ASTM D3803-91(1998)
(Test Method)Standard Test Method for Nuclear-Grade Activated Carbon
Standard Test Method for Nuclear-Grade Activated Carbon
SCOPE
1.1 This test method is a very stringent procedure for establishing the capability of new and used activated carbon to remove radio-labeled methyl iodide from air and gas streams. The single test method described is for application to both new and used carbons, and should give test results comparable to those obtained from similar tests required and performed throughout the world. The conditions employed were selected to approximate operating or accident conditions of a nuclear reactor which would severely reduce the performance of activated carbons. Increasing the temperature at which this test is performed generally increases the removal efficiency of the carbon by increasing the rate of chemical and physical absorption and isotopic exchange, that is, increasing the kinetics of the radioiodine removal mechanisms. Decreasing the relative humidity of the test generally increases the efficiency of methyl iodide removal by activated carbon. The water vapor competes with the methyl iodide for adsorption sites on the carbon, and as the amount of water vapor decreases with lower specified relative humidities, the easier it is for the methyl iodide to be adsorbed. Therefore, this test method is a very stringent test of nuclear-grade activated carbon because of the low temperature and high relative humidity specified. This test method is recommended for the qualification of new carbons and the quantification of the degradation of used carbons.
1.1.1 Guidance for testing new and used carbons using conditions different from this test method is offered in Annex A1.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D 3803 – 91 (Reapproved 1998)
Standard Test Method for
Nuclear-Grade Activated Carbon
This standard is issued under the fixed designation D 3803; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This test method is a very stringent procedure for 2.1 ASTM Standards:
establishing the capability of new and used activated carbon to D 1193 Specification for Reagent Water
remove radio-labeled methyl iodide from air and gas streams. D 2652 Terminology Relating to Activated Carbon
The single test method described is for application to both new D 2854 Test Method for Apparent Density of Activated
and used carbons, and should give test results comparable to Carbon
those obtained from similar tests required and performed E 300 Practice for Sampling Industrial Chemicals
throughout the world. The conditions employed were selected E 691 Practice for Conducting an Interlaboratory Test Study
to approximate operating or accident conditions of a nuclear to Determine Precision of a Test Method
reactor which would severely reduce the performance of 2.2 Code of Federal Regulations:
activated carbons. Increasing the temperature at which this test CFR Title 49, Section 173.34, “Qualification, Maintenance,
is performed generally increases the removal efficiency of the and Use of Cylinders’’
carbon by increasing the rate of chemical and physical absorp- CFR Title 49, Part 178, Subpart C, “Specifications for
tion and isotopic exchange, that is, increasing the kinetics of Cylinders’’
the radioiodine removal mechanisms. Decreasing the relative 2.3 Military Standards:
humidity of the test generally increases the efficiency of methyl MIL-F-51068D Filter, Particulate High Efficiency, Fire Re-
iodide removal by activated carbon. The water vapor competes sistant
with the methyl iodide for adsorption sites on the carbon, and MIL-F-51079A Filter, Medium Fire Resistant, High Effi-
as the amount of water vapor decreases with lower specified ciency
relative humidities, the easier it is for the methyl iodide to be MIL-STD-45662 Calibration Systems Requirements
adsorbed. Therefore, this test method is a very stringent test of 2.4 Other Standards:
nuclear-grade activated carbon because of the low temperature ANSI/ASME N45.2.6 Qualifications of Inspection, Exami-
and high relative humidity specified. This test method is nation, and Testing Personnel for Nuclear Power Plants
recommended for the qualification of new carbons and the
3. Terminology
quantification of the degradation of used carbons.
3.1 Definitions of Terms Specific to This Standard:
1.1.1 Guidance for testing new and used carbons using
conditions different from this test method is offered in Annex 3.1.1 counter effıciency (CE)—the fraction of the actual
number of disintegrations of a radioactive sample that is
A1.
1.2 This standard does not purport to address all of the recorded by a nuclear counter.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
Annual Book of ASTM Standards, Vol 11.01.
priate safety and health practices and determine the applica-
Annual Book of ASTM Standards, Vol 15.01.
bility of regulatory limitations prior to use. 4
Annual Book of ASTM Standards, Vol 15.05.
Annual Book of ASTM Standards, Vol 14.02.
Published by the General Service Administration, 18th and “F’’ St., N. W.,
This test method is under the jurisdiction of ASTM Committee D-28 on Washington, DC 20405.
Activated Carbon and is the direct responsibility of Subcommittee D28.04 on Gas Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
Phase Evaluation Tests. Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Current edition approved April 15, 1991. Published June 1991. Originally Available from American National Standards Institute, 11 W. 42nd St., 13th
published as D 3803 – 79. Last previous edition D 3803 – 86. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 3803 – 91 (1998)
3.1.2 effıciency (E)—the percentage of the contaminant 6.2 Sample and Backup Bed Assemblies:
removed from a gas stream by an adsorption bed; expressed 6.2.1 The sample bed canister and backup bed canisters
mathematically as E = 100 − P, where E and P are given in must each be either a single unit capable of containing carbon
percent. to a depth of 50 6 1 mm, or they may be assembled from two
3.1.3 penetration (P)—the percentage of the contaminant separate units each capable of containing carbon to a depth of
(CH I) which passes through the equilibrated test bed of 25 mm. Two backup canisters, each of 50 6 1 mm total depth,
standard depth, and is collected on the backup beds during the are required. Canisters may be reused after being decontami-
feed and elution periods under specified conditions. nated to remove residual radioactivity. An acceptable bed
3.1.4 relative humidity (RH)—for the purpose of this test construction is shown in Fig. 1 with critical dimensions noted.
method, relative humidity is defined as the ratio of the partial 6.2.2 Clamping assemblies are needed for sample and
pressure of water in the gas to the saturation vapor pressure of backup beds. The only requirements for these assemblies are
water at the gas temperature and pressure. At temperatures that they provide a smooth sealing face, uniform alignment of
below 100°C, this is the normal definition and relative humid- bed canisters, and sufficient clamping force so that the leak test
ity can range from 0 to 100 %. in 10.2 can be met. A suggested design for clamping assemblies
3.2 Definitions—for additional terms relating to this stan- is shown in Fig. 2.
dard, see Terminology D 2652. 6.3 A schematic of a generalized test system is shown in
Fig. 3. This system is designed to operate at approximately
30°C and 95 % relative humidity, with a gas flow of 24.7 L/min
4. Summary of Test Method
4.1 Both new and used carbons are first exposed to humid
air (pressure, approximately 1 atm; temperature, 30.0°C; rela-
tive humidity, 95 %) for a pre-equilibration period of 16 h.
During this pre-equilibration period, the test system may be run
unattended with the required parameter monitoring and ad-
equate control devices. Following pre-equilibration, the air
flow is continued for a two-hour equilibration period, during
which the acceptable variability of all parameters is reduced.
The test system must be closely monitored and controlled
during the final four hours of the test. Qualification of
personnel to perform this testing must meet or exceed ANSI/
ASME N 45.2.6—1978, Level II, which requires a combina-
tion of education and actual test system operation experience.
During the challenge or feed period, radio-labeled methyl
iodide at a mass concentration of 1.75 mg/m of humid air
flow is passed through the beds for a period of 60 min.
Following the feed period, humid air flow without test adsor-
bate is continued at the same conditions for a 60-min elution
period. Throughout the entire test, the effluent from the sample
bed passes through two backup beds containing carbon having
a known high efficiency for methyl iodide. The two backup
beds trap essentially all the radio-labeled methyl iodide that
passes the test bed and provide a differential indication of their
efficiency. At the end of the elution period, the gamma activity
of I in the test and backup beds is measured by a gamma
counter, and the percent of adsorbate penetrating the test bed is
determined.
5. Significance and Use
5.1 The results of this test method give a conservative
estimate of the performance of nuclear-grade activated carbon
used in all nuclear power plant HVAC systems for the removal
* Standard canister dimension may be used in multiples if desired.
of radioiodine. Single test canisters of full depth may be used.
1—Bed holder
2—Adsorption media
6. Apparatus
3—O-ring gland
4—Perforated screen (both ends)
6.1 Sample Preparation Apparatus:
5—Retaining snap ring (both ends)
6.1.1 Riffle Sampler, in accordance with 32.5.2 of Practice
6—Baffle (both ends)
E 300. 7—Holes for assembly tie-rods (four)
6.1.2 Feed Funnel and Vibrator, in accordance with the
FIG. 1 Adsorption Media Test Bed Holder (Canister)
Procedure Section of Test Method D 2854.
D 3803 – 91 (1998)
of the test system. A dryer, carbon adsorber, and HEPA
(high-efficiency particulate air) filter are required for either
system to condition the inlet air. Flow measurement and
control should be accurate and stable to within 6 2% of
specified flow rate. System capacity shall meet or exceed the
volumetric flow requirements as calculated from the specified
face velocity. A surge tank and pressure control valve should be
employed in either type of system to ensure stable and accurate
flow measurement and control. For safety, it is important that
the pressure system be equipped with a pressure relief valve. It
is important that the pipe diameter and inlet air filters for a
vacuum system be designed and maintained to minimize the
pressure drop from ambient to ensure that the specifications for
absolute pressure at the test bed are met (see Table 1).
6.6 Moisture Separator—A moisture separator should be
used to protect the HEPA filter by removing large quantities of
entrained particulate water, if present, after humidification. A
HEPA filter (or equivalent) is required to function as a final
droplet trap to remove small amounts of fine particulate water
from the carrier gas ahead of the test bed.
6.7 Adsorbate Supply—This system shall consist of a stain-
less steel cylinder, pressure gage, pressure regulator, and a flow
regulator capable of providing a steady flow of the challenge
gas, that is, radio-labeled methyl iodide in dry nitrogen, for the
duration of the test feed period. The point of injection into the
main gas flow of the system must be such that the cross-
sectional distribution of the adsorbate at the face of the test bed
can be ensured to be homogeneous. A mixing chamber, baffles,
glass beads, etc. should be used to achieve adequate mixing.
6.8 Constant Temperature Cabinet—An enclosure and as-
sociated thermoregulatory system must be used that is capable
of maintaining the inlet gas stream temperature from the point
of humidity control to the test bed, and the surface temperature
of all carbon canisters at 30.0 6 0.2°C, except during the first
several hours of pre-equilibration, during which the adsorption
of water by the carbons may increase these temperatures
slightly. All tubing downstream of the moisture separator, the
carbon bed canisters and holders, temperature and pressure
ports and measurement devices upstream and downstream of
the test bed, and an upstream port and tubing to the dew point
1—Canister (four shown)
sensor all must be included within the temperature controlled
2—Inlet cap
3—Outlet cap
enclosure. In addition, it is highly recommended that a bypass
4—Thermocouple
line be included around the sample bed assembly to avoid
5—Thermocouple fitting
exposing the sample to start-up conditions possibly outside
6—Static tap
7—Tie bar (four)
those specified.
8—O-ring seals
6.9 Flow Measurement and Control—Mass flow control-
FIG. 2 Canister Assembly (Test or Backup Beds)
lers, control valve and orifice meter, rotameter or any other
device with adequate stability and demonstrated measurement
system accuracy of 6 2 % of specified flow rate at the test
at atmospheric pressure. If test conditions which differ signifi-
conditions. All flow measuring devices must use correction
cantly from these are required, then separate calibrations or
factors for interpretation and application to actual test condi-
instrumentation, or both, may be required.
tions. These factors must be carefully predetermined and
6.4 Saturator System—This system may be a controlled
documented. No flow measuring device should be located
temperature saturator (bubbler) or spray chamber (environmen-
directly downstream of the test bed such that it is subject to
tal condition generator), or any other device of sufficient
variable temperature and humidity conditions during a test as a
stability and capacity to supply the required mass flow of water
result of water absorption by the carbon.
vapor at test conditions.
6.5 Flow Generator—This system may be an air compres- 6.10 Interconnecting Tubing—Tubing must be non-reactive
sor upstream of the test system or a vacuum pump downstream with methyl iodide, such as stainless steel, glass, etc., with a
D 3803 – 91 (1998)
FIG. 3 Schematic of Activated Carbon Test System
TABLE 1 Parameter Specifications
6.11 Temperature Measurement Devices— Platinum resis-
tance thermometers (RTDs) with certified accuracy and mea-
NOTE 1—Temperature, relative humidity, pressure, and gas velocity are
surement system calibration to 6 0.2°C are required for the
to remain constant within the specified maximum variations throughout
the entire test, that is, for each test period. Parameter excursions outside
measurement of test bed inlet air temperature and dew point.
the limits specified in this table will invalidate the test results. If results
The placement of the air temperature RTD must be such that it
based on a test containing such variations must be reported, then these
is not subject to radiative heating from the test bed. It is critical
variations must be noted in the comments section of the external report
to the exact measurement of relative humidity that the chilled
form and flagged in the parameter monitoring portion of the internal
mirror RTD and the inlet air temperature RTD be matched
report.
exactly (6 0.1°C) or that differences are exactly corrected for
Equilibration, Chal-
Pre-Equilibration
Parameter lenge, and Elution in relative humidity calculations.
(First 16 h)
(Final 4 h)
6.12 Pressure Measurement Devices—Absolute pressure
Temperature, °C 30.0 6 0.4 30.0 6 0.2
measuring devices must be accurate to within 6 1 % of the
Range 29.6 to 30.4 29.8 to 30.2
Relative humidity, % 91.0 to 96.0 93.0 to 96.0 reading at standard atmospheric pressure and be capable of
Flow, m/min 12.2 6 0.6 12.2 6 0.3
digital or analog output to meet the specified recording
Face velocity, m/min 11.6 to 12.8 11.9 to 12.5
requirements. The sensors and output devices must be cali-
Absolute pressure, kPa 101 6 5 101 6 5
Bed diameter and depth, mm 50
...
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