7010 Introduction

7010 INTRODUCTION*
7010 A. General Discussion
1. Occurrence and Monitoring
Radioactivity in water and wastewater originates from both
natural sources and human activities (e.g., nuclear fuel-related
operations, from mining to reprocessing; medical uses of radio-
isotopes; industrial uses of radioisotopes; worldwide fallout from
atmospheric testing of nuclear devices; and enhanced concentra-
tion of naturally occurring radionuclides). Water and wastewater
monitoring programs should be designed to realistically assess
the degree of radioactive contamination. In some cases (e.g.,
compliance monitoring for drinking water), the conditions are
clearly defined.
1
In others, it may be necessary to examine the
individual situation
2
to determine the critical radionuclide(s), the
critical pathway by which such radionuclide(s) move(s) through
the environment, and a critical population group that is exposed
as a result. This approach will help narrow the list of possible
radionuclides to monitor.
A relevant list of the most hazardous radionuclides can be
created by examining the radioactivity concentration standards
issued by the International Committee on Radiation Protection
(ICRP),
3
the Federal Radiation Council (FRC),
4
the National
Committee on Radiation Protection and Measurement (NCRP),
2
the U.S. Environmental Protection Agency,
1
and agencies in
other countries. Applicable regulatory standards and action lev-
els may vary from state to state in the USA, as well as from
country to country.
Monitoring programs should provide both assurances when
environmental conditions are safe and adequate warning when
they are not so proper precautions can be taken. Therefore, it is
necessary to establish baselines for naturally occurring radionu-
clides (kinds and quantities) so changes can be measured. This
will help decision-makers make sound judgments on the hazard-
ous or nonhazardous nature of increased concentrations.
2. Types of Measurement
Meaningful measurements require careful application of good
scientific techniques. The types of measurements to be made
depend on the testing objectives. Gross alpha and gross beta
screening measurements are relatively inexpensive, can be com-
pleted quickly, and are useful for determining whether further
analysis for specific radionuclides may be merited. However,
they do not provide information about the sample’s isotopic
composition, cannot be used to estimate radiation dose, and are
subject to significant bias if the sample contains other radionu-
clides or has a high concentration of dissolved solids. While
calibration standards that closely match the samples’ character-
istics and carefully applied self-absorption and cross-talk correc-
tions may help minimize bias and optimize precision, gross
activity measurements are generally not capable of providing
reliable, unbiased results of known precision that reflect the
samples’ isotopic makeup.
Specific radionuclide measurements must be made if dose
estimates are needed [e.g., when gross analyses
1
results exceed
established action limits (regulatory or other) or long-term trends
are being monitored]. They usually are more expensive and
time-consuming than a gross analysis. Specific measurements
identify radionuclides by the type and energy of emitted radia-
tion, chemical techniques, half-life, or some combination of
these. Gamma-emitting radionuclides can be measured rapidly
and with minimal sample preparation via gamma spectrometry.
Chemical separations make it possible to improve measurement
results by increasing the quantity of sample that can be measured
and decreasing interference from non-target radionuclides in
samples.
Knowing the chemical and radiochemical characteristics of
the measured radionuclide is critical for satisfactory results.
Gross alpha and gross beta results cannot provide accurate
information about radionuclides whose energies are significantly
different from those of the calibration standard. When concen-
trating water samples via evaporation, certain radionuclides
(e.g., radioiodine, polonium, tritium, and carbon-14) may be lost
to volatilization. If the sample is ignited, the chance of volatil-
ization loss is even greater. When analyzing samples containing
uranium and thorium, keep in mind that members of these series
are rarely present in secular equilibrium. Identifying short-lived
radionuclides, which may not be in secular equilibrium during
sampling, may require that samples be analyzed shortly after
collection and that analysts consider the dynamic nature of
radionuclide concentrations as a result of decay and ingrowth
phenomena.
3. References
1. U.S. ENVIRONMENTAL PROTECTION AGENCY. 2000. National primary
drinking water regulations; radionuclides; final rule. 40 CFR Parts 9,
141 & 142. Fed. Reg. 65(236):76708.
2. U.S. ENVIRONMENTAL PROTECTION AGENCY. 2004. National primary
drinking water regulations: analytical method for uranium. Fed. Reg.
69(164):52176.
3. U.S. ENVIRONMENTAL PROTECTION AGENCY. 2002. Implementation
Guidance for Radionuclides, EPA 816-F-00-002. U.S. Environmen-
tal Protection Agency, Off. Ground Water and Drinking Water,
Washington, D.C. Available at http://water.epa.gov/lawsregs/rules-
regs/sdwa/radionuclides/compliancehelp.cfm. Accessed August
2011.
4. NATIONAL COMMITTEE on RADIATION PROTECTION and MEASUREMENTS.
1959. Maximum Permissible Body Burdens and Maximum Permis-
sible Concentrations of Radionuclides in Air and Water for Occupa-
tional Exposure, NBS Handbook No. 69, pp. 1, 17, 37, 38 & 93.
National Committee on Radiation Protection and Measurements,
Bethesda, Md.
* Approved by Standard Methods Committee, 2011.
Joint Task Group: Robert T. Shannon (chair), Shiyamalie R. Ruberu, Bahman
Parsa.
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4. Bibliography
FEDERAL RADIATION COUNCIL. 1961. Background Material for the Devel-
opment of Radiation Protection Standards, Rep. No. 2 (Sept.). U.S.
Government Printing Off., Washington, D.C.
INTERNATIONAL ATOMIC ENERGY AGENCY. 1971. Disposal of Radioactive
Wastes into Rivers, Lakes, and Estuaries, IAEA Safety Ser. No. 36,
St. 1/PUB 283. International Atomic Energy Agency, Vienna, Aus-
tria.
NATIONAL COUNCIL on RADIATION PROTECTION and MEASUREMENTS. 1976.
Environmental Radiation Measurements, NCRP Rep. No. 50. Na-
tional Council on Radiation Protection and Measurements, Wash-
ington, D.C.
INTERNATIONAL COMMISSION on RADIATION PROTECTION. 1979. Limits for
Intakes of Radionuclides by Workers, ICRP Publ. 30. Pergamon
Press, New York, N.Y.
FRIEDLANDER, G., J.W. KENNEDY, E.S. MACIAS & J.M. MILLER. 1981.
Nuclear and Radiochemistry, 3rd ed. John Wiley & Sons, New
York, N.Y.
FIRESTONE, R.B., V.S. SHIRLEY, C.M. BAGLIN, S.Y.F. CHU & J.J. ZIPKIN.
1996. Table of Isotopes, 8th ed. John Wiley & Sons, New York,
N.Y.INTRODUCTION (7010)/Sample Collection and Preserva-
tionFirestone, R.B., S.Y.F. Chu & C.M. Baglin. 1999. Table of
Isotopes, Update to 8th ed. John Wiley & Sons, New York, N.Y.
7010 B. Sample Collection and Preservation
1. Collection
The principles of representative water and wastewater sam-
pling apply to sampling for radioactivity testing (see Section
1060).
Because radioactive elements often are present in subnano-
gram quantities, a significant fraction may be lost via adsorption
to the sampling container’s surface. Similarly, radionuclides may
be largely or wholly adsorbed on the surface of suspended
particles.Sample container sizes vary from 0.02 to 18 L, depend-
ing on required analyses. Use plastic (polyethylene or equiva-
lent) or glass containers (required for tritium). Consider the
possibility of radioactivity deposition on container and equip-
ment surfaces, which may cause a loss of radioactivity. To
eliminate possible cross-contamination of subsequent samples,
do not reuse sample containers.
2. Preservation
For general information on sample preservation, see Section
1060. For guidance on sample handling, preservation, and hold-
ing times for compliance measurements of radionuclides in
drinking water in the United States, see Table 7010:I. Optimally,
add preservative at time of collection unless sample will be
separated into suspended and dissolved fractions, but do not
delay acid addition beyond 5 d. Use conc nitric (HNO
3
)or
hydrochloric (HCl) acid to obtain a pH h, then recheck pH before
analysis to verify successful acidification. For further details, see
references.
1–3
Reagents used to preserve samples should be tested for con-
centrations of radioactivity that could compromise test results
(e.g., by using a reagent or method blank).
TABLE 7010:I. SAMPLE HANDLING,PRESERVATION,AND HOLDING TIMES
Constituent Preservative*Container† Maximum Holding Time‡§
Gross alpha Conc HNO
3
or HCl to pH ⬍2储P or G 6 months
Gross beta Conc HNO
3
or HCl to pH ⬍2储P or G 6 months
Radium-226 Conc HNO
3
or HCl to pH ⬍2P or G 6 months
Radium-228 Conc HNO
3
or HCl to pH ⬍2P or G 6 months
Radon-222 Cool G with TFE-lined septum 8 d#
Uranium, natural Conc HNO
3
or HCl to pH ⬍2P or G 6 months
Radioactive strontium Conc HNO
3
or HCl to pH ⬍2P or G 6 months
Radioactive iodine None P or G 14 d
Tritium None P or G 6 months
Photon-emitters Conc HNO
3
or HCl to pH P or G 6 months
*
(All except radon-222 samples). Add preservative at time of sample collection unless suspended solids activity is to be measured. If sample must be shipped to a laboratory
or storage area, acidification (in original sample container) may be delayed for no more than 5 d. At least 16 h must elapse between acidification and analysis.
†P ⫽plastic, hard or soft; G ⫽glass, hard or soft.
‡Holding time is time elapsed between sampling and analysis. In all cases, analyze samples as soon after collection as possible.
§A 1-year holding time allows for compositing four quarterly samples.
㛳If HCl is used to acidify samples that will be analyzed for gross alpha or gross beta activities, the chloride salts must be converted to nitrate salts by evaporation with nitric
acid before transferring samples to planchets.
#
When analyzing short-lived radionuclides, adjust maximum holding time based on the radionuclide’s half-life (e.g., 72 h for Ra-224).
** Cooling at 4°C is recommended. Large temperature changes will cause dissolved radon to outgas from sample.
INTRODUCTION (7010)/Sample Collection and Preservation
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INTRODUCTION (7010)/Sample Collection and Preservation

3. Wastewater Samples
Wastewater often contains more nonradioactive suspended
and dissolved solids than most drinking, surface, or ground water
does. Often, the sample’s radioactivity is distributed between the
solid and liquid phases. Using carriers in the analysis is generally
ineffective unless the solid phase is dissolved; even then, high
solids content in the sample may interfere with radioanalytical
procedures.
Radioelements may exhibit unusual chemical characteristics
due to complexing agents or the waste-production method. For
example, tritium may be part of an organic compound when used
in the manufacture of luminous articles. Radioiodine from hos-
pitals may occur as complex organic compounds, while the
fission products from processing spent nuclear fuels typically
contain elemental and iodide forms. Uranium and thorium prog-
eny often exist as inorganic complexes (rather than oxides) after
processing in uranium mills. Strontium-90 titanate waste from
radioisotope heat sources is quite insoluble when compared to
most other strontium wastes. Valuable information on the chem-
ical composition of wastes, the behavior of radioelements, and
the quantity of radioisotopes in use appears in the literature.
4,5
4. References
1. U.S. GEOLOGICAL SURVEY. 1977. Methods for Determination of Ra-
dioactive Substances in Water and Fluvial Sediments. U.S. Govern-
ment Printing Off., Washington, D.C.
2. U.S. DEPARTMENT of ENERGY. 1997. EML Procedures Manual, HASL-
300, 28th ed. (rev.), Vol. 1. Environmental Measurements Lab., U.S.
Dep. Energy, New York, N.Y. Available online at http://ww-
w.orau.org/ptp/PTP%20Library/library/DOE/eml/hasl300/
HASL300TOC.htm. Accessed May 2011.
3. U.S. ENVIRONMENTAL PROTECTION AGENCY. 2005. Manual for the Cer-
tification of Laboratories Involved in Analyzing Public Drinking
Water Supplies, 5th ed., EPA-815-R-05-004. U.S. Environmental
Protection Agency, Washington, D.C.
4. INTERNATIONAL ATOMIC ENERGY AGENCY. 1960. Disposal of Radioac-
tive Wastes. International Atomic Energy Agency, Vienna, Austria.
5. NEMEROW, N.L. 1963. Industrial Waste Treatment. Addison-Wesley,
Reading, Mass.
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INTRODUCTION (7010)/Sample Collection and Preservation