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Undereround Injection Control Branch Guidance No. 5 <br />, t. • <br />wySi wyg://35/h ttp: //www.epa. gov/reg5oh 20/u i c/r5_O5. h tm <br />defines the upward distance a slug travels and, more importantly, 2) confirms the direction <br />travel of any RA material observed after the slug is ejected. Often ejectors leak a small amc <br />of tracer. The direction of movement of extraneous slugs passing by a single detector cannc <br />determined and may confuse interpretation. <br />The scaling should allow the easy calculation of time period and deflections should not be <br />smeared out over so much paper that they are diff"icul[ to identify. The time scale should nc <br />compressed so much [hat determining the time, to at least the minute, at which the increase <br />radioactivity begins is questionable; <br />3. The tool is run in time drive for a period sufficient to allow the RA material to reach the <br />perforations, casing shoe, or end of the tailpipe and travel upward to the detectors assumin! <br />upward movement at a rate of no more than two feet per minute; <br />4. If upward moving RA material is detected, following the detection of the slug a[ the top <br />detector, move the tool upward a short distance and again record in time drive until the RA <br />material is detected. Record [he times at which the RA material reaches the detectors to hel <br />evaluate how far the detectors should be moved; <br />5. Continue [o monitor the upward movement of the slug until the limit of upward movement <br />reached. The limit can be considered to be the elevation of a detector which did not record <br />passage of the slug after allowing travel time of two minutes per foot from the point of last <br />detection. <br />E. Interpretation <br />Each of the three testing methods is interpreted individually. The slug tracking records are evalua <br />by: <br />Reviewing the statistical check performed before testing began to check the sensitivity of tl <br />log display, check to be sure the scaling used for the logging is the same as was used for the <br />statistical check; <br />2. Checking [he deflection caused by the slug within the tubing or casing. It should be at least <br />times greater than that caused by lithological background; <br />3. Checking to see if a slug split occurred at the base of the tubing or casing. Identify any <br />increases of radioactivity along the well bore above the base of the tubing or casing; <br />4. Evaluating the slug split for upward movement. Turbulence at the base of the tubing often <br />causes some tracer to remain. If only a slow dissipation of the resulting hot spot, with no <br />upward movement, is observed, the split has no significance; <br />5. If the tubing extends below the casing, upward movement to the base of the casing commo <br />occurs, this also has no environmental significance; <br />6. If movement above the base of [he casing occurs, its extent must be very carefully determir <br />and recorded. It is not uncommon or of concern if there is some limited movement, particu <br />where the base of the casing is within a porous, permeable interval. The extent of upward <br />movement should be compared with previous measurements to confirm that the cement se: <br />28 0(34 5/28/99 1:09 PM <br />