skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Modeling fission product vapor transport in the Falcon facility

Abstract

An extensive database of aerosol Experiments exists and has been used for checking aerosol transport codes. Data for fission product vapor transport are harder to find. Some qualitative data are available, but the Falcon thermal gradient tube tests carried out at AEA Technology`s laboratories in Winfrith, England, mark the first serious attempt to provide a set of experiments suitable for the validation of codes that predict the transport and condensation of realistic mixtures of fission product vapors. Four of these have been analyzed to check how well the computer code VICTORIA can predict the most important phenomena. Of the four experiments studied, two are reference cases (FAL-17 and FAL-19), one is a case without boric acid (FAL-18), and the other is run in a reducing atmosphere (FAL-20). The results show that once the vapors condense onto aerosols, VICTORIA can predict their deposition rather well. The dominant mechanism is thermophoresis, and each element deposits with more or less the same deposition velocity. The behavior of the vapors is harder to interpret. Essentially, it is important to know the temperature at which each element condenses. It is clear from the measurements that this temperature changed from test to test-caused mostly by themore » different speciation as the composition of the carrier gas and the relative concentration of other fission products changed. Only in the test with a steam atmosphere and without boric acid was the assumption valid that most of the iodine is cesium iodide and most of the cesium is cesium hydroxide. In general, VICTORIA predicts that, with the exception of cesium, there will be less variation in the speciation-and, hence, variation in the deposition-between tests than is in fact observed. VICTORIA underpredicts the volatility of most elements, and this is partly a consequence of the ideal solution assumption and partly an overestimation of vapor/aerosol interactions.« less

Authors:
;  [1];  [2]
  1. Joint Research Center, Ispra (Italy)
  2. AEA Technology, Winfrith (United Kingdom)
Publication Date:
OSTI Identifier:
64628
Resource Type:
Journal Article
Journal Name:
Nuclear Technology
Additional Journal Information:
Journal Volume: 110; Journal Issue: 2; Other Information: PBD: May 1995
Country of Publication:
United States
Language:
English
Subject:
22 NUCLEAR REACTOR TECHNOLOGY; 21 NUCLEAR POWER REACTORS AND ASSOCIATED PLANTS; WATER COOLED REACTORS; REACTOR ACCIDENTS; FISSION PRODUCTS; VAPOR CONDENSATION; ENVIRONMENTAL TRANSPORT; RADIOACTIVE AEROSOLS; V CODES; THERMOPHORESIS; DEPOSITION; FISSION PRODUCT RELEASE

Citation Formats

Shepherd, I M, Drossinos, Y, and Benson, C G. Modeling fission product vapor transport in the Falcon facility. United States: N. p., 1995. Web.
Shepherd, I M, Drossinos, Y, & Benson, C G. Modeling fission product vapor transport in the Falcon facility. United States.
Shepherd, I M, Drossinos, Y, and Benson, C G. 1995. "Modeling fission product vapor transport in the Falcon facility". United States.
@article{osti_64628,
title = {Modeling fission product vapor transport in the Falcon facility},
author = {Shepherd, I M and Drossinos, Y and Benson, C G},
abstractNote = {An extensive database of aerosol Experiments exists and has been used for checking aerosol transport codes. Data for fission product vapor transport are harder to find. Some qualitative data are available, but the Falcon thermal gradient tube tests carried out at AEA Technology`s laboratories in Winfrith, England, mark the first serious attempt to provide a set of experiments suitable for the validation of codes that predict the transport and condensation of realistic mixtures of fission product vapors. Four of these have been analyzed to check how well the computer code VICTORIA can predict the most important phenomena. Of the four experiments studied, two are reference cases (FAL-17 and FAL-19), one is a case without boric acid (FAL-18), and the other is run in a reducing atmosphere (FAL-20). The results show that once the vapors condense onto aerosols, VICTORIA can predict their deposition rather well. The dominant mechanism is thermophoresis, and each element deposits with more or less the same deposition velocity. The behavior of the vapors is harder to interpret. Essentially, it is important to know the temperature at which each element condenses. It is clear from the measurements that this temperature changed from test to test-caused mostly by the different speciation as the composition of the carrier gas and the relative concentration of other fission products changed. Only in the test with a steam atmosphere and without boric acid was the assumption valid that most of the iodine is cesium iodide and most of the cesium is cesium hydroxide. In general, VICTORIA predicts that, with the exception of cesium, there will be less variation in the speciation-and, hence, variation in the deposition-between tests than is in fact observed. VICTORIA underpredicts the volatility of most elements, and this is partly a consequence of the ideal solution assumption and partly an overestimation of vapor/aerosol interactions.},
doi = {},
url = {https://www.osti.gov/biblio/64628}, journal = {Nuclear Technology},
number = 2,
volume = 110,
place = {United States},
year = {Mon May 01 00:00:00 EDT 1995},
month = {Mon May 01 00:00:00 EDT 1995}
}