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Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
Vogtle-3 shuts down for valve issue
One of the new Vogtle units in Georgia was shut down unexpectedly on Monday last week for a valve issue that has since been investigated and repaired. According to multiple local news outlets, Georgia Power reported on July 17 that Unit 3 was back in service.
Southern Company spokesperson Jacob Hawkins confirmed that Vogtle-3 went off line at 9:25 p.m. local time on July 8 “due to lowering water levels in the steam generators caused by a valve issue on one of the three main feedwater pumps.”
Kazuya Idemitsu, Ken-ichiro Kuwata, Hirotaka Furuya, Yaohiro Inagaki, Tatsumi Arima
Nuclear Technology | Volume 118 | Number 3 | June 1997 | Pages 233-241
Technical Paper | Radioactive Waste Management | doi.org/10.13182/NT97-A35364
Articles are hosted by Taylor and Francis Online.
Diffusivities of cesium in a water-saturated mortar were measured in an attempt to investigate the migration of radionuclides into the matrix of the mortar. The measured penetration profiles of the tracer were composed of two parts. There was a steep slope near the surface and a gradual slope in the mortar interior. This kind of profile has been reported by many researchers. This profile was successfully explained by considering two diffusion paths in the mortar. One diffusion path was through fissures with a width of a few microns, and the other was through the intact mortar network of submicron pores. This model was supported by autoradiography of some cross sections of a mortar specimen. The volume of submicron pores was ∼95% of the total pore volume in the mortar. The order-of-magnitude values for the apparent diffusivities for cesium were 10−2 m2/s through the fissure and 10−14 m2/s through the network of pores. The effective diffusion coefficient for cesium was estimated at ∼10−13 m2/s by using the apparent diffusivities through the fissures, the aperture of the fissures, and the fissure interval. Geometric factors in the two paths were also estimated by using the apparent diffusivity and diffusion coefficients for free ions; they were estimated at ∼0.13 for fissures and ∼0.01 for the mortar matrix. This model was applied to other researchers’ data to estimate the effective diffusion coefficient. This model and estimation method show the consistency of the data from through-diffusion and penetration experiments.