A Study on the Pure Separation for Determination of Molybdenum Isotopes in a Simulated Fuel Solution

(1)

418

2019 ⦽ǎႊᔍᖒ⠱ʑྜྷ⦺⫭⇹ĥ⦺ᚁݡ⫭םྙ᫵᧞Ḳ

A Study on the Pure Separation for Determination of Molybdenum Isotopes

in a Simulated Fuel Solution

Jung Suk Kim*, Kyungwon Suh, Byungman Kang, Yang-Soon Park, and Yeong Keong Ha

Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon, Republic of Korea

*

[email protected]

1. Introduction

One of the important parameters required for the study of a nuclear fuel is its burnup, which is the number of fissions per 100 heavy nuclide atoms (mass 232) initially present in the fuel. The burnup of important fissile isotopes and the composition of an irradiated fuel depend on the nature of the fuel and on the conditions of an irradiation. A detailed knowledge of these quantities is useful for a reactor work as well as for the effective utilization of a nuclear fuel. Of the many stable nuclides formed in the fission, Some Mo isotopes (97Mo, 98Mo and

100

Mo) satisfied most of the necessary requirements for a burnup monitor as Nd, Cs and Ce monitor isotopes. U and Mo isotopes can be measured using isotope dilution mass spectrometric techniques (IDMS), and U and Mo elements can be also determined with by inductively coupled plasma atomic emission spectrometry (ICP-AES) [1-3].

The aim of the present work is to separate individually without the isobaric interferences the U and Mo from a simulated fuel solution by using anion exchange chromatographic techniques.

2. Experiments

2.1 Chemicals

The Certified 96Mo (95.78 atom%) spikes was obtained from Oak Ridge National Laboratory (ORNL). This spike solution was prepared by dissolving its oxide in 8 M HNO3-0.01 M HF. The

concentration of the spike solution was determined by calibrating that with a standard solution and ICP-AES. The simulated fuel solution was prepared by mixing with the 96Mo spike and fifteen standard solutions (Table 1). All standard solutions were obtained from AccuTrace and Spex Industries Inc.

Table 1. Compositions of a Solution Simulated for Irradiated Nuclear Fuel

Element Quantity added (ȝg) Remark

96 Mo 40 ORNL U 100 Certified standard solution Nd 40 La 40 Ce 40 Pr 40 Sm 40 Eu 40 Gd 40 Sr 40 Ba 40 Zr 40 Cs 40 Ru 40 Rh 40 Pd 40

2.2 Separation and Determination by ICP-AES

The separation procedure of the U and Mo from the simulated fuel solution was carried out by two analytical schemes. Analytical scheme-I was composed of the two-steps sequential anion exchange separations in media HCl and HNO3 (Fig. 1).

Analytical scheme-II was composed of the one-step sequential anion exchange separation in media HCl and HF. The concentrations of U, Mo, and Ru and Zr, which are considered as the isobaric elements in the separated solutions were determined using a ICP-AES (Jobin Yvon).

3. Results & Discussion

3.1 Determination of Mo and U by ICP-AES

(2)

2019 ⦽ǎႊᔍᖒ⠱ʑྜྷ⦺⫭ ⇹ĥ⦺ᚁݡ⫭ םྙ᫵᧞Ḳ

419

sepatated from the simulated fuel solution sample by

the analytical scheme-I. The U was separated purely without interference of Mo, which is appeared the similar anion exchange behavior in HCl solution. The Mo was separated purely without the interference of the isobaric elements, Ru and Zr through two-steps anion exchange separations.

6LPVROQ¶

Acid treat. Dry, 1M HF, 1M HClO4, 12M HCl

BioRad AG 1X8, 100-200 mesh, Cl-form, 5cm H.

Loading 12M HCl 0.5mL Elution-1 12M HCl 4mL _Partial Ru removal Elution-2 12M HCl-0.1M HI 2mL Pu Portion Elution-3 12M HCl-0.1M HI 4mL Ru removal Elution-4 7M HCl 4mL Zr removal

Elution-5 0.1M HCl 5mL U+Mo Portion

(Continued)

U+Mo

Acid treat. Dry, 14M HNO3

BioRad AG 1X8, 100-200 mesh, NO3-form, 5cm H.

Loading 6M HNO3 0.5mL

Elution-6 6M HNO3 1mL Mo Portion

Elution-7 0.1M HNO3 5mL U Portion Fig. 1. Analytical Scheme-I for the Mo and U Separations

.

Table 2. ICP-AES results for Each Portions Separated from the Simulated Fuel Solution

Sample ȝg/mL Mo U Ru Zr S-21 <0.10 <0.10 0.389 <LOD S-22 <0.10 <0.10 <0.10 2.398 S-23 1.767 <0.10 <0.10 <LOD S-24 <0.10 5.954 <0.10 <LOD LOD(Zr) : 0.169 ȝg/mL

4. Conclusion

The Mo and U in the simulated fuel solution can be separated and determined simultaneously by the inductively coupled plasma atomic emission spectrometry. It is expected that the contents of U, Mo and their isotopes in the simulated fuel solution and the real irradiated fuel solution can be determined simultaneously by the isotope dilution mass spectrometric method using 233U and 96Mo as spikes. A comparison between values determined by two analytical techniques provides a check on the validity of the results. The separation procedures established in the present work would be applied for burnup determination by the isotope dilution mass spectrometric method by using quadrupole spikes (233U, 242Pu, 150Nd and 96Mo).

REFERENCES

[1] J. S. Kim, Y. S. Jeon, S. D. Park, S. H. Han, and J. G. Kim, ³%XUQXS'HWHUPLQDWLRQRI+LJK%XUQXS and Dry Processed Fuels Based on Isotope 'LOXWLRQ 0DVV 6SHFWURPHWULF 0HDVXUHPHQW´ J. Nucl. Sci. Technol, 44(7), 1015-1023 (2007). [2] F. L. Lisman, W. J. Maeck, and J. E. Rein,

³'HWHUPLQDWLRQ RI 1XFOHDU )XHO %XUQXS IURP )LVVLRQ 3URGXFW $QDO\VLV´ 1XFO 6FL (QJ 215-219 (1970).

[3] P. W. J. M. Boumans, ³,QGXFWLYHO\ &RXSOHG 3ODVPD (PLVVLRQ 6SHFWURVFRS\´ &KHPLFDO Analysis: Volume 90, John Wiley & Sons, Inc. (1987).