1998 Fiscal Year Final Research Report Summary
A STUDY ON THE PRODUCTION TECHNIQUE OF PLUTONIUM TRACER AS THE STANDARD FOR THE ENVIRONMENTAL ANALYSIS
| Project/Area Number |
09680507
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
NISHIKAWA Sataro Research Reactor Institute, KYOTO UNIVERSITY Research Assistant, 原子炉実験所, 助手 (60027430)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Katsuhei Research Reactor Institute, KYOTO UNIVERSITY Associate Professor, 原子炉実験所, 助教授 (80027466)
MITSUGASHIRA Toshiaki Institute for Materials Research, Tohoku University Associate Professor, 金属材料研究所, 助教授 (30005938)
MORIYAMA Hirotake Research Reactor Institute, KYOTO UNIVERSITY Professor, 原子炉実験所, 教授 (90127150)
YAMANA Hajimu Research Reactor Institute, KYOTO UNIVERSITY Associate Professor, 原子炉実験所, 助教授 (30283683)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Plutonium / ^<236>Pu / ^<237>Np / Electron LINAC / Bremsstrahlung / isotope production |
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| Research Abstract |
A production method of ^<236>Pu that is useful as a spike isotope for the analysis of Pu in the environment was studied. A production method by ^<237>Np(gamma, n)^<236m>Np * ^<236>Pu using e-bremsstrahlung of electron -LINAC of Research Reactor Institute, Kyoto University was studied. On the purpose of reducing the thermal neutron flux to avoid the (n, gamma) reaction, three irradiation tests were performed using water-flow type cooling column of 4cmX4cm dimension, and the following results were obtained.
1. Safe and reliable irradiation performance was confirmed for the double-sealed quartz target of Np.
2. The nuclear reaction rate of ^<237>Np(gamma, n)^<236m>Np was revealed to be c.a. 3.6 X 10^<-12> (1/sec) on the electron beam condition of 120mA/30MeV.With this condition, 5 hours irradiation of 1mg Np resulted in the production of 0.65 kBq of ^<236>Pu.
3. The content of ^<238>Pu which is an interfering by-product was found to be <0.06% of ^<236>Pu in the radioactivity ratio, which suggests that this method ensures quite high radiochemical purity.
4. Reported data of decay of ^<236m>Np agreed well with the observed production rate of ^<236>Pu.
5. It is considered to be feasible that one irradiation of ^<237>Np(10mg, 30 hours) produces about 35 kBq of 236 radiochemically pure ^<236>Pu which will be sufficient for the application.
As a result of this study, we confirmed that the successful production of highly-pure ^<236>Pu by the bremsstrahlung irradiation at Research Reactor Institute, Kyoto University. By this method consisting of rather easy techniques for target preparation and irradiation, we believe that the safe and reliable production of pure ^<236>Pu will be ensured for the assessment of trace Pu in the environment.
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