On the basis of theory of stationary thermal explosion of A.D. Frank-Kamenetsky, depending on the temperature of the critical size of the ammonium nitrate embankment, the calculations were performed, which show that it can be stored in the large volumes at the temperatures up to 30 °C. On the contrary, at the temperatures above 100 °C (for example, at 200 °C), the decomposition of nitrate occurs with acceleration and can lead to an explosion.
Based on the studies performed, it is shown that the changes and additions to the fire safety requirements for ammonium nitrate storage in the buildings and structures should be determined by the requirements for fire resistance of buildings (at least II degree of fire resistance), for the purity of the product and its packaging, for the exclusion of contacts with organic substances and materials, storage conditions.
Additional fire safety requirements were developed for inclusion in the normative document regarding ammonium nitrate storage. Ammonium nitrate is allowed to be stored in one-story warehouse buildings of at least II degree of fire resistance, structural fire hazard class C0. The floor area within the fire compartment should not exceed 10 500 m2. Between the fire-fighting walls of the 1st type, it is allowed to store no more than 25 000 tons of nitrite in bulk or in the special bags, as well as in the soft specialized containers for bulk products in accordance with GOST 2—2013.The conditions for placing ammonium nitrate in the stacks should be accepted in accordance with the requirements of SP 92.13330.2012. Temperature in the storage room of ammonium nitrate should not exceed 30 °C with a relative humidity of not more than 60 %. Warehouses for storing ammonium nitrate should be equipped with general exchange supply and exhaust and (or) emergency ventilation, in order to exclude the formation of a fire and explosion hazardous environment in the room during the decomposition of ammonium nitrate. Warehouses for storing ammonium nitrate in an amount of not more than 5 thousand tons may be separated from other premises, including from the warehouses for fertilizers and pesticides, by solid (without openings) type 2 fire walls.
2. Rules for safe warehousing, storage, transportation, preparation for the introduction of ammonium nitrate. Мoscow: Kolos, 1973. 9 p. (In Russ.).
3. Recommendations for hazardous goods transportation. Available at: https://unece.org/DAM/trans/danger/publi/manual/Rev5/Russian/00ru_intro.pdf (accessed: August 3, 2021). (In Russ.).
4. Karmolin A.L., Chernyugov A.D., Korshunov Yu.N. Explosives safe transportation by rail. Moscow: Transport, 1992. 383 p. (In Russ.).
5. Uniform safety rules for blasting operations. Available at: https://www.meganorm.ru/Data2/1/4293742/4293742419.pdf (accessed: August 3, 2021). (In Russ.).
6. SP 4.13130.2013. Systems of fire protection. Restriction of fire spread at object of defense. Requirements to special layout and structural decisions. Available at: https://docs.cntd.ru/document/1200101593 (accessed: August 3, 2021). (In Russ.).
7. SP 92.13330.2012. Warehouses of dry mineral fertilizers and chemical plant protection products. Updated edition of SNiP II-108—78. Available at: https://files.stroyinf.ru/Data2/1/4293802/4293802583.pdf (accessed: August 3, 2021). (In Russ.).
8. Vogman L.P., Molchanova T.A., Taratanov N.A. Theory of Combustion and Explosion. Мoscow: Kurs, 2019. 224 p. (In Russ.).
9. GOST 2—2013. Ammonium nitrate. Specifications. Available at: https://docs.cntd.ru/document/1200107273 (accessed: August 3, 2021). (In Russ.).
10. Tsvetkov V., Telkov G., Lyashov S., Shevtsova L. Safe storage of ammonium nitrate. Information and advisory publication on industrial and environmental safety. TekhNadzor = TechNadzor. 2015. № 11 (108). pp. 372–375. (In Russ.).
11. Hazardous Materials Code. Available at: https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=400.pdf (accessed: August 3, 2021).
12. Kersten R.J.A., Mak W.A. Explosion hazards of ammonium nitrate, How to assess the risks? The International Symposium on Safety in the Manufacture, Storage, Use, Transport and Disposal of Hazardous Materials. Tokyo, 2004. pp. 113–125.
13. Kiiski H. Properties of Ammonium Nitrate Based Fertilisers. Helsinki, Finland: University of Helsinki. Available at: https://helda.helsinki.fi/bitstream/handle/10138/21085/properti.pdf?sequence=1 (accessed: August 3, 2021).
14. Pearce N. Safer Storage. NFPA Journal. 2015. № 109 (3). pp. 60–63.
15. Methodology for ensuring fire safety in the transportation of spontaneously combustible cargo. Available at: https://files.stroyinf.ru/Data2/1/4293830/4293830297.pdf (accessed: August 3, 2021). (In Russ.).