Study of mineral grains extracted from the Chernobyl “lava”

Safely probing the chemistry of Chernobyl nuclear fuel using micro-focus X-ray analysis

“…3 Investigation of a limited number of samples of these materials has been conducted but analysis was restricted by their high radioactivity, complicating the handling and characterisation process. [6][7][8][9][10][11] To gain deeper insight into the properties of materials arising from nuclear reactor accidents, in a safe and efficient manner, a suite of simulant brown and black LFCM samples with much lower radioactivity, i.e. excluding ssion products, were synthesised and characterised.…”

Оновлена Модель Еволюції Мікроструктури Лавоподіб-Них Паливовмісних Матеріалів 4-Го Блока ЧАЕС. Коричнева Кераміка

“…The emergency situation at Unit 4 of Chornobyl NPP on April 26, 1986, led to intensive heat generation and low heat removal in the fuel rods [1][2][3][4][5][6][7][8][9][10][11]. This circumstance stimulated a substantial increase of the temperature (to 2500-2600 ∘ C) of uranium oxide UO 2 in fuel tablets and in the contact areas between uranium oxide and zirconium alloy Zr + 1 wt%.Nb.…”

“…This led to the oxidation of a considerable part of each uranium-containing phase (UO 2 , UO with Zr, and (Zr,U)O ) and metallic zirconium. The materials of the destroyed reactor core entered into a reaction with the structural materials of the reactor [1,2,[6][7][8][9][10][11][12] and formed a melt on the basis of the ternary system UO 2 -SiO 2 -ZrO 2 . Besides the elements of this system, the melt also included a substantial number of other elements [1,2,[7][8][9]11].…”

“…The LFCM were formed in the course of the nuclear reactor accident, when the nuclear reactor got out of control. During the first decade after the accident, experts determined and analyzed actor structural materials (the serpentinite backfill, sand, concrete, and others) [1][2][3][4][5][6][7][8][9][10][11].…”

“…Some experts consider that the zirconium alloy in the fuel rod shells had melted from the inside on the first day of the accident and began to dissolve uranium oxide fuel tablets, which resulted in the formation of the zirconium-uranium-oxygen melt [1][2][3][4][5][7][8][9][10]. It happened due to the intensive heat generation and the low heat removal in the fuel rods after the introduction of a positive reactivity.…”