| Project/Area Number |
08458136
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Nuclear fusion studies
|
|---|
| Research Institution | KYUSHU UNIVERSITY |
|---|
Principal Investigator |
MOMOSHIMA Noriyuki Kyushu Univ., Fac.Sci., Associate Prof., 理学部, 助教授 (80128107)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OKAI Tomio Kyushu Univ.Fac.Eng., Assistant Prof., 工学部, 講師 (50150488)
|
|---|
| Project Period (FY) |
1996 – 1998
|
| Project Status |
Completed (Fiscal Year 1998)
|
| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1996: ¥3,100,000 (Direct Cost: ¥3,100,000)
|
|---|
| Keywords | Oxidation / Soil organic / Organically bound tritium / Soil microorganism / Free water tritium / Molecular tritium |
|---|
| Research Abstract |
The research was carried out to obtain information on environmental monitoring around nuclear fusion reactor, which will be a major energy source in future. Especially the study was focused on elucidation of the mechanism which is elevating tritium level of organic material on a forest floor, from environmental measurements and laboratory experiments using radioisotopes.
FWT (free water tritium) in Toki showed a similar level between litter and humus, and had a comparable level with rain, However, the FWT varied with sampling times that the tritium level increases in dry periods and decreases by rain. This would be attributed to microorganism, which oxidized atmospheric HT to HTO.The laboratory experiments showed that any environmental soil samples could oxidize atmospheric HT to HTO, suggesting the oxidation of atmospheric LIT by microorganism is cause for the fluctuation of FWT level. OBT (organically bound tritium) in litter and humus was higher than the FWT.This suggests that formation of high HTO concentration spot in a forest floor progresses formation of high OBT microorganism. Formation of high OBT organisms is elevating the apparent OBT level of organic material on a forest floor. The same distribution pattern was observed on the litter and humus samples collected at Fukuoka, proving that oxidation of atmospheric HT to HTO and following increase in OBT is a common phenomenon occurring in the general environment.
It is not clear what chemical forms of tritium will be released from nuclear fusion reactor. Our findings, however, suggest that any form of tritium could be incorporated into organic materials in soil environment when tritium is released from reactors. It is necessary to include measurement of organic material in a forest floor in a monitoring program of nuclear fusion reactors.
|
