ML19224B178
| ML19224B178 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 09/07/1976 |
| From: | Metropolitan Edison Co |
| To: | Mullinix W NRC/IE |
| References | |
| 1702, TM-0109, TM-109, NUDOCS 7906140167 | |
| Download: ML19224B178 (4) | |
Text
s TMI DOCt'ENTS
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DOCUMENT NO:
COPY MADE ON OF DOCUMENT PROVIDED BY METROPOLITW EDISON COMPANY.
Wilda R. Mullinix, NRC 7906140167 e
l90 204
1702 Revision 1 09/07/76 THREE MILE ISLAND NUCLEAR STATION
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STATION HEALTH PHYSICS PROCEDURE 1702 Background Determination for NMC Proportional Counter Model PCC-11T 1.0 PURPOSE The purpose of this procedure is to list the steps taken to determine the background counts rate for the PCC-llT Proportional Counter.
2.0 DISCUSSION Due to the variation of the natural background radiation, a background count rate should be determined at least once a day.
3.0 REFERENCES
3.1 PCC-11T Tech. Manual 3.2 520 IL Scaler Tiotr Manual 3.3 6516A D C Power Supply Manual 4.0 EQUIPMENT 4.1 PCC-llT Proportional Counter 4.2 520 ll Scaler Timer 4.3 6516A D C Power Supply 5.0 OPERATING INSTRUCTIONS 5.1 This instrument may be used for either Alpha or Beta counting.
Therefore, a background determination must be made for each type of radiation at its respective operating plateau.
190 206
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- 1702 Rev/07/76 09 ision 1 NOTE: Fully open the Gas Supply valve (behind i1strument).
Check for flow bubbles in the indicator window.
If bubbles do not appear, check the counting gas cylinder supply.
5.1.1 Depress LINE button on power supply (when the power supply is on, the button will light).
5.1.2 Turn sample drawer latch counterclockwise, pull out sample drawer, insert clean planchet and close and latch sample drawer.
5.1.3 Turn detector toggle switch to ON.
5.1.4 Insure Polarity switch in _.
Insure Sampling mode switch in MANUAL.
Insure Scaler pulse height mode switch in E RAX.
Insure E MAX - E MIN Window corresponds to most recent plateau determination settings.
Insure Display switch in COUNT.
Insure Power Supply voltage is as determined in most recent plateau determina tion.
(Posted on scaler.)
5.1.5 Set Scaler timer for 10 minutes or as desired. Set High Voltage on.
D. C. Power supply as posted on instrument by adjus ting thumb dials.
5.1.6 Depress RESET button on scaler.
5.1.7 Depress START button on scaler.
The " armed" light should light, then the " gate" light should light.
The " gate" will go out when the preset time is past and counting is completed.
5.1.8 Record total coants indicated and calculate background of Section 6.
5.1.9 Repeat steps 5.1.5 through 5.1.8 alpha.' beta.
2.0 i
190 20,'
-1702 2/2/74 Revision 0 6.0 CALCULATIONS counts total counts o.1
Background
min.
time counted (minutes) 10 counts counts 1.0
=
6.2 Example (alpha) 10 minutes min.
220 counts counts
= 22 6.3 Example (Ceta) 10 minutes min.
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NASTER COPY
,702 Revision I DO NOT REMOVE 09/07/76 THREE MILE ISLAND NUCLE AR STATION 3
H o u 0 C O U; STATION HEALTH PHYSICS PROCEDURE 1702 BACKGROUND DETERMITIATION FOR fiMC PROP 0RTIONAL COUNTER MODEL PCC-llT Table of Effective Pages Page Date Revisio,
Pace Date Revision Page Date he:9n 1.0 09/07/76 1
26.0 51.0 2.0 09/07/76 1
27.0 52.0 3.0 02/02/74 0
28.0 53.0 4.0 29.0 54.0 5.0 30.0 55.0 6.0 31.0 56.0 7.0 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 46.0 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 Unit 2 Staff ecommends Approval Approval 8_
Date 9f'A!7(o Approvalnda Date 9f2!T0 0
{ognizant Dept. Head Q C'dgnizant Dept. Head Unit 1 PORC Re mmends pp aval Unit 2 PORC kecom ends Approval k
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Date Date Chairmai of ORC Chai m)19f FOR PORC comment of included PORC com nts o' included
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(d e)
/ (date By Date By 1
Date Date $7-5 !9-7-76 Appro 8c/
' Station Sdperin6' relent / /
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Unit Superintendent
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