Radioactive Facility Research Articles

The LiFIRE experimental facility: Final design, construction and experimental campaign

Recently, nuclear fusion-related experiments and dedicated facilities worldwide relying on the usage of liquid metals are experiencing a renewed interest.This is the case of the International Fusion Materials Irradiation Facility – DEMO-Oriented Neutron Source (IFMIF-DONES), a radioactive facility which will use several cubic meters of pure liquid lithium as a target for deuterons to produce high neutron fluxes having an energy spectrum as effective as the expected fusion reactors. The primary mission of IFMIF-DONES will be to irradiate selected candidate structural materials for building a comprehensive database on fusion material properties.Generally, alkali metals, such as lithium, exhibit safety issues related to their chemical reactive nature and material compatibility. Due to the wide uncertainty regarding the lithium behavior confirmed by an extensive literature review, a dedicated experimental facility has been conceived to primarily study lithium ignition conditions in support of the licensing process of IFMIF-DONES. The ultimate purpose of the LiFIRE facility will be to demonstrate by means of experimental evidences the set of requirements on lithium fire protection to be applied to the final engineering design of IFMIF-DONES.This work describes the final design, construction and experimental campaign of the LiFIRE facility currently under development at CIEMAT's premises.

Implementation of Safety Aspects in IFMIF-DONES Design

Integration of safety aspects in IFMIF-DONES design is a main objective of EUROfusion and European Commission projects. IFMIF-DONES will be a radioactive facility of the first category, and stringent safety objectives must be achieved and demonstrated. A very low acceptable risk for the worker, the public and the environment is the main principle in the design phase. The progress of safety activities is performed iteratively as detailed engineering develops, taking into account the uniqueness of the facility: a high-power deuterons accelerator (125 mA, 40 MeV), a target of flowing liquid lithium, traps for activation products, a dedicated-design module for irradiated samples, a massive shielding cooled room with confinement function, and a number of conventional systems with safety functions. Several phases are developed: (i) identification of sources and materials at risk, radioactive and nonradioactive, subject to potential mobilization, (ii) failure mode analysis and effects of systems, starting at the functional level, and support with probabilistic analysis, (iii) identification of scenarios leading to unacceptable risk if unmitigated, (iv) proposal of layers of defense by means of safety-credited components and design features, (v) deterministic analysis of scenarios in support of requirements, and (vi) definition and demonstration of safety requirements charged to components.

Surface removal of stainless steel using a single-mode continuous wave fiber laser to decontaminate primary circuits

Removing radioactive contaminated metal materials is a vital task during the decommissioning of nuclear power plants to reduce the cost of the post-dismantling process. The laser decontamination technique has been recognized as a key tool for a successful dismantling process as it enables a remote operation in radioactive facilities. It also minimizes exposure of workers to hazardous materials and reduces secondary waste, increasing the environmental friendless of the post-dismantling processing. In this work, we present a thorough and efficient laser decontamination approach using a single-mode continuous-wave (CW) laser. We subjected stainless steels to a surface-removal process that repetitively exposes the laser to a confined region of ∼75 μm at a high scanning rate of 10 m/s. We evaluate the decontamination performance by measuring the removal depth with a 3D scanning microscope and further investigate optimal removal conditions given practical parameters such as the laser power and scan properties. We successfully removed the metal surface to a depth of more than 40 μm with laser power of 300 W and ten scans, showing the potential to achieve an extremely high DF more than 1000 by simply increasing the number of scans and the laser power for the decontamination of primary circuits.

Clearance of building of a former uranium concentrates plant

The decommissioning is the last stage in the shelf-life period of any nuclear or radioactive facility. The goal is the controlled removal of the source term in a way that the future use of the buildings decommissioned does not entail any radiological risk for both people and environmental according to a radiological criteria regulator approved. MARSSIM is the methodology followed by many countries to demonstrate compliance with these radiological criteria.This paper describes the adaptation of the MARSSIM methodology to demonstrate compliance of radiological criteria established by European Commisión recommendation (trivial dose equal to 10µSv·y−1, (Comision for European Communities, Radiation Protection 113. Recommended radiological protection criteria for the clearance of buildings and building rubble from the dismantling of nuclear installations, Luxembourg: Office for Official Publications on the European Communities, 2000). Particularly, it has been applied to a former U concentrate facility located in the heart of Madrid (Spain), at the site known today as CIEMAT. The obtained results guarantee that demolition rubbles can managed as non-radiactive waste and that there are not any radiological risk for people in case of building reuse.

Establishing levels of retained radioactivity in cats receiving radioactive iodine treatment.

Radioactive iodine (RAI) is considered the gold standard treatment for feline hyperthyroidism. Currently exposure limits to radiation are regulated by national legislation, therefore the length of the isolation period in hospital for cats receiving radioactive treatment varies according to the place where the radioactive facility is located. The aim of this study was to establish when retained radioactivity decreases in cats receiving subcutaneous I-131 to a level that would allow discharge of cats from the hospital while being compliant with current United Kingdom legislation. Clinical records of cats treated with subcutaneous I-131 were retrospectively reviewed. Radioactive emission rates were measured using an external probe. Retained radioactivity below 11 MBq at the point of discharge was required by the initial risk assessment to ensure that a 0.3 mSv dose constraint was maintained for owners following standard cat-owner contact restrictions. Average retained activity for each treatment regimen at the time of discharge was calculated. The biological half-life for iodine retention was also calculated. Overall, an end activity below 11 MBq was reached at day 11 in 49% of cats, and at day 13 in 91% of cats. These cats were allowed to be discharged according to UK legislation, as long as contact restrictions were applied at home for 2 weeks. Based on our study, an isolation period of 13 days before allowing discharge of cats treated with subcutaneous RAI (I-131) is compliant with current UK legislation.

Percepciones del impacto de la pandemia de COVID‑19 en las instalaciones radiactivas de Colombia

La pandemia de COVID-19 ha generado impactos a nivel mundial en la salud pública, la economía, el transporte, las comunicaciones, el trabajo, la tecnología y la vida cotidiana. De igual forma, las instalaciones radiactivas se vieron afectadas en su operación, lo que ocasionó la toma de decisiones relacionadas con la seguridad tecnológica y seguridad física.
 Se realizó un estudio exploratorio tipo encuesta para conocer las percepciones del impacto de la pandemia de COVID-19 en las instalaciones radiactivas de Colombia, excluyendo las operadas por el Servicio Geológico Colombiano. Se encontró que la pandemia ocasionó el cese de operación del 43,2 % de las instalaciones encuestadas, el 26,4 % reportó sobrecostos, el 4,8 % desvinculó trabajadores ocupacionalmente expuestos y el 0,8 % ha contemplado la posibilidad de clausurar la instalación. La investigación evidenció el potencial de los desarrollos tecnológicos para la supervisión remota de las instalaciones, así como, la importancia de intercambiar experiencias y lecciones aprendidas durante la pandemia para facilitar la toma de decisiones.

Selection of sites for the construction of radioactive waste disposal points

The article deals with the selection of sites for the construction of nuclear installations, radioactive waste disposal sites and other facilities for the use of nuclear energy. The review of modern approaches to the selection of sites for placement of near-surface radioactive waste disposal points shows that the system research in this area is not fully presented, and is mainly aimed at solving problems of an engineering-geological nature for the location area, as well as the choice of materials for engineering protection barriers. In this paper, using the example of radioactive waste disposal sites, we review the requirements set by the regulatory documents of the Russian Federation and the International Atomic Energy Agency in the field of site selection. The authors proposed additions to the methodology for selecting sites for the construction of low-and medium-level waste disposal sites based on the system and GIS analysis of the ALARA principles, as well as the method of weighted evaluation of criteria and their pairwise comparisons. The multi-criteria nature of the site selection problem is proposed to be described by GIS analysis of data with drawing the corresponding limiting and preferred requirements directly on the map of the area, which is shown in the article by the example of selecting sites for radioactive waste disposal points. Taking into account the necessary requirements at various stages of the life cycle, as well as their significance, can be assessed by weighted estimates and pairwise comparisons, followed by their introduction into the GIS analysis. This approach allows to choose rational options for placing potential sites, taking into account the life cycle of the object, in a rational way, with compliance with all necessary regulatory requirements.

Laser sterilization of hydroxyapatite implants as an alternative to using radioactive facility

Modern technology, including 3D printing, provides enormous potential for shape- and size-tailored treatments, especially in orthopedic surgery and dentistry. However, for a medical device produced in the clinical setting that is not compatible with autoclaving or gas sterilization, the choices are very limited, especially because there are a lot of obstacles to using a radiation facility to sterilize a few small-size devices. The goal of this study was to verify the efficacy of laser sterilization of discs made from hydroxyapatite (HA), a material that can be 3D printed and widely used as bone substitute. For this purpose, we compared sterilization efficacy for E. coli and S. mutans when using a range of laser, γ-ray, and e-beam irradiation. Furthermore, we compared biocompatibility by culturing adult stem cells and MC3T3-E1 on HA discs before and after irradiation. Irradiation by UV-C (266 nm) at 100 mJ/cm2 showed 3 kGy of γ-ray or e-beam equivalent sterilization efficacy, without causing physical or chemical changes in the HA discs. In conclusion, in addition to offering affordable maintenance costs, laser sterilization can be used in small-size facilities and can sterilize an object within nanoseconds; this demonstrates its potential to be used on custom small-size medical devices as an alternative sterilization technique that can replace autoclaving, gas sterilization, or the use of radiation facilities.

Neutron Activated 153Sm Sealed in Carbon Nanocapsules for in Vivo Imaging and Tumor Radiotherapy.

Radiation therapy along with chemotherapy and surgery remain the main cancer treatments. Radiotherapy can be applied to patients externally (external beam radiotherapy) or internally (brachytherapy and radioisotope therapy). Previously, nanoencapsulation of radioactive crystals within carbon nanotubes, followed by end-closing, resulted in the formation of nanocapsules that allowed ultrasensitive imaging in healthy mice. Herein we report on the preparation of nanocapsules initially sealing "cold" isotopically enriched samarium (152Sm), which can then be activated on demand to their "hot" radioactive form (153Sm) by neutron irradiation. The use of "cold" isotopes avoids the need for radioactive facilities during the preparation of the nanocapsules, reduces radiation exposure to personnel, prevents the generation of nuclear waste, and evades the time constraints imposed by the decay of radionuclides. A very high specific radioactivity is achieved by neutron irradiation (up to 11.37 GBq/mg), making the "hot" nanocapsules useful not only for in vivo imaging but also therapeutically effective against lung cancer metastases after intravenous injection. The high in vivo stability of the radioactive payload, selective toxicity to cancerous tissues, and the elegant preparation method offer a paradigm for application of nanomaterials in radiotherapy.

Integration of Safety in IFMIF-DONES Design

The IFMIF-DONES (International Fusion Material Irradiation Facility-DEMO Oriented NEutron Source) facility is being designed with the general objective of providing irradiation of representative samples of power fusion machine materials under prototypical conditions. A linear accelerator will deliver deuterons at high intensity to circulating lithium in a loop, which will produce neutrons capable of obtaining the required damage conditions. As a result of this process, radionuclides will be produced as a by-product, which is characterized by several degrees of mobility. Shielding and radiation protection measures will be required in the facility. IFMIF-DONES will be classified as a first class radioactive facility according to national regulations, with Spain being the European candidate to site the facility. Several aspects of the main safety instructions affecting the facility’s design are explained and discussed in this paper.

Total Workload for Radioactive Facilities with Volumetric Modulated Arc Treatment

In recent years, there have been major changes in radiotherapy, particularly in dose delivery for treatments using the techniques of Three-Dimensional Conformal Radiation Therapy (3D-CRT), Intensity-Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT). However, in the literature, no workload results for radiation therapy treatments performed exclusively with the VMAT technique were found. In this study, a new workload and a new VMAT factor will be proposed. For such, patient data originating from management and planning systems were acquired, such as dose values, monitor units, numbers of arcs per patient and number of hypofractionated treatments. The average clinical workload values for conventional treatments were 328 Gy/week, resulting in a VMAT factor of 1.97; similarly, for hypofractionated treatments, the clinical workload was 33Gy/week and the VMAT factor was 1.54. The total workload has a value of 596 Gy/week, less than the value used in the facility shielding design, 1250 Gy/week, and the average value of VMAT factor for conventional and hypofractionated treatments showed that a smaller amount of C should be used at facilities that perform exclusive VMAT treatment.

Abstract P3-03-21: Usefulness of sentinel lymph node biopsy by indocyanine green fluorescence method for cN0 breast cancer patients

Abstract Background. Indocyanine green (ICG) fluorescence method (ICG-f) has been recently widely used in sentinel lymph node (SLN) detection. The advantages of ICG-f are no radiation exposure, no limitation to use in high-volume medical centers without radioactive facility, and to confirm lymph flow as a real-time image from outside the body. ICG-f identified an average of 2.3-3.4 SLNs and the detection rate was 99%, compared to 1.7-2 SLNs by RI methods. Long-term observation after SNB using ICG-f has not been reported, including arm lymphedema as the complication of this method.We evaluate the usefulness of SLN biopsy (SNB) for cN0 breast cancer patients from data of multicenter cohort study on long-term results after negative SNB by ICG-f. Methods. Eleven hundred and thirty-two women were enrolled who had histologically proved clinical stage T1-4, pN0, M0 primary invasive breast cancer with SNB using ICG-f (ICG alone or combination of RI/blue dye method) sparing axillary lymph node dissection from May 2007 to December 2015. This study is retrospective, multicenter cohort study conducted at 6 centers in Japan. Primary endpoint is axillary recurrence rate. We analyzed the correlation with the axillary recurrence and adjuvant systemic therapy, adjuvant radiotherapy, and the clinicopathological characteristics. Secondary endpoint is lymphedema. Results and Discussion. The median follow-up time was 41 (range 21-117) months, and axillary recurrence was found in 6 patients (0.53%). Five out of 6 patients were not received standard adjuvant systemic therapy or adjuvant radiation therapy after breast conserving surgerybecause of patient's preference or old age. Lymphedema was identified only 4 patients in 632 patients. It is reported that axillary recurrence after SNB was 0.3-1.65%, which was consistent with our result. Lymphedema was not frequent in patients received SNB using ICG-f, because SLNs are removed along with lymphatic ducts in the limited area of axillary adipose tissue. Conclusion.Axillary recurrence after negative SNB using ICG-f was comparable to RI or blue dye method. It might be important to perform appropriate adjuvant medication or radiation therapy for preventing axillary recurrence after SNB using ICG-f. Next, ICG-f after neoadjuvant chemotherapy is to be investigated, because itis reported that removing more than 2 SLNs were associated with a lower likelihood of false negative ratio in patients with clinically node-positive disease converted to clinically node-negative after chemotherapy, and ICG-f might overcome this issue. Citation Format: Maeshima Y, Takahara S, Yamauchi A, Yamagami K, Sugie T, Yamashiro H, Kato H, Torii M, Takada M, Torii M. Usefulness of sentinel lymph node biopsy by indocyanine green fluorescence method for cN0 breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-21.

Abstract PD2-03: Sentinel lymph node mapping with dual tracer combination: Fluorescent fluorescein with methylene blue compared to radio active sulphur colloid with methylene blue: A randomised comparison

Abstract Objective-Fluorescein and methylene blue (FWMB) combined tracer is non-inferior to Tc99- Sulphur colloid and methylene blue (TWMB) in identification of sentinel lymph nodes in women with operable breast cancer. Rationale-Sentinel node biopsy (SNB) is the standard procedure for axillary nodal evaluation. Most authors recommend dual tracers, a radioactive dye tagged with large particulate matter like albumin or sulphur colloid and blue dye like lymphazurin, methylene blue or patent blue for identification of sentinel lymph nodes. In Asian countries like India, the availability of radioactive pharamaceutical and gamma probe facility are sparse. Hence, we have compared a combination of fluorescein and methylene blue with technetium and methylene blue in a two arm randomized controlled trial with non-inferiority hypothesis and 1:1 allocation ratio on 81 patients with operable breast cancer. The non inferiority margin was set at 5 %.The study was conducted in All India Institute of Medical Sciences, New Delhi from June 2015 to November 2016. The study included ladies with operable breast cancer of all histological types after getting informed written consent. Novelty- This is the first randomized trial comparing fluorescein with technetium sulphur colloid in sentinel lymph node biopsy in breast cancer . In the fluorescein and methylene blue arm, one ml of 20% fluorescein diluted with 4 ml of normal saline was injected in the periareolar region, half the dye injected intradermally and half in the sub areolar plane. One ml of 1% Methylene blue dye diluted in 4 ml normal saline was also injected in similar manner. It was followed by gentle massage for 5 minutes. An incision was made on lateral axillary skin crease and fluorescent or blue lymphatics dissected to the level of sentinel lymph nodes. Fluorescent lymphatics were identified with a blue light lamp (480 nm). Sentinel lymph node(s) were excised and sent for histopathological examination. Radioactive node was picked up by gamma probe. Results- The base line patient and tumour characteristics of the two groups showed no significant difference. Since it was a non inferiority trial, we performed per protocol analysis revealing the identification of sentinel nodes = 84.6% in both arms (effect size-zero and 90% confidence interval -13.4 to +13.4.). Results of subgroup analysis before and after chemotherapy and SNB done under local and general anaesthesia has been given in tables 1 and 2. Table 1. Identification of sentinel nodes (Per protocol analysis) TWMBFWMBEffect size (ninety percent confidence interval)Total33/39(84.6)33/39(84.6)0.0(-13.4,13.4)Prechemo patients26/29(89.7)26/30(86.7) Postchemo patients7/10(70)7/9(77.8)7.8(-25.2,+40.8)Local Anaesthesia23/25(92.0)22/23(95.7)3.7(-7.7,+14.9)General Anaesthesia10/14(71.4)11/16(68.8) Table 2. Identification of sentinel nodes (Intention to treat analysis) TWMBFWMBTotal33/39(84.6)33/40(82.5)Prechemo patients26/29(89.7)26/31(83.9)Postchemo patients7/10(70)7/9(77.8)Local Anaesthesia23/25(92.0)22/24(91.7)General Anaesthesia10/14(71.4)11/16(68.8) Conclusion- Fluorescein + methylene blue offer an attractive cheap method of SNB. Citation Format: Srivasatava A, Suresh J, Ranjan P, Kumar A, Kataria K, Dhar A, Vathulru S. Sentinel lymph node mapping with dual tracer combination: Fluorescent fluorescein with methylene blue compared to radio active sulphur colloid with methylene blue: A randomised comparison [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-03.

Current significant challenges in the decommissioning and environmental remediation of radioactive facilities: A perspective from outside the nuclear industry

This paper presents the results of implementing an extrajudicial environmental mediation procedure in the socioenvironmental conflict associated with routine operation of the El Cabril Disposal Facility for low- and medium- activity radioactive waste (Spain). We analyse the socio-ethical perspective of this facility's operation with regard to its nearby residents, detailing the structure and development of the environmental mediation procedure through the participation of society and interested parties who are or may become involved in such a conflict. The research, action, and participation method was used to apply the environmental mediation procedure. This experience provides lessons that could help improve decision-making processes in nuclear or radioactive facility decommissioning projects or in environmental remediation projects dealing with ageing facilities or with those in which nuclear or radioactive accidents/incidents may have occurred.

Оценка влияния Sr-90 на морфометрические показатели и уровень белков металлотионеинов в мягких тканях сухопутных моллюсков Bradybaena fruticum на биотопе регионального хранилища радиоактивных отходов

Оценка влияния Sr-90 на морфометрические показатели и уровень белков металлотионеинов в мягких тканях сухопутных моллюсков Bradybaena fruticum на биотопе регионального хранилища радиоактивных отходов

Impact of pressure of surrounding medium on plain water jet cutting of rocks

The goal of this contribution is to investigate problems connected with the application of plain water jets in surroundings between jet outlet and target differing from standard atmosphere. Two cases are especially interesting from the practical viewpoint. Application of water jets under the water level, i.e., in pressurized water: it is sometimes necessary to perform certain reparations on dam walls, bridge pillars, and other structures under the water level without emptying the dam or changing the river flow. The second case particularly involves water jets used for cleaning of chemical or radioactive facilities, which is much safer if done in underpressure. By these reasons, behavior of plain water jets on several different rock materials was tested inside the pressure vessel with the application of normal air pressure, air underpressure, and water overpressure. The effectiveness of rock material disintegration by water jet in various environmental conditions has been described. The depth of penetration decreases with increasing water overpressure, approximately with the second degree of the overpressure value. The cut depth decreases with the increasing value of certain material characteristics. The cut depth decreases also with decreasing pressure of air between nozzle outlet and sample surface. The dependence seems to be linear within the experimental range.

방사성폐기물 유리화설비의 배기가스 처리계통 운영 사례 연구

방사성폐기물 유리화설비의 배기가스 처리계통 운영 사례 연구

The Importance of Maintaining a Mosaic of Different Plant Communities for Arthropod Biodiversity Conservation at the Vaalputs Radioactive Waste-Disposal Site, Bushmanland, South Africa

Effective biodiversity monitoring and rehabilitation relies on a good understanding of the factors that influence species distributions and assemblage composition. Here we investigated the influence of plant community characteristics on arthropod diversity, abundance and community composition at the radioactive waste-disposal facility of the South African Nuclear Energy Corporation (NECSA), Northern Cape Province. Plant alpha-diversity and cover was similar between all five plant communities surveyed. Similarly, total arthropod alpha-diversity did not differ between these plant communities. In contrast, arthropod abundance differed between the different plant communities and was negatively correlated with plant alpha-diversity and positively correlated to vegetation cover. Also, more beta-diverse plant communities did not necessarily support greater beta-diversity of arthropods. However, different plant communities generally had different arthropod communities. This highlights the importance of maintaining a mosaic of different plant communities for the effective conservation of arthropod biodiversity in this semi-arid region.

放射性廃棄物処分施設におけるセメント系材料の溶脱モデルと溶解変質評価

放射性廃棄物処分施設におけるセメント系材料の溶脱モデルと溶解変質評価

Establishment and Validation of a Non-Radioactive Method for In Vitro Transcription Assay Using Primer Extension and Quantitative Real Time PCR.

Primer extension-dependent in vitro transcription assay is one of the most important approaches in the research field of gene transcription. However, conventional in vitro transcription assays incorporates radioactive isotopes that cause environmental and health concerns and restricts its scope of application. Here we report a novel non-radioactive method for in vitro transcription analysis by combining primer extension with quantitative real time PCR (qPCR). We show that the DNA template within the transcription system can be effectively eliminated to a very low level by our specially designed approach, and that the primers uniquely designed for primer extension and qPCR can specifically recognize the RNA transcripts. Quantitative PCR data demonstrate that the novel method has successfully been applied to in vitro transcription analyses using the adenovirus E4 and major late promoters. Furthermore, we show that the TFIIB recognition element inhibits transcription of TATA-less promoters using both conventional and nonradioactive in vitro transcription assays. Our method will benefit the laboratories that need to perform in vitro transcription but either lack of or choose to avoid radioactive facilities.