Santa Clara, California, Financial Analyst In the wake of the Chernobyl Reactor fire, the United States Department of Energy had a serious concern. Even Chernobyl's engineers couldn't fully grasp the consequences of their actions. add to list. in order to have self-sustained rapid graphite oxidation in any of these reactors certain necessary conditions of geometry, temperature, oxygen supply, reaction product removal and favorable heat balance must exist. The DoE wanted to know if a Chernobyl type accident would be possible at Hanford. When the power began to increase, more steam was produced, which in turn led to an increase in power. Reliable quality, sincere service and good credit, we are honored to be able to work with you! As with a boiling water reactor (BWR), water boils in the fuel channels (at about 6.9 MPa) and steam is separated above them in a single circuit. The graphite in a pencil is unlikely to have any radioactive carbon-14 in it, your own body probably has more. 75-INSAG-7, 1992, (ISBN: 9201046928). The value of the void coefficient is largely determined by the configuration of the reactor core. On Wednesday, Ukrainians who were involved in the cleanup of Chernobyl - the so-called liquidators - protested in central Kiev to demand the government acknowledge their sacrifice with improved social benefits. Some 600,000 of the medals were awarded to soldiers, rescuers, firefighters, police, and civilian workers during the Soviet era. After Chernobyl, a number of changes were implemented in the RBMK reactors across Russia. . For h values lower than 10~ cal/cm-sec-C maximum temperature rises were 0-50C and remained essentially constant for long periods of time (five hours). It's kind of insane to think that humans can control the power of the atom. Chernobyl was a failure on the human scale, long before it was a failure on the atomic one. The additional absorbers require the use of higher fuel enrichment to compensate for the increased neutron absorption. Since the experiments were designed to minimize all heat losses other than those associated with the air flow, 650C can be considered a lower bound for burning. On a scram signal, as the rod falls, the water at the lower part of the channel is replaced by the bottom of the graphite displacer, thus initially adding reactivity to the bottom part of the core. To attempt to get the power back up to an acceptable level, the workers removed the control rods in the core, hoping to kickstart the reaction again and move the power back up. The ratio of water to steam is known as the "void coefficient." Estimated amount of ejected {sup 14}C The steam is then condensed and fed back into the circulating coolant. Amazon.com: graphite block 51 1-16 of 755 results for "graphite block" RESULTS 2 Packs Graphite Ingot Block 99.9% High Purity EDM Graphite Plate Graphite Blank Milling Surface Melting Casting Mould (50mm x 50mm x 20mm) 4.6 (70) $1099 FREE delivery Sat, Jan 7 on $25 of items shipped by Amazon To be able to know our solutions and enterprise. As we have seen, the use of graphite in a reactor core is consistent with safe reactor operations. No power means water is no longer being pumped to cool down the reactor -- and that can quickly lead to disaster. 1 bath. OSTI.GOV Journal Article: Graphite specimens from the fourth block of the Chernobyl Atomic Energy Station. More heat boils the water away faster. Its been a lucrative business for sellers in former Soviet republics who work out of their homes and have easy access to an industrial supply of Soviet-era artifacts. An eBay vendor in Ukraine was asking $2,800 for what he claimed was an "original Soviet USSR Chernobyl nuclear reactor RBMK-1000 core graphite block.". The time has now arrived to ask the question, is it dangerous to use graphite in the core of a Molten Salt Reactor. The Energy Central Power Industry Network is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other. See especially: Annex I of INSAG-7, the Report by a Commission to the USSR State Committee for the Supervision of Safety in Industry and Nuclear Power (SCSSINP); and Annex II of INSAG-7, the Report by Working Group of USSR Experts, Causes and Circumstances of the Accident at Unit 4 of the Chernobyl Nuclear Power Plant and Measures to Improve the Safety of Plants with RBMK Reactors (Moscow, 1991), 2016-2023 World Nuclear Association, registered in England and Wales, number 01215741. As the Chernobyl accident showed, several of the RBMK's design characteristics in particular, the control rod design and a positive void coefficient were unsafe. "In this accident they were operating outside their rules and defeating protection which was designed to keep the reactor safe.". The efficiency and speed of the emergency protection system was improved by implementing three independent retrofitting operations: One of the most important post-accident changes to the RBMK was the retrofitting of the control rods. Thus, the test was hoping to show how an RBMK reactor could bridge the 60 seconds and keep pumping cool water into the system by using spare power generated as the plant's turbines slowed down. The HBO series teaches us that they can become dangerous if we fail to understand the potential of atomic science. Things are messy and confusing. All operating RBMKs began operation between 1979 (Kursk 2) and 1990 (Smolensk 3). Download: free Website: Printables. If the salt is drained, either deliberately, by accident or by operation of the freeze valve safety system, then the heat producing fission products will be drained from the core as well. print now. Self-sustained rapid graphite oxidation cannot occur unless a geometry is maintained that allows the gaseous reaction products to be removed from the surface of the graphite and be replaced by fresh reactant. A Ukrainian online vendor in June was auctioning off a pre-catastrophe Soviet medallion minted in 1983 to mark the launch of Chernobyls ill-fated fourth reactor. City of Tallahassee Experiments were also carried out on channel diameters of one to three Inches on 10-foot long test channels In order to obtain generic Information. Austin, Texas, PUC Engineer (Engineer IV - VI) (00029045) increased reactor power level), the rods can be dropped into the core to reduce or stop reactor activity. 2 Beds. As long as we try to harness the power of the atom, the odds will fall in favor of disaster. A few short rods, inserted upwards from the bottom of the core, even the distribution of power across the reactor. This medallion was minted in 1983 to mark the startup of Chernobyls ill-fated Reactor No. I concluded my Windscale review with the statement. A combination of fear and ignorance. The installation of a fast-acting emergency protection (FAEP) system. According to the World Nuclear Association, nuclear energy accounts for approximately 11% of all energy generated on the Earth. Want CNET to notify you of price drops and the latest stories? At every step, Chernobyl touched on the ineptitude of Russian governance, the uncompromising courage of the liquidators tasked with cleaning up the site, the weight that hung over the shoulders of every scientist investigating the disaster and the stark reality of atomic power. Support jpg, jpeg, png, gif, txt, doc, pdf, xls, docx, xlsx , less than 5MB), The factory can meet continuously developing economic and market needs, so that their products are widely recognized and trusted, and that's why we chose this company.I will come back to buy Graphite Block Chernobyl again., " " , Perfect Graphite Block Chernobyl with perfect service.I can complain nothing!, Everything is good.I can complain nothing about it., " " . History. This temperature must be maintained either by the heat of combustion or some outside energy source.3. This group brings together the best thinkers on energy and climate. LCRA One RBMK (Smolensk 3) has been built to these third-generation standards. Folsom, California, Sr. Electrical Engineer But if the plant itself loses power, then what happens? Yes. I think we are meant to presume from his statement, that he can see a significant amount of black colored debris on the roof of the building. A backup set of diesel-fuelled generators kick in after 60 seconds in such an instance -- but this timeframe risks putting the reactor in danger. It's not a nuclear explosion, but a steam explosion, caused by the huge buildup of pressure within the core. The DoE commissioned a review of N Reactor safety in light of the Chernobyl accident. Your access to Member Features is limited. It was designed over 1964-66 and is very different from most other power reactors. So can this kind of nuclear catastrophe happen again? Molded GraphiteIsostatic GraphiteMedium Grain GraphiteEDM GraphiteGraphite PartsGraphite Powder. The four first-generation units are Leningrad 1&2 (both now shutdown), and Kursk 1 (now shutdown) and 2. He also owns a lot of ugly Christmas sweaters. Below 650C it was not possible to get large temperature rises along the channel with 30C inlet air temperatures at any flow rate. The automatic rods are regulated by feedback from in-core detectors. What Is Isostatic Graphite? elations with us. "Graphite reactor" directs here. 21372 Brookhurst St Unit 227, Huntington Beach, CA 92646. 3,485 sqft lot. CHERNOBYL, Ukraine (Reuters) - In the middle of a vast exclusion zone in northern Ukraine, the world's largest land-based moving structure has been built to prevent deadly radiation spewing from. Following the Chernobyl accident, this 'positive scram' effect was mitigated by retrofitting the control rods so that, with the rods fully retracted, there would not be a region containing water at the bottom of the core. Recall how the water both cools the core and "slows" the reaction down. However, the dimensions of the rod and displacers were such that, with the rod fully withdrawn, the 4.5 m displacer sat centrally within the fuelled region of the core with 1.25 m of water at either end. In the Chernobyl accident sequence, the plant was effectively destroyed and conditions for exothermic chemical reactions involving a number of core materials were present before graphite fire made any contribution. Tags Chernobyl graphite block add to list print now Tags KrAZ-256B is a Soviet heavy mining dump truck and. OPEN TODAY, 1PM TO 4PM. In one of the most remarkable online solicitations, a Ukrainian eBay vendor on May 31 asked $2,800 for what he claimed was an "original Soviet USSR Chernobyl nuclear reactor RBMK-1000 core graphite block." The graphite displacer improved the efficiency of the cycle by improving the geometry and 'coupling' between the upper and lower active sections of the core when the control rod was fully withdrawn. The first artificial nuclear reactor, the Chicago Pile-1, used nuclear graphite as a moderator. In the event of a blackout or loss of power to the plant, the RBMK reactor will stop pumping water through the core. Second-generation RBMKs, brought online since the late 1970s and early 1980s include Leningrad 3&4; Kursk 3&4; Ignalina 1 (now shutdown); and Smolensk 1&2. Tallahassee, Florida, Deputy Electrical Safety Officer They are themselves composed of three particles: protons, neutrons and electrons. Email agent. INSAG-7, The Chernobyl Accident: Updating of INSAG-1, A report by the International Nuclear Safety Advisory Group, International Atomic Energy Agency, Safety Series No. The eBay website allows documents, medals, and protective clothing to be sold on its pages, but it prohibits the sale of radioactive or contaminated nuclear materials. Privacy statement: Your privacy is very important to Us. DC Public Service Commission Fill in more information so that we can get in touch with you faster, (Max 5 files. Did the Graphite in the Windscale Reactor Burn? After the accident at Chernobyl, several measures were taken to improve the safety of RBMK plants. Each channel is individually cooled by pressurised water which is allowed to boil in the tube and emerges at about 290C. Emily Watson is riveting as a nuclear physicist who represents all of the real life scientists that worked to unravel how Chernobyl exploded. The water is critical to understanding what happened at Chernobyl. To perform the test, the reactor had to be put into a dangerous low-power state. The danger of a core fire due to graphite burning is quite limited. Our company promises not to disclose your personal information This design is not implemented in the same way in any other nuclear reactors in the world. A preheater at the inlet of the graphite channel was used to adjust the air to the desired temperature. This post considers several reports that are relivant to an evaluation of the role of graphite in te Chernobyl fire. Graphite Block Chernobyl - manufacturer, factory, supplier from China (Total 24Products for Graphite Block Chernobyl) Artificial High Purity Molded Graphite Round Block Brand: PDSKY Packaging: Wooden case or according to cu. The caps on the top of the reactor core, weighing more than 750 pounds, begin to literally bounce in the reactor hall. 4. It cannot be returned to its usual power state quickly. Menlo Park, California, Senior Electrical Estimator See here for a complete list of exchanges and delays. The control rods were made more plentiful and can be inserted into the core faster. All but six of the 211-plus control rods have been removed from the core and the water is no longer providing any cooling effects. o build business enterprise. The fuel rods are the powerhouse of the core and are composed of uranium atoms. In fact, this part of the process was the subject of a 2011 Ukranian documentary . The Chernobyl release must be viewed as resulting from both very high temperatures in the core rubble, extensive mechanical disruption and dispersal of core material and the large draft chimney effect that followed the total disruption of that particular reactor configuration. Concomitantly, coals, cokes and charcoals develop a porous white ash on the burning surfaces which greatly reduces radiation heat losses while simultaneously allowing air to reach the carbon surfaces and maintain the burning. Sustained combustion is distinguished from self-sustained combustion when, in the first case, the combustion is sustained by a heat source other than the graphite oxygen reactions (e.g., decay heat from reactor fuel). Replacement of the SKALA process computer. After the Chernobyl accident, Soviet safety standards were revised again (OPB-88). As the temperature Increased along the channel CO formed either directly at the surface of the channel or by the reaction CO2 + C. At temperatures above 700C, CO reacts in the gaseous phase to form CO2 with accompaniment of a visible flame. The fuel rods feature slightly more enriched uranium which helps control the nuclear reactions a little better. Major modifications have been made to the RBMK reactors still operating. Timely delivery, strict implementation of the contract provisions of the goods, encountered special circumstances, but also actively cooperate, a trustworthy company! One more was under construction in Russia (Kursk 5), but it is now cancelled. We could supply fine-grain graphite, Medium Grain Graphite, high pure. Our company promises not to disclose your personal information All quotes delayed a minimum of 15 minutes. Marin Clean Energy (MCE) The main control rods are inserted from the top down and provide automatic, manual, or emergency control. 1,620 sqft. This necessary gas flow of Incoming reactant and outgoing products is Intrinsically associated with a heat transfer mechanism. Verified account Protected Tweets @; Suggested users New Open House 3/4. We know that Kouts view cannot be correct, nuclear graphite does not burn like charcoal, and the assertion that only 10% of the Chernobyl core graphite burned does not suggest graphite was the major source of the Chernobyl fire. It may have taken some artistic liberties for the sake of story, but refused to sweep the truth of the catastrophe under the rug. The installation of 80-90 additional fixed absorbers in the core to inhibit operation at low power. Should really you be interested in our company and solutions, please make contact with us by sending us emails or call us straight away. Public Power Council CHERNOBYL, Ukraine (Reuters) - In the middle of a vast exclusion zone in northern Ukraine, the worlds largest land-based moving structure has been built to prevent deadly radiation spewing from the Chernobyl nuclear disaster site for the next 100 years. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful. The variations in the reactor design allowed it to use less-enriched fuel than usual and to be refueled while running . But if liquid salt is present then air cannot be. The objectives of the full scale channel experiments were to determine under what conditions burning might initiate in the Brookhaven Graphite Research Reactor (BGRR) and how it could be controlled if it did start. Then, at 1:23:45 a.m., the . US Stock High Purity 99.9% Graphite Ingot Block 3X2X2, Coarse Grain Graphite Blocks Approximately 1" x 2" x 3.25", Round Graphite Block Disk Ingot Graphite Electrode Plate 50x10mm, High Purity 99.9% Fine Graphite Graphite Bars Blank Block Sheet, 2 PCS. They were designed and brought online in the early-to-mid-1970s, before new standards on the design and construction of nuclear power plants, the OPB-82 General Safety Provisions, were introduced in the Soviet Union in 1982. The core is now a giant kid's ball pit in an earthquake, with neutrons bouncing around the chamber and constantly colliding with one another. Every Day new 3D Models from all over the World. The DoE operated a reactor that was similar to the Chernobyl reactor, the N reactor at Hanford, Washington. Two of these end on end occupy each pressure tube. ar more, you'll be able to come to our factory to see it. print now. Soviet-era military gas masks have become popular memorabilia items sold online since the Chernobyl TV miniseries began in May. The NRC report described the limitations of graphite fires. High quality isostatic pressed graphite is made of high purity graphite. It was found that the maximum temperature at which thermal equilibrium (between heat generated by graphite oxidation and heat removed by the air stream) will occur in a channel can be predicted from the heat transfer coefficient, the energy of activation and a single value of the graphite reactivity at any temperature. Over its five episodes, Chernobyl constantly moved toward answering one question -- "How?" Introduction of calculation programs to provide an indication of the value of the operating reactivity margin (ORM. add to list. Her advice proved to be superfluous. The Russian nuclear program developed the technology for RBMK reactors throughout the '50s, before the first RBMK-1000 reactor began construction at Chernobyl in 1970. Let us move forward hand in hand and achieve win-win situation. Graphite blocks absorb some energy from the neutrons that pass through them. Improvement of the response efficiency of the emergency protection system. Great River Energy 1pcs High Purity Density Graphite Round Cylinder Block Electric Spark Graphite. And this process went on for quite some time. Thus, the water in the channel boils, turns to steam and is used to create power. At high flow rates, the rate of cooling by the flowing gas can exceed the rate of heat produced by oxidation. Stray shoes and family photos still fixed to bedroom walls show the speed with which families were evacuated. Please show them your appreciation by leaving a comment, 'liking' this post, or following this Member. The reactor core is located in a reinforced concrete lined cavity that acts as a radiation shield. Unacceptably large void coefficients were prevented for initial cores by increasing fuel enrichment levels, with the excess reactivity balanced by fixed absorbers. A medallion given to a Soviet soldier who took part in the cleanup operation within the Chernobyl exclusion zone Soviet-made dosimeters used to measure radiation levels have been selling steadily. The Fukushima disaster that affected a Japanese nuclear plant in 2011 demonstrates that catastrophes still lurk within reactors around the world and we are not always prepared for them. Download: for sale Website: Cults. To obtain a lower bound on the minimum temperature at which burning could occur, the experiments were specifically designed to minimize heat losses from radiation, conduction, and convection. Then, at 1:23:45 a.m., the explosion occurs. He used to be a scientist but he realized he was not very happy sitting at a lab bench all day. Tags RBMK-1000 Reactor Graphite & Cutaway Model (1. add to list. During the 10 hour delay, the core's low-power state caused a build-up of xenon, another type of atom that in essence blocks the nuclear fission process. Tests in 1987-'88 at the Ignalina and Leningrad plants (the first RBMKs to be fitted with the new FAEP system) confirmed these characteristics. For Sale. The extruded graphite blocks we produce use high-quality petroleum coke as raw materialare widely used in metallurgy, machinery, electronics and chemical industry, etc. A disregard for the rules -- and the science -- exposed them to the RBMK's great danger: The positive void coefficient. to any external company with out your explicit permission. The operators were not aware of the 'positive scram' effect where, following a scram signal, the initial entry of the control rods actually added reactivity to the lower region of the core (see section below on Post accident changes to the RBMK). Im sure he knew what he is looking at. For reasons that are well understood, graphite is considerably more difficult to burn than is coal, coke, or charcoal. Weve already gone through a number of very risky stages We always have fears, we are people, but there is nothing technical left that is a challenge, said Vince Novak, the Nuclear Safety Director of the European Bank for Reconstruction and Development (EBRD). The internal diameter of the BGRR channel was 2.63 Inches. Nature has been quick to reclaim the areas abandoned infrastructure. Dana Drabova, a 58-year-old nuclear physicist who heads the Czech Republics State Office for Nuclear Safety, told the Czech magazine Reflex that it could be a legitimate graphite block from a Chernobyl-type RBMK nuclear reactor. add to list. Rochester, Minnesota, Transmission Trading Specialist (Hybrid) At first, it was believed that approximately 3,400 men did this job, but the real number came out at a later point. To be sure, vendors say online demand for vintage communist-era relics has been booming during the past decade, driven mostly by buyers in the United States. The type of Soviet military gas masks issued to Chernobyl workers, which were common across the entire Soviet Union, have been selling in recent weeks at prices ranging from $20 to $50. In some of these reactors, most notably the RBMK, the neutron absorbing properties of the cooling water are a significant factor in the operating characteristics. It is likely that the major contribution from graphite was to serve as a refractory container for decay heat buildup, zirconium oxidation along with carbothermic reduction of the UO2, and complex gas producing redox reactions. Colliding with this net can knock more neutrons loose. Jackson Ryan is CNET's award-winning science editor. But after broadcasts of the Chernobyl miniseries began in May, his sales went into hyperdrive with nearly 700 sold for about $11 each. He was standing at the windows staring at smoldering graphite. Electrode Paste Carbon Anode Scraps 150-300mm, China manufacturers supplier RP graphite electrodes, GPC/Graphitized Petroleum Coke for foundry. Brokered by CENTURY 21 Union Realty Co. New. The report also stated that. Within the reactor each fuel assembly is positioned in its own vertical pressure tube or channel about 7 m long. Showing 163 homes around 20 miles. Henan Carbons New Material Technology Co., Ltd. Thus, more heat. But we're talking about nuclear physics here. But should we stop trying to do so? Drabova noted that Russia continues to produce graphite core blocks for the functioning reactors at the Smolensk, Kursk, and Leningrad nuclear power plants. An increase in fuel enrichment from 2% to 2.4%. Although I did not come to a firm conclusion, i did find strong evidence that Nuclear Graphite does not burn under many conditions in which one would expect fire. Across the planet, 450 reactors are currently in operation -- only 10 of them are RBMK reactors with enhanced safety features -- and as we look at ways to reduce our reliance on harmful fossil fuels, nuclear energy must be considered as a viable alternative. The term "positive void coefficient" gets thrown around and that's not a term you hear every day. x 4 in, blocks of AGOT graphite used in the original construction. add to list print now Tags Pripyat city sign (Chernobyl) add to list print now Tags Monument in Chernobyl 3D model 3D printable add to list print now Tags RBMK Nuclear Reactor from Chernobyl nuclear plant add to list print now Early attempts to model the events at Windscale [Robinson, 1961; Nairn, 1961] were followed by the BNL work described here. Join us for smart, insightful posts and conversations about where the energy industry is and where it is going. Given these facts, the assertion that there was a core graphite fire at Chernobyl ought also to be revisited. When the incoming air is lower in temperature than the reacting graphite, the flow rate is a deciding factor in determining whether the graphite cools or continues to heat. In a reactor, the neutrons collide with atoms another, splitting them apart and generating heat in a process known as nuclear fission. Fuel temperature must have reached 3000 degrees centigrade. Original USSR Chernobyl RMBK-1000 graphite block for sale ebay 41 15 Chernobyl Ukraine Europe Place 15 comments Best Add a Comment notFidelCastro2019 4 yr. ago It's fake. Improvements to the emergency core cooling systems. The issue is the nuclear fuel which was melted to graphit chunks during the explosion. In the early hours of April 26, 1986, the reactor was undergoing a safety test which aimed to fix this issue. At temperatures above about 650C, in realistic geometries where radiation is a major heat loss mechanism, graphite will burn only in a limited range of flow rates of air and only when the air temperatures are high. With our loaded encounter and considerate services, we have now been recognized as a trustworthy supplier for lots of worldwide consumers for Graphite Blocks For Sale, graphite electrode manufacturer , Electrode Paste Carbon Anode Scraps 150-300mm , Graphite electrodes to melt scrap metal ,Uhp Graphite Electrodes . I. Radiocesium in graphite and its behavior. The FAEP system was designed so that 24 emergency protection control rods would insert negative reactivity of at least 2 in under 2.5 seconds. $4.71 to $66.96. We have to. The first of these, Obninsk AM-1 (" ", Atom Mirny, Russian for "peaceful atom," analogous to the American Atoms for Peace) generated 5 MW of electricity from 30 MW . Even with export duties, they say, theyve been able to turn profits of up to 500 percent on legitimate Soviet articles sold via online marketplaces like eBay and Etsy. a huge spike in searches for terms related to the science of the show, The Fukushima disaster that affected a Japanese nuclear plant in 2011, According to the World Nuclear Association, Do Not Sell or Share My Personal Information. The void coefficient is only one contributor to the overall power coefficient of reactivity, but in RBMK reactors it is the dominant component, reflecting a high degree of dependence of reactivity on the steam content of the core. Graphite specimens from the fourth block of the Chernobyl Atomic Energy Station. Washington, District of Columbia, Sr. Environmental Economist US Stock High Purity 99.9% Graphite Ingot Block 4X3X1 1/8, EDM Graphite Blocks, 12 x 12 x 3 +, EDM Sinker, Graphite, Graphite Block Ingot Rectangle Graphite Electrode Plate 100x50x25mm, Graphite Blank Block Sheet Plate High Density Fine Grade 1/4 x 6 x 6, High Purity Graphite Ingot Block High Quality High Temperature Module 4250, Graphite Block Ingot Rectangle Graphite Electrode Plate 50x50x20mm, Pack of 2, 1pcs High Purity Density Graphite Round Cylinder Block Electric Spark Graphite, EDM Graphite Blocks, 12 x 12 x 3 +, EDM, Graphite, EDM Graphite Block 1.25x1.75x6 Machining High Temp Mold Molten Metal Mold Glass, Graphite Block Sheet Plate Blank 8" X 1.6" X 1.09", ONE NEW High Purity 99.9% Graphite Ingot Block Sheet 50* 50* 20mm, 100*100*10mm 99.9%Pure Graphite Block Electrode Rectangle Plate Z4K2h, Great price compared to similar brand new items, 1pc Graphite Blank Block Sheet Plate High Purity/Density Fine Grain 10x10x2.5CM, Round Graphite Block Disk Ingot Graphite Electrode Plate 14x2mm, Pack of 10, Graphite Ingot Blank Block Sheet Plate High Density Fine Grain 1/2" X 4" X 4", Round Graphite Block Disk Ingot Graphite Electrode Plate 30x5mm, Pack of 2, High Density Graphite Ingot Blank Block Sheet Plate 3/4" X 4" X 4" New, Graphite Blank Block Sheet Plate High Density Fine Grade 1/2" x 3" x 3", Graphite Block Ingot Rectangle Graphite Electrode Plate 200x50x10mm, 100*100*10mm 99.9%Pure Graphite Block Electrode Rectangle Plate R4T1h, Graphite Plate 100mmx50mmx3mm Graphite Blank Block Black 1pcs.