Adequacy of radioiodine control and monitoring at nuclear fuels reprocessing plants [electronic resource]
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| Online Access: |
Online Access |
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| Corporate Authors: | , |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Richland, Wash. : Oak Ridge, Tenn. :
Pacific Northwest National Laboratory (U.S.) ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
1984.
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| Subjects: |
| Abstract: | The present backlog of irradiated reactor fuel leads to projections that no fuel out of the reactor less than 10 years need be reprocessed prior to the year 2000. The only radioiodine present in such aged fuel is ¹²⁹I (half-life 1.6 x 10⁷ y). The ¹³¹I initially present in the fuel decays to insignificance in the first few hundred days post-reactor. The ¹²⁹I content of irradiated fuel is about 1 Ci per gigawatt-year of electricity generated (Ci/GW(e)-y). The US EPA has specified, in 40 CFR 190, a release limit for ¹²⁹I of 5 mCi/GW(e)-y. Thus a retention factor (RF) of 200 for ¹²⁹I at the fuel reprocessing plant (FRP) is required. Experience indicates that RF values obtained under actual FRP operating conditions can average as little as 10% of experimentally determined RF values. Therefore processes theoretically capable of achieving RF values of up to 10⁴ have been investigated. The US EPA has also specified in 40 CFR 90 a thyroid dose limit of 75 mrem/y for a member of the general public. This dose limit could be readily met at a typical FRP site with an RF value of about 10 or less. Therefore, the limit of 5 mCi/GW(e)-y is more restrictive than the thyroid dose limit for ¹²⁹I. The absence of ¹³¹I in effluents from processing of aged fuels makes analysis of ¹²⁹I somewhat easier. However, in-line, real-time monitoring for ¹²⁹I in FRP gas streams is currently not feasible. Moisture, chemicals, and other radioactive fission products interfere with in-plant measurements. Samples collected over several days must be taken to a laboratory for ¹²⁹I analysis. Measurement techniques currently in use or under investigation include neutron activation analysis, scintillation counting, mass spectroscopy, and gas chromatography coupled with electron capture detection. 26 references, 3 figures, 7 tables. |
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| Item Description: | Published through the Information Bridge: DOE Scientific and Technical Information. 06/01/1984. "pnl-5108" "DE84013311" Soldat, J.K.; Burger, L.L.; Scheele, R.D. |
| Physical Description: | Pages: 38 : digital, PDF file. |