and immobilization in contaminated soil/ash is
recognized to be one of the most difficult problem solved by taking advantage of suitable technologies.
Present study, concern these problems by applying potential Nano-Fe/Ca/CaO Composite Enabled Environmental Remediation Technologies for Radioactive Waste
PAPER NUMBER #46
The treatment of highly radioactive liquid waste
originating from a severe accident at a VVER 440
NPP V. Havlová1. V. Brynych1, L. Szatmáry1, P. Franta1, M. Gajdoš2
1ÚJV Řež, a.s., Husinec, Czech Republic, 2Slovenské elektrárne, a.s., Bratislava,
Slovak Republic; [email protected]
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a summary of a design concept for a modular unit that
can be used for the treatment of large volumes of
radioactive waste produced as a consequence of a severe
accident of a VVER 440 NPP
one of a number of post-accident measures following the
Fukushima Daichi accident
accident coolant water: 10 000 m3; H3BO3 15g/l, N2H4
0.8g/l, KOH + NaOH up to 3.3g/l; wall alkalies: K approx.
0.2g/l and Ca approx. 0.3g/l; mechanical impurities up to
0.7mm in diameter 0.1 – 0.2g/l
main contaminants: 137Cs, 90Sr, actinides
the modular unit is made up of three main parts: a
sorption unit (mordenite, clinoptilolite, Fe2O3, TiO2)
vitrification module (vitrification up to up to 1050ºC)
gaseous capture module
•FIG. 1. Modular decontamination system concept.
FIG. 1. Modular decontamination system
concept.
Approaches of Selection of Adequate Conditioning Methods
for Various Radioactive Wastes in Fukushima Daiichi NPS Y. Meguro1,2, A. Nakagawa1,2, J. Kato1,2, J. Sato1,2, O. Nakazawa1,2, T. Ashida1,2 1Japan Atomic Energy Agency, Tokai, Japan, 2International Research Institute for Nuclear Decommissioning, Tokyo, Japan
• A variety of radioactive wastes are being generated in decommissioning of 1F.
• These wastes differ in type and show different chemical composition and radioactive inventory from those of
wastes from conventional commercial NPP.
• Conditioning methods of the wastes have to be developed toward disposal of them.
It is important to select suitable conditioning methods of high general versatility and to apply them to the wastes
as many as possible.
A screening way that is newly proposed to narrow down the several applicable conditioning methods from the
viewpoint of technical feasibility using the findings of the existing methods and the results of fundamental
solidification tests.
Conditioning Method Screening Approach
Study of existing waste
conditioning methods
Evaluation of characteristics of
1F wastes
Radioactive Waste
A-1: Feasibility evaluation of pre-treatment method
A-2: Characterization of treated waste
No A: Judgement of pre-treatment
Yes
B: Judgement of solidification
B-1: Feasibility evaluation of solidification method
No
Yes
B-1-1: Method only preparing solidified waste
B-1-2: Method directly preparing
waste package
B-1-1-1: Characterization of solidified waste
B-2: Feasibility evaluation of immobilization method
B-3 Characterization of waste package
Findings Synthetic Wastes
Fundamental
Solidification Tests
13 wastes were picked up
cementation,
geopolymerization,
vitrification,
melt-solidification,
sintering solidification
From contaminated water
treatment devices
Results
The screening flow was proposed to confirm the feasibility of the conditioning methods.
A trial screening test was conducted for the sludge.
Several issues and missing information were extracted from the trial test.
The priority of the issues may be different for each waste, and therefore the priority has to be decided individually.
Background
Objective
Conclusion
Judge items at the point and criteria at the steps in the screening flow will be described at Poster session. Also results of trial screening using a sludge waste will be shown.
Pilot Screening Flow
ID-139
Thank you!
