1、Designation: D3803 91 (Reapproved 2014)Standard Test Method forNuclear-Grade Activated Carbon1This standard is issued under the fixed designation D3803; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is a very stringent procedure forestablishing the capability of new and used activated carbon toremove radio-labeled me
3、thyl iodide from air and gas streams.The single test method described is for application to both newand used carbons, and should give test results comparable tothose obtained from similar tests required and performedthroughout the world. The conditions employed were selectedto approximate operating
4、or accident conditions of a nuclearreactor which would severely reduce the performance ofactivated carbons. Increasing the temperature at which this testis performed generally increases the removal efficiency of thecarbon by increasing the rate of chemical and physical absorp-tion and isotopic excha
5、nge, that is, increasing the kinetics ofthe radioiodine removal mechanisms. Decreasing the relativehumidity of the test generally increases the efficiency of methyliodide removal by activated carbon. The water vapor competeswith the methyl iodide for adsorption sites on the carbon, andas the amount
6、of water vapor decreases with lower specifiedrelative humidities, the easier it is for the methyl iodide to beadsorbed. Therefore, this test method is a very stringent test ofnuclear-grade activated carbon because of the low temperatureand high relative humidity specified. This test method isrecomme
7、nded for the qualification of new carbons and thequantification of the degradation of used carbons.1.1.1 Guidance for testing new and used carbons usingconditions different from this test method is offered in AnnexA1.1.2 The values stated in SI units are to be regarded asstandard. No other units of
8、measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory
9、 limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD2652 Terminology Relating to Activated CarbonD2854 Test Method for Apparent Density of ActivatedCarbonE300 Practice for Sampling Industrial ChemicalsE691 Practice for Conducting an Interlaborat
10、ory Study toDetermine the Precision of a Test Method2.2 Code of Federal Regulations:CFR Title 49, Section 173.34, “Qualification, Maintenance,and Use of Cylinders3CFR Title 49, Part 178, Subpart C, “Specifications forCylinders32.3 Military Standards:MIL-F-51068D Filter, Particulate High Efficiency,
11、FireResistant4MIL-F-51079A Filter, Medium Fire Resistant, High Effi-ciency4MIL-STD-45662 Calibration Systems Requirements42.4 Other Standards:ANSI/ASME N45.2.6 Qualifications of Inspection,Examination, and Testing Personnel for Nuclear PowerPlants53. Terminology3.1 Definitions of Terms Specific to T
12、his Standard:3.1.1 counter effciency (CE)the fraction of the actualnumber of disintegrations of a radioactive sample that isrecorded by a nuclear counter.3.1.2 effciency (E)the percentage of the contaminantremoved from a gas stream by an adsorption bed; expressedmathematically as E = 100 P, where E
13、and P are given inpercent.1This test method is under the jurisdiction of ASTM Committee D28 onActivated Carbon and is the direct responsibility of Subcommittee D28.04 on GasPhase Evaluation Tests.Current edition approved July 1, 2014. Published September 2014. Originallyapproved in 1979. Last previo
14、us edition approved in 2009 as D3803 91 (2009).DOI: 10.1520/D3803-91R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe AS
15、TM website.3Published by the General Service Administration, 18th and “F” St., N. W.,Washington, DC 20405.4Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.5Available from American National Standa
16、rds Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.3 penetration (P)the percentage of the contaminant(CH3I) which passes through the equilibrated
17、test bed ofstandard depth, and is collected on the backup beds during thefeed and elution periods under specified conditions.3.1.4 relative humidity (RH)for the purpose of this testmethod, relative humidity is defined as the ratio of the partialpressure of water in the gas to the saturation vapor pr
18、essure ofwater at the gas temperature and pressure. At temperaturesbelow 100C, this is the normal definition and relative humid-ity can range from 0 to 100 %.3.2 Definitionsfor additional terms relating to thisstandard, see Terminology D2652.4. Summary of Test Method4.1 Both new and used carbons are
19、 first exposed to humidair (pressure, approximately 1 atm; temperature, 30.0C; rela-tive humidity, 95 %) for a pre-equilibration period of 16 h.During this pre-equilibration period, the test system may be rununattended with the required parameter monitoring and ad-equate control devices. Following p
20、re-equilibration, the airflow is continued for a two-hour equilibration period, duringwhich the acceptable variability of all parameters is reduced.The test system must be closely monitored and controlledduring the final four hours of the test. Qualification ofpersonnel to perform this testing must
21、meet or exceed ANSI/ASME N45.2.61978, Level II, which requires a combinationof education and actual test system operation experience.During the challenge or feed period, radio-labeled methyliodide at a mass concentration of 1.75 mg/m3of humid air flowis passed through the beds for a period of 60 min
22、. Followingthe feed period, humid air flow without test adsorbate iscontinued at the same conditions for a 60-min elution period.Throughout the entire test, the effluent from the sample bedpasses through two backup beds containing carbon having aknown high efficiency for methyl iodide. The two backu
23、p bedstrap essentially all the radio-labeled methyl iodide that passesthe test bed and provide a differential indication of theirefficiency. At the end of the elution period, the gamma activityof131I in the test and backup beds is measured by a gammacounter, and the percent of adsorbate penetrating
24、the test bed isdetermined.5. Significance and Use5.1 The results of this test method give a conservativeestimate of the performance of nuclear-grade activated carbonused in all nuclear power plant HVAC systems for the removalof radioiodine.6. Apparatus6.1 Sample Preparation Apparatus:6.1.1 Riffle Sa
25、mpler, in accordance with 32.5.2 of PracticeE300.6.1.2 Feed Funnel and Vibrator, in accordance with theProcedure Section of Test Method D2854.6.2 Sample and Backup Bed Assemblies:6.2.1 The sample bed canister and backup bed canistersmust each be either a single unit capable of containing carbonto a
26、depth of 50 6 1 mm, or they may be assembled from twoseparate units each capable of containing carbon to a depth of25 mm. Two backup canisters, each of 50 6 1 mm total depth,are required. Canisters may be reused after being decontami-nated to remove residual radioactivity. An acceptable bedconstruct
27、ion is shown in Fig. 1 with critical dimensions noted.6.2.2 Clamping assemblies are needed for sample andbackup beds. The only requirements for these assemblies arethat they provide a smooth sealing face, uniform alignment ofbed canisters, and sufficient clamping force so that the leak testin 10.2 c
28、an be met.Asuggested design for clamping assembliesis shown in Fig. 2.6.3 A schematic of a generalized test system is shown inFig. 3. This system is designed to operate at approximately30C and 95 % relative humidity, with a gas flow of 24.7 L/min* Standard canister dimension may be used in multiples
29、 if desired.Single test canisters of full depth may be used.1Bed holder2Adsorption media3O-ring gland4Perforated screen (both ends)5Retaining snap ring (both ends)6Baffle (both ends)7Holes for assembly tie-rods (four)FIG. 1 Adsorption Media Test Bed Holder (Canister)D3803 91 (2014)2at atmospheric pr
30、essure. If test conditions which differ signifi-cantly from these are required, then separate calibrations orinstrumentation, or both, may be required.6.4 Saturator SystemThis system may be a controlledtemperature saturator (bubbler) or spray chamber (environmen-tal condition generator), or any othe
31、r device of sufficientstability and capacity to supply the required mass flow of watervapor at test conditions.6.5 Flow GeneratorThis system may be an air compressorupstream of the test system or a vacuum pump downstream ofthe test system. A dryer, carbon adsorber, and HEPA (high-efficiency particul
32、ate air) filter are required for either system tocondition the inlet air. Flow measurement and control shouldbe accurate and stable to within 62 % of specified flow rate.System capacity shall meet or exceed the volumetric flowrequirements as calculated from the specified face velocity. Asurge tank a
33、nd pressure control valve should be employed ineither type of system to ensure stable and accurate flowmeasurement and control. For safety, it is important that thepressure system be equipped with a pressure relief valve. It isimportant that the pipe diameter and inlet air filters for avacuum system
34、 be designed and maintained to minimize thepressure drop from ambient to ensure that the specifications forabsolute pressure at the test bed are met (see Table 1).6.6 Moisture SeparatorA moisture separator should beused to protect the HEPA filter by removing large quantities ofentrained particulate
35、water, if present, after humidification. AHEPA filter (or equivalent) is required to function as a finaldroplet trap to remove small amounts of fine particulate waterfrom the carrier gas ahead of the test bed.6.7 Adsorbate SupplyThis system shall consist of a stain-less steel cylinder, pressure gage
36、, pressure regulator, and a flowregulator capable of providing a steady flow of the challengegas, that is, radio-labeled methyl iodide in dry nitrogen, for theduration of the test feed period. The point of injection into themain gas flow of the system must be such that the cross-sectional distributi
37、on of the adsorbate at the face of the test bedcan be ensured to be homogeneous.Amixing chamber, baffles,glass beads, etc. should be used to achieve adequate mixing.6.8 Constant Temperature CabinetAn enclosure and asso-ciated thermoregulatory system must be used that is capable ofmaintaining the inl
38、et gas stream temperature from the point ofhumidity control to the test bed, and the surface temperature of1Canister (four shown)2Inlet cap3Outlet cap4Thermocouple5Thermocouple fitting6Static tap7Tie bar (four)8O-ring sealsFIG. 2 Canister Assembly (Test or Backup Beds)TABLE 1 Parameter Specification
39、sNOTE 1Temperature, relative humidity, pressure, and gas velocity areto remain constant within the specified maximum variations throughoutthe entire test, that is, for each test period. Parameter excursions outsidethe limits specified in this table will invalidate the test results. If resultsbased o
40、n a test containing such variations must be reported, then thesevariations must be noted in the comments section of the external reportform and flagged in the parameter monitoring portion of the internalreport.ParameterPre-Equilibration(First 16 h)Equilibration,Challenge, and Elu-tion (Final 4 h)Tem
41、perature, C 30.0 0.4 30.0 0.2Range 29.6 to 30.4 29.8 to 30.2Relative humidity, % 91.0 to 96.0 93.0 to 96.0Flow, m/min 12.2 0.6 12.2 0.3Face velocity, m/min 11.6 to 12.8 11.9 to 12.5Absolute pressure, kPa 101 5 101 5Bed diameter and depth, mm 50 1 50 1Adsorbate concentration, mg/m3. 1.75 0.25Test dur
42、ations:Pre-equilibration, h 16.0 0.1 .Equilibration, min . 120 1Challenge, min . 60 1Elution, min . 60 1D3803 91 (2014)3all carbon canisters at 30.0 6 0.2C, except during the firstseveral hours of pre-equilibration, during which the adsorptionof water by the carbons may increase these temperaturessl
43、ightly. All tubing downstream of the moisture separator, thecarbon bed canisters and holders, temperature and pressureports and measurement devices upstream and downstream ofthe test bed, and an upstream port and tubing to the dew pointsensor all must be included within the temperature controlledenc
44、losure. In addition, it is highly recommended that a bypassline be included around the sample bed assembly to avoidexposing the sample to start-up conditions possibly outsidethose specified.6.9 Flow Measurement and ControlMass flow controllers,control valve and orifice meter, rotameter or any other
45、devicewith adequate stability and demonstrated measurement systemaccuracy of 62 % of specified flow rate at the test conditions.All flow measuring devices must use correction factors forinterpretation and application to actual test conditions. Thesefactors must be carefully predetermined and documen
46、ted. Noflow measuring device should be located directly downstreamof the test bed such that it is subject to variable temperature andhumidity conditions during a test as a result of water absorptionby the carbon.6.10 Interconnecting TubingTubing must be non-reactivewith methyl iodide, such as stainl
47、ess steel, glass, etc., with aminimum of38-in. outside diameter, and kept as short aspossible to reduce the system pressure drop.6.11 Temperature Measurement DevicesPlatinum resis-tance thermometers (RTDs) with certified accuracy and mea-surement system calibration to 60.2C are required for themeasu
48、rement of test bed inlet air temperature and dew point.The placement of the air temperature RTD must be such that itis not subject to radiative heating from the test bed. It is criticalto the exact measurement of relative humidity that the chilledmirror RTD and the inlet air temperature RTD be match
49、edexactly (60.1C) or that differences are exactly corrected for inrelative humidity calculations.6.12 Pressure Measurement DevicesAbsolute pressuremeasuring devices must be accurate to within 61 % of thereading at standard atmospheric pressure and be capable ofdigital or analog output to meet the specified recordingrequirements. The sensors and output devices must be cali-brated as a unit to ensure system accuracy. The differentialpressure device required for measurements across the test bedmust be capable
