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Portable Alpha Meter (PAM) Operation and Source Checks

Type

ROUTINE Document No.

TF-RC-010 Rev/Mod

D-7 Release Date

07/09/2018 Page

1 of 15

Tank Farm Plant Operating Procedure RADCON

USQ # N/A-4

CHANGE HISTORY ( LAST 5 REV-MODS )

Rev-Mod Release Date Justification: Summary of Changes

D-7 07/09/2018 RadCon Request Addressing WRPS-PER-2018-0857 in relation to procedure

including references BT-6002-880 and BT-6007-237.

D-6 02/06/2018 RadCon Request

Incorporated changes involving “Saturation Checks” being

performed during “Daily Source Checks” in addition to the “Initial

Source Checks.”

D-5 02/07/2017 RadCon Request Modified Steps 5.2.3, 5.2.4, 5.2.15, and 5.2.16 to reflect the

consensus for “single background” checks throughout procedure.

D-4 11/16/2016 RadCon Request Modified Step 5.2.7.2 and updated Records section.

D-3 09/01/2016 PER Updated Records section to current standard and added reference

to TF-RC-043.

Table of Contents Page

1.0 PURPOSE AND SCOPE ................................................................................................................ 2

1.1 Purpose ................................................................................................................................ 2

1.2 Scope ................................................................................................................................... 2

2.0 INFORMATION............................................................................................................................. 2

2.1 General Information ............................................................................................................ 2

3.0 PRECAUTIONS AND LIMITATIONS......................................................................................... 3

3.1 Equipment Safety ................................................................................................................ 3

4.0 PREREQUISITES .......................................................................................................................... 3

4.1 Special Tools, Equipment and Supplies.............................................................................. 3

4.2 Performance Documents ..................................................................................................... 3

5.0 PROCEDURE ................................................................................................................................. 4

5.1 Operational Check .............................................................................................................. 4

5.2 Source Check ...................................................................................................................... 7

5.3 Operating Instructions ....................................................................................................... 12

5.4 Correction Factors ............................................................................................................. 14

5.5 Records ............................................................................................................................. 15


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D-7 Release Date

07/09/2018 Page

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1.0 PURPOSE AND SCOPE

1.1 Purpose

This procedure provides specific information regarding the Portable Alpha Meter (PAM).

1.2 Scope

This procedure provides instruction for operation and performing operational, source and

response checks of the PAM.

2.0 INFORMATION

2.1 General Information

2.1.1 Specific information regarding theory of operation, calibration, maintenance

and instrument specifications and limitations, including environmental and

interfering radiation can be obtained from the Calibration Services Provider

and found in MA-562, Radiation Protection Instrument Manual (or

equivalent).


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3.0 PRECAUTIONS AND LIMITATIONS

3.1 Equipment Safety

3.1.1 The temperature range for the PAM has been extended beyond the range

listed in MA-562. The acceptable temperature range is -22º F to 122º F.

4.0 PREREQUISITES

4.1 Special Tools, Equipment and Supplies

The following supplies may be needed to perform this procedure:

Alpha check source assembly (ACS)

Four 9-volt alkaline batteries.

Mylar Tape

Testor brand silver model paint (MSDS-SDS 068329)

4.2 Performance Documents

The following documents may be needed to perform this procedure:

BT-6002-880, Instrument Service Tag

BT-6007-237, Instrument Service Tag - RSS

A-6002-895, Daily Instrument Source Check Log

BL-6006-213, Daily Source Check

TF-RC-043

TFC-ESHQ-RP_MON-C-28.

A-6006-668, Radiation Protection Portable Survey Instrument Mean Source

Response

A-6006-669, Radiation Protection Portable Survey Instrument Mean Source

Response Addendum, if required.


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5.0 PROCEDURE

5.1 Operational Check

NOTE - Steps within this section may be performed in any logical order.

5.1.1 CONFIRM calibration of instrument meter body and probe is current.

5.1.2 CONFIRM source check of instrument is current.

NOTE - An inspection of the instrument is required before each intermittent use of the

PAM.

5.1.3 INSPECT the instrument for following physical defects:

Broken meter glass

Loose knobs

Punctured probe window

Defective cables

Any other observable defects that would affect operation.

5.1.3.1 IF any defects, other than defective cables, are found,

PERFORM the following:

a. TAG the instrument with a completed Instrument Service

Tag (BT-6002-880 or BT-6007-237).

b. SEGREGATE the instrument to prevent inadvertent use.

c. NOTIFY RadCon management.

5.1.3.2 IF cable was replaced, PRIOR to use PERFORM daily source

check per Section 5.2.


Type


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D-7 Release Date

07/09/2018 Page

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5.1 Operational Check (Cont.)

5.1.4 IF it is determined that the Instrument Service Tag was installed in error,


5.1.4.1 CONFIRM the instrument passes all required operational

checks.

5.1.4.2 OBTAIN concurrence from the First Line Manager to place the

instrument back in service.

5.1.4.3 REMOVE the Instrument Service Tag.

5.1.4.4 PLACE the instrument back in service.

5.1.5 TURN selector switch to “BATT” position AND

CONFIRM meter reading is above “BATT cutoff” position on meter face.

5.1.5.1 IF “Battery” indicates left end of “BATT cutoff” band, ENSURE

batteries are replaced AND

PERFORM daily source check per Section 5.2 prior to use.

5.1.6 TURN selector switch to the X1 position AND

ALLOW a 10 second warm-up.

5.1.7 TURN instrument’s speaker ON.

5.1.8 RESPONSE CHECK instrument as follows:

5.1.8.1 PLACE probe next to 230Th check source mounted on instrument

case.

5.1.8.2 CONFIRM instrument meter increases.

5.1.8.3 CONFIRM audible indication from speaker.


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5.1 Operational Check (Cont.)

5.1.9 HOLD probe toward source of light at work location AND

CONFIRM instrument meter does not increase.

5.1.10 IF instrument meter increases when probe is exposed to light, COVER probe

with a light shield (such as the probe cover or dark cloth) AND

CONFIRM count rate drops.

5.1.11 INSPECT mylar for damage.

5.1.11.1 IF mylar has been damaged, REPAIRS may be performed using

either Testor brand or equivalent silver paint or Mylar tape.

(Repairs of up to 9 screen segments [50 cm2 probe] and 18 screen

segments [100 cm2 probe] total are permitted.)

5.1.12 IF the PAM fails any of the checks, PERFORM the following:

5.1.12.1 TAG instrument with a completed Instrument Service

Tag (BT-6002-880 or BT-6007-237).

5.1.12.2 SEGREGATE the instrument component to prevent inadvertent

use.

5.1.12.3 NOTIFY RadCon management.




checks.






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5.2 Source Check

NOTE - The Portable Alpha Meter (PAM) is source checked using an alpha check

source assembly (ACS).

- - All three ranges of the instrument should be source checked.

Initial Source Check

NOTE - Minimum acceptable efficiency for 50 cm2 probe is 16% and for 100 cm2 is

15%.

- A saturated PAM probe with a large light leak may exhibit zero response (no

clicks or other indication) when exposed to alpha radioactivity or an alpha

source. When the source position over the detector face shields the light leak,

the PAM will respond to the source.

5.2.1 IF cover is installed, REMOVE cover from probe

5.2.2 CONFIRM efficiency is 16% for 50 cm2 probe and 15% for 100 cm2

probe.

5.2.2.1 IF efficiency is 16% for 50 cm2 probe or 15% for 100 cm2

probe, PERFORM the following:

a. SEGREGATE the instrument to prevent inadvertent use.

b. NOTIFY RadCon management.

5.2.3 PERFORM a single minute background count AND

CONFIRM background is 3 cpm.

5.2.4 IF background is 3 cpm, MOVE the PAM to a lower background area

prior to obtaining the response reading.


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5.2 Source Check (Cont.)

5.2.5 PERFORM a saturation check as follows:

5.2.5.1 HOLD the PAM probe toward a source of light.

5.2.5.2 USE a 47 mm diameter or smaller alpha source.

5.2.5.3 SLOWLY MOVE the source over the entire detector face while

holding the source within ¼ in of the detector face.

5.2.5.4 IF the instrument does not respond to the alpha source at any

location on the probe face, TAG the instrument with a completed

instrument service tag (BT-6002-880 or BT-6007-237)

identifying the problem(s).

a. SEGREGATE the instrument to prevent inadvertent use.

b. NOTIFY RadCon management.

5.2.6 CENTER probe over source position on check source assembly.

5.2.7 MOVE source to appropriate position for each range of the instrument AND

ALLOW instrument’s reading to stabilize (approximately 10 seconds).

5.2.8 EVALUATE initial source count response.

5.2.8.1 IF alpha response is within 20% of the mean or typical

instrument response for that source (3-5 instruments),

OR

IF alpha response is within 20% of source activity as determined for the

source by a source calibration provider, ATTACH a Daily

Source Check label (BL-6006-213) to the instrument AND

COMPLETE the label.


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D-7 Release Date

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5.2.8.2 IF alpha response is not within 20% of the mean or typical

instrument response for that source,

OR

IF alpha response is not within 20% of source activity as

determined for the source by a source calibration provider,


a. IF reading is high out-of-range, CONTACT the

Instrument FPOC for evaluation for continued use.

b. IF the reading is low out-of-range or Instrument FPOC

determines not acceptable for continued use, THEN:

1. TAG the instrument with a completed instrument

service tag (BT-6002-880 or BT-6007-237)

identifying the problem(s).

2. SEGREGATE the instrument to prevent inadvertent

use.

3. NOTIFY RadCon management.

5.2.9 DOCUMENT the instrument's response on each range on the Daily

Instrument Source Check Log (A-6002-895).

5.2.10 MULTIPLY instrument's response for each range by 0.8 and 1.2 to

determine acceptable range for that instrument AND

RECORD acceptable range on the Daily Instrument Source Check Log (A-

6002-895).

5.2.11 COMPLETE remainder of the Daily Instrument Source Check Log (A-

6002-895).

5.2.12 IF the response is acceptable, ATTACH AND COMPLETE a Daily Source

Check label (BL-6006-213) to the instrument.

5.2.13 IF the instrument fails the initial source check, PERFORM the following:

5.2.13.1 TAG with a completed Instrument Service Tag (BT-6002-880 or

BT-6007-237).

5.2.13.2 SEGREGATE the instrument to prevent inadvertent use.



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checks.





Daily Source Check

5.2.15 IF cover is installed, REMOVE cover from probe.


CONFIRM background is 3 cpm.

5.2.17 IF background is 3 cpm, MOVE the PAM to a lower background area

prior to obtaining the response reading.

5.2.18 PERFORM a saturation check as done during the initial source check (Step

5.2.5.).

5.2.19 CENTER probe over source position on check source assembly.

5.2.20 MOVE source to appropriate position for each range of the instrument.

5.2.21 ALLOW instrument’s reading to stabilize (approximately 10 seconds).

5.2.22 OBSERVE instrument's response on each range.

5.2.23 IF instrument response is within the acceptable ranges, COMPLETE the

following:

Daily Instrument Source Check Log (A-6002-895)

Daily Source Check label (BL-6006-213).


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5.2.24 IF the instrument failed the source check, PERFORM the following:

5.2.24.1 TAG with a completed Instrument Service Tag (BT-6002-880 or

BT-6007-237).

5.2.24.2 SEGREGATE the instrument to prevent inadvertent use.





checks.






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D-7 Release Date

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5.3 Operating Instructions

5.3.1 WHEN using the PAM at temperatures below 14ºF, PERFORM the

following;

Battery checks (Step 5.1.5) approximately every hour

Source checks (Steps 5.2.15 through 5.2.24) approximately every four

hours of continued exposure to temperatures < 14 F

Source Check (Steps 5.2.15 through 5.2.24) post use in temperatures

< 14 F.

5.3.2 PERFORM Instrument Operational Check per Section 5.1.

NOTE - An established field value may be a previous reading or a well-known,

constant, non-zero field.

5.3.3 IF damage to the PAM is suspected during survey (e.g., instrument is

dropped), PERFORM either of the following steps:

5.3.3.1 IF an established field is available, CHECK response is within

20% of established value.

5.3.3.2 IF an established field is not available, PERFORM the Daily

Source Check portion of Section 5.2.

5.3.4 PERFORM Response Checks intermittently during use.


CONFIRM background is ≤ 3 cpm.


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5.3 Operating Instructions (Cont.)

NOTE - Survey protocols for unconditional release of material and equipment are

performed in accordance with TF-RC-043, Perform Release Surveys for

Material and Equipment, or TFC-ESHQ-RP_MON-C-28, Release Survey

Plans.

5.3.6 SURVEY material, personnel or samples as follows:

5.3.6.1 HOLD probe 41 inch from surface.

5.3.7 EVALUATE work locations being surveyed.

5.3.7.1 WHEN material release (clearance) surveys are performed,

ENSURE surfaces are reasonably clean, dry, and relatively

smooth.

5.3.7.2 WHEN non-release (non-clearance) surveys are performed and

surfaces are not reasonably clean, dry, and relatively smooth,

RECORD survey results as directed by work control/task

instruction documents or RadCon Management.

5.3.7.3 PERFORM a survey per the appropriate methodology to meet

required Minimum Detectable Activity (MDA) for the type of

survey being performed.

5.3.8 OPERATE the digital scaler as follows:

5.3.8.1 DEPRESS AND RELEASE the Scaler button.

5.3.8.2 CONFIRM red LED illuminates and scaler counts.

5.3.8.3 CONFIRM red LED goes OFF when scaler counting is

complete.

5.3.8.4 OBSERVE the reading.

5.3.9 IF performing a scanning survey to verify the absence of contamination and

the audible count rate is elevated above background, INVESTIGATE by

pausing over the suspected area for 5 seconds AND

SCAN approximately 13 cm (5 in.) of the previous path at a reduced rate.


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D-7 Release Date

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5.4 Correction Factors

NOTE - Correction factors are calculated as the inverse of the probe’s decimal

efficiency (e.g., 1/0.16 = 6.25 for a 16% efficient PAM and 1/0.15 = 6.67 for a

15% efficient PAM). A conservative correction factor of 7 may be used for all

measurements. This correction factor is the correction factor for the least

efficient PAMs allowed (16% for the 50 cm2 and 15% for the 100 cm2 probe)

rounded up to the next whole number for conservatism and ease of field use.

5.4.1 MULTIPLY the net count rate by the instrument correction factor to convert

an instrument response (cpm) to activity (dpm) for the PAM.


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5.5 Records

5.5.1 PERFORM the following for records identified within this procedure.

5.5.1.1 On the Records Submittal Checklist, RECORD the number of

pages that were completed

OR

PLACE a check mark () in the N/A column.

5.5.1.2 ATTACH the completed records to the Records Submittal

Checklist AND

SIGN Records Submittal Checklist indicating the package is

complete.

5.5.1.3 SUBMIT the completed records to an approved RadCon Record

Storage Area for retention.

The record custodian identified in the Company Level Records Inventory

and Disposition Schedule (RIDS), is responsible for record retention in

accordance with TFC-BSM-IRM_DC-C-02.

Records Submittal Checklist

Number

of pages

completed

N/A

()

Site Form A-6002-895, Daily Instrument Source Check Log

/ /

Signature Print (First & Last Name) Date

First Line Manager (or designee)