Radon Review Quiz 6 (Mitigation) Questions And Answers With Complete Solutions

RADON REVIEW QUIZ 6 (MITIGATION)
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS
A measurement of the differential pressure across a slab is carried out by a mitigator
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on a day characterized by gusts of wind. In comparison to measurements made on a
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calm day, the windy day pressure differential readings across the slab will:
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Select one: fx




a. Remain constant
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b. Increase
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c. Fluctuate
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d. Decrease - ANSWERS-c. Fluctuate
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A mitigator is called to a house with a basement that has a radon reading of 20 pCi/
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L. Half of the basement is finished, and it has parquet flooring. Since all diagnostic te
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sting is to be performed, which of the following would be the most logical test to perfor
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m FIRST? fx


Select one: fx




a. Suction-
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field extension testing in the unfinished portion of the basement, with one or two vacu
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um-cleaner suction holes, and with pressure- fx fx fx fx fx


test holes at distances of 1, 5, 10, and 15 feet in at least two directions away from eac
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h test hole.
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b. Suction-field extension testing, with one vacuum-
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cleaner suction hole each in the finished and unfinished portions of the basement, an
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d four pressure-test holes (one in each corner) in each portion.
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c. Sub-
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slab radon concentration measurements, through three or four sample holes each in t
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he finished and unfinished portions of the basement.
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d. Suction-field extension testing in the unfinished port - ANSWERS-d. Suction-
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field extension testing in the unfinished portion of the basement, with one vacuum-
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cleaner suction hole, and one to four pressure-
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test holes at remote corners of the unfinished portion.
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A Pressure Field Extension (PFE) diagnostic test has been conducted with a vacuum
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xcleaner attached at preferred sub-slab suction point via a 2-foot length of 3-
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inch pipe. Three pitot tube measurements to determine air volume were made with re
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sults of 0.045, 0.036 and 0.058 inches of water column. How much air is being extrac
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ted by your shop vacuum (assuming an air temperature of 70 degrees F)?
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Select one: fx




a. 41 CFMfx fx


b. 5,828 CFM
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c. 72 CFM
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d. 88 CFM - ANSWERS-a. 41 CFM
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, Assuming a pipe diameter of 3 inches since that is what you made the pitot tube mea
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surements inside, one multiplies the velocity obtained by the cross-
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sectional area of the pipe. fx fx fx fx




Cross sectional Area = п r2 fx fx fx fx fx


Cross sectional area of 3 inch pipe = 3.14 x 1.52 = 3.14 x 2.25 = 7.065 sq inches.
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Cross Sectional Area =7.065 sq in / 144 = 0.049 sq ft
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825 Feet per minute x 0.049 Sq feet = 40.5 CFM Cubic Feet per Minute (round up to
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41 CFM) fx




A radon mitigation worker spends a day and a half working in a house that had been
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previously tested at 12 pCi/L with a follow-up test of 8 pCi/
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L. What exposure has the worker received that would be recorded in their file, assumi
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ng after completing the job he/she went fishing rather than start another radon job?
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Select one: fx




a. 0.080 WLM
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b. 0.0085 WLM
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c. 0.0094 WLM
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d. 0.0042 WLM - ANSWERS-b. 0.0085 WLM
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Calculate radon decay products in units of WL assuming a 100% Equilibrium Factor
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WL = 12 * 1.0/100 = 0.12 WL
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WLM = WL x hours/170 hours fx fx fx fx fx




A single point sub-
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slab suction system was installed in a basement house, with a 200-
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cfm fan capable of drawing 1.5 inches of water (WC) suction. Radon levels, however,
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xare still somewhat elevated. During cold weather, suctions are measured under the s
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lab in four test holes, each 15 feet away from the suction pipe in a different direction.
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The pressure differentials across the slab at the four holes are: Hole A: -
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0.015 inch of water (WC); Hole B: -0.02 inch of water (WC); Hole C: -
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0.002 inch of water (WC); Hole D: +0.002 inch of water (WC). Measurements in the s
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uction pipe indicate flows of 150 cfm and suction of 0.1 inch of water (WC). From the
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available information, which of the following would be the most reasonable next respo
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nse?
Select one: fx




a. Immediately install two additional suction pipes in the vicinity of holes C and D.
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b. Remove the pipe and excavate a hole of at least 2 cubic feet underneath the slab a
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t - ANSWERS-
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c. Inspect the system piping and the slab for sites where basement air could be leakin
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g into the system; close any leaks discovered.
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A sole proprietor is required to develop a Mitigation Installer Protection Plan.
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