Lesson Plan Template s29

Operation of the Canberra Fastscan Whole Body Counting System

ACADs (08-006) Covered

Keywords

Description

Supporting Material HPT001.208 Revision 0 Page 2 of 29

SEQUOYAH NUCLEAR PLANT NUCLEAR TRAINING TRAINING MATERIALS COVERSHEET

RADIOLOGICAL PROTECTION TECHNICIAN INITIAL TRAINING PROGRAM

RADIOLOGICAL PROTECTION TECHNICIAN INITIAL TRAINING HPT001 COURSE COURSE NO.

OPERATION OF THE CANBERRA FASTSCAN WHOLE BODY HPT001.208 COUNTING SYSTEM LESSON TITLE LESSON PLAN NO.

INPO ACCREDITED YES X NO

MULTIPLE SITES AFFECTED YES X NO

PREPARED BY ------Sue Payne Signature / Date

PROCESS REVIEW ------Gail Blount Signature / Date

LEAD INSTRUCTOR/PROGRAM MGR. REVIEW ------Roy Goodman Signature / Date

PLANT/CORP CONCURRENCE ------Signature / Date

Receipt Inspection and Distribution: Training Materials Coordinator / Date

Standardized Training Material Copies to: BFN Accreditation Support Manager, BFT 2A-BFN SQN Accreditation Support Manager, STC 2A-SQN WBN Training Manager, WTC 1G-WBN

TVA 40385 (NP11/95) Page 1 of 2 HPT001.208 Revision 0 Page 3 of 29

SEQUOYAH NUCLEAR PLANT

NUCLEAR TRAINING

REVISION/USAGE LOG

REVISION DESCRIPTION DATE PAGES REVIEWED BY NUMBER OF CHANGES AFFECTED

0 New Instruction All Sue Payne

TVA 40385 (NP 11/95) Page 2 of 2 HPT001.208 Revision 0 Page 4 of 29

I. PROGRAM: RADIOLOGICAL TECHNICIAN INITIAL TRAINING PROGRAM

II. COURSE: RADIOLOGICAL TECHNICIAN INITIAL TRAINING PROGRAM

III. LESSON TITLE: OPERATON OF THE CANBERRA WHOLE BODY COUNTING FASTSCAN SYSTEM

IV. LENGTH OF LESSON/COURSE: 24 Hours

V. TRAINING OBJECTIVES:

A. Terminal Objective:

Upon completion of this course the participant will demonstrate an understanding of the subject matter by successfully completing a lab exercise, and by obtaining a score of >80% on a written examination.

B. *Enabling Objectives:

1. Describe the theory of operation of the Canberra Whole Body Counting Fastscan System.

2. Describe how to power up and power down the whole body counting system.

3. Describe/demonstrate how to perform a Quality Control Check (QCC).

4. Describe/demonstrate how to perform a Quality Background Check (QBC).

5. Describe/demonstrate how to perform a Resolution Check.

6. Describe/demonstrate how to perform whole body counts (WBCs) on personnel, and the frequency of performing WBCs.

7. Describe how to interpret results of WBCs.

8. Describe/demonstrate how to setup and generate the whole bodying counting system control charts.

9. Describe the QA records that are generated during the activities performed in this lesson plan.

*Standard and conditions are implied for all enabling objectives. They include: Under the examination ground rules and utilizing information and materials presented by the instructor. HPT001.208 Revision 0 Page 5 of 29

VI. TRAINING AIDS:

A. Whiteboard/flip chart and Markers

B. Computer and projector for PowerPoint Presentation (Optional)

C. Overhead/multi-media projector and screen

D. Canberra Whole Body Counting System with ABACOS Plus Software

VII. TRAINING MATERIALS:

A. Appendices

Appendix A – The Signal Processing Chain

Appendix B – MCA Block Diagram

Appendix C – Bioassay Logsheet

Appendix D – Principle Background Gamma Ray Peaks

Appendix E – Whole Body Count Derived Investigation Levels (DILs)

Appendix F – Positive Whole Body Count Tracking Log (QA Form 1.36)

Appendix G – Lab Exercise Sheet

B. Attachments

HO -1 - Lesson Plan HPT207.038, Isotopic Identification, Rev. 0

HO – 2 – Examples of positive WBC’s for discussion

VIII. REFERENCES:

A. RCI-05, Attachment 27, Radiological Control Instruction, Routine Operation of the Canberra Fastscan System for Internal Dosimetry with ABACOS Plus, rev. 038

B. SU-425 ABACOS Plus Body Burden System Operation, rev. 8/97 HPT001.208 Revision 0 Page 6 of 29

IX. INTRODUCTION:

It is our responsibility in Health Physics (RADCON) to provide an effective whole body counting system to perform whole body counts on personnel to obtain baseline levels of any internal depositions for incoming personnel, to provide termination counts when access to radiologically controlled areas are no longer necessary, and to assess exposures resulting from internal depositions of radionuclides. This lesson will provide the instruction on how to meet our responsibility of providing an effective whole body counting system. HPT001.208 Revision 0 Page 7 of 29

A. Theory of Operation of the Canberra Whole Body Counting Obj. B.1 Fastscan System

The electronic components that make up the signal Note: Refer to Appendix A, processing chain between the detector and the displayed Signal Processing Chain. spectrum on the MCA (multi-channel analyzer) screen is displayed in Appendix A, Signal Processing Chain. These components are housed in a cabinet called the NIM BIN (Nuclear Instrumentation Module BIN).

1.The detectors used in the Canberra Whole Body Counting Fastscan Systems is Sodium Iodide doped with Thallium NaI(Tl). This type of detector is a scintillation detector. These detectors operate by producing light as a result of electron interactions in the material. The electrons are produced as a result of the gamma interactions with the material. Therefore, the amount of light produced is directly proportional to the energy deposited by the gamma ray.

2. The light emitted by the scintillator is optically coupled to a photo multiplier tube (PMT) consisting of a photocathode and electron multiplier. The photocathode converts the incident light pulse into a few hundred low energy electrons, the number being produced is proportional to the size of the light pulse. This number of electrons is insufficient to produce a useable signal, so they are focused to a series of dynodes to increase their numbers.

3.The High Voltage Power Supply provides the bias voltage to move the charged particles. The polarity of this voltage is positive in most gamma applications. Changes in high voltage show up as changes in tube gain of the NaI detector, and therefore the overall system gain. NaI detectors are also subject to temperature drifts.

4.The preamplifier associated with radiation detectors performs three essential functions:

a. Conversion of charge to voltage pulse b. Signal amplification c. Pulse shaping

Most preamps in use today are charge sensitive and provide an output pulse with an amplitude proportional to the integrated charge output from the detector. HPT001.208 Revision 0 Page 8 of 29

5. The amplifier is a voltage sensitive device that receives Obj. B.1 the tail pulse from the preamplifier. The amplifier differentiates the input tail pulse to remove the long (50 microsecond) tail yet pass the amplitude information. The differentiated pulse is then increased in amplitude through 1 or more gain stages. The gain of the amplifier is used to position the peaks in the spectral display for the energy range of interest.

The amplifier also shapes the signal for further processing. Better amps have a number of pulse shaping time constants. These represent the frequencies of the band-pass for the shaping circuit. Short time constants are required for higher count rates, but introduce noise and degrades resolution. Long time constants improve resolution but introduce baseline shifts due to pulse pile-up. Amplifiers offer linear amplification and constant shaping for counting purposes.

6. The Analog to Digital Converter (ADC) converts the linear, shaped, signals from the amplifier into a digital value which becomes a memory location in the Multi- Channel Analyzer (MCA). This location is called a channel. If the entire system is linear this channel value will be proportional to the original gamma ray energy which struck the detector. Each detected and converted event adds one count to the appropriate channel (or memory address).

7.The Multi-Channel Analyzer (MCA) consists of a few basic Note: Refer to Appendix B, blocks. Refer to Appendix B. The channel number MCA block diagram. generated by the ADC is converted to a memory address. Each pulse that is digitized adds one count to Note: The Canberra the appropriate memory location. A spectrum (or Fastscans have 512 histogram) indicating the number of pulses versus channels per detector. The voltage (energy) is obtained. This is called a Pulse keV equivalent is Height (Distribution) Analysis, or PHA. Analysis of the approximately 3.9 keV per data can include the use of such functions as: cursors channel. This gives the which are moved from channel to channel to inspect the energy spectrum per number of counts at each level, mathematical and detector of 0 keV to 2000 statistical treatments, such as integral and area, and keV, which will cover the ROIs (Regions Of Interest) to highlight portons of the spectrum of energies found spectrum, e.g. the spectral peaks. in the plant.

B. Powering Up and Powering Down the Whole Body Counting Obj. B.2 System Human error reduction tool: 1. Log onto the system at the Canberra Nuclear Data Logo Stress procedure adherence by inputting the proper data at User Name and when performing these Password. tasks. HPT001.208 Revision 0 Page 9 of 29

2. To log off the system, press PF3 at the Routine Operations Menu, and again at the Main Menu. Click on Session at the Session Manager window, then on Reboot, and appropriately respond to the questions the system asks.

3. When there has been (or will be) a loss of power to the system, it is desirable to power down detectors in the following manner:

a. Slowly reduce the high voltage to all detectors, . using first the coarse (kV) control then the fine (0- 1000 V) control, with a few seconds pause between each control decrease.

b. Turn off the power switch to each NIM BIN.

4. When power has been restored to the system, it is Human error reduction tool: desirable to power up the detectors in the following Extreme caution is needed manner: when powering up the detectors. A power surge a. Turn on the power switch to each NIM BIN. could damage the detectors

b. Slowly increase the high voltage to all detectors, using first the coarse control then the fine control, with a few seconds pause between each control increase to obtain the appropriate settings are recorded in the WBC Logbook.

c. Perform system logon and routine QCC processes before performing personnel bioassays.

C. Quality Control Checks Obj. B.3

1.Quality Control Checks (QCCs) are conducted at least once Note: There may be some per shift when the counter is in use, following any differences between plants adjustment of the lower level discriminator, high voltage on how quality control or ADC zero. checks are performed. For this lesson one application is being given.

2. The check source shall have energy reference peaks approximating the low and high ends of the calibration energy region. Typical reference peaks for a Eu-152 source are 344 keV and 1408 keV.

3.Place the check source in the appropriate location on the counter and perform a manual (visual) calibration by going to the Special Operation Menu and “Start” a collect for the same length of time as the QCC (typicall 60 seconds). HPT001.208 Revision 0 Page 10 of 29

4.Compare the detectors spectrum peak’s centroid with the Obj. B.3 centroid channel of the reference peak.

5.If the centroid channel of the reference peak appears to divide the peak into half, proceed to step 7 if performing a routine QCC; otherwise, the visual QCC is now complete. If the centroid channel of the reference peak does not appear to divide the peak into half, proceed to Step 6 to perform adjustments.

6.Select the centroid channel of the reference peak. Adjust the fine gain potentionmeter upward (clockwise) to shift the centroid channel into higher channels. Adjust it downward (counterclockwise) to shift the centroid channel into lower channels. Continue adjustment of the fine gain for the appropriate input until the centroid channel appears in the reference peak channel. Repeat this process for the other input of the counter. Document gain adjustments in the WBC Logbook, and perform a routine QCC per step 7.

7.Perform a routine QCC count by selecting the Calibration Check option at the Routine Operations Main Menu.

a. The system will display the demographic data for the count. Select the file identification that matches the appropriate source ID number. Add or edit as needed.

b. Enter appropriate information on the Bioassay Note: Refer to Appendix C, Logsheet (QA Form 1.03 – Appendix C). Bioassay Logsheet.

c. The parameters that are checked to determine whether the system has passed or failed are:

(1) The appropriate peaks of interest have been Note: Reference peaks for a reported. Eu-152 source are 344 and 1408 keV. This source also (2) The percent gain statistic for the 344 keV and has 121 and 778 keV peaks 1408 keV reference peaks are within that should be reported on + 2.0%. the peak results.

(3) The activity for the reference peaks is within + 3 standard deviations. HPT001.208 Revision 0 Page 11 of 29

8.Check the results of the QCC printout for compliance with Obj. B.3 the above criteria. If all of the criteria are not met, then perform the following:

a. If there is an investigation flag, note it in the WBC Note: An investigation flag Logbook and review the logbook for trends. Do not indicates a parameter is remove the system from service. outside of two standard deviations, or test b. If there is an action flag, check the geometry and boundaries. repeat the QCC. If after three attempts all criteria are not met, contact the RADCON Shift Supervisor An action flag indicates a or cognizant Health Physicist for resolution. Note parameter is outside of three any actions in the WBC Logbook. standard deviations, or test boundaries.

9.Sign and date the QCC printout. Note: Complete Appendix G, Lab Exercise Sheet after completing the activities in Section C.

D. Quality Background Check (QBC) Obj. B.4

Daily background checks shall be performed once per day (as Note: There may be some a minimum) when the Fastscan whole body counting system is differences between plants in use. The background check shall be performed on how quality background immediately following the first acceptable QCC of the day. checks are performed. For this lesson one application is 1. The background count shall be performed with an empty being given. booth.

2. Select Background Check at the Routine Operations Main Menu.

3. Enter appropriate information on the Bioassay Logsheet.

4. Review the report for any radionuclides or peaks, other Note: Appendix D, Principle than K-40. The peak search results and radionuclide Background Gamma Ray results may include the following: Peaks, can be used to assist in identification of a. Peaks which are 511 keV (single escape annihilation radionuclides. peak energy) may be reported as Ru/Rh-106.

b. Peaks which are 1022 keV (double escape Refer to HO-1, Lesson Plan annihilation peaks energy) may be reported as HPT207.038, Isotopic Ru/Rh-106. Identification, pages 24-29. HPT001.208 Revision 0 Page 12 of 29

c. A 70-90 keV Pb x-ray may be reported as I-131. Obj. B.4

d. A peak at 100-200 keV from Compton continuum.

e. A peak at 200-250 keV from Compton backscatter.

f. A peak at a Compton edge, approximately 200 keV from a major photopeak.

g. Statistical distribution of K-40 peak (e.g., 1408 keV).

h. Naturally occurring products from the Thorium series.

5.If the system passes the QBC check, then place the system in service. Repeat the QBC if an action flag is reported.

6. Document on the printout any evaluation or identification of peaks and action taken (e.g., reviewed spectrum, peaks due to Compton edge, etc.).

7.If the background count is low, document it in the WBC Logbook and continue. If the background count is high, check for any apparent reasons as listed below and repeat the background check. Document results in the WBC Logbook.

a. Ensure that one or more of the following is performed:

(1) Wipe down the booth.

(2) Have any person with a possible or known uptake leave the area.

(3) Remove or block any sources possible causing the abnormal results.

(4) Document that natural products may have increased due to humid weather conditions (e.g., rain, high humidity, etc.).

b. After two attempts the RADCON Shift Supervisor must determine the protocol to be followed prior to Note: Complete Appendix using the WBC for personnel counting. G, Lab Exercise Sheet, after completing the activities in 8.Sign and date the QBC printout. Section D. HPT001.208 Revision 0 Page 13 of 29

E. Resolution Checks Obj. B.5

1.Perform a resolution check on each in-service Fastscan Note: There may be some monthly. differences between plants on how resolution checks 2. Manually acquire a spectrum from the Special are performed. For this Operations menu. Collect approximately 10,000 counts lesson one application is in the peak of interest (i.e., CS-137, 662 keV). being given.

3. Obtain the FWHM (Full-Width at Half Maximum) by bounding the peak of interest:

a. Select the detector to be viewed by clicking on Data Source, and then click on the appropriate detector in the drop down box.

b. View the Marker Info screen in the lower left of the MCV1 window.

c. Set the left and right marker, then press the Shift key and the left mouse button at the base of the peak of interest.

d. Set the right marker, press the Ctrl key and the left mouse button at the base of the peak.

e. Set the centroid marker, by holding the left mouse button and dragging the marker to the center of the peak of interest. (i.e., Cs-137, 662 kev).

f. Compare the energy of the channel at the upper left of the MVC1 window with the centroid energy displayed on the Marker Info screen. The peak centroid energy and the expected energy should be within + 2 keV. If the energies are outside of this range an adjustment of the fine gain may be necessary.

4. Calculate the percent resolution of both detectors using the following equation:

%R = [ FWHM (keV) ÷ Peak Energy (keV) ] X 100

5.Perform a FWHM calibration if the percent resolution is > 10% for the 662 keV peak.

6.Document the resolution for each detector in the WBC Complete Appendix G, Lab Logbook. Exercise Sheet after completing the activities in Section E. HPT001.208 Revision 0 Page 14 of 29

7.Another quality control check performed on the whole body Obj. B.5 counter (done every 6 months on each counter) is the Measurement Quality Control (MQA). This is a blind test using sources supplied by the Western Area Radiological Laboratory (WARL). Results of testing is sent to WARL for analysis. If the counters tested pass the acceptance criteria, counters remain in use. If the counter(s) fail the acceptance criteria, then an Energy Calibration must be performed on the failed counter. Site procedures address how to perform the MQA and an Energy Calibration.

F. Performing Whole Body Counts (WBCs) on Personnel Obj. B.6

1.All individuals require an initial WBC prior to entry into a bioassay area. Other WBCs are given as follows:

a. Entrance and Exit WBCs. Note: No exit WBC is required if no entry is made into a Contamination Area or Airborne Radioactivity Area.

b. TVA personnel returning to their permanent site after going to another TVA site require an entrance WBC only.

c. Contractors require entrance and exit WBCs, unless exempted by the RADCON superintendent.

2. Other reasons for performing a WBC:

a. Greater than 20 DAC-hrs in a calendar year.

b. Random bioassay.

c. Facial and/or nasal contamination.

d. Ingestion or suspected ingestion of radioactive material..

f. Contamination of an open wound.

g. As requested by RADCON.

h. As requested by the individual.

3.Record the appropriate information on the Bioassay Note: Refer to Appendix C, Logsheet (Appendix C). Bioassay Logsheet, and note the information that is recorded on this form. HPT001.208 Revision 0 Page 15 of 29

4. Have the individual step into the whole body counter. Obj. B.6

5. Log onto the ABACOS Plus software and select the appropriate count type.

6.Enter the appropriate information into the Personnel Record Complete Appendix G, Lab Screen and depress “enter”. Exercise Sheet, after completing exercises in Section G.

G. Interpretation of Results of WBCs Obj. B.7

Review peak search results and the nuclide results for Note: There may be some abnormal occurrences. Interpret the WBC results as differences between plants follows: on how positive wbcs are handled. For this lesson one 1.Consideration should be given to the following nuclides that application is being given. may interfere with the interpretation of WBC results: K-40, Ga-67, Tc-99m, and Bi-204. Consideration should also be given to the possibility that other nuclides that appear in the background or from a medical injection will be identified.

2.Medical injections of radionuclides will typically be reported as unknown at lower energies. Such peaks shall be manually identified on the WBC report and recorded on the count file. Edit the demographics for the count with a notation made in the Comments field, or make a notation on the WBC report.

a. Verify the presence of medical isotopes with the employee.

b. Obtain information on the nuclei and amount of radioactivity, if known.

c. Perform reanalysis of suspected medical isotopes using the Reanalysis option on ABACOS Plus, under the Special Operations Menu. Selecting the Medical Isotope Library is recommended.

d. If necessary schedule the individual for a recount, and perform subsequent recounts.

e. Individuals with diagnostic medical injections may Note: Refer to Appendix E, have their TLDs (Thermolumuninescent Whole Body Count Derived Dosimeters) returned when they are <100 cpm (as Investigation Levels (DILs). measured with a frisker), and after clearing a personnel contamination monitor, and when no DILs are exceeded on the WBC, or unless waived by the RADCON Superintendent. HPT001.208 Revision 0 Page 16 of 29 f. If no radionuclides (excluding those due to K-40, Obj. B.7 noble gases, or medical treatments, etc.) are identified, then release the individual. Note: If a radionuclide is present only in the thyroid, a reanalysis with a different efficiency may be warranted. g. If radionuclides (excluding those due to K-40, noble gases, or medical treatments, etc.) are identified in the initial count, a verification WBC can be performed, if necessary.

(1) Place the individual in clean clothing (i.e., papers or other suitable clothing) and frisk the individual. If contamination is indicated the individual may possibly be contaminated. Arrange for decontamination as appropriate.

(2) Frisk the individual’s clothing (a Gamma Tool Monitor, or equivalent, may be used). If contamination is indicated, then confiscate the items and properly bag and tag them as radioactive material in accordance with RCI- 21, Control of Radioactive Materials.

(3) Verify the status of the whole body counter used.

(4) Perform a verification WBC.

(5) Some or all of the steps listed below should be completed to document an event. Steps do not have to be performed in the sequential order provided.

(6) If the backward facing count is significantly less than the forward facing count, then the presence of contamination on the front of the body is indicated. If the backward facing count is significantly more than the forward facing count, then the presence of contamination on the back is indicated. If the backward facing and the forward facing counts are approximately the same, then an uptake is indicated.

HPT001.208 Revision 0 Page 17 of 29

(7) If the count verifies the presence of Obj. B.7 radionuclides (excluding those due to K-40, noble gases or medical treatments, etc.), then:

(a) Conduct another verification count with the individual facing the rear of the booth.

(b) Notify the Dosimetry Supervisor, or duty RADCON Shift Supervisor, if external contamination is indicated.

(c) Log all verified positive in vivo Note: Refer to Appendix F, measurements (>1% ALI – Annual Positive Whole Body Count Limit of Intake) exceeding the levels in Tracking Log (QA Form Appendix E, Whole Body Count 1.36). Derived Investigation Levels (DILs), on a Positive Whole Body Count Tracking Log (QA Form 1.36), Appendix F.

(e) For any WBC that is confirmed to exceed any DIL, an assessment shall be performed in accordance with site procedures.

(f) Schedule the individual for follow-up counts, if necessary.

(g) Document survey results in the appropriate RADCON computer system.

(h) Document appropriate information in the RADCON Log.

(i) Document pertinent information on the WBC Report.

(j) Ensure that the WBC printout is signed and dated (under Reviewed By.)

(k) Release the individual when the data review and necessary follow-up actions are complete. HPT001.208 Revision 0 Page 18 of 29

H. Whole Body Count Control Charts Obj. B.8

1.The daily control chart shall be developed by performing at Note: There may be some least 20 measurements in the established geometry from differences between plants the appropriate sources. The mean and three standard on how control charts are deviation values of the reference or activity areas shall handled. For this lesson one be plotted on the control charts and used in establishing application is being given. the limiting parameters in the Fastscan plotting operation.

2.Quality control and background data files are maintained on Note: Instructions for setup the ABACOS Plus software. From the “Main Menu” go of control chart parameters to the “Special Operations Menu”, then to “Quality can be found in the Control Menu”. At the next menu, select “Process Canberra SU-425 ABACOS Results”. This function brings up another menu of Plus Body Burden System functions that allow the user to edit, list, plot, add, reject, Operation, rev. 8/97 and delete results.

3.Select the desired files to be manipulated (quality control or Note: Demonstrate these background). If quality control is selected the software screens on the ABACOS will ask if you want to use detector 1, detector 2, or the Plus software. sum of the detectors. Select “Sum”.

4.Select whichever function is desired and enter the required information, i.e., print, plot, etc).

5.Place the generated printouts from ABACOS Plus with the Stress human error appropriate quality control printouts and forward to the reduction tool: Any Electronic Data Management Services (EDMS). discrepancies on generated Control Charts are to be routed for both QCC and QEB printouts from ABACOS Plus every quarter. must be investigated and corrected prior to transmitting to EDMS.

Complete Appendix G, Lab Exercise Sheet, after completing the activities in Section H.

I. QA Records Obj. B.9

The following records generated during whole body counting Note: These records are activities are QA records and are handled in accordance protected by the Privacy Act with site procedures: and are maintained as Sensitive Information prior to A. QA Form 1.03, Bioassay Logsheet transmittal to the Electronic Document Management B. QA Form 1.36, Positive Whole Body Count Tracking System (EDMS). Log HPT001.208 Revision 0 Page 19 of 29

C. WBC Logbook

D. WBC QCC printout (included with WBC Control Charts)

E. WBC QBC printout (included with WBC Control Obj. B.9 Charts)

F. WBC Control Charts

G. WBC Report HPT001.208 Revision 0 Page 20 of 29

XI. SUMMARY:

The Canberra Fastscan Whole Body Counting System is in place to provide baseline and exit WBCs on personnel to determine if there are any internally deposited radionuclides, and to access exposures resulting from any internally deposited radionuclides.

The scintillation detectors used in the Fastscan are Sodium Iodide doped with Thallium NaI(Tl). They operate by producing light as a result of electron interactions in the material when gamma radiation interacts with the detector. The amount of light produced is directly proportional to the energy deposited by the gamma ray. This light is coupled to a PMT. The High Voltage Power Supply provides the bias voltage to move the charged particles. The preamplifier associated with the detector converts the charged particles to voltage pulse, provides signal amplification, and pulse shaping. The amplifier receives the pulse from the preamplifier and increases the amplitude of the pulse. It also shapes the signal for further processing. The ADC converts the linear shaped signals from the amplifier into a digital value which becomes a memory location in the MCA. The MCA consists of a few basic blocks and stores the signals according to pulse height and displays the information in a spectrum or histogram.

Follow site procedures when powering the whole body counting system up or down. When powering down, slowly reduce the high voltage to all detectors using the coarse kV control then the fine 0-1000V control with a few seconds pause between each control decrease. Turn off the power switches to each NIM BIM. When powering up, turn on the power switches on the NIM BIN and slowly increase the high voltage to all detectors, using first the coarse control then the fine control to obtain the appropriate settings in the WBC Logbook.

QCCs are conducted at least once per shift when the counter is in use, following any adjustment to the lower level discriminator, high voltage, or ADC zero. Place the source in the counter and adjust the gain if necessary prior to performing the check. Check for the reference peaks of interest to be reported, 344 and 1408 keV, and if it is within +2.0% gain statistic. If an investigation flag is reported note in the WBC Logbook. If an action flag is reported, check geometry and repeat. HPT001.208 Revision 0 Page 21 of 29

QBCs are performed once per shift when counter is in use. It is performed with an empty booth. Review the report for any radionuclides or peaks, other than K-40. Repeat if an action flag is reported. If background counts are high or action flags are repeated, wipe down the booth, check for persons in area with possible uptakes, remove or block any sources possible causing the abnormal results. Document that natural products may have increased due to humid weather conditions.

Resolution Checks are typically performed monthly. The peak of interest is the Cs-137 662 keV peak. Obtain the FWHM by bounding the peak of interest and calculate the percent resolution by the following equation:

%R = [FWHM (keV) ÷ Peak Energy (keV)] X 100.

Perform a FWHM calibration if the percent resolution is >10% for the 662 keV peak. Document the resolution for each detector in the WBC Logbook.

Individuals are required to receive an initial WBC prior to entry into a bioassay area and when no longer requiring entrance into bioassay areas. TVA personnel require an entrance WBC when returning from other TVA sites. WBCs are given when individuals receive greater than 20 DAC-hrs in a calendar year, randomly selected, facial or nasal contamination, suspected ingestion of radioactive material, contamination of an open wound, and upon the request of RADCON or the individual.

When performing WBCs on personnel, If no radionuclides (excluding K-40, noble gases, or medical treatments) are identified in a WBC, then release the individual. If any radionuclides are identified, then perform a verification WBC. The individuals can be placed in clean clothing if contamination is suspected. The individual’s clothes may be frisked or placed in a Gamma Tool Monitor and confiscated if they are found to be contaminated. Another WBC can be performed facing backwards in the counter to determine if contamination is on the front or the back of the individual, or is an actual uptake. HPT001.208 Revision 0 Page 22 of 29

Any WBCs that are >1% ALI shall be logged on the Positive Whole Body Counting Tracking Log. For any wbc that is confirmed to exceed a DIL, an assessment shall be performed in accordance with site procedures. Schedule the individual for a follow-up count, if necessary. Document any survey results in the appropriate RADCON computer system, and on the WBC Report and in the RADCON log.

WBC Control Charts are printed from the Quality Control Menu of the ABACOS Plus software and transmitted to EDMS on a quarterly basis with the QCCs and QBCs performed during the quarter. Any discrepancies noted in the QCC and QBC control chart files must be investigated and corrected prior to transmitting to EDMS.

QA records generated in the whole body counting activities are transmitted to EDMS in accordance with site procedures. HPT001.208 Revision 0 Page 23 of 29

APPENDIX A

The Signal Processing Chain HPT001.208 Revision 0 Page 24 of 29

APPENDIX B

MCA BLOCK DIAGRAM HPT001.208 Revision 0 Page 25 of 29

Appendix C Bioassay Logsheet HPT001.208 Revision 0 Page 26 of 29

Appendix D

Principle Background Gamma Ray Peaks HPT001.208 Revision 0 Page 27 of 29

APPENDIX E Page 1 of 2

Whole Body Count Derived Investigation Levels (DILs) - 0.5 Days (12 Hours) Post-Intake – - 1% ALI Level (μCi) - HPT001.208 Revision 0 Page 28 of 29

APPENDIX E Page 2 of 2

Whole Body Count Derived Investigation Levels (DILs) - 0.5 Days (12 Hours) Post-Intake - - 1% ALI Level (μCi) - HPT001.208 Revision 0 Page 29 of 29

APPENDIX F

QA FORM 1.36 - POSITIVE WHOLE BODY COUNT TRACKING LOG

Name: SSN: Comments Date Count Nuclide Activity DateTime of Initials Time (nCi) Intake, etc.

 Reviewed By Date HPT001.208 Revision 0 Page 30 of 29

APPENDIX G Page 1 of 1

LAB EXERCISE SHEET

Student Name SSN Classroom Exercises Completed

SAT UNSAT

______

______Instructor Signature/Date

Note: The instructor will provide a method for the student to be reexamined in the event of an unsatisfactory mark in any of the above exercises.