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1 Journal of the Korean Ceramic Society Vol. 43, No. 12, pp. 865~871, Evaluation of Characteristics of Simulated Radioactive Vitrified Form Using Cooling Methods Kang-Taek Lee, Kyu-Ho Lee, Duk-Ki Yoon, Bong-Ki Ryu, Cheon-Woo Kim,* Jong-Kil Park,* and Tae-Won Hwang* School of Materials Science and Engineering, Pusan National University, Busan , Korea *Nuclear Engineering and Technology Institute, Korea Hydro and Nuclear Power Co., Ltd., Daejeon , Korea (Received October 19, 2006; Accepted November 6, 2006) þƒ s» šy p sƒ ká ³yÁ»Á» Á½ *Á ¼*Áyk * w œw *w ( )» ( ; ) ABSTRACT In order to examine and compare the characteristics of two vitrified forms ( and ) simulated for the operation of a commercial vitrification facility being constructed in Ulchin nuclear power plant, the vitrified forms were cooled by the natural cooling and annealing methods, respectively. And the Product Consistency Test (PCT), compressive strength, thermal conductivity, specific heat, phase stability, softening point and Coefficient of Thermal Expansion (CTE) of the vitrified forms were experimented. Consequently, it was shown that there were no significant differences on the physiochemical properties of the vitrified forms performed the natural cooling and annealing. Key words : Annealing, PCT, Compressive strength, Thermal conductivity 1. s» y(vitrification) w»(canister/ container) š (, ) l þ (annealing) w z w ƒ» þƒ(, þ) w k w ƒ, sƒw ü y» y wš w. /š šy, ƒ w w šy y w yw ü p w m šy þ þ z œ y, / y m. šy z œ þ Corresponding author : Bong-Ki Ryu bkryu@pusan.ac.kr Tel : Fax : þ œ w e t l pƒ w, œ k e, z w m w, œ w x, m» w. t z v þ þ, w šy y wì p y j w. 1,2) þƒ k k ƒ k ³ w šy w. 1,3), þƒ j w y ƒ wì, w. 4-6) w, w þƒ ü k w w t, w ü x., ¾ þƒ p w, šy w w e ƒ. w» w š ƒ w 865

2 866 ká ³yÁ»Á»Á½ Á ¼Áyk j» w þƒw þ(annealing) ww. 3) w y šy þƒw š þ w, v,, 4. 7) p, š s» y y ww šy w þ w š s» y wš Hanford wz þ w. 8,9) þ šy 773 K w w. ƒ ww þ šy» j» w ) x y 14) w t ƒ (, ) w þƒ k þ p x sƒw» w yw t(raw chemical) w 600 e(glass batch). þƒ k w, š œ» þƒw w þ þƒw w. w yw t Al 2, B 2, CaC, Co(N ) 2 6H 2 O, Cr 2, CuO, Fe 2, K 2 C, Li 2 C, MgO, MnO 2, Na 2 C, NiO, P 2 O 5, Na 2 SO 4, SiO 2, TiO 2 ƒƒ. yw t e v p» yww z ƒ MoSi 2» 1423 K 1 w. 45 k z ƒ Éü w ³ w yww š» z w 15 w þƒw. þƒ w ƒ x w. þƒ( þ) ¼ p w» w Table 1 þ w p šy w PCT(Product Consistency Test) e x þƒ þ yw ü p y w» w 15) (DOE) w PCT(Product Consistency Test) 7 w Na, B, Li, Si e w. PCT ww» w 149 µm(100 mesh) m wš 74 µm(200 mesh) 10 w l (SUS 304L)» š 10 w w ASTM Type I k w. t e (SA/V) 2000 m K š 7 ù z Éü e 1ml w 1% HN 20 ml ¼ vial šy l e ù Na, B, Li, Si e» e w.» Savannah River National Laboratory(SRNL) w Environmental Assessment(SRL-EA) w þƒ þw šy ƒƒ w» p sƒw» w d»(universal Testing Machine, x» ) w r Fig. 1 w. þƒ þw šy r ³ Table 2 ùkü. w y ƒwƒ r q w d w w z w w ƒ r w w šy þƒ ƒ r p sƒwš d (TPA 501, Sweden) w w j(hot disk) d w. d r Fig. 2 w, d R.T. (303 K), d 80, d j» mm w ƒƒ 3z d w šy þ y w» w (DSC 2910, Simadzu Co.) w q 325 mesh mw. þƒ þ ww ƒ r wš t r w 773 K¾ d w. Table 1. Annealing Schedule for and Thickness (mm) Annealing temperature (K) Annealing time (min) Increasing rate (K/min) Decreasing rate (K/min) w wz

3 냉각 방법에 따른 모의 방사성폐기물 유리고화체의 특성평가 Fig Glass samples for compressive strength test. Sample Preparation for Compressive Strength Test of and cooled (mm2) (mm2) cooled (mm2) Table 2. Fig. 2. Photographs of samples for thermal conductivity measurement: (left) and (right). 상 안정성 유리고화체의 냉각방법에 따른 상 안정성을 확인하기 위해 시차열분석(DTA 50, Simadzu Co.) 장치를 이용한 상 동정 및 SEM(JSM 5600, JEOL Korea)에 의한 시료내부 의 상분포에 대한 관찰을 각각 수행하였다. 자연냉각 유 2.6. (mm2) 리와 서냉유리를 각각 조분쇄, 미분쇄처리 한 후 최종적 으로 325 mesh의 체로 전통하여 얻어진 유리분말을 비등 온법으로 측정하였다. 30 mg의 시료를 백금 도가니에 담 아 측정하였고 기준 시료로는 α-al O 를 사용하였으며 상 온에서부터 1273 K까지 승온속도 10 K/min로 측정하였다. 2 3 제 43 권 제 12호(2006)

4 868 ká ³yÁ»Á»Á½ Á ¼Áyk SEM w þƒ þ šy w ³ w y q y q d»» (TMA 50, Simadzu Co.) w. y q d 2~3 mm š ¼ ƒ 10 mm z syw w w 10 K/min w. 3. š 3.1. PCT k ¾ þƒ k šy þw šy w 7 e x PCT ww Fig. 3 šy (Si, B, Na, Li) e (g/m ) j yƒ 2 ùkû., þw šy Li þƒw šy e ùkû ù» (SRL- EA) e û ùkû. š y þƒw þw yw p e p y sƒ Table 3 þƒ þw w d, r j» x s³ eƒ. d w w d w. d þ e r s³ ùküš ù w, þ z ƒ y j š sƒ þƒ þw w Table 4 w. r w d þw r (W/mK) ùkû. š r þw r (W/mK) û ùkû. š w x 0.03(W/mK). x ù r ƒ 0.03 w ƒ þƒ e šy š þƒ þw w DSC d w Table 5 ùkþ. ƒ þ ƒ þƒw r w w, þw r ùkû. ù 373~498 K þw r ùkùù, 498~663 K Fig day PCT leach rates for glasses of natural cooled and annealed: (left) & (right). Table 3. Compressive Strengths of and cooled (psi) (psi) cooled (psi) (psi) 1 2,057 2,053 2,119 2, ,949 2,060 2,217 2, ,981 2,073 2,250 2,251 Average 2,000 2,063 2,195 2,203 w wz

5 냉각 방법에 따른 모의 방사성폐기물 유리고화체의 특성평가 Thermal Conductivities of and cooled (W/mK) (W/mK) Average Table 4. cooled (W/mK) Specific Heat Changes for Vitrified Forms of Cooled and 373 K(J/g) 473 K(J/g) 573 K(J/g) cooled cooled (W/mK) Table 5. 서 비열의 크기가 낮게 나타났다. 즉, 자연 냉각한 시 편의 경우 423 K 부근에서 비열이 급격히 상승하며 663 K 부근에서 비열이 급격이 하락하게 되는데 이에 대한 정 확한 원인규명은 할 수 없었다. 다만, DTA 측정결과자 료를 참고하면 자연 냉각한 시편의 경우 523 K에서 급격한 발열현상이 나타났었는데 이러한 결과로부터 이 Fig. 4. Table 6. Tg 673 K(J/g) K(J/g) DTA Results of and cooled (K) (K) cooled (K) (K) SEM micrographs of (top) and (bottom): natural cooled(left) and annealed(right). 제 43 권 제 12호(2006)

6 870 ká ³yÁ»Á»Á½ Á ¼Áyk x w ƒ w þƒ þw DTA d w w Table 6. SEM w z šy w ³ w z p w. z ³ w œ»d œ w wš. z w SEM Fig. 4 ùkü. z DTA d w T g ƒ»¼ w T g z vj z w ƒ š sƒ. mw, ³ y y y q þƒ þw y (T f ) q (CTE) Table 7 ùkü. þƒ þw y w, þw r 10 K ƒ ùkû ù 10 K ƒ û ùkû. š 373~573 K q w, þƒ þw r q wù þw r q ƒ ùk û. w, þƒw r 423 K w ùk ûš, 663 K w w ùkû. q 373~573 K d w q w ƒ 423~663 K q w. ù w q w þƒ þw šy y q p w y q. Table 7. Softening Temperatures and CTE of and w wz cooled cooled T f (K) CTE (10 7 /K) /š šy, þƒ œ k» œ y, n œ, w» sƒ š. s» w þ þ þƒ yw p, mw y wš w. x w z r w, þ þ wš yw ü p PCT,» p, š,,, y q p p w mw þ þ» p j p w, þ z v w. w x ƒ, w l ü Á s» y šy w z œ, e, x y q. REFERENCES 1. W. Vogel, Glass Chemistry, 2nd Ed., pp , Springer Verlag, New York, H. Scholze, Glass Science, pp , Translated by Lee Joung Heon, Chong Moon Gak, R. H. Doremus, Glass Science, 2nd Ed., pp , John Wiley & Sons Inc., New York, M. B. Volf, Chemical Approach to Glass, pp , Elsevier, New York, L. D. Pye, H. J. Stevens, et al., Introduction to Glass Science, pp , Plenum Press, A. Paul, Chemistry of Glasses, pp , Chapman and Hall, W. Lutze, R. C. Ewing, Eds., Radioactive Waste Forms for the Future, pp , North Holland, Amsterdam, C. N. Wilson, Ed., Evaluation of Melter Technologies for Vitrification of Hanford Site Low Level Tank Waste Phase I Testing Summary Report, WHC SD WMER 498, Revision 0, IAEA, Regulations for the Safe Transport of Radioactive Material, Safety Standards Series No. ST 1, Vienna (1996). 10. IAEA Technical Reports Series No. 176, Techniques for the Solidification of High Level Wastes, International Atomic Energy Agency, Vienna, IAEA Technical Reports Series No. 187, Characteristics of Solidified High Level Waste Products, International Atomic

7 þƒ s» šy p sƒ 871 Energy Agency, Vienna, IAEA Technical Reports Series No. 339, Design and Operation of High Level Waste Vitrification and Storage Facilities, pp , International Atomic Energy Agency, Vienna, US EPA, Vitrification Technologies for Treatment of Hazardous and Radioactive Waste, April, C.-W. Kim, J.-Y. Kim, S.-J. Maeng, J.-K. Park, and T.-W. Hwang, Evaluation of Chemical Durability of Vitrified Forms for Simulated Radioactive Waste Using Product Consistency Test(PCT) and Vapor Hydration Test(VHT)(in Korean), J. Kor. Rad. Waste Soc., 4 [3] (2006). 15. C. M. Jantzen and N. E. Bibler, Product Consitency Tests (PCT) Method Version 3.0, WSRC TR , Westinghouse Savannah River Laboratory, Aiken, SC, «12y(2006)