ML19224B186
| ML19224B186 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 02/25/1977 |
| From: | Metropolitan Edison Co |
| To: | Mullinix W NRC/IE |
| References | |
| 1706, TM-0113, TM-113, NUDOCS 7906140183 | |
| Download: ML19224B186 (6) | |
Text
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TMI DOCUMENTS DoCumNr No. TM-O//3 COPY MADE ON OF DOCUMENT PROVIDED BY f
METROPOLITAN EDISON COMPAlW.
Wilda R. Mullinix, NRC 7906140133 h
6 191 044
1706 Revision 2
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02/25/77 THREE MILE ISLAND NUCLEAR STATION STATION HEALTH PHYSICS PROCEDURE 1706
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EFFICIENCY DETERMINATION FOR BECKMAN WICE BETA Table of Effective Pages Pace Date Revision Pace Date R evision Pace Date Revision 1.0 02/25/77 2
26.0 51.0 2.0 09/17/75 1
27.0 52.0 3.0 09/17/75 1
28.0 53.0 4.0 09/17/75 1
29.0 54.0 hhp;L.LCo COPY.
55.0 5.0 09/17/7b 1
30.0 ie 6.0 31.
v 56.0 34.0 g,7O7;g COOY 7.0 32.
57.0 33.0 i
58.0 8.0 9.0 O h Uq *[ C 5 9.0 iiti 10.0 35.0
'- 6 0. 0 36.U.n t!O"t is 11.0 ei.c 12.0 3 7. 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 Recommends Approval w9 Date dt 9 b7 Approval Date 2 [i9[77 Approval u
Cognizant Dept. Head Cognizant Dept. Head Unit 1 PORC R ommed ds Ap roval Unit 2 PORC ecomm lnds pproval Date i
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Date ChairrnAn a P0R0 Chailma of PURC f I l
PORC comments of I
included PORC comme,ts o I
included
'(datf) date)
By j
ate By
,1 Date YM Mih Dated-V-77 A
,/j Approval a Approval IT Date Y
Approv M9 pt ND7 '
M;r., Operarienal
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' it " Superintendents Quality Assurance
1706
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Revision 2 02/25/77 THREE MILE ISLAND NUCLEAR STATION STATION HEALTH PHYSICS PROCEDURE 1706 1706 Efficiency Determination Beckman Wide Beta II 1.0 PURPOSE The purpose of this procedure is to list the steps taken to determine the efficiency for the Beckman Wide Beta II.
2.0 DISCUSSION The Beckman Wide Beta II is an automatic proportional counting instru-ment for determining alpha and for beta sample activities.
Efficiency determinations should be determined monthly to check on machine opera-tion.
The efficiency is used in the determination of sample activity.
3.0 REFERENCES
Beckman Wide Beta II Instruction Manual 4.0 EQUIPMENT 4.1 Beckman Wide Beta II Cour :ing System 4.2 Teletype Printer 4.3 100% 0xygen Free Methane Gas 4.4 Two Inch Diameter Beta Source 4.5 Two Inch Diameter Alpha Source 5.0 OPERATING INSTRUCTION 5.1 Open valve controlling gas supply behind the instrument.
Check that gas flow reads approximately 0.2 CFH.
NOTE:
If gas flow is not indicated, a gas cylinder refill may be 3
required.
e 1.0
s' 1706' 09/17/75 Revision 1 5.2 Wait 30 minutes, open the lower right panel and turn PLATEAU POINT KNOB to the OPERATE position.
NOTE:
If the gas supply valve is in the open position and gas flow is indicated as in Step 5.1, eliminate the 30 minute wait period.
5.3 Turn analyzer MODE SELECTOR knob to BETA THEN ALPHA.
5.4 Set the preset MIN. knob on front panel to a counting time of two (2) mi nu tes.
5.5 Insure count mode switch in NET.
Set operate load switch (in upper right panel) to LOAD _.
5.6 After changer has stopped, press red cage advance button (uuper right panel) to bring changer to #1 cage position.
5.7 Place Beta source standard on planchet in changer magazine on top of
- 1 cage. (This is sample position 10) Place Beta source standard on the changer planchet with activity side in the up position.
5.8 Set first sample selector and final sample selector to 10.
5.9 Set OPERATE LOAD SWITCH to OPERATE.
Af ter counting starts return switch to LOAD.
5.10 Set output selector switch to TELETYPE. (Lower right panel) 5.10.1 Teletype output format (example)
BETA Sample #
Time of Day Counts Time 2 Sicma Std. Dev.
000.10 3:42 044008 0010.00 00.0 ALPHA Sample #
Time of Day Counts Time 2 Sicma Std. Dev.
000.10 3:52 000001 0010.00
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00.0 2.0
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1706-09/17/75 Revision 1 5.11 Af ter counting is completed, calculate the counting efficiency using formula / example of section 6.0 5.12 Record output data on form 1701-1.
5.13 Record the total counts in the background and efficiency log book.
5.14 Calculate efficiency as per Section 6.0.
5.15 Plant and record efficiency in the background and efficiency log book.
5.16 Check that current efficiency is within the + 2 sigma operating range.
If not, contact the Radiation Protection Foreman.
5.17 Return source to the source cabinet.
5.18 Repeat step 5.3 through 5.17 substituting in step 5.7 the ALPHA Standard Source.
6.0 CALCULATIONS 6.1 Efficiency (%) = Source counts min.
X 100 Source Dis.
Min.
WHERE:
Source counts _ Total counts obtained in Step 5.10.1 divided by min.
- counting time of step 5.4.
Scurce dis.
Disintegrction rate of source (may be modified by
=
min.
Step 6.2) 6.2 Source dis correction:
min A= Ace
.693t T
WHERE:
A = Disintegration data corrected to current date Ao = Original activity (disintegration rate) obtained from source certificate
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e = Base of natural log 3.0 I9L 048
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09/17/75 1706 Revision 1 t = elapsed time (days) since original certification date.
T = Isotopic half life (same units as t)
NOTE:
If Ao (original activity) is given in uCi; to c,nvert to dis / min, mui+iply the pCi value by 2.22E6 6.3 Examoles 6.3.1 Beta efficiency calculation Reta Source counts / min. = 44008 Beta Source dis / min. = 1.28E5 Efficiency % = counts / min x 100 dis./ min
= 44008-x 100 = 34.4%
1.28Ed 6.3.2 Alpha efficiency calculation Alpha source counts / min. = 5681 Alpha source dis / min. = 1.55E4 Efficiency % = counts / min x 100 dis./ min x 100 = 36.7%
E4 6.3.3 Source decay correction calculation A= Ace
.693t th WHERE:
A = present source activity, dis./ min.
Ao = Source activity at certificate date
= 3.37E4 dis./ min.
Certificate Date = 3/6/67 Present date = 1/1/74 t = time from certificate date to present date
= 2.48E3 days 191 04f 4o
09/17/75
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e ' ',
1706' Revision 1 th = source half life
= 22 years x 3.6425E2 days / year = 8.01E3 days A = (3.37E4) e - (.693)(2.48E3) 8.01E3
= 2.72E4 dis.
min.
5.0 191 050
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