Radiochemistry Laboratory Research Articles

Metal ions binding by chelating ligands from new polymer bearing amidoxime functional groups

Chelating polymer materials are mainly used in analytical, industrial and radiochemical laboratories, but only to a limited extent in solving environmental problems. Metal pollution of the environment presents a unique problem, since metals are not subjected to biodegradation. The chelating resins containing amidoxime groups have been playing a vital role in environmental monitoring of toxic trace metals. The amidoxime chelating resins can be used for extraction of toxic metals in the environment and sewage waters. The possibility of uranium recovery from seawater has been studied in many countries, a particularly high number of publications come from Japanese scientists, which contain the synthesis of macroreticular resins bearing amidoxime groups, because of their use in extraction of uranium from seawater. 1‐4 Most of these papers involve the incorporation of a nitrile group into a polymer matrix, followed by the conversion of the nitrile group into an amidoxime group using the alkaline solution of hydroxylamine. Egawa et al. 5 prepared a macroreticular chelating resin containing amidoxime by reacting acrylonitrile-divinyl benzene copolymer with hydroxylamine. Kubota and Shigehisa 6 proposed a new route in which amidoxime groups were prepared by the reaction of cyanoethylcellulose and acrylonitrile grafted cellulose with hydroxylamine. Fetscher 7 described the extraction of metals from dilute solutions by poly(amidoxime) resin derived from fibrous homopolymers and copolymers of acrylonitrile. Divinylbenzene cross-linked poly(acryloamidoxime) resins were obtained and successfully used in the determination of trace metals in natural waters. 8,9 Most of the work centralised on the uranium extraction in sea water by poly(amidoxime) resin. There are very few articles published for transition metal uptake by poly(amidoxime) resin. This may first be introduced by the preparation of poly(amidoxime) chelating resin from polyacrylonitrile (PAN) grafted sago starch. In this report, the PAN grafted copolymer was used as a cheapest starting material to obtain the poly(amidoxime) resin and the binding property of the chelating resin was examined with a series of metal ions. The PAN grafted sago starch was prepared from acrylonitrile monomer and sago starch using the free radical initiating process according to the reaction mechanism suggested by Ceresa. 10 The grafting procedure was described elsewhere. 11 The optimum yield of PAN grafted copolymer at the concentration of ceric ammonium nitrate, acylonitrile, sago starch (AGU, anhydroglucose unit) and sulfuric acid were 9.52 〈 10 ‐3 , 0.506, 0.146 and 0.190 mol/l respectively, as well the reaction temperature and period were 50°C and 90 min, respectively. The conversion of the nitrile group into amidoxime was carried out by the treatment of hydroxylamine in an alkaline medium. According to the mechanism suggested by Schouteden, 12 the reaction of PAN with hydroxylamine is shown in Scheme 1, where P is the backbone polymer.

Radiochemistry in India

A major expansion in the experimental programme of Atomic Energy occurred with the establishment of Atomic Energy Establishment at Trombay (AEET). Along with the setting up of the India's first reactor APSARA, a prototype radiochemistry laboratory was set up at the Trombay site. This laboratory was to serve as a training ground for a team of chemists, chemical engineers and metallurgists in the handling of high radioactive substances. This prototype laboratory having an active area of 375 m 2 . and associated service area was fully commissioned and was operational by 1958. In view of high technology involved in the design and operation of a Class A radioactive laboratory, Dr. H. Bhabha sought the support of United Kingdom Atomic Energy Authority (UKAEA). This laboratory at south site of Trombay complex had two radioactive wings equipped with six fume hoods in each wing. In addition, there were a large number of β, γ boxes and glove boxes. There was a well equipped counting room with facilities for α and β counting and γ spectrometry with a 100 channel analyser. The experience gained during this period became useful in planning the future facilities such as plutonium laboratory at Fuel Reprocessing Plant, the Radiological Laboratories at Trombay, BARC, and similar laboratories at IGCAR. Initially, radiochemistry research programme was based on the availability of APSARA reactor for nuclear and radiation chemistry studies and plutonium, protactinium, and actinium obtained from UKAEA for research in actinide chemistry. Dr. M.V. Ramaniah who had taken over as Head, Radiochemistry Division in 1965 was the driving force for the completion and commissioning of radiological laboratories at Trombay around 1969. The chemistry wing of the new complex has 14 laboratories of size 7 × 10m, three low active laboratories of size 6 × 10m, a modern counting room equipped with state-of-the-art instruments, and an alpha tight hot cell with master slave manipulators. Each laboratory room was provided with a large number of fume hoods and glove boxes, conditioned fresh air supply with 10−12 air changes/hr, well managed liquid effluent system connecting all the laboratories and state-of-the-art health and safety devices for continuous monitoring of radioactivity. The alpha tight hot cell was commissioned for synthesis of transplutonium elements as well as burn up studies. The laboratory is equipped with a variety of modern instrumentation such as mass spectrometer, ESR spectrometer, modern spectrophotometer, thermal analyser, XRD system, and α and γ spectrometer. The area of research and development were also broadened with the availability of variable energy cyclotron at Calcutta and medium energy heavy ion accelerator Pelletron at TIFR, Mumbai. The area of research activities which are actively being carried out are (1) Nuclear chemistry, (2) Actinide and process chemistry, (3) Studies on solid state chemistry and spectroscopy of actinide and analytical spectroscopy, and (4) Training and services. This paper highlights some of the important achievements in the first two areas in brief.

ROBL – a CRG beamline for radiochemistry and materials research at the ESRF

The paper describes the Rossendorf beamline (ROBL) built by the Forschungszentrum Rossendorf at the ESRF. ROBL comprises two different and independently operating experimental stations: a radiochemistry laboratory for X-ray absorption spectroscopy of non-sealed radioactive samples and a general purpose materials research station for X-ray diffraction and reflectometry mainly of thin films and interfaces modified by ion beam techniques.

Long-distance transport of radionuclides between PET cyclotron and PET radiochemistry

At the Rossendorf PET Centre the PET cyclotron and the radiochemical laboratories are 500 m away from each other. The distance is bridged by a radionuclide transport system (RATS) whose details such as layout, technical parameters, control system and radiation protection are described along with our experience in long-distance transport of radionuclides.

Separation of iodine produced from fission with a porous metal silver column in99Mo production

In Argentina, at the Ezeiza Atomic Center,131I is produced by wet distillation of natural tellurium dioxide irradiated with thermal neutrons in a pool-type reactor. In order to recover the131I present in the production process of fission99Mo obtained by irradiation of UALx/Al targets (with 90% enriched uranium) a separation method was developed. Iodine isotopes can be separated from a sodium hydroxide solution containing fission products using a column filled with alternate beds of glass microspheres and porous metal silver. Tests with tracers were performed in radiochemical laboratory. Following this results, a series of tests with higher activities (3 TBq of99Mo and 0.7 TBq of131I) were carried out in hot cells. Molybdenum passes through the silver column, while131I retention was 92–97% in tracer test and 90% in optimised hot cell tests. This result depends on several facts that are discussed. An initial separation of iodine isotopes diminishes radiation damage on ion-exchange resin used in the subsequent molybdenum purification, improving its retention and elution yield.

Advanced separation of harmful metals from industrial waste effluents by ion exchange

Advanced separation methods of harmful metals from industrial waste effluents, i.e., radionuclides from nuclear waste solutions, transition metals from metallurgical waste effluents, developed at the Laboratory of Radiochemistry, are discussed.

North Korean Plutonium Production

In 1992, as part of its obligations under the Nuclear Non‐Proliferation Treaty, North Korea declared that it had earlier separated abut 100 grams of plutonium from damaged fuel rods removed from a 25 megawatt‐thermal (MWt) gas‐graphite reactor at Yongbyon. The plutonium was separated at the nearby “Radiochemical Laboratory.” Separated plutonium is the raw ingredient for making nuclear weapons, but 100 grams is too little to make a crude bomb. Following its inspections of North Korea's facilities, the International Atomic Energy Agency (IAEA) concluded that North Korea had separated more plutonium than it had declared to the Agency. However, the IAEA could not tell if the discrepancy was in grams or kilograms. Based on information gathered by intelligence agencies and IAEA inspections, North Korea may have already separated 6 to 13 kilograms of weapons‐grade plutonium, enough for one or perhaps two nuclear weapons. In spring 1994, North Korea unloaded the 25 MWt reactor. Our best estimate of the amount of ...

Out of the textbook and into the world: Student projects in the radiochemistry laboratory

A major objective of any laboratory course should be to stimulate students to extend their knowledge of the subject to specific problems. In the radiochemistry laboratory course at the University of Kentucky, we encourage students to make the transition from the textbook or laboratory manual to the “real” world through the use of a special project. This project, which typically replaces two normal laboratory exercises, is a short research problem that the student independently develops and executes. An overview of the incorporation of special projects into our radiochemistry laboratory course is presented.

Education in the nuclear sciences in Japanese universitites

Although there are 430 govemment and private universities in Japan, only a limited number of them have departments associated with nuclear science education. Moreover, mainly because of financial pressures, this association is often limited to government universities. Nuclear engineering departments are incorporated with only seven of the larger universities, and there are three institutes with nuclear reactors. In these facilities, education in reactor physics, radiation measurements, electromagnetic and material sciences, are conducted. In terms of radiation safety and radiological health physics, tem radioisotope centers and seven radiochemistry laboratories in universities play an important role. Virtually all of the financial support for nuclear education comes from the Japanese Govemment via the Ministry of Education, Science, and Culture. These are supplemented via private and corporate grants to various university faculty members. In addition to these universities, and private/corporate research institutes, The Japan Atomic Energy Research Institute teaches a short lecture course in nuclear science on a regular basis.

Future challenges in nuclear science education

The role of the Division of Nuclear Chemistry and Technology of the American Chemical Society in nuclear science education is reviewed, and suggestions for enhanced involvement in additional areas are presented. Possible new areas of emphasis, such as educational programs for pre-college students and the non-scientific public, are discussed. Suggestions for revitalizing the position of radiochemistry laboratories in academic institutions are offered.

The approach towards NAMAS accreditation for a radiochemical laboratory

With the prospect of commercial contracts occupying an increasing part of the workload of the laboratory when it became an Executive Agency on 2nd April 1990, a formal recognition of quality and standard of performance was considered to be a high priority. Many of the radiochemical laboratories in the UK are well known to each other, but convincing new customers of the ability to carry out analyses to a standard would be difficult to achieve without this recognition. Formal recognition of standing in the medical and pharmaceutical fields can be achieved through the Department of Health's Good Laboratory Practice’ (GLP) accreditation scheme. For a discipline involving more physical measurements the Department of Trade and Industry offers accreditation through the National Measurement Accreditation Service (NAMAS). This paper describes the work carried out by the Isotope Unit of the Biochemistry Department at CVL in preparing for an accreditation application. Accreditation was sought for the radiochemical determination of certain alpha, beta and gamma emitting radionuclides in milk. The preparation of both the laboratory staff and the paperwork is discussed.

Implementation of a quality assurance scheme in an environmental radiochemical laboratory in preparation for accreditation by the National Measurement Accreditation Service (NAMAS)

The Laboratory of the Government Chemist is undertaking a programme to improve the validity of analytical measurement in the United Kingdom and to achieve wide mutual acceptance of analytical data in Europe. Within this programme, the accreditation of laboratories by the National Measurement Accreditation Service (NAMAS) is strongly advised and supported. An account is given of how NAMAS is seen from a laboratory worker's point of view, reflecting the regulations and criteria necessary for accreditation. The paper then outlines a programme of work that the Environmental Radiochemistry Section at the Laboratory of the Government Chemist put forward for accreditation. Staged implementation of a quality assurance scheme is covered, giving a comprehensive insight into the issues that need to be addressed by an environmental radiochemical laboratory to meet accreditation.

The radiological services laboratory: Designed for the future

A new state of the art radiochemistry laboratory incorporating advanced design and environmental control elements has been constructed in Atlanta, Georgia. The design of the facility is oriented to the efficient production of analytical sample results which meet regulatory requirements while at the same time provides an atmosphere that is pleasurable for analysts and visitors alike. The laboratory building contains two separate and distinct laboratories under one roof. This allows the facility to handle samples with low levels of radioactivity on one side of the lab without fear of contamination of environmental work on the other side. Unlike most laboratories, this facility utilizes a scrubber system and liquid waste holdup system to prevent accidental releases to the environment. The potential spread of radioactive contamination is controlled through the use of negative pressure ventillation zones. Construction techniques, laboratory systems, instrumentation and ergonomic considerations will also be discussed.

The Quality Management System at the European Tritium Handling Experimental Laboratory

The main limitations of conventional Quality Assurance (QA) are discussed with reference to the operational phase of a radiochemical research laboratory. The paper suggests a broader approach utilising a Quality Management System (QMS) which focuses on the operational efficiency of a R&D organisation in terms of reliability, reproducibility, cost effectiveness and safety. The management’s role is presented with particular reference to the best fit of managerial style to the organisation’s mission, culture, personnel and surrounding environment. QMS policies and QA criteria are suggested for ETHEL to replace conventional QA requirements. Finally, guidelines for designing the ETHEL organisational structure are discussed.

Nuclear decay studies of rare-earth fission-product nuclides using fast radiochemical separation techniques

A facility for the rapid radiochemical separation of individual rare-earth fission product nuclides from mixed fission products has been developed at the Idaho National Engineering Laboratory (INEL). This facility, called the INEL ESOL (elemental separation on-line) facility, includes an electroplated spontaneously fissioning252Cf source, a He jet transport system to deliver short half-life fission products from the252Cf hot cell to the radiochemistry laboratory, and a high pressure liquid chromatograph for the individual separation of rare-earth radioelemental fractions. The fission product collection and separation instrumentation is interfaced to a microprocessor that controls valves, motors and other devices and monitoring instrumentation. The data acquistion instrumentation can be controlled from a signal originating from the microprocessor or initiated manually. The results of some recent decay scheme studies on153Pm and154Pm are reported.

A robotic sample changer for a radiochemistry laboratory

A Microbot Alpha robot has been interfaced to a Nuclear Data Model 680 multichannel analyzer (MCA) and computer to allow unattended accumulation and storage of gamma-ray spectra. Software was written in DEC RT-11 system language to control the robot, MCA and dual floppy disk system from a DEC LSI-11 microcomputer. Typically, 8 spectra are accomulated for 3 hours each, providing 24 hours of unattended operation for one detector or 12 hours for two detectors. The system has proven to be highly reliable and has eliminated the need for operator intervention after working hours.

Analytical viewpoint. The use of robots for automation in the radiochemical laboratory

Analytical viewpoint. The use of robots for automation in the radiochemical laboratory

Radiochemical neutron activation analysis determination of rare earth elements in geological materials with ppb sensitivity

Rare earth elements are determined, with ppb sensitivity, by radiochemical activation analysis using a fusion dissolution process and a quantitative group separation scheme, followed by radioassaying. Spectral interference is avoided, or corrected for, by repeating the counting operation with a delay of four to six weeks. This allows for the decay of shorter lived interfering isotopes such as155Eu on160Tb and175Yb on141Ce. The scheme is rapid, sensitive and uses standard radiochemical laboratory facilities and counters. It has been applied to a wide range of rocks and minerals and data for eleven rare earths (La, Ce, Nd, Sm, Eu, Gd, Tb, Ho, Tm, Yb and Lu) is presented here and compared with literature values.

Rapid radiochemical separation in neutron activation analysis : Part 1. The use of C 18-bonded silica gel and selective complexation for determinations of manganese, copper and zinc in biological materials

A rapid radiochemical separation method based on the removal of metal ions by columns of C 18-bonded silica gel after selective complexation by 8-quinolinol, ammonium pyrolidinedithiocarbamate or cupferron is described for the determination of manganese, copper and zinc in neutron-activated biological materials. The removal of the metal ions, either by adsorption or by a combination of filtration and adsorption on columns of C 18-bonded silica gel, was investigated to optimise the separation procedure. Analysis of several National Bureau of Standards and International Atomic Energy Agency biological reference materials demonstrated the effectiveness of this technique. The method is simple and reliable and readily adaptable in all radiochemical laboratories. Furthermore, columns of C 18-bonded silica gel have been successfully recycled a number of times without deterioration.

Mechanical shielded hot cell

It is planned to erect a mechanical shielded hot cell in the process hall of the Radiochemical Laboratory at Inchas. The hot cell is designed for safe handling of spent fuel bundles, from the Inchas reactor, and for dismantling and cutting the fuel rods in preparation for subsequent treatment. The biological shielding allows for the safe handling of a total radioactivity level up to 10,000 MeV-Ci. The hot cell consists of an α-tight stainless-steel box, 1.6 × 1.5 × 1.5 m 3, connected to a λ-shielded SAS, 0.9 × 1.0 × 1.6 M 3, through an air-lock containing a movable carriage. The α-box is tightly connected with six dry-storage cavities for adequate storage of the spent fuel bundles. Both the α-box, with the dry-storage cavities, and the SAS are surrounded by 200-mm thick biological lead shielding. The α-box is equipped with two master-slave manipulators, a lead-glass window, a monorail crane and Padirac and Minirag systems. The SAS is equipped with a lead-glass window, tong manipulator, a shielded pit and a mechanism for the entry of the spent fuel bundle. The hot cell is served by adequate ventilation and monitoring systems.