RU826872C - Composition for dry deactivation of surfaces - Google Patents

Description

The invention relates to compositions for dry decontamination of surfaces from | 3-active contaminants under conditions of freezing temperatures (-15) - and can be used in nuclear facilities

A known composition for decontamination based on polyvinyl alcohol (PVA) of weakly basic anion exchange resin of polycondensation thia, ethoxylated alkyl phenol with

Also known is a composition containing the triethanolamine salt of coconut oil, polyethylene glycol, glycerin, carboxymethyl cellulose, corrosion inhibitor, water o

However, this composition is removed by water and therefore cannot be used for dry decontamination.,

Closest to the claimed is a composition for dry surface decontamination from radioactive contamination, including an aqueous solution of PVA, glycerin, oxalic acid, a surfactant

The well-known PVA-based composition exhibits deactivating properties and is well removed at a temperature of 8-2S ° Cf. However, when the temperature decreases, the polymerization processes slow down, the deactivation coefficient (KI,) drops sharply, at a temperature of (-15) -, the coating does not it freezes and does not have the deactivating properties of j,

The aim of the invention is the provision of a decontamination process at low temperatures (-15) - О С “For a composition for dry decontamination of surfaces from radioactive contaminants, including aqueous, PVA solution, glycerin, oxalic acid, surfactant, additionally contains an aqueous solution of chloride sodium, phosphoric acid and microtalc in the following ratio of components, Mae cho in terms of dry matter: PVA 17, 95 glycerol 5.0-15.0, oxalic acid 6.5-1.0, a surfactant (for example, OP- 7) 0.2-0.8, phosphorus and acid (NDRO)., 80) 5.0-10.0, sodium chloride 13.5 22.5p microtalc 5.0-10.0, water the rest. Example U 17s1 PVA is dissolved at 77 ° C. 9 ppm of water about the solution is cooled to .18-25 ° C; to 95 ppm of iB-Horo PVA solution, add 5 ppm of glycerol, 5 ppm of oxalic acid, 0.2 OP-7, May 5, h, phosphoric acid (solution ), May 82.5, hours 2.2 sodium chloride solution, 5 mOhs microtalc and mix thoroughly. “The prepared composition is applied in a single layer with a brush at 0 ° C. The coating is kept for 4.5 hours. Kjj steel, contaminated with dry residue of the L-active solution, amounts to 190 (per cycle) with a coating thickness of 180 μm, a tensile stress at a tensile strength of 50.0 MPa, an elongation at break of 275, adhesion to stainless steel not exceeding 1.7 gsm / cm, hardness in accordance with M-3 0, The coating is removed manually. Example 2 A composition is prepared as in Example 1, applied in one layer at -5 ° C, dried for 5 hours, KU 225 (after dyne cycle) p Coating thickness l80 μm, tensile strength at tension 52.0 MPa, elongation at break 288, adhesion to stainless steel no more than 1.7 gsm / cm2, hardness M-3 0, Example Z Ready t the composition, as in example 1, is applied in a single layer at -1.5, dried 5.5 hours, KD - 230 (per cycle Coating thickness 180 μm, tensile stress at 9.0 MPa, elongation at break 2bO %, adhesion to stainless steel no more than 1.8 gsm / cm, hardness according to M-3 0,041 „Example 4o 18.0 mAS; PVA is dissolved at 60-80 ° C in 82 water, 100 wt% of the 18th PVA solution are added 100 wt. Cho glycerin, 7.5 wt. Oxalic acid, 0.5 may about OP-7, 7, May 5th. h ,, phosphoric cellulose (80% solution), 83.8 mOCHO 25j4 -Horo sodium chloride solution, 7.5 mOCHO microtalc o. The composition is applied with a brush in one layer at 0 ° C. The coating can withstand 4 Cho Kj, 190. Coating thickness 180 μm, tensile stress at 50 MPa, elongation at break 275, adhesion to stainless steel no more than 1.7 kgcm / cm , hardness in accordance with M-3 0.042 Example 5. After combining, prepared as in Example 4, put in one spruce, dry for 4.5 hours Kj, 225 (per cycle), Coating thickness not more than 185 μm, stress breaking at a tension of 50 NPa, elongation at break of 288%, adhesion to stainless steel no more than 1.7 gsm / cm, hardness M-3 0.04, Example 6 The composition prepared as in example 4 is applied in a single layer at -15 ° C, dried for 4 hours at Kp 2bO (per cycle) Coating thickness not more than 185 μm, tensile stress at 52.5 MPa, relative elongation at break 290, adhesion to stainless steel no more than 1.6 gsm / cm hardness according to M-3 0.04U Example 7o 18.9 mOPS PVA is dissolved at 60-80 ° C in 86.1 water, to 105 mOCHs prepared 18-ml solution. 15 mOCH, glycerol, 10 mAH, 10% oxalic acid, 0.8 mAH OP-7, 10mAh phosphoric acid (solution) are added, 85 macheo 2b, 5% solution sodium chloride, 10 ma SOCHO microtalc Composition applied with a chisel at, the coating can withstand 3.5 Cho x 220 (per one cycle) Coating thickness, not more than 0.2 μm, tensile stress at 54.0 MPa, elongation at break 300 , adhesion to stainless steel 1.4 gsm / em2, hardness according to M-3 0.04. 5 Example BO The composition prepared as in example .7 is applied at -5 ° C, dried j Cho K.JJ 280 (per cycle) s Coating thickness no more than 0.2 μm, tensile stress at 57, In MPa, elongation at break of 300, adhesion to stainless steel 1, A gsm / cm, hardness M-3 0, OAl. 26872., 6 Example 9. The composition prepared as in Example 7 is applied in one layer at, drying time e A, 5 hours, Kp - 350 (per olin cycle). The coating thickness is not more than 190 µm, the tensile stress at 68.2 MPa, the elongation at break, the adhesion to stainless steel is not more than 1, A gsm / cm, M-3 hardness is 0.0.