Removal of silver and antimony radionuclides from low-level liquid radioactive waste of a research reactor through different scavenging precipitations

2004 ◽  
Vol 92 (7) ◽  
Author(s):  
F. Jan ◽  
M. Aslam ◽  
S. D. Orfi ◽  
A. Wahid

SummaryAfter upgrading the Pakistan Research Reactor-1, the amount of liquid waste and its increased radioactivity content necessitated a pre-disposal treatment to bring the activity down to disposal limits. Amongst several radionuclides in the waste,

Author(s):  
Juan Zhao

Radioactive wastes are produced within the nuclear fuel cycle operations (uranium conversion and enrichment, fuel fabrication and spent fuel reprocessing). Evaporation is a proven method for the treatment of liquid radioactive waste providing both good decontamination and high concentration. Two technical designs of nuclear facilities for low-level liquid radioactive waste treatment are presented in the paper and the evaluation of both methods, as well. One method is two-stage evaporation, widely used in the People’s Republic of China’s nuclear facilities; another is two evaporator units and subsequently ion exchange, which is based on the experience gained from TIANWAN nuclear power plant. Primary evaporation and ion exchange ensure the treated waste water discharged to environment by controlling the condensate radioactivity, and secondary evaporation is to control concentrates in a limited salt concentration.


Author(s):  
David P. Field ◽  
Jim Stephens

Basic Technical Details: Displacement: 5000 tonnes; Width: 23.2m; Height: 6.6m; Length: 65m; Draught: 3.5m; Processing Throughput: 7000m3/year. In October 1993, the Governments of Japan and the Russian Federation signed an Intergovernmental Agreement to reduce the threat of nuclear weapons in the Former Soviet Union. Towards achieving this goal, the Japanese Government had initially allotted $100 million towards, which was increased to $200 million in 1999. The main objective of the Suzuran project is to process low-level liquid radioactive waste, which has been in storage for some years, and prevent it from being dumped into the seas shared by Japan and Russia. The construction and completion of the Suzuran, in the Russian Far East, is the brainchild of the Japanese Government, and is the first successful international project of its kind in Russia. Suzuran neatly solves the problem of making safe the liquid radioactive waste being derived from general purpose and missile nuclear submarines of the Russian Pacific Fleet as they are decommissioned and dismantled. The project was administered by the Technical Secretariat of the Japan-Russia Committee for Co-operation on Reducing Nuclear Weapons, who appointed Crown Agents as their agent and RWE NUKEM as their Technical Consultants to manage the project on a day to day basis and oversee the tender, construction and commissioning. This project is unique and complex in that it is, in reality, two projects. Firstly, the construction of a sea-going barge and, secondly, the construction of a complex radioactive liquid waste processing facility. Changes in the Russian Radiation Regulations during the course of the project, required the design to be altered significantly; for example, the facility had to be mounted within the structure of the vessel. Numerous regulators, design and testing institutes were involved throughout the project, to ensure it complied with both Russian and International regulations. Suzuran is the only floating complex that can operate independently for up to 30 days away from base. It is also exceptional in having the greatest throughput capacity of any project of its type and in being fully actively commissioned and licensed to operate, as part of the original contract. Other similar projects, which have a lower throughput and are land-based, have been handed over prior to completion of active commissioning. The international project was particularly complex since it involved not only Japan and Russia but also a Japanese-American contractor, who subcontracted the construction work to Russian shipyards. The Amurski Shipyard at Komsomolsk-na-Amur constructed the Vessel and the processing Facility was constructed in America and shipped to Russia where it was installed on the Barge. The Barge was then towed down the Amur River and down the Russian East Coast to Bolshoi Kamen where it was inactively and actively commissioned. The completed Barge was completed and is now operating, following a one-year warranty period. The project required everyone’s close co-operation and understanding. Particularly onerous was the need to comply with comprehensive Russian regulations, both for sea-going vessels as well as for nuclear facilities. This is a success story in itself. The official Handover ceremony of Suzuran was held in November 2000 and is now operating at the Far Eastern Shipyard, Zvezda. This paper will describe the history and process involved in establishing the Barge project for the treatment of Low Level Liquid Radioactive Waste.


Author(s):  
Tadashi Tokuhiro ◽  
Josh W. Carey ◽  
Massimo Bertino ◽  
Akira Tokuhiro

Within the management of radioactive waste, we sought to consider a new approach radioactive hazardous waste processing in aqueous or similar (low-level waste; LLW) forms LLW and in fact, ‘contaminants of concern’ is often stored as diluted aqueous solutions of radioactive (or non) elements and contained in storage containers. One of the general problems associated with mixed liquid waste is the lack of an efficient, effective, and inexpensive means of processing (separating) its constituents. Two of the objectives in processing solid, radioactive laden liquid LLW are as follows: 1) to separate/extract the radioisotopes from the rest of the mixed constituents, and 2) to produce stable solidified forms encapsulating radioactive elements. Recent R&D in the physical chemistry of gel materials, have identified promising approach to simultaneously achieve the above objectives. That is, by utilizing and manipulating the physicochemical properties of various silica- and polymer-based gels at the nanoscale, we have demonstrated a process by which to specific chemical species are encapsulated.


2012 ◽  
Vol 1475 ◽  
Author(s):  
Grazyna Zakrzewska-Trznadel ◽  
Marian Harasimowicz ◽  
Agnieszka Miskiewicz ◽  
Agnieszka Jaworska-Sobczak

ABSTRACTThe first step in the processing of low- and medium-level liquid radioactive waste is the reduction in the volume of liquid containing small concentrations of radionuclides. Various methods for concentration of radioactive waste have been studied and developed at the Institute of Nuclear Chemistry and Technology, including membrane processes. Reverse osmosis was implemented at the Radioactive Waste Management Plant. Other methods such as ultrafiltration, membrane distillation, adsorption and different integrated processes were studied in the scope of national and international projects.This paper presents the results of research performed at Institute of Nuclear Chemistry and Technology in Warsaw concerning radioactive liquid waste treatment and the programs of implementation of these methods at nuclear centers producing such wastes, as well as the plans for the utilization of the knowledge and experience and designs of schemes for radioactive waste management in future nuclear power industry. The integrated system developed on the basis of research will be a prototype for further implementation.


Author(s):  
Hee Reyoung Kim ◽  
Wanno Lee ◽  
Kun Ho Chung ◽  
Mun Ja Kang ◽  
Dong Gyu Lee ◽  
...  

The radioactivity of 14C of the graphite samples from the dismantled Korea Research Reactor 1&2 (the KRR-1&2) site was analyzed and proposed to be disposed of as a low level radioactive waste rather than self-disposed of. The graphite wastes, with a weight of seven tons, have been generated during the dismantling of a research reactor with a capacity of one MW from 1995 to 2006. The graphite was used as a moderator for the research reactor and so has been radioactivated by thermal neutron. It was thought that the graphite wastes mainly included a radioisotope of stable carbon, 14C, a pure beta emitter with a half life of 5,730 years and with a maximum decay energy of 156 keV. Therefore, it has been requested to see whether the dismantled graphite radioactive wastes including 14C can be self-disposed of or not. In the present study, the radioactivity of 14C in the graphite sample used in the research reactor was analyzed by using a commercialized high temperature furnace and a Liquid Scintillation Counter (LSC). The combustion temperature of the furnace was five hundred degrees centigrade and especially the temperature in the catalyst region was eight hundred degrees centigrade. The recovery from the furnace was 95% for 14C and the LSC had a quenching efficiency of approximately 66%. Carbosorb was used as a trapping solution for 14C. The radioactivity of 14C was measured by a LSC through the procedure of a pre-treatment such as the combustion of a sample in the temperature range of 500–800 degrees centigrade by a high temperature furnace, trapping of 14C into carbosorb and cocktailing it with a scintillator. The radioactivity was analyzed to have a concentration with a value of much more than a domestic legal limit for a self-disposal. And an individual effective dose rate estimation was also carried out. Finally, it is suggested that the graphite wastes from the dismantled research reactor should be disposed of at a low level radioactive waste disposal site and monitored.


2010 ◽  
Vol 5 (2) ◽  
pp. 238-242 ◽  
Author(s):  
Younjin Park ◽  
Won Sik Shin ◽  
G. Sankara Reddy ◽  
Soo-Jeong Shin ◽  
Sang-June Choi

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Vinod Vellora Thekkae Padil ◽  
Michael Rouha ◽  
Miroslav Černík

Liquid radioactive waste is a common by-product when using radioactive isotopes in research and medicine. Efficient remediation of such liquid waste is crucial for increasing safety during the necessary storage of the material. Herein, we present a novel Gum Karaya stabilized magnetite for the efficient removal of radioactive phosphorus32P from liquid radioactive waste. This environmentally friendly material is well suited to be used as a nanohydrogel for the removal of liquid waste, which can then be stored in a smaller space and without the risk of the spills inherent to the initial liquid material. The maximum adsorption capacity of the GK/M in this study was found to be 15.68 GBq/g. We present a thorough morphological characterization of the synthesised GK/M, as well as a discussion of the possible phosphorus adsorption mechanisms.


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