Academic literature on the topic 'Radioactive substances Heat'

This study applies a thermo-elasto-plastic-creep finite element procedure to the analysis of an accidental behavior of nuclear fuel as well as normal behavior. The result will be used as basic data for the robust design of nuclear power plant and fuels. We extended the range of mechanical strain from small or medium to large adopting the Hencky logarithmic strain measure in addition to the Green-Lagrange strain and Almansi strain measures, for the possible large strain situation in accidental environments. We found that there is a critical heat generation after LOCA without ECCS (event category 5), under which the cladding of fuel sustains the internal pressure and temperature for the time being for the rescue of the power plant. With the heat generation above the critical value caused by malfunctioning of the control rods, the stiffness of cladding becomes zero due to the softening by high temperature. The weak position of cladding along the length continuously bulges radially to burst and to discharge radioactive substances. This kind of cases should be avoid by any means.

Safety is an issue that is of considerable concern in the design, operation and development of a nuclear reactor. Therefore, the method of analysis used in all these activities should be thorough and reliable so as to predict a wide range of operating conditions of the reactor, both under normal operating conditions and in the event of an accident. Performance of heat transfer to the cooling of nuclear fuel, reactor safety is key. Poor heat removal performance would threaten the integrity of the fuel cladding which could further impact on the release of radioactive substances into the environment in an uncontrolled manner to endanger the safety of the reactor workers, the general public, and the environment. This study has the objective is to know is profile contour of fluid flow and the temperature distribution pattern of the cooling fluid is water (H2O) in convection in to SMR reactor with fuel sub reed arrangement of hexagonal in forced convection. In this study will be conducted simulations on the SMR reactor core used sub channel hexagonal using CFD (Computational Fluid Dynamics) code. And the results of this simulation look more upward (vector of fluid flow) fluid temperature will be warm because the heat moves from the wall to the fluid heater. Axial direction and also looks more fluid away from the heating element temperature will be lower.

Human health is a state of complete physical, mental and social well-being. Good health also includes physical health, mental health, intellectual health, spiritual health, and social health. A person goes to health when his body is healthy and healthy and calm.Pollution is a kind of disease through age, water, dust, etc. not only in humans' bodies, but also on the animals, animals, animals, trees, animals and animals. Fatigue, cough, throat disease, cardiovascular disease, kidney disease, chest pain etc.Pryavarnkopradusitkrnewaleanekpramuk Praduskhakpraduskvepdarthhajinhenmnushy Bnataha, Upyogkrtahaawrantmen Seshbagkopryavarnmenfenkdetahakpryavarnkopradusitkrnewalapramuk Pdarthjmahuyepdarthjase- smoke, dust, grit, Gradi, Rasyanikpdarthjase-Ditrjents hydrogen fluoride, Fasginadi, Dhatuyenjase-iron, mercury, zinc, Sisaadi, Gasjase-Kaॅrbnmonaॅksaid, Slfrday oxide, ammonia, chlorine, Florinadi , Fertilizers such as urea, potassic etc., pasticides such as DTM herbicides, insecticides etc., aerated sludge, sound heat, radioactive substances. मानवस्वास्थ्य एक पूर्ण शारीरिक, मानसिकऔरसामाजिक खुषहाली की स्थितिहै।अच्छेस्वास्थ्य में शारीरिकस्वास्थ्य, मानसिकस्वास्थ्य, बौद्धिक स्वास्थ्य, आध्यात्मिकस्वास्थ्य औरसामाजिकस्वास्थ्य भी शामिलहै। एक व्यक्तिकोस्वस्थतबकहांजाताहैजबउसका शरीरस्वस्थऔरमनसाफऔर शांतहो।प्रदूषण एक प्रकारकाजहरहैजोवायु, जल, धूलआदि के माध्यम से न केवलमनुष्य के शरीरमेंप्रवेषकरउसे रूग्णबनादेताहैवरन् जीवजन्तुओं, पशुपक्षियों, पेड़पौधेओरवनस्पतियोंकोभीनष्टकरदेताहै।प्रदूषणअनेकभयानकबिमारियोंकोजन्मदेताहै।जैसे-कैंसर, तपेदिक, रक्तचाप, दमा, हैजा, मलेरिया, चर्मरोग, नेत्ररोग, कान के रोग, स्वाइन फ्लू, सिरदर्द, थकान, खांसी, गले की बिमारी, हृदय संबंधीरोग, वृक्करोग, सीनेमेंदर्दआदि।पर्यावरणकोप्रदूषितकरनेवालेअनेकप्रमुख प्रदूषकहै।प्रदूषकवेपदार्थहैजिन्हेंमनुष्य बनाताहै, उपयोगकरताहैऔरअंतमें शेषभागकोपर्यावरणमेंफेंकदेताहै।पर्यावरणकोप्रदूषितकरनेवालाप्रमुख पदार्थजमाहुयेपदार्थजैसे- धुआं, धूल, ग्रिट, घरआदि, रासयानिकपदार्थजैसे-डिटरजेंटस् हाइड्रोजन फ्लोराइड, फास्जीनआदि, धातुयेंजैसे-लोहा, पारा, जिंक, सीसाआदि, गैसजैसे-काॅर्बनमोनाॅक्साइड, सल्फरडाॅय आॅक्साइड, अमोनिया, क्लोरिन, फ्लोरिनआदि, उर्वरकजैसे यूरिया, पोटाषआदि, पेस्टीसाइड्सजैसे-डी.टी.टीकवकनाषी, कीटनाषीआदि, वाहितमलजैसे-गंदापानी, ध्वनिउष्मा, रेडियोंएक्टिवपदार्थहै।

The benchmark experiments of Adolfo de Bold and Harald Sonnenberg revealed that heart atria contained a substance or substances (atrial natriuretic factor) which when injected into rats caused a profound diuresis, natriuresis, and fall in blood pressure. Acid extraction and purification of atrial natriuretic factor resulted initially in the purification of a low molecular weight peptide containing a disulfide bond. This peptide was named cardionatrin I. Amino acid sequencing of less than 1 nmol of cardionatrin I revealed it to be a 28-residue peptide with the following structure: [Formula: see text]The position of the disulfide bond was verified by a radioactive method. From the sequence of complementary DNA for atrial natriuretic factor, the 28-residue peptide was shown to be the C-terminal portion of a larger protein called pro-atrial natriuretic factor. The discovery and characterization of atrial natriuretic factor substantiated the idea that the heart atria serve in an endocrine capacity.

Perfusion of Langendorff rat hearts with [14C]adenosine yields an acid-insoluble, radioactive product whose concentration falls during ischaemia. The properties of the substance show that it is a polyribonucleotide. It is suggested that it may be mitochondrial poly A acting as a storage form of adenine nucleotides.

At present, at the Chornobyl NPP, the main building of the general-purpose storage system for spent nuclear fuel is the "wet type" storage of spent nuclear fuel number 1 (SNF-1), designed for receiving and storing spent nuclear fuel. In the light of the post-Fukushima events, the task of increasing the explosion and fire safety is a priority direction of the Chornobyl NPP operation. SNF-1 should meet the current requirements of safety regulatory documents, both under normal operating conditions and during emergency situations. Among the emergencies that are likely to occur in the SNF-1 repository, the occurrence and development of fire in the interior space of reinforced concrete blocks should be considered. This condition is conditioned by the extraordinary importance of this radiation-hazardous object. An explosion on SNF-1 may occur, mainly due to violation of the rules of operation and fire safety, as well as in the event of malfunctions or failures of individual systems. Thus, the problem of providing explosion and fire safety on SNF-1 is extremely relevant. The purpose of this work was to calculate the study of the formation of radionuclide hydrogen and its explosion in the premises of SNF-1. Methods. Measurement, comparison, system analysis, physical and mathematical modeling. Results. The main purpose of ensuring the explosion and fire danger of SNF-1 is to prevent the uncontrolled development of nuclear reactions and the spread of radiation. In the case of irradiation of water with low ionization radiation (for example, by gamma rays), the formation of radicals prevails, whereas for radiation with high ionization density (for example, α- and β-particles, splinters of division), the formation of molecules becomes more important. In a nuclear reactor where there are different types of radiation (γ-rays and high-energy protons formed during interaction with neutrons), both of these reactions take place simultaneously. Radicals H and OH are extremely reactive substances that are rapidly interconnected with the products formed as a result of the reaction. In the case of radioactive contamination of water in open containers filled with air and does not contain any active acceptors of OH radicals at appreciable concentrations, the observed hydrogen output is usually equal to 0.1-0.2 molecules/100 eV, which is significantly less the initial release of hydrogen formation. The larger the vessel in height, the greater the likelihood of this reaction compared with the likelihood of removing hydrogen from the liquid phase. But if we organize a non-equilibrium open system by forcing the removal of hydrogen from water, for example, by bubbling an inert gas, then the rate of its removal will exceed the rate of chemical decomposition. In this case, the hydrogen yield will increase and at the boundary it will be equal to the initial yield (unless, of course, there are no impurities of organic substances in the water, the radiolysis of which leads to the formation of molecular hydrogen). Therefore, to calculate the rate of formation of radio-hydrogen hydrogen in the reservoir basin water, the initial yield is used, that is, the maximum possible rate of hydrogen generation is calculated. Since the radioisotopes of water in the basin are mainly due to gamma radiation (beta and alpha radiation are delayed by the shells of the fuel assemblies and their energy is transferred to heat), the initial yield of the radiolytic formation of hydrogen is 0.45 molecules/100 eV. Under normal operation of SNF-1 in the basement area, the accumulation of radioactive hydrogen is eliminated at the expense of the work of the exhaust ventilation system of the surface area. The main factors determining the conditions for the formation of an explosive gas mixture based on hydrogen are the amount of stored spent fuel and the volume of water and air in the space where spent SNF is stored. The calculation is made from all sources of γ-radiation with a uniform distribution by source volume. For calculation, the main radionuclide composition of fuel in the lower beam of the fuel element was used in the case of holding 20 years and the burning depth of 24 MW×day/kg. The estimated value of the power absorbed by the water in terms of the total spent fuel, is I=1,098×1024 eV/(m3/h). The failures of the equipment of the complex of the storage system, caused by both external and internal events, which lead to failures of the ventilation system of the surface of the basin, can lead to the accumulation of radio-hydrogen hydrogen in the air volume of SNF-1 premises in the absence of ventilation systems. The break in the operation of the ventilation system, during which it is theoretically possible to achieve the lower limit of the explosive concentration of hydrogen, may be 12 days. In order to ensure explosion-proof safety in the pool of pools, it is necessary that the concentration of radiolytic hydrogen in the air be lower than the lower concentration limit of hydrogen explosion in a mixture with air (~ 4% of volume) with a stockrate of 10. Thus, the concentration of hydrogen should not exceed 0.4% of the permissible concentration of hydrogen in the air to exclude the formation of an explosive mixture with oxygen. For the case of placing all spent nuclear fuel (21284 units) in the compartments of the catchment pool 1-5, W(H2)=1.34 Hm3/h. Thus, the reasonable time of inactivity of the ventilation system will be no more than 7 days. In order to ensure that the concentration of radical hydrogen above the surface of the pool does not exceed 0.4% of the volume, the blowdown must be 250 times higher than the hydrogen generation rate, that is, the flow of air blown over the pool (ventilation) to ensure explosion-proof safety must be equal to g=250 W(H2), m3/year. The temperature of self-ignition of hydrogen in the presence of water vapor is 970 K, and the explosive properties of the hydrogen mixture are characterized by an outbreak of 4.12–75% of the volume. The degree of damage to building structures of the building of SNF-1 will be determined by the deformations and destruction that they received during the explosion of hydrogen. The formation of shock loads during an accidental explosion is directly determined by the number (volume) of stoichiometric ratios of hydrogen with the vapor and the limits of hydrogen ignition. Conclusion. Thus, the presented methodology for the estimation of the formation of radiolithic hydrogen and its possible explosion in the premises of SNF-1 allows, within the framework of a conservative approach, to conduct an explosion safety assessment and the consequences of an accidental explosion of radioactive hydrogen.

Dalam high temperature reactor, koefisien reaktivitas temperatur yang didesain negatif menjamin reaksi fisi dalam teras tetap berada di bawah kendali dan panas peluruhan tidak akan pernah melelehkan bahan bakar yang menyebabkan terlepasnya zat radioaktif ke lingkungan. Namun masuknya air (water ingress) ke dalam teras reaktor akibat pecahnya tabung penukar panas generator uap, yang dikenal sebagai salah satu kecelakaan dasar desain, dapat mengintroduksi reaktivitas positif dengan potensi bahaya lainnya seperti korosi grafit dan kerusakan material struktur reflektor. Makalah ini akan menganalisis efek kecelakaan water ingress terhadap reaktivitas Doppler teras RGTT200K. Kapabilitas koefisien reaktivitas Doppler untuk mengkompensasi reaktivitas positif yang timbul selama kecelakaan water ingress akan diuji melalui serangkaian perhitungan dengan program MCNPX dan pustaka ENDF/B-VII untuk perubahan temperatur bahan bakar dari 800K hingga 1800K. Tiga opsi kernel bahan bakar UO2, ThO2/UO2 dan PuO2 dengan tiga model kisi bahan bakar pebble di teras reaktor diterapkan untuk kondisi water ingress dengan densitas air dari 0 hingga 1.000 kg/m3. Hasil perhitungan memperlihatkan koefisien reaktivitas Doppler tetap negatif untuk seluruh opsi bahan bakar yang dipertimbangkan bahkan untuk posibilitas water ingress yang besar. Efek water ingress lebih kuat pada model kisi dengan fraksi packing lebih rendah karena lebih banyak volume yang tersedia untuk air yang memasuki teras reaktor. Efek water ingress juga lebih kuat di teras uranium dibandingkan teras thorium dan plutonium sebagai konsekuensi dari fenomena Doppler dimana absorpsi neutron di daerah resonansi 238U lebih besar daripada 232Th dan 240Pu. Secara keseluruhan dapat disimpulkan bahwa, koefisien Doppler teras RGTT200K mampu mengkompensasi insersi reaktivitas yang diintroduksi oleh kecelakaan water ingress. Teras RGTT200K dengan bahan bakar UO2, ThO2/UO2 dan PuO2 dapat mempertahankan fitur keselamatan melekat dengan cara pasif. Kata kunci: Water ingress, reaktivitas Doppler, RGTT200K In high temperature reactor, the negative temperature reactivity coefficient guarantees fission reaction in the core remain under the control and decay heat will not melt the fuel which cause the release of radioactive substances into the environment. But the entry of water (water ingress) into the reactor core due to rupture of a steam generator tube heat exchanger, which is known as one of the design basis accidents, can introduce positive reactivity with other potential hazards such as graphite corrosion and damage of the reflector structure material. This paper will investigate the effect of water ingress accident on Doppler reactivity coefficient of RGTT200K core. The capability of the Doppler reactivity coefficient to compensate positive reactivity incurred during water ingress accident will be examined through a series of calculations with MCNPX code and ENDF/B-VII library for fuel temperature changes from 800K to 1800K. Three options of UO2, ThO2/UO2 and PuO2 fuel kernels with three lattice models of fuel pebble in the reactor core was applied for condition of water ingress with water density from 0 to 1000 kg/m3. The results of the calculations show that Doppler reactivity coefficient is negative for the entire fuel options being considered even for a large possibility of water ingress. The effects of water ingress becomes stronger in lattice model with lower packing fraction because more volume available for water entering the reactor core. The effect of water ingress is also stronger in the uranium core compared to thorium and plutonium cores as a consequence of the Doppler phenomenon where the neutron absorption in resonance region of 238U is greater than 232Th and 240Pu. It can be concluded overall that Doppler coefficient of RGTT200K core has capability to compensate the reactivity insertion introduced by water ingress accident. RGTT200K core with UO2, ThO2/UO2 and PuO2 fuels can maintain the inherently safety features in a passive way. Keywords: Water ingress, Doppler reactivity, RGTT200K

Further studies on the acid-precipitable radioactive substance formed during perfusion of Langendorff rat hearts with [14C]adenosine have shown that very brief (30 s) ischaemia causes a sudden rise (20–35%) in its level in the tissue which is followed by the steady fall we have previously described. Analysis of the products of alkaline hydrolysis of this compound shows that at least 96% of the radioactivity appears in the form of a mixture of 2′- and 3′-AMP as would be expected for RNA while its relatively high resistance to dilute alkali suggests that it is poly A. Subcellular localization studies indicate that radioactivity enters all compartments of the cell, with maximum label in the nucleus. However, a significant proportion is present in the mitochondria and may be poly A acting as the mitochondrial storage form of adenine nucleotides whose existence we have proposed.

Background: A bone scan or commonly referred to as bone print is nuclear medicine examination using a radioactive substance or radiopharmaceutical that is inserted into the body through intravenous injection which aims to help diagnose abnormalities that occur in the bone. This imaging procedure uses a radiopharmaceutical 99mTc-MDP (methylenediphosphonate) is the most commonly used radiopharmaceutical.Methods: The patient will be injected with this radiopharmaceutical at a dose of 15-20 mCi, through the vein in the hand. Imaging can be done as soon as the radiopharmaceutical is injected or after a while to wait for the radiopharmaceutical to be distributed and absorbed by the bone, about 3-5 hours later. Imaging is done by three-phase method, namely the first phase (Vascular phase), the second phase (Blood Pool phase), and the third phase (Total body phase) l.Results: The bone scan method is an efficient examination because in 1x the imaging can provide a complete picture from the head to the foot. Evaluation of results, under normal conditions the distribution of radioactivity in the bone appears symmetrical.Conclusion: In the process of bone metastasis, it can be seen that typical pathological radioactivity can be multiple (multiple hot spots). Malignant tumors can be distinguished from benign tumors by blood pool examination.

The comprehensive assessment of medical and social risk factors and their impact on the health of children working at industrial waste landfills of the Kyrgyz Chemical Metallurgical Plant has presented. Various industrial and environmental factors were covered. To identify signs of environmental pollution by radioactive substances of natural and artificial origin the average values of gamma-radiation power levels have been examined. The hygienic, sociological, medical and statistical research methods are used. During the study, the social-hygienic and living conditions of life and work of children were studied. The selection of respondents conducted by random sampling. The health condition of children living in the region but not working at industrial waste landfills has studied to compare the data of a control group. An assessment of the physical and biological development of children in the experimental and control groups was carried out by measuring somatometric indicators (length and body weight, head circumference), as well as indicators of dynamometry and their external respiration function. The intensive morbidity rates of children have been studied. The article analyzes the impact of medical and social risk factors that adversely affect the health conditions of working children. It describes the various factors of the working environment and the labor process, which form the occupational risk of morbidity. An important part of the study was to assess the situation and identify possible causes that force families to involve children to work at industrial waste landfills.

In 1896, Henri Becquerel (1852–1908) had discovered, by chance, the phenomenon of radioactivity, after he found that uranium salts left on top of covered photographic plates produced an image on the plates when they were later developed. Soon afterwards, thorium was also found to be radioactive. In 1898 Marie Curie (née Sklodovska) realized that certain minerals were more ‘radioactive’ (a term she first introduced) than could be rationalized by the amount of uranium or thorium that they contained. She guessed that they might contain trace amounts of an even more radioactive element, and during the long purification process, she eventually realized that two such elements were present. The naming of the first of these, discovered in July 1898, is described by her daughter Eve Curie in her biography of her mother: . . . ‘You will have to name it,’ Pierre said to his young wife, in the same tone as if it were a question of choosing a name for little Irène [their first daughter]. The one-time Mlle Sklodovska reflected in silence for a moment. Then, her heart turning toward her own country which had been erased from the map of the world, she wondered vaguely if the scientific event would be published in Russia, Germany and Austria—the oppressor countries—and answered timidly: ‘Could we call it “polonium”?’ . . . Marie Curie named the element after her homeland, Poland, but the country did not exist as a separate entity at that time, and her choice was something of a political statement. The second element discovered by Marie and Pierre Curie was found to be millions of times more radioactive than uranium. This element they called ‘radium’ because of its intense radioactivity. Over three and a half years later, when they finally isolated a tenth of a gram of purified radium salts from tonnes of pitchblende ore, the Curies were delighted to find that the substance was spontaneously luminous. After the discovery that uranium and thorium were radioactive, in September 1899, Ernest Rutherford (1871–1937) made a further discovery: ‘In addition to this ordinary radiation, I have found that thorium compounds continuously emit radio-active particles of some kind, which retain their radio-active powers for several minutes.

In Germany low / medium level waste, which is classified here as radioactive waste with negligible heat generation, will be disposed of in the Konrad underground repository. The construction and the operation of this nuclear facility required authorization by different fields of law, i.e., by nuclear law, mining law and water law. Whereas the nuclear law considers solely radiological aspects, the relevant permit issued according to the water law considers the impact of radioactive as well as non-radioactive harmful substances. The Federal Office for Radiation Protection (BfS) as operator of the repository and permit holder has (a) to record the disposed of radioactive and non-radioactive harmful substances and (b) to balance them. To meet these requirements BfS has developed a concept, which led to a site specific solution. Threshold values were defined for recording and for balancing the harmful substances. It had to be verified that by disposal of radioactive waste packages according to these values an adverse effect on the near-surface groundwater can be excluded. The Lower Saxony Water Management, Coastal Protection and Nature Conservation Agency (NLWKN) as the responsible water law regulatory authority approved the operator’s concept as appropriate to comply with the requirements of the Water Law Permit. Nonetheless, collateral clauses were imposed to assure this.

A low decay heat (implying Spent Fuel (SF) pebbles older than 8–9 years) bulk dry storage section is proposed to supplement a 12-tank wet storage section. Decay heat removal by passive means must be guaranteed, taking into account the fact that dry storage vessels are under ground and inside the building footprint. Cooling takes place when ambient air (drawn downwards from ground level) passes on the outside of the 6 tanks’ vessel containment (and gamma shielding), which is in a separate room inside the building, but outside PBMR building confinement and open to atmosphere. Access for loading / unloading of SF pebbles is only from the top of a tank, which is inside PBMR building confinement. No radioactive substances can therefore leak into atmosphere, as vessel design will take into account corrosion allowance. In this paper, it is shown (using CFD (Computational Fluid Dynamics) modelling and analytical analyses) that natural convection and draught induced flow combine to remove decay heat in a self-sustaining process. Decay heat is the energy source, which powers the draught inducing capability of the dry storage modular cell system: the more decay heat, the bigger the drive to expel heated air through a higher outlet and entrain cool ambient air from ground level to the bottom of the modular cell.

Containment is the ultimate barrier which protects the radioactive substance from spreading to the atmosphere. Sensitivity analysis on AP1000 containment during postulated design basis accidents (DBAs) was studied by a dedicated analysis code PCCSAP-3D. The code was a three-dimensional thermal-hydraulic program developed to analyze the transient response of the containment during DBAs; and it was validated at a certain extent. Peak pressure and temperature were the most important phenomena during DBAs. The parameters being studied for sensitivity analysis were break source mass flow rate, containment free space, surface area and volume of heat structures, heat capacity of the containment shell, film coverage, cooling water tank mass flow rate and initial conditions. The results showed that break mass flow rate as well as containment free space had the most significant impact on the peak pressure and temperature during DBAs.