ML19296C817

Operating Procedures for Process Control Program

ML19296C817
Person / Time
Site:	Arkansas Nuclear
Issue date:	12/10/1979
From:	ARKANSAS POWER & LIGHT CO.
To:
Shared Package
ML19296C816	List: ML19296C814 ML19296C817
References
PROC-791210, NUDOCS 8002280559
Download: ML19296C817 (10)

Text

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v a e PROCESS CONTROL PROGRAM

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g g ab Incontainer Solidification EfEA3 I'O'.'.ER & UGHT CO.

lECil. & DiV. SERVICES 1.0 Purpose .

1.1 The purpose of the Process Control Program (PCP) for -

incontainer solidification is to provide a program which will assure a solidified product with no free liquid prior to trans-portation for disposal.

The program consists o ' three major steps, which are:

a. Procedures for collecting and analyzing samples;

b. Procedures for solidifying samples;

c. Criteria for process parameters for acceptance or rejection as solidified waste.

2.0 System Description The systems described herein are designed to handle the solidification of liquids, evaporator bottoms or other concen-trated liquids, spent resin, filter sludge and other miscella-neous wastes. Concentrated liquids are processed at elevated temperatures as required to key the salts in solution. The various operations are as described below.

2.1 h'aste_ _ Feed System 2.1.1 Concentrated and Miscellaneous Liquids The waste feed system consists of a progressive cavity positive displacement pump mounted on a bed plate and a waste supply line to convey waste to the fill head. The pump takes suction from the liquid waste storage tank and pumps the waste into the liner. The liner is filled until a preset level is reached as detected by a level sensor suspended from the fill head.

2.1.2 Bead Resin, Powdered Resin & Filter Sludge The waste feed system consists of a progressive cavity positive displacement pump which takes suction from the discharge of the plant installed transfer pump. The pump capacity is adjusted to be lower than the transfer pump with the excess being recirculated to the holdup tank. The pump dis-charges to the liner and is stopped when the resin level reaches a preset level. A dewatering pump, operating during the fill cycle at a flow rate less than the progressive cavity pump, continues to dewater the liner until loss of flow is detected, 8002c30 5N

PEMD!ARY COPY At this time the dewatering pump is stopped and restarted after ,

the pump is restarted. During the time the pump is stopped the plant transfer pump is kept in a recirculation mode. The fill and dewater procedure is repeated entil the dewatering cycle no longer brings the resin level down below the preset level. Based on the liner size used a predetermined quantity of water is added back into the liner through the dewatering element to fluff the bed to relieve any bed packing. -

Liners used for powdered resin and filter sludge have special bottom designs to preclude plugging of the dewatering elements.

2.2 Cement Feed Subsystem

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Cement and additives are added from bags into the respective hoppers and the material is mixed as it enters the cement metering unit. Air under pressure is supplied to the metering unit from an air compressor. A rotary valve arrangement in the metering unit allows specifp;a amounts of cement and additives to etter into the cement / additive feed line where it is conveyed by air to the fill head. The cement feeder can be up to 150 feet from the cask being filled. The quantity of additive required is determined by the pli of the waste af ter any waste conditioning or pretreatment.

2.3 Mixing Each liner is supplied with an internal mixing device designed to provide thorough mixing of the entire liner contents.

A mixing motor mounted on the top of the liner prior to the filling operation is started prior to the addition of cement.

Mixing continues for approximately twenty minutes or until the motor automatically trips off due to high resistance to mixing.

The mixture will be completely firm within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and be suit-able for transport.

2.4 Vent Air Filter Subsystem The fill head also includes an elbowed vent line. The vent line is hard piped to the edge of ehe cask where hoses can be connected to allow the air being vented from the cask to be conveyed to the vent air filter. This unit uses flat fabric filters to remove particulates from the vent air.

. 2 E ENARY COPY 3.0 Collect _i_on and Analysis of Samples 3.1 General Requirements 3.1.1 As required by the Radiological Effluent Technical Specifications for PWR'sl and pRW's2 the PCP shall be used to verify the solidification of at least one representative '

test specimen from at least every tenth batch of each type of wet radioactive waste (e.g. evaporator bottoms, boric acid solution, sodium sulfate solutions, resin and precoat filter sludge).

3.1.2 For the purposes of the PCP a batch is defined as that quantity of waste required to fill a disposable liner to the waste level indicator.

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3.1.3 If any test specimen fails to solidify, the batch under test shall be suspended until such time as addition-al test specimens can be obtained, alternative solidification parameters can be determined in accordance with the Process Control Program, and a suosequent test verifies solidification.

Solidification of the batch may then be resumed using the alter- ,

nate solidification parameters determined.

3.1.4 If the initial test specimen f rom a batch of waste fails to verify solidification then representative test specimens shall be collected from each consecutive batch of the same type of waste until three (3) consecutive initial test specimens demonstrate solidifications. The Process Control Program shall be modified as required to assure solidification of subsequent batches of waste.

3.1.5 For high activity wastes, such as sodium sulfate from regeneration of deep bed resins, where the handling of samples could result in personnel radiation exposures which are inconsistent with the ALARA principle, representative non-radioactive samples wi]l'be producea and tested. These samples should be as close to the actual waste in their physical and chemical properties as possible to verify proper solidification parameters.

3.2 Collection of Samples

• 3.2.1 Rad _i_ological Protection These procedures must be followed during sampling to minimize personnel exposure and to prevent the spread of contamination.

3.2.1.1 All persons involved in the collecting and handling of test samples shall wear adequate protective clothing which at a minimum will include cloth gloves, rubber gloves and apron or lab coat.

'E_U!MY COPY

. 3.2.1.2 Any additional requirements established by the plant Health Physics Department must also be followed.

3.2.1.3 Test samples which use actual waste will be disposed of by belug solidified in the liner.

3.2.1.4 A Waste Solidification Data Sheet '

will be maintained for each test sample solidified. Each data sheet will contain pertinent information on the test sample and the batch numbers of wastes solidified based on each test s ample .

3.2.2 Waste Solidification Data Sheet The Waste Solidification Data Sheet will contain

,- pertinent information on the characteristics of the test sample solidified so as to verify solidification of subsequent batches of similar wastes without retesting.

3.2.2.1 The Test Sample Data will include, but not be limited to, the type of waste solidified, major consti-tuents, percent solids, pH, volume of sample, amount of oil in sample and the ratio of the sample volume to the final volume of the solidified product.

3.2.2.2 The Waste Solidification Data Sheet will include the Batch Number, Batch Volume, and Date Solidified, for each batch solidified based on sample described on the Test Sample Data Sheet.

3.2.3 Collection of Samples 3.2.3.1 Evaporator bottoms are normally stored at elevated temperatures (1600 to 1800) and must therefore be collected in insulated containers. It is recommended that stainless steel thermos b.ottles be used.

3.2.3.2 Two samples shall be taken for analysis.

Sample sizes shall be compatible with the standard size sample used for the radioactivity analysis and the second for the chemical amalysis. If the radioactivity levels are too high to permit full size samples to be taken then smaller samples shall be taken with the results corrected accordingly. Sample sizes '

shall be determined by the plant Health Physics Staff.

3.2.3.3 Samples should be drawn at_least six hours prior to the planned waste solidification procedure to allow adequate time to complete the required testing and verifi-cation of solidification.

3.2.3.4 The tank containing the waste to be solidified should be mixed by recirculating the tank contents for at len.st one volume change prior to sampling to assure a representative sample.

4 E O!MY COPY 3.2.3.5 If the contents of more than one tank are to be solidified in the same liner then representative samples of each tank should be drawn. These samples should be of such size that when mixed together they form samples of standard size as prescribed in Section 3.2.3.2. If the contents of a particular tank represents X% of the total waste quantity to be solidified then the sample of that tank should be of such size to represent X% of the composite samples. .

3.3 Analysis of Samples This document only defines the parameters to be analyzed and not the methodology. This is left to the plant staff.

a. pH

- b. Boron or Boric Acid

c. Sulfates

d. Detergents

e. Oil

f. Weight % Solids

g. Any other suspected major constituent 4.0 Test Solidification and Acceptance Criteria 4.1 Waste Conditioning 4.1.1 prior to the test sample solidification the pH of the sample shall be adjusted to a range of 5 to 8 if Metso Beads are used or a range of 8 to 10 if they are not used.

4.1.2 For Boric Acid wastes it is recommended that sodium hydroxide be used to adjust the pH.

4.1.3 If large quantities of detergents are present, the sample should be treated with an anti-foaming agent. The quantity of anti-foaming agent required should be recorded.

4.1.4 If oil is present in quantities greater than 1%

by volume, the oil should either be removed by skimming or emulsification agents should be used to break up the oil. The quantity of any substance added to the sample for this purpose should be rccorded.

4.2 Test Solidif2 cation 4.2.1 Any sample to be solidified shall be.pretreated as specified in Section 4.1.

4.2.2 Test Solidifications should be conducted using a 1000 ml. disposab'.e beaker or similar size container. Mixing should be accomplished by ' stirring with a rigid stirrer until a homogeneous mixture is obtained, but in no case for less than five (5) minutes.

• J E U \'ARY. COPY 4.2.3 Measure into the mixing vessel 400 ml. of the waste to be solidified.

4.2.4 Measure out 400 ml. (590 grams) of loose or uncompacted cement and 40 ml. (60 grams) of uncompacted Metso Beads. ,

4.2.5 Mix the cement and Metso Beads together and -

slowly add this mixture to the test sample while it is being stirred. .

4.2.6 After ten (10) minutes of mixing and a homogen-eous mixture is obtained allow the waste to stand for a minimum of 30 minutes.

4.3 Solidification Acceptability The following criteria define an acceptable solidifi-cation process and process parameters.

4. 3.1 The sample solidification is considered acceptable if there is no visual or drainable free water.

4.3.2 The sample solidification is considered acceptable if upon visual inspection the waste appears that it would hold its shape if removed from the beaker and it resists penetration by a rigid stick.

4.4 So_1_idification Unacceptability 4.4.1 If the waste f ails any of the criteria set forth in Section 4.3, the solidification will.be termed unacceptable and a new set of solidification parameters will need to be es-tablished under the procedures in Section 4.5.

4.4.2 If the test solidification is unacceptable then the same test procedures must be followed on each subsequent bctch of the same type of waste .until three consecutive test samples are solidified.

4.5 Alternate Solidification Parameters 4.5.1 If a test sample fails to provide acceptable solidification of the waste the following procedures should be followed.

(1) Mix equal volumes of dry cement and water to ensure that the problem is not a bad batch of cement.

(2) Add additional caustic solution to the sample to raise the pH above 8.

(3) If the waste only partially solidified, try using lower waste to cement ratios. Try 350 ml. of waste to ,400 ml. of cement and 40 ml. of Metso Beads and continue reducing

• the waste volume by 25 ml. with each test until the acceptability criteria of Section 4.3 are met.

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?E_1 NARY COPY CALCULATION SHEET FOR RESIN, POWDEX & FILTER SLUDGE (DEWATERED)

Volume of Dewatered Waste Transfered to Liner ft3 (1)

(the recommended waste volume for each size liner is given below,. additional data is on the reverse side).

Quantity of Water to Be Added Waste Vol ft3 (from (1))

x 2.5 gallons of water per ft 3 of waste

.' gallons of water to be added (2)

Divide the gallons of water in (2) by the flowrate of water into the liner to determine how long the pump should operate:

gallons of water

= minutes gallons per minute pumping time Quantity of Cement to be Added Waste Vol ft3 (from (1), if greater than recommended see instruction-removal of excess resin.

x 64.0 lbs. cement per ft 3 of waste lbs. of cement (3)

The recommended quantity of cement is 64.0 pounds (0. 68 bags) per f t3 of waste.

9 Maximum Waste Volumes-ft3 hN-100 Series 1 - 90, HN-100 Series 2 - 87 , HN-100S - 109, HN-200 - 56, HN-600 - 56 .

3E V NAlY COPY Liner: HN-100 HN-100S HN-200 HN-600 Series 1 Series 2 Max. Capacity ft3: 1 121 116 145 75 75 Max. Rad Level R/hr: 12 12 5 800 100 3

Wasto Volume-ft Maximum: 90 87 109 56 56 -

Water Added - gallons at Max. Waste Volume: 225 217.5 272.5 140 140 Cement Added - pounds at Max. Waste Volume: 5760 5568 6976 3584 3584 (61)1 (59)2 (74)2 (38)2 (38)2

1. Based on licensed pay load less weight of liner and mixing blades with a solidified product density of 101.5#/ft3,

2. Numbers in parenthesis indicate the number of one (1) ft3 bags to be added rounded off to the nearest whole bag.

]ENNMY COM'

Measurement of Waste Volume The quantity of waste can be measured using a graduated, metal metering stick. The stick is inserted into the liner until it rests on the settled resin. The volume of the resin in the liner is determined by measuring the distance from the top of the reain.to the top edge of the loading flange. The minimum distances which correspond to the maximum waste volume are as follows

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Type of Cask Maximum Resin Volume Distance Resin to (ft 3) Top of Flange (in)

HN-100 (Series 1) 90 31.5 HN-100 (Series 2) 87

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32.75 HN-100S 109 23.15 HN-200 HN-600 If the radiation levels at the top of the liner are high, a horizontal member can be attached to the metering stick to permit remote handling into the liner. If desired, a flat disk can be attached to the bottom of the metering stick so that it will not penetrate into the resins while making measurements.

Excess Resins In the event that the quantity of resins in the liner exceed the vclues noted above it will be necessary to remove a portion of the resin prior to solidification. Otherwise, the allowable weight or volume of the liner will be exceeded or it will not be possf.ble to add the required amount of cement.

For removing resins, water should be added to the liner until it covers the resin by 12 to 18 inches. A pump should be used to recirculate the water above.the resin and to fluidize the upper portion of the resin bed. This is accomplished by using the reture.

line to agitate the bed and the inlet line to pickup the suspended material. Af ter an upper portion of the bed has been resuspended, the outlet of the pump should be diverted to carry off the excess '

resin. The water and resin from the liner should be returned to waste hold up tank.