Reference

Adsorption of nitrogen dioxide by acid-resistant zeolites

Adsorption of nitrogen dioxide by acid-resistant zeolites. Pimkin, V. G.; Gavlovskaya, S. S.; Orlov, G. D. (Gos. Inst. Prikl. Khim., Leningrad, USSR). Vestsi Akad. Navuk BSSR, Ser. Fiz.-Energ. Navuk, (1), 114-17 (Russian) 1985. CODEN: VAFEAW. ISSN: 0374-4760. DOCUMENT TYPE: Journal CA Section: 71 (Nuclear Technology) Section cross-reference(s): 66 With respect to the use of N2O4 [10544-72-6] as a dissocg. coolant for nuclear reactors and its purifn., a no. of acid-resistant zeolites were studied. The adsorption of NO2 [10102-44-0] on the zeolites of type Y, e, and a was investigated at a flow rate of 0.3 ± 0.02 L/cm2-min, length of adsorbent layer 10 cm, initial concn. 20 mg/L, and temp. 20 ± 1°. The proposed granulated acid-resistant adsorbent for NO2 (i.e. the zeolite NaY) is comparatively easily regenerated, stable in cyclic operation, and can be used for purifying periodic gas discharges from the circuits of power plants using a dissocg. coolant based on N2O4.

Separation of fission product gases from irradiated nuclear fuels

Separation of fission product gases from irradiated nuclear fuels. Bray, Lane A.; Boldt, Allyn L. (Exxon Nuclear Co., Inc., USA). Ger. Offen. DE 2801744 10 Aug 1978, 18 pp. (German). (Germany). CODEN: GWXXBX. CLASS: IC: G21C019-48. PRIORITY: US 77-766142 7 Feb 1977. DOCUMENT TYPE: Patent CA Section: 71 (Nuclear Technology) A process is described for liberating volatile fission products from irradiated nuclear fuels by heating the fuel pellets with a e.g. NO2 [10102-44-0] oxidizing agent dild. with N or NO at a reaction temp. of preferably 350-650° for a period of time sufficient to transform the material into a fine powder, allowing the volatile fission products to escape. The irradiated fuel consists of U oxide, Pu oxide or mixts. of both. The fission products are mainly I, Xe, Kr and T. For example, a 1 g sample of irradiated UO2 and a mixed oxide (UO2-PuO2) was oxidized at 400° for h to yield a very fine powder. The powder was dissolved in 15 cm3 of 8M HNO3 for 3-4 h at 100°, filtered and the filtrate was tested for T content. A std. was run without oxidn. for comparison. The residual filtered solid, as well as that from the std. sample, was again dissolved in 8 M HNO3 with addn. of 0.005 M HF, and the T content of the solid was detd. by testing the resulting soln. Thus, oxidn. of fuel with NO2 before dissoln. effectively seps. T from the fuel. The soln. of the mixed oxide and solid contained 5% of the original T content.