ML20126F229

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Forwards Process Control Program Covering Solidification &/Or Dewatering Using NUS Supplied Temporary Processing & Solidification Sys & Solidification Using Permanently Installed Asphalt Extruder/Evaporator
ML20126F229
Person / Time
Site: Fermi DTE Energy icon.png
Issue date: 06/12/1985
From: Jens W
DETROIT EDISON CO.
To: Youngblood B
Office of Nuclear Reactor Regulation
References
NE-85-0722, NE-85-722, NUDOCS 8506170406
Download: ML20126F229 (10)


Text

. - -

I J -c. .: Wayne H. Joni

, Vice Prssident '

  • Nuclear Operations Fu mi2

~ 6400 North Dixie Highway i n Newport uctugan 48 tee June 12, 1985 I I I 01a sas-4 iso .NE-85-0722 Director of NuclearuReactor Regulation Attention: Mr. B. J. Youngblood, Chief Licensing Branch N o. 1 Division of Licensing U.- S.' Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Youngblood:

Reference (1)- Fermi 2 NRC Docket No. 50-341 Subjects -Fermi 2 Process Control Program Please< find a'ttach'edlthe: proposed Fermi 2 Process Control'

-Program (PCP). .It' covers solidification and/or dewatering

using:the NUS supplied temporary processing and solidifi-cation system-and solidification using the permanently-

-installed ~ asphalt extruder / evaporator. The approval of this PCP istneeded to'-support'heatup phase and.thus is needed approximately one week after initial criticality. It should be noted that this material has been submitted informally in the past during the review process leading to issuance of the-Fermi'2 Technical Specifications.

Testingoof'theLpermanently installed solidification system will begin soon after. initial criticality. Testing will confirm the parameters for proper solidification of-waste.

The test results relating to solidification will be submitted for review by the NRC staff upon completion.

Please direct any questions to Mr. O. K. Earle at (313) 586-4211.

Sincerely, Enclosure .

cca Mr. P. M. Byron Mr. M. D. Lynch Mr. C. R. Nichols USNRC: Document Control Desk Washington, D.C. 20555 850617 PDR A 6 B50612 K 05000341

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FERMI 2 PROCESS CONTROL PROGRAM The Fermi 2' Process Control Program (PCP) covers three dis-Ltinct_ processes for solidification or dewatering of radio-active-waste. The three processes are described below:

1. For the dewatering of NUS Corporation " TRANSFIX"

. temporary liquid radwaste system disposable pressure vessels, Fermi 2.will follow the PCP described in the NUS document FI-002-Revision.C which was submitted in a letter to the NRC dated October 11, 1984.

2. For the solidification of radioactive waste using the NUS Corporation temporary radwaste solidification system, Fermi :2 will follow the PCP described in the NUS document SS-001 Revision F, with. approved Procedure

-Change Request (PCR) SS-001/F1, which was submitted in a letter to the NRC dated December 18, 1984.

3. :For the solidification oh radioactive waste using the Fermi-2 permanent solid radwaste system, Fermi 2 will

' follow the PCP described in Attachment 1.

The General' Supervisor - Radwaste is responsible for the implementation of the_ Fermi 2 PCP. Nuclear Quality Assurance will audit the solidification and dewatering of radioactive waste including record keeping activities in accordance with QAPR 24.

Attachment 1

\

PROCESS CONTROL PROGRAM

-FOR THE PERMANENTLY INSTALLED FERMI 2 RADWASTE SOLIDIFICATION SYSTEM C-I. Introduction LLong-term experience with various binding. agents used

.to solidify radioactive waste indicates that stringent process controls are required to assure that complete solidification takes, place.

.The purpose of this document is to identify process parameters within which the-Fermi 2 radwaste solidifica-tion system must be operated to obtain. complete solidif-ication.- Solidification of radwaste at Fermi 2 using permanent. plant equipment is accomplished using a Waste.

Chem Inc. (Werner and Pfleiderer Corporation) (WPC)

Volume Reduction and Solidification System (VRS). This

~ system is described in the Topical Report, "Radwaste

~

~

Volume Reduction and Solidification System", Report lNo.'WPC-VRS-001, November 1976 with Revision 1, May,

, 1978.-

' Dun WPC-VRS System utilizes a thermal process and therm-

?! oplastic binder material (asphalt) to reduce the volume, and encapsulate and solidify process' wastes.

Thermoplastic. materials reversibly soften (liquify)

--when heated and-harden-(solidify) when cooled. This

^

solidification process is insensitive to waste feed chemistry; i .e.,pH, chemical species, etc., and requires only the removal of heat to assure complete.

solidification. ,

. 1II. Solid Waste System Description A. Solidification.

The WPC-VRS System is a one-step VRS process. A

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heated extruder / evaporator is employed to evapo-

- rate free water, mix and disperse radioactive waste in an asphalt matrix, and discharge the product into 55 gallon drums. Volume reduction is achieved by evaporation of water from the waste /

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- asphalt! mixture through devolatilizing ports located along the length of the machine. The 1 extruder / evaporator is maintained at elevated temperatures to control the evaporative rate and 1

a 4 , ,,. ,e ,. .,,4 >.m-e - ,,,,w-e. + p., _ , , - - , - . . . - -w--,~--. - ry,- - - , -

Attachment 1 maintain the waste / asphalt mixture in a fluid state until it is discharged into a container.

Cooling to ambient, temperatures causes the asphalt /

waste' mixture to harden and form a freestanding monolith. Elevated process temperatures assure complete; evaporation of free water; hence, no free

-water is present in the end product. A detailed

~

description of the solidification system can be found in Section 11.5-of the Fermi 2 FSAR, and details of.the various systems and interfaces are contained in FSAR Figures 11.2-2 (Sheets 1 and 3) and 11.2-1 (Sheets 7-12 and 14).

B.. Sources of Wastes Wastes to be processed by the permanent solid waste system are of three types:

. 1. Powdered resins and slurries from the reactor water clean-up system, the condensate deminer-alizers, backwash of the fuel pool and. rad-waste system filter /demineralizers, and rad-waste system etched disc filters.

2. Bead resins from the liquid radwaste system-demineralizers.

5 3. Concentrates from the liquid radwaste evapor-e ator bottoms and chloride waste tank.

During normal operations, powdered resins,-sludges, and bead resins are processed through the centri-

_fuge from the centrifuge feed tank. The dewatered radwaste is then " dry fed" by gravity to the extruder / evaporator, c

Additionally, powdered resins and sludges may be

" slurry fed" directly to the extruder / evaporator from the centrifuge feed tank. Bead resins may also-be " slurry. fed" to the extruder / evaporator from the slurry feed tank. Because of the larger amounts of water which must be handled by the extruder / evaporator in the slurry feed mode, processing times will be somewhat longer, although product adequacy will be unaffected.

Concentrated solutions of radsalts from the rad-waste evaporators are fed directly to the extruder / evaporator.

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4-Attachment - Regardless of the -. feed ' mode, waste feed rates are automatically:meaaured and regulated. Asphalt feed rates are automatically adjusted based on the

~~ waste' feed rate's to provide the-desired binder /

' waste ratio.

III.. Variables' Influencing'End Product Properties

'Certain process ~ variables have a direct bearing on the properties of'the final product.which relate to-the l ability to form a freestanding menolith with-no free water. Plant procedures.will-detail the sampling requirements:necessary to insure proper solidification.

The system will.normally be operated.with the extruder 1 feed within a specified.pH range in. order to protect equipment from corrosion, and operations within this range will: assure proper solidification and end-Lproduct.

'In accordance with.the foregoing limitations, the following variables influence the properties and consis-tency of the final solid product:

A. Asphalt' type; B. Waste chemical species being' incorporated into the; asphalt. matrix; C.- -Ratio of waste-to-asphalt; and

'Ih Process temperature.

A detailed discussion of the effect and' limitations placed on each of.the foregoing items follows:

A. Asphalt Type WPC recommends use of an oxidized petroleum-based asphalt, conforming to ASTM-D-312-71, Type'III requirements. ~This grade of asphalt has a low, residual,; volatile content, and a high - molecular weight. At room temperature, and at all normal ambient conditions, this material is a freestand-ing-monolith.

'B. Waste Chemical Species

.The waste chemical makeup might be expected to influence the ability of the extruder / evaporator to form a; satisfactory product.- In their Topical 3

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I Attachment l 2 ,

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' Report, WPC describ'es results of testing' performed to demonstrate the ability of the extruder /

evaporatory system.to produce an adequate product.

The simulated waste, systems tested are conserva-

'tively representative offthe Fermi-wastes expected

.to be processed by1the-extruder / evaporator _(boric acid and sodium sulfate should not be present in Fermi' wastes).

~

In support of the Fermi 2. installation, WPC per- .

formed additional testing,to confirm:the. adequacy of operation with dry feeds such as those result-ing.from processing by the centrifuge., These results confirm the_ adequacy.of product produced usingithe dry feed: mode._ ,

WPC has placed a limit of 1 percent oillin-the waste feed streams. An extensive review of-the entire Fermi liquid and solid radwaste processing systems failed to identify-a credible mechanism 4

for concentration of oil in solid waste processing

, feed streams, such that the 1l percent limit would be approached. Nevertheless, a process' limit of 1

? percent oil inLthe waste-feed stream to the

, extruder will be-maintained. Implementing proce-1dures will detail the ' methods used to ensure this

]_ :limitJis met. '

C. Ratio of Waste to Asphalt The limits for the ratio of waste to. asphalt to ensure an acceptable product _are presented in.

Table 1. Iffthe ratio of: waste-to-asphalt were to exceed the limits, the end product 1 viscosity will-

. increase and the end product may exhibit a grainy.  ;

texture. This could-result in " pyramiding" of the product in_the container with a loss of filling efficiency.-LWith lower than specified-ratios, product properties approach'those of pure asphalt, resulting in loss of volume reduction. In any event, the product will be a freestanding monolith upon cooling. Constant viewing of the product texture during container filling is available to

-the operator through a Closed Circuit Television Camera.

Desired ~ waste-to-asphalt ratios in the product are maintained automatically by a coordinated propor-tioning feed system to the extruder / evaporator.

In all feed modes, the solids content of the waste-  ;

4

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Attachment 1 stream is measured prior to initiation of feed flow. The measured solids content is used to de-termine the proper' waste and asphalt feed control settings by consulting a graph in the operating procedure. A' separate graph will be provided for each~ waste species and each feed mode.

In the centrifuge feed mode, the flow rate to the r centrifuge is controlled automatically using a flow control valve. With a uniform feed, the centrifuge will provide a uniform flow of dried (approximately 40-50 w/o solids) product as feed to the extruder / evaporator.

In both-slurry feed modes and in the concentrates feed mode, constant waste flow rates are main-tained by flow measurement with feed back control to variable speed metering pumps.

D. Process Temperature Profile A proper' temperature profile'along the length of-the_ extruder is required to ensure that free water is not discharged. The process temperature ranges

for each of the Fermi 2 waste types are given in Table 1.

L Low temperature alarms are provided to alert the operator to a low temperature out-of-specification condition.-

Should an out-of-specification condition persist for two (2) minutes, the extruder / evaporator will be automatically tripped to prevent free water from being discharged into the container. Under this-condition, residual free water in the extruder / evaporator cannot be discharged since the residual heat content of'the machine itself is sufficient to evaporate it.

IV. Spent Filters Spent cartridge filters will either be air-dried, compacted, and disposed of as Dry Active Waste (DAW),

placed in drums with an absorbent as required, or placed in drums to be filled with asphalt.

Spent cartridge bundles from the Waste-Collector Oil Coalescer or from the Floor Drain Oil Coalescer will be encapsulated in asphalt. Each bundle will be thorough-5

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Attachment:

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.ly. drip dried,.placed inLa drum, transferred to'the

,~ turntable-of the solidification systemi and thereupon.

. filled with asphalt / waste mixture from the extruder /

evaporator.

'This method of oil filter encapsulation will be proven during the preoperational test.

V. Conformance to 10CFR Part 61 (Land Disposal of Radioactive Faste)

A'. Fe'rmi-2 willimeet the. waste classification requirements of 10CFR61.55 by-the followings p.

l. -Measuring gamma-emitting; radionuclides and using interim' correlation' factors based on calculational methods described in the Atomic -Industrial Forum's

" Methodologies for Determining the Classification-of Low-Level Radioactive Wastes From Nuclear Power Plants."

2. Carrying out a sampling and analysis program

. -necessary to determine subsequent specific corre-lation factors to be used for the plant.

3. If the- subsequent. sampling and anaylsis program-indicates results such that the correlation

, factors 1b eing.~used may not give upperbound limits, then the wastes.will be stored until they can be classified on the basis of correlation factors developed-from actual sample analysis.

~

B. Fermi 2 will meet the waste form requirements of

~

10CFR61.56 when solidifying waste using the extruder /

evaporator by the following:

1. Class A wastes (as defined by.10CFR61.55) will be solidified in- accordance with this PCP. The end-product of this solidification process meets the requirements of 10CFR61.56a for this' class of -

4 waste.

t 6

nw-r Attachment 1

2. Prior to the solidification of class B and C wastes (as defined by 10CFR61.5S) with the installed Fermi 2. asphalt extruder system, waste-form test data will be submitted to the NRC for approval. Prior to such approval, class B and C wastes will either be a) dewatered and shipped in~ approved High-Integrity Containers, or b) solidified by a mobile vendor using an approved PCP.

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TABLE 1 PROCESS: PARAMETERS TO-

'2 ENSURE PROPER PRODUCT TEMPERATURE PROFILES

  • Resins / Sludges -

Zone: 1 2 3 4 5 6 7 8 160- 230- 260- 320- 350- 350- 180-

. Temperature-(*F)-140 max 200 270 320 350 380 380 200 Evaporator Bottoms zone 1- 2 3 4 5 6 7 8 160- 230- 260- 320- 350- 350- 320-Temperature ('*F) 140 max 200 270 320 350 380 380 370 WASTE / ASPHALT RATIOS *

-Evaporator. Bottoms 1 50/50 Resins / Sludges. 1 50/50

-LI'MIT ON OIL IN FEED STREAM

'One percent

' ASPHALT. TYPE Meet ASTM D-312-71, Type III

  • The values given in this section are testative. The preopera-tional test program will determine the high and low ranges of these variables for acceptable solidification. Final operating '

. points ~and acceptable ranges will then be incorporated in a

-revision to.this PCP.

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