Pool scrubbing

A-9b. J. Hakii, H. Kaneko, M. Fukasawa, Y. Masahiro, and M. Matsumoto, Experimental Study of Aerosol Removal Effect by Pool Scrubbing, Second Workshop on LWR Severe Accident Research at JAERI, Tokyo, Japan, 1991. 

A-9c. K. Hashimoto, K. Soda, and S. Uno, High Pressure Pool Scrubbing Experiment for a PWR Severe Accident, Proceedings of the ANS International Topical Meeting, Portland, Oregon, July 1991. 

The purpose of this question is to find out whether any passive sink for the iodine has been provided to supplement the natural iodine removal mechanisms, like deposition, adsorption, chemical reaction, mass transfer into the water pool or into the droplets, and pool scrubbing, etc. Table 6 presents a summary of the responses. Except the borax used in the ice condenser of the Loviisa units (Finland) no other passive means have been reported. 

Adsorption/deposition on walls and aerosol particles, removal by mass transfer Into pool water or Into droplets, wetwell pool scrubbing, etc. 

Kashiwazaki Kariwa -3 BWR Toshiba 11.8.1993 3293 Improved MARK-11 Containment gas volume 14400 Drywell gas volume 8700 Wetwell gas volume 5700 Wetwell pool volume 4000 Injection phase capacity 0 m3/h Recirculation phase capacity 1690 m3/h Chemical additive No none - Prefilter - HEPA >99.97 % - Charcoal filter > 99.99 % suppression pool scrubbing... 

Kashiwazaki Kariwa -3 - Spray - SGTS (2) Filter - Suppression pool scrubbing in case of containment venting PASS (3) Yes ... 

Table 7.12. Results of the ACE pool scrubbing tests (according to Ramsdale et al., 1992 by courtesy of the European Conununities)...

Guntay, S. Experiment Poseidon Pool scrubbing effect on iodine decontamination. Paper presented at the ENC 90, ENS/ANS - Foratom Conf. Lyon, Sept. 1990 Hahn, R., Ache, H. J. Thermodynamic calculations on the behavior of gaseous iodine species following a hypothetical severe LWR accident. Nucl. Technology 67,407-410 (1984) Harman, N. F., Clough, P. N. A review of radionuclide release and transport in recent inpile experiments. Report EUR 14230 EN (1992)... 

Ramsdale, S. A., Bamford, G. J., Fishwick, S., Starkie, H. C. Status of research and modelling of water-pool scrubbing. Report EUR 14566 EN (1992)... 

Pool scrubbing is produced in the secondary side of the broken steam generator, starting with the gap release, at 8276 s, and ending the dryout of the failed steam generator at 16401 s. During this time, 7.5 Kg of materials, most of it Cs(OH), are retained, as given in table 4.3.2.3. Nevertheless, it is considered that the SPARC model in MELCOR does not properly represent the complicated phenomena taken place under such accidental conditions. 

Table 4.3.2.3.- Pool Scrubbing in Broken Steam Generator.

Pool scrubbing may be particularly important in the secondary side of a broken steam generator, mainly if feed water is added to prevent its dryout. Nevertheless, the SPARC models included in MELCOR may not represent correctly the complicated phenomena taking place under such accidental circunstances. 

The scrubbing liquid is fed into the pool at the bottom of the scrubber and later recirculated from the entrainment separator baffles by gravity instead of being circulated by a pump as in venturi scrubbers. Many devices using contactor ducts of various shapes are offered commercially. The principal advantage of this scrubber is the elimination of a pump for recirculation of the scrubbing liquid. 

Scrub radioactive materials Suppression pool Containment spray system Scrub radioactive materials Suppression pool Containment spray system... 

The bottom section of the main column provides a heat transfer zone. Shed decks, disk/doughnut trays, and grid packing are among some of the contacting devices used to promote vapor/liquid contact. The overhead reactor vapor is desuperheated and cooled by a pumparound stream. The cooled pumparound also serves as a scrubbing medium to wash down catalyst fines entrained in the vapors. Pool quench can be used to maintain the fractionator bottoms temperature below coking temperature, usually at about 700°F (370°C). 

Citrus Fruit Types. The method previously described 11) consisted essentially of scrubbing the fruits with a warm 10% trisodium phosphate solution, rinsing with distilled water, halving each fruit, and reaming the juice and pulp from each half with a power juicer. Pieces of pulp adhering to the insides of the individual hemispheres of peel were carefully scraped free and combined with the remainder of the pulp and juice. Independent analyses were then completed on the discrete peel and pulp-juice samples. Whenever desirable the flavedo and albedo components of the peel were separated with peeling tools, and each was pooled and analyzed. 

Approximately 8 pounds of fruit were scrubbed manually in warm 10% trisodium phosphate solution. One hemisphere of peel was then removed from each fruit, using a household-type peeler. From the pooled segments of peel a 1-pound subsample was used for processing. 

Pome Fruit Types. As with citrus fruit types, the method of sample preparation was modified for the parathion studies. In the earlier studies the DDT-treated apples and pears were scrubbed in a warm 10% solution of trisodium phosphate, and all the peel was removed from the water-rinsed fruit with a household-type potato peeler. The pooled samples of peel and pulp were then processed independently to recover the contained toxicant for subsequent estimation. 

Hydrogen chloride typically is the desired chlorine-containing product in combustion, because it can easily be removed from the flue gas by a scrubbing process. However, even HCI may create some problems, because it can inhibit oxidation of combustibles such as CO under postflame conditions. The interaction of HCI with the O-H radical pool is quite complex, and even though the overall mechanism of inhibition is known [336], details are still under investigation. 

Pulchan [106] thus used DMBA as a derived marker of vascular plant material (trees and scrubs) in offshore sediments in Trinity Bay (Figs. 6-8). Such terrestrial organic matter may play a significant role in the productivity of marine ecosystems by adding to the marine carbon pool. 

The self-depressurization of the Primary System, the scrubbing effect of the pools and the absence of significant Reactor Containment pressurization under all accident conditions drastically reduce radioactive releases to the environment,... 

Reactor pool (decay heat removal and fission product scrubbing) X Concrete pool containing 6000 m of cold and boronated water... 

Fission product containment Intermediate pool and reactor pool Containment Passive (A) Passive (A) Scrubbing effect provides sigmfioant decontammation factor No containment pressurization is possible... 

Ex-5. D.A. Powers and J.L. Sprung, A Simplified Model of Aerosol Scrubbing by a Water Pool Overlying Core Debris Interacting With Concrete, NUREG/CR-5901, SAND92-1422, Sandia National Laboratories, Albuquerque, NM, November 1993. 

A-11. D.D. Paul, L.J. Flanigan, R.A. Cudnik, and J.C. Cunnane and R.P. Collier, Radionuclide Scrubbing in Water Pools, Volume 1 Gas-Liquid Hydrodynamics, NP-4154, Volume 1, Battelle Columbus Laboratory, Columbus, OH, August 1985. 

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