New Jersey Administrative Code
Title 7 - ENVIRONMENTAL PROTECTION
Chapter 18 - REGULATIONS GOVERNING THE CERTIFICATION OF LABORATORIES AND ENVIRONMENTAL MEASUREMENTS
Subchapter 6 - RADIOCHEMICAL TESTING PROCEDURES INCLUDING RADON GAS/RADON PROGENY
Section 7:18-6.3 - Requirements for radiochemistry laboratory equipment and instruments
Universal Citation: NJ Admin Code 7:18-6.3
Current through Register Vol. 56, No. 24, December 18, 2024
(a) The supervisor shall have control over the equipment and instruments used in radiochemical testing and radon/radon progeny-in-air testing. The laboratory shall have equipment and instruments that satisfy the applicable requirements listed in (a)1 and 2 below, in (b) and (c) below, in N.J.A.C. 7:18-3, and in the applicable DSAM.
1. The laboratory shall
have a muffle furnace that:
i. Is
automatically controlled;
ii. Has a
chamber capacity of at least 2,200 cubic centimeters (cc), and measures at
least 10 centimeters (cm) by 9.5 cm by 23 cm; and
iii. Has a maximum operating temperature of
1,000 degrees Celsius continuous and 1,100 degrees Celsius intermittent;
and
2. The laboratory
shall have a general purpose table-top centrifuge that has a maximum speed of
at least 3,000 revolutions per minute (rpm) and a loading option of 4 x 50
mL.
(b) A laboratory performing measurements involving radiation counting (as set forth in 40 CFR 141 and required by the Federal Safe Drinking Water Act) shall have the instruments meeting the requirements in (b)1 through 6 below and the requirements of the applicable DSAM:
1. The
laboratory shall have a liquid scintillation system to measure tritium in
drinking water samples or radon in drinking water or wastewater samples. The
system shall meet or exceed the sensitivity requirements of
40 CFR
141.25;
2. The laboratory shall have a gas-flow
proportional counting system (as described in the reference cited in
40 CFR
141.25(a)) to measure gross
alpha and gross beta activities, radium-226, radium-228, strontium-89,
strontium-90, cesium-l34, and iodine-l3l. The detector shall be either a
"windowless" (internal proportional counter) or a "thin window" type. A
combination of shielding and a cosmic (guard) detector operated in
anticoincidence with the main detector shall be used to achieve low background
beta counting capability. The alpha and beta background count of the system
shall be such that the sensitivity of the radiochemical analysis of the water
sample will meet or exceed the requirements of
40 CFR
141.25 with a reasonable counting time of not
more that 1,000 minutes (16.6 hrs);
3. Instead of the gas-flow proportional
counter described in (b)2 above, a laboratory may use a scintillation system
designed for alpha counting to measure gross alpha activities and radium-226.
When the laboratory uses a scintillation system for counting, it shall follow
the sample setup for measurement described in EPA 600-4-80-032, Appendix D,
item 2;
4. The laboratory shall
have a scintillation cell system designed to accept scintillation flasks
("Lucas cells") to specifically measure radium-226 by the radon emanation
method. The system consists of a light-tight enclosure capable of accepting the
scintillation flasks, a detector (phototube), a high voltage supply, an
amplifier, timers, and scalers. The laboratory shall either purchase the flasks
(cells) required for this measurement from commercial suppliers, or construct
the flasks (cells) in accordance with the specifications set forth in Lucas,
H.F., "Improved Low-Level Alpha Scintillation Counter for Radon". Rev. Sci.
Instrum., 28:680, l967;
5. The
laboratory shall have a gamma spectrometer system equipped with one of the
following to analyze manmade photon emitters:
i. A sodium iodide NaI(Tl) crystal detector
that:
(1) Uses a NaI(Tl) crystal measuring at
least 7.5 cm x 7.5 cm (though the Department recommends using a crystal
measuring 10 cm x 10 cm);
(2) Is
shielded with at least 10 cm of iron or the equivalent thereof;
(3) Has sufficient distance from the center
of the detector to other part of the shield (the Department recommends a
distance of at least 30 cm); and
(4) Has a multichannel analyzer with a memory
of not less than 200 channels and at least one readout device for each
system;
ii. A solid
state lithium drifted germanium detector that meets the requirements of
(b)5ii(1) and (2) below, or a gamma-X photon detector that meets the
requirements of (b)5ii(1), (2) and (3) below:
(1) The detector shall be sufficiently
efficient to make the gamma spectrometry system sensitive enough to meet the
minimum detectable activity requirements cited in 40 CFR l41.25;
(2) The detector shall be shielded with at
least 10 cm of iron or the equivalent thereof; and
(3) The gamma-X photon detector shall be
connected to a multichannel analyzer that has a memory of at least 2,000
channels and at least one readout device for each system; and
6. The laboratory shall
have a fluorometer capable of detecting 0.5 nanogram (ng) of uranium for the
analysis of uranium by the fluorometric method.
(c) A laboratory certified to perform measurements involving radiation counting (as set forth in the Radon Act) shall meet the following requirements when performing radon/radon progeny-in-air analyses:
1. If required by the authorized
measurement protocols, the laboratory shall use a microscope or automated
counting system capable of detecting and counting alpha tracks. A laboratory
performing an analysis with a radon progeny-in-air integrating sampling unit
(RPISU) shall use a thermoluminescent dosimeter (TDL) reader; and
2. To analyze manmade photon emitters, the
laboratory shall use a gamma spectrometer system equipped as described under
(b)5 above.
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