ML19224B152
| ML19224B152 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/12/1977 |
| From: | Metropolitan Edison Co |
| To: | Mullinix W NRC/IE |
| References | |
| 1760, TM-0137, TM-137, NUDOCS 7906140125 | |
| Download: ML19224B152 (8) | |
Text
lt TMI DOCUMENTS DOCUMENT NO:
[I) f COPY MADE ON OF DOCUMENT PROVIDED BY EDISOl COMPANY.
I METROPOLITAN Wilda R. Mullinix, NRC 7906140125 e
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05/12/77 THREE MILE ISLAND NUCLEAR STATION STATION HEALTH PHYSICS PROCEDURE 1760 J
CPERATION AND CALIBRATION OF THE EBERLINE RAD OWL - I Table of Effective Pages (Pace Date R evision Page Date R evision Pace Date R evision 1.0 05/12/77 2
26.0 51.0 2.0 02/08/74 0
27.0 52.0 3.0 02/08/74 0
28.0 53.0 4.0 02/08/74 0
29.0 54.0 5.0 02/08/74 0
30.0 55.0 6.0 02/08/74 0
31.0 56.0 7.0 02/08/74 0
32.0 57.0 8.0 33.0 58.0 9.0 34.0 59.0 10.0 35.0 60.0 11.0 36.0 61.0 12.0 37.0 62.0 13.0 38.0 63.0 14.0 39.0 64.0 15.0 40.0 65.0 16.0 41.0 66.0 17.0 42.0 67.0 18.0 43.0 68.0 19.0 44.0 69.0 20.0 45.0 70.0 21.0 43.0 71.0 22.0 47.0 72.0 23.0 48.0 73.0 24.0 49.0 74.0 25.0 50.0 75.0 Unit 1 Staff Recommends Approval Ur.it 2 Staff Recommends A proval H!?7 Date bil[77 Approval n v>
Date 5 A pprova! '
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- Cognizant Dept. Head Cognizant Dept. Head Unit 1 PORC comm nds Approval Unit 2 PORC R ecor,me ds Approval I
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1760 Revision 2
05/12/77 THREE MILE ISLAND NUCLEAR STATION STATION HEALTH PHYSICS PROCEDURES Operation and Calibration of the Eberline Rad Owl - I 1.0 PROCEDURE The purpose of this procedure is to explain in detail the operation and calibration of the Eberline Rad Owl-I.
2.0 DISCUSSION 2.1 The Rad Owl-I is an ion chamber instrument that can be used either as a dose rate instrument or an integrating instrument.
2.2 The zero setting of the instrument may be checked at any time on any range and in any radiation field by mirely depressing the ZERO push button.
Since any zero offset will be most noticable on the 5 R/hr, 5 mR/hr and 5 mR ranges, adjusting the meter reading to zero with the ZERO SET knob should be done only on one of these three ranges.
Once set, no adjustment should again be necessary when using the "500" or "50" ranges.
Small readjustments may be necessary on the "5" ranges.
2.3 Depressing the ZERO pushbutton will erase the integrated reading when en one of the three integration ranges.
To check for possible zero offset without losing the reading, switch to tne 5 mR/hr on 5 R/hr position, depress the ZERO pushbutton and set to zero using the ZER0 SET knob.
Release the ZERO pushbutton.
Return to the integrate position and read the meter or continue integratir.g if so desired.
2.4 When selecting the most sensitive ranges (5 mR/hr) switcn'19, transient nolae, including releasing the ZERO pushbutton, may cause a temporary off scale reading on the meter.
This can be avoided by first selecting 500 mR/hr letting the needle settle, then repeating at 50 mR/hr, and then switching to 5 mR/hr.
1.0
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1760 2/8/74 Revisicn 0 2.5 The effective center of the ion chamber is marked by a groove around the outside about 1 3/4" from the front end.
2.6 Since the ion chamber is ventcd to atmo. c' oric pressure, it is se:i. tive to both changes in a. - pressure and temperature.
Tables 1760-1 and 1760-2 give correction factors to be used if the use conditions are different from the calibration conditions.
3.0 REFERENCES
3.1 Portable Ion Chamber Technical manual, Eberline Model R0-1.
4.0 EQUIPMENT 4.1 Portable Ion Chamber Model R0-1 Rad Owl (Figure 1760-1) 4.2 High Range Calibrator 4.3 Low Range Calibrator 5.0 CPERATING INSTRUCTIONS 5.1 Description of external controls 5.1.1 FUNCTION SWITCH:
Eleven position switches that turn the instrument 0FF, checks the BATTERY condition and selects the range and/or mode of operation to be used.
5.1.2 ZERO pushbutton; used to bring the meter reading to zero to start an integration period or to check instrument zero when in a radiation field.
5.1.3 ZERO SET knob; used to set the meter to zero when ZEP0 push-button is depressed.
5.2 Descr'ption of internal controls.
5.2.1 Calibration Controls:
Nine variable resistors, one for each range.
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' 1760 2/8/74 Revision 0 5.2.2 Amplifier Current Controls:
Two variable resistors on plug-in printed ci-ait board, factory set for proper amplifier current.
5.3 Using the instrument.
5.3.1 Turn the function switch to BATTERY position.
The meter should read above the BATT cutoff line.
5.3.2 Turn the function switch to the 5 R/hr position and check that the meter reads ::ero (assuming the absence of a high radiation field).
5.3.3 Set the function switch to the desired range of operation. The switch position selected is the full' scale reading of that range.
5.3.4 If one of the six dose rate ranges R/hr or mR/hr was selected, read the dose rate directly on the meter by keeping in mind what the full scale reading represents.
5.3.5 If one of the three integrating ranges (mR-INT) was selected, momentarily depress the ZERO pushbutton to start the integration period. At the end of the period, read the total dose received directly on the meter by keeping in mind what the full scale reading represents.
5.4 Calibration 5.4.1 For maximum accuracy, the Rad Owl should be calibrated at approxi-mately the same temperature and air pressure as is expected for its use.
If the conditions for calibration and for use are necessarily different, an offset may be used during calibration so that the instrument will read properly when put in use. Tables 1760-1 and 1760-2 may be used to select the proper offset.
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1760 2/8/74 Revision 0 5.4.2 To calibrate the dose rate ranges, remove the right side cover and position the Rad Owl in the High Range calibrator.
5.4.3 Set the function switch on the 500 R/hr position.
The high range calibrator without any attenuators will produce about 239 R/hr radiation field, adjust the pot corresponding to the 500 R/hr position.
The Rad Owl is now calibrated on the 500 R/hr range.
5.4.4 Set the function switch to the 50 R/hr position.
Put in the proper attenuators to produce a radiation field of approximately 40 R/hr. Adjust the pot corresponding to the 50 R/hr position.
Check to see if proper reading occurs on the 500 R/hr scale.
5.4.5 Set the function switch on the 5 R/hr position.
Insert the proper attenuators in the high range calibrator that will produce a radiation field of approximately 4 R/hr. Adjust the pot corres-ponding to the 5 R/hr range.
Check to see if the proper reading occurs on the 50 R/hr range.
5.4.6 Set the function switch on the 500 mR/hr position.
Place the proper attenuators in the calibrator to produce a radiation field of approximately 400 mR/hr.
Adjust the pot corresponding to the 500 mR/hr range.
Chec! to see if the proper reading occurs on the 5 R/hr range.
5.4.7 Change attenuators so radiation field will read approximately 24 R/hr.
Set function switch to mR-INT 500 mR. At 24 R/hr radiation field a dose of 400 mR should accumulate in one minute 24 r 1 hr _.4 R/ min or 400 mR/ min.
If a reading of 400 mR hr 60 min.
doest c register adjust calibration pot until correct reading occurs.
1760 2/8/74 Revision 0 5.4.8 Change function switch to 50 mR position.
Change attenuators so a dose rate of approximately 2.4 R/hr is being emitted.
In one minute a dose of 40 mR should accumulate.
If necessary adjust the calibration pot until proper reading is indicated.
5.4.9 Change function switch to 5 mR position.
Change attenuators so a dose rate of approximately.24 R/hr is being emitted.
In one minute a dose of 4 mR should accumulate.
If necessary adjust the calibration pot until proper reading has accumulated.
5.4.10 The Rad Owl will have to be calibrated on the 50 mR/hr and 5 mR/hr range with the Low Range calbrator.
5.4.11 Setting the Rad Owl at 90 cm on the calibration table a reading of approximately 41 mR/hr should be registered on the meter.
If necessary, adjust the calibration pot until proper reading occurs.
5.4.12 Set the Rad Owl at 300 cm on the calibration table.
Set the function switch at 5 mR/hr. A reading of about 3.7 mR/hr should register on the meter.
If necessary, adjust the cali-bration pot so that a reading of 3.7 mR/hr is read on the meter.
5.4.13 After calibration is complete place a calibration sticker on instrument, dated and initialed. Also record this information in the instrument log book located in the H.P. laboratory.
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Revision 0 RAD OWL ALTITUDE WHEN CALIBRATED SEA LEVEL 1000' 2000*
3000' 4000' 5000' 6000*
7000' S000' 9000' 10,000' SEA LEVEL 1
.96
.93
.90
.S6
.83
.80
.77
.74
.71
.69 1000* l1.04 l1 l.96
.93
.90
.86 l.83 l.80
.77 l.74 l.71 2000' l 1.08 l 1.04 l1
.96
.93
.S9 l.86 l.83
.80 l.77 l.74 ALTITUDE 3000*
1.12 l 1.08 l 1.04 l 1
.96
.93
.89 l.86 l.83 l.80 l.77 WHEN 4000* l 1.16 l 1.12 l 1.03 l 1.04 l1 l.96
.93
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l.86 l.83 l.80 USED 5000' l 1.20 l 1.16 l 1.12 1.08 l 1.04 l1
.96 23
.89 l.36 l.83 6000' l 1.25 l 1.20 i 1.16 1.12 1.08 l 1.04 1
l.96
.93 l.89 l.86 7000' l 1.30 l 1.25 1.20 1.16 1.12 l 1.08 l 1.04 1
l.96 l.93 89 i
800C' l 1.35 l 1.30 1.25 l 1.21 l 1.16 l 1.12 l 1.03 1.04 l1 l.95 l.93 9000'
'l.40 l 1.35 1.30 1.25 1.21 1.16 1.12 l1.0S I 1.04 l1
.96 10000' l.45 l 1.40 1.35 1.30 1.26 l 1.21 1.17 1.12 1.03 1.04 l1 h!ULTIPLY METER READING BY GIVEN CORRECTION FACTOR I
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Table 1760-1
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TEMPERATURE WHEN CALIBRATED (O'F) l 30 40 50 60 l70 80 90 100 l !!0 120 1 *>J l140 30 l 1
.93
.96
.94
.92
.91
.89
.87 l.86
.S 4
.83
.82 40 l 1.C 2 1
I.98
.96
.94
.93
.91
.S9 l.38 M
.85
.83 50 l 1.04 1.02 1
.98
.96
.94
.93
.91 l 89
.88
.86
.S5 TEMPERA'I11RE 60 1.06 l 1.04 1.02 1
.93
.96 I.95 l.93 i.91
.90
.88
.87 WHEN USED 70 1.C3 l 1.06 1.04 1.02 1
.93
.96
.95
.93
.91
.90 38 (0* F) 80 1.10 1.08 1.06 1.04 1.02 1
.98
.96
.95
.93
.92
.90 90 1.12 1.10 1.08 1.06 l 1.04 1.02 1
98 l.96 i.95
.93
.92 100 1.14 1.12 1.10 1.03 1.06 1.04 1.02 1
l.98
.97
.95
.93
!!O 1.16 1.14 1.12 1.10 1.08 1.06 1.04 1.02 1
.93
.97
.95 120 l 1.18 1.16 1.14 1.12 1.09 l 1.C 7 1.05 1.04 1.02 1
.98
.97 130 1.20 1.18 l 1.16 1.13 1.11 l 1.09 1.07 1.05 1.04 1.02 1
.98 140 } 1.22 1.20 1.18 1.15 1.13 1.11 1.09 1.07 1.05 1.03 1.02
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MULTIPLY METER RE ADING BY CIVEN CORRECTION FACTOR 6.0 01 Table 1760-2
L/ Of / 4 Revision 0 NINE Call 8 RATION CONTRCLS
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