hollow fiber filter system used for liquid radioactive

- _ _ _ _ _ ' , - , ,. 1 - | ? , , Mrs. Leo Drey JuN 15 !E9,. 515 West Point Avenue University City, MO 63130 Dear Mrs. Drey: I received your April 24, 1989 letter in which you requested information on a hollow fiber filter system used for liquid radioactive waste filtration at nuclear power plants. Your letter cited an inspection report from the Callaway County Nuclear Station that described the " reuse" of the filters after cleaning. You said in your letter that you did not understand how a ' filter could be reused. There are several types of reusable liquid radwaste filters currently in use at nuclear power plants. They provide the necessary filtration of the liquid radwaste stream without creating the solid radwaste problem of disposable filter cartridges, the type of filtration system replaced at the Callaway plant. I have enclosed one section from the document entitled, "The Use of Filtration to Treat Radioactive Liquids in Light-Water Cooled Nuclear Reactor Power Plants," (NUREG/CR-0141) which addresses reusable filters. Unfortunately, this document does not address the hollow fiber filter system specifically, however, it works essentially the same as the porous metallic filters described in 4.2.1.1 of the enclosed materials. The hollow fiber filter system installed at the Callaway plant consists of 32 , ' filter modules enclosed in a unit approximately 5 feet tall that is designed to handle the flow of Callaway's liquid radioactive waste system. The filter system is essentially a " membrane system", where each filter module consists of a bundle of spaghetti sized-hollow tubes that hang down vertically from the attachment point, and filtration is provided as the liquid radwaste stream flows through the nominal 0.1 micron pore openings of the fibers. The hollow fiber filter tubes are made from treated polyvirtyl alcohol, a type of plastic. j Cleaning of these filters for reuse is accomplished by the backflushing i procedure, which is described in the enclosed materials. Two hollow fiber filter systems are currently marketed in the United States. Ons is manufactured and marketed by the Japanese Gas Company (JGC). The other is manufactured by Toshiba, and marketed in the United States by HPD, Inc. The Callaway Plant's system was designed by Toshiba, and if you desire more information about that specific system, I suggest that you contact HPD. Their address is 1717 N. Naper Boulevard, Naperville, IL, 60566. 8906290138 890615 PDR WASTE WM-3 PDC iJtJ 4 _-__ m.3 ;

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Page 1: hollow fiber filter system used for liquid radioactive

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Mrs. Leo Drey JuN 15 !E9,.515 West Point AvenueUniversity City, MO 63130

Dear Mrs. Drey:

I received your April 24, 1989 letter in which you requested information on ahollow fiber filter system used for liquid radioactive waste filtration atnuclear power plants. Your letter cited an inspection report from theCallaway County Nuclear Station that described the " reuse" of the filtersafter cleaning. You said in your letter that you did not understand how a'

filter could be reused.

There are several types of reusable liquid radwaste filters currently in useat nuclear power plants. They provide the necessary filtration of the liquidradwaste stream without creating the solid radwaste problem of disposablefilter cartridges, the type of filtration system replaced at the Callawayplant. I have enclosed one section from the document entitled, "The Use ofFiltration to Treat Radioactive Liquids in Light-Water Cooled Nuclear ReactorPower Plants," (NUREG/CR-0141) which addresses reusable filters.Unfortunately, this document does not address the hollow fiber filter systemspecifically, however, it works essentially the same as the porous metallicfilters described in 4.2.1.1 of the enclosed materials.

The hollow fiber filter system installed at the Callaway plant consists of 32 ,

filter modules enclosed in a unit approximately 5 feet tall that is designedto handle the flow of Callaway's liquid radioactive waste system. The filtersystem is essentially a " membrane system", where each filter module consistsof a bundle of spaghetti sized-hollow tubes that hang down vertically from theattachment point, and filtration is provided as the liquid radwaste streamflows through the nominal 0.1 micron pore openings of the fibers. The hollowfiber filter tubes are made from treated polyvirtyl alcohol, a type of plastic. j

Cleaning of these filters for reuse is accomplished by the backflushing i

procedure, which is described in the enclosed materials.

Two hollow fiber filter systems are currently marketed in the United States.Ons is manufactured and marketed by the Japanese Gas Company (JGC). The otheris manufactured by Toshiba, and marketed in the United States by HPD, Inc.The Callaway Plant's system was designed by Toshiba, and if you desire moreinformation about that specific system, I suggest that you contact HPD. Theiraddress is 1717 N. Naper Boulevard, Naperville, IL, 60566.

8906290138 890615PDR WASTE .

WM-3 PDC

iJtJ 4_-__

m.3 ;