lc-fs-pr-018 rev 1 radiation surveys of pipe interiors ...lc-fs-pr-018 radiation surveys of pipe...

LC-FS-PR-018

Radiation Surveys Of Pipe Interiors Using Sodium/Cesium Iodide Detectors Revision 1

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TABLE OF CONTENTS

1. PURPOSE AND SCOPE .......................................................................................................4

Purpose ........................................................................................................................4 1.1.

Scope ...........................................................................................................................4 1.2.

2. REFERENCES .......................................................................................................................4

NUREG-1757, Volume 2, Revision 2 “Consolidated Decommissioning Guidance - 2.1.

Characterization, Survey, and Determination of Radiological Criteria” ....................4

NUREG-1575, “Multi-Agency Radiation Survey and Site Investigation Manual” 2.2.

(MARSSIM) ...............................................................................................................4

La Crosse Boiling Water Reactor License Termination Plan (LTP) ..........................4 2.3.

LC-AD-PR-003, “Records” ........................................................................................4 2.4.

LC-QA-PN-001, “Final Status Survey Quality Assurance Project Plan”...................4 2.5.

LC-FS-PR-008, “Final Status Survey Data Assessment” ...........................................4 2.6.

LC-FS-PR-002, “Final Status Survey Package Development” ..................................4 2.7.

LC-FS-PR-011, “Operation of the Ludlum 2350-1 Data Logger and Associated 2.8.

Detectors” ...................................................................................................................4

3. GENERAL ..............................................................................................................................5

Definitions...................................................................................................................5 3.1.

Responsibilities ...........................................................................................................6 3.2.

Precautions, Limitations and Prerequisites .................................................................7 3.3.

Records .....................................................................................................................10 3.4.

4. PROCEDURE ......................................................................................................................10

Efficiency Factor Determination...............................................................................10 4.1.

Pre-Use and Post-Use Operational Response and Background Check .....................13 4.2.

Acquiring FSS Data in Pipe Interiors with NaI/CsI Detectors .................................15 4.3.

5. ATTACHMENTS ................................................................................................................19

Attachment 1, Pipe Detector Efficiency Determination ...........................................19 5.1.

Attachment 2, Daily Pipe Survey Detector Control Form ........................................19 5.2.

Attachment 3, Pipe Interior Radiological Survey Form ...........................................19 5.3.

Attachment 4, DCGLs for FSS of Buried Pipe .........................................................19 5.4.

Attachment 5, Pipe Source Efficiency Positions ......................................................19 5.5.

Attachment 6, Example of Source Efficiency and MDCStatic ....................................19 5.6.

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Summary of Changes in this Revision:

Revision 1 – Changes made to align with responses to Requests for Information and proposed

Revision 1 of the License Termination Plan.

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1. PURPOSE AND SCOPE

Purpose 1.1.

The purpose of this procedure is to describe the approach utilized at the La Crosse

Station Restoration Project (LSRP) to assess the radiological conditions of the interior

surfaces of piping that will remain at the end-state condition to demonstrate

compliance with the release criteria. This procedure provides instructions for the

acquisition of measurements and recording of data in performing radiological surveys

of the inside of piping using Sodium Iodide (NaI) and/or Cesium Iodide (CsI)

detectors.

Scope 1.2.

This procedure implements the requirements of applicable U.S. Nuclear Regulatory

Commission (NRC) regulations and guidance documents; specifically, NUREG-

1757, Volume 2, Revision 2, “Consolidated Decommissioning Guidance -

Characterization, Survey, and Determination of Radiological Criteria”

(Reference 2.1), NUREG-1575, “Multi-Agency Radiation Survey and Site

Investigation Manual” (MARSSIM, Reference 2.2) and Chapter 5 of the “2.3. La

Crosse Boiling Water Reactor License Termination Plan” (LTP) (Reference 2.3).

This procedure applies to all personnel performing surveys of the interior surfaces of

buried piping for the purpose of Final Status Surveys (FSS).

2. REFERENCES

NUREG-1757, Volume 2, Revision 2 “Consolidated Decommissioning Guidance - 2.1.

Characterization, Survey, and Determination of Radiological Criteria”

NUREG-1575, “Multi-Agency Radiation Survey and Site Investigation Manual” 2.2.

(MARSSIM)

La Crosse Boiling Water Reactor License Termination Plan (LTP) 2.3.

LC-AD-PR-003, “Records” 2.4.

LC-QA-PN-001, “Final Status Survey Quality Assurance Project Plan” 2.5.

LC-FS-PR-008, “Final Status Survey Data Assessment” 2.6.

LC-FS-PR-002, “Final Status Survey Package Development” 2.7.

LC-FS-PR-011, “Operation of the Ludlum 2350-1 Data Logger and Associated 2.8.

Detectors”

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3. GENERAL

Definitions 3.1.

3.1.1 Calibration - The adjustment and/or determination of an instrument’s response

relative to a standard and/or series of conventional true values.

3.1.2 Certification – The use of a derived standard to determine an exposure rate,

activity or other value to the specified and/or required degree of accuracy.

3.1.3 Check Source – A radioactive source, not necessarily calibrated, that is used to

confirm the continuing satisfactory operation of an instrument.

3.1.4 Efficiency – A correction factor determined during detector calibration to convert

the detector output in “counts per minute” to “disintegrations per minute”

assuming a worst-case geometry between the detector and the source.

3.1.5 Final Status Survey (FSS) – Measurements and sampling to quantify the

radiological conditions of a survey unit, following completion of decontamination

activities (if any) to demonstrate compliance with the release criteria.

3.1.6 Performance Test/Response Check – A procedure whereby an instrument or a

component is evaluated against accepted criteria for continuing satisfactory

operation and use.

3.1.7 Turnover - Acknowledgement of cognizant project personnel that a system,

structure, or open land survey unit meets the physical and radiological conditions

necessary to perform FSS.

3.1.8 Acronyms

1.) CsI Cesium Iodide

2.) DCGL Derived Concentration Guideline Level

3.) FSS Final Status Survey

4.) GPS Global Positioning System

5.) LTP License Termination Plan

6.) MDC Minimum Detectable Concentration

7.) MDCR Minimum Detectable Count Rate

8.) NaI Sodium Iodide

9.) NIST National Institute of Standards and Technology

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10.) NRC U.S. Nuclear Regulatory Commission

11.) QA Quality Assurance

12.) QAPP Quality Assurance Project Plan

13.) SER Surface Emission Rate

Responsibilities 3.2.

3.2.1 RP/FSS Manager – is responsible for:

Providing overall guidance and support for the development and

implementation of FSS sample plans and survey packages.

Reviewing and approving all FSS sample plans.

3.2.2 FSS Supervisor – is responsible for:

Providing direction to D&D Manager for pipe access and decontamination

requirements and determining adequacy of pipe access.

Preparing FSS sample plans and survey packages.

Ensuring FSS surveys are conducted in accordance with approved survey and

sampling plans, procedures, and work instructions.

Providing technical direction and guidance for field survey and sampling

activities.

Controlling and implementing sample plan instructions during field activities.

Survey area/unit preparation, isolation, turnover and prerequisites (e.g.,

reference grid layout, identification of working constraints and accessibility

needs).

Providing daily supervision and guidance to field survey and sampling crews

and performing quality checks of field activities.

Overseeing the preparation of samples for transfer to onsite or offsite

laboratories.

Ensuring all necessary instrumentation and other equipment is available to

support survey activities.

Ensures FSS sample plans and packages are properly labeled, stored and

controlled per LC-AD-PR-003, “Records” (Reference 2.4) and LC-QA-PN-

001, “Final Status Survey Quality Assurance Project Plan” (Reference 2.5).

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3.2.3 Administrative Assistant – is responsible for:

Maintains a signature list for FSS personnel to access FSS files.

Maintains a key to the cabinets for FSS file storage.

Serves as Department Records Custodian.

3.2.4 Graphics/GPS Specialist – is responsible for:

Preparation of drawings and other graphics as necessary to be included in the

survey package.

3.2.5 FSS Technicians – are responsible for:

Obtaining and documenting survey measurements in accordance with the

survey package instructions.

Ensuring that all activities, actions, observations and obstructions that are

encountered during the performance of FSS are documented in

Attachment 13, “FSS Field Log” for that survey unit.

Precautions, Limitations and Prerequisites 3.3.

3.3.1 Precautions

1.) Documents and databases containing FSS data and survey records are

Quality Assurance (QA) records when complete.

2.) When documenting survey information, ensure that all QA records are of

good quality and legible. Legibility is determined to be readable and

reproducible.

3.) Isolation and control measures are implemented to ensure that the final

radiological and physical condition of the interior surfaces of the pipe is not

compromised and/or re-contaminated.

4.) Do not use any instrument if improper operation is suspected.

5.) Ensure the length of the cable between the detector and data logger does not

exceed the maximum cable length used during the calibration.

6.) If a signal amplifier is used, then the detector and data logger pairing must

be calibrated, and efficiency factors determined with the signal amplifier in

place.

7.) Whenever possible, a detector should be calibrated at the same time as the

data logger to which it is paired.

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8.) Detectors that fall outside the accepted criteria shall be tagged “Out of

Service” and segregated for further evaluation. DO NOT use a detector

and/or data logger with an “Out of Service” tag attached.

9.) When there is a potential for thermal shock, ensure a protective insulator

with end cap is installed on sodium iodide detectors during survey

operations to minimize damage from shock and thermal changes. The

detector crystal may fracture if the temperature increases or decreases

rapidly.

10.) Radiological detectors that are to be inserted into known contaminated or

potentially contaminated piping systems will be wrapped to the extent

practical to minimize the contamination of equipment. This can include the

sleeving of cables and fiber rods and the application of tape to exposed

detector surfaces.

11.) Do not use liquid decontamination solutions on exposed electrically

energized equipment.

12.) Do not insert radiological detectors into areas of piping where video shows

standing water, or where significant physical interferences exist that may

damage the detector.

3.3.2 Limitations

1.) All attachments described in this procedure may be generated electronically.

If electronic attachments are used, then the physical layout of the attachment

may be modified provided the intent described in this procedure is not

changed.

2.) Detector parameters are determined during calibration and shall not be

altered during the field operation of the equipment.

3.) If a detector fails a pre-use or a post-use background count, the most likely

causes are the inadvertent contamination of the detector housing, the

inadvertent contamination of the pipe or the introduction of another

radiological source into the vicinity of the background count. If the cause of

the increase in background is readily apparent or can be mitigated (e.g.,

decontamination of the detector housing or pipe), then the background count

may be repeated without any additional action. If the pre-use or a post-use

background count continues to fall outside of the acceptable range, then a

new efficiency factor determination must be performed in accordance with

section 4.1.

4.) After completion of the FSS in a pipe, the sample plan is reviewed for

completeness and the data validated in accordance with LC-FS-PR-008,

“Final Status Survey Data Assessment” (Reference 2.6) before sample plan

closure and the reporting of results.

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3.3.3 Prerequisites

1.) A FSS Sample Plan will be prepared for pipe surveys in accordance with

LC-FS-PR-003, “Final Status Survey Package Development”

(Reference 2.7). A sample plan may be prepared for individual runs of pipe

or grouping of pipes based on classification, or location. A folder

designated as the FSS package should be utilized to keep original

documents. The folder shall be controlled in accordance with the record

quality requirements of LC-QA-PN-001, “Final Status Survey Quality

Assurance Project Plan” (Reference 2.5).

2.) The equipment and services necessary to perform radiological surveys of

pipe interior surfaces may include the following:

Miniature video camera and lighting A.

Video console with recording capabilities B.

Appropriate length cables and sleeving C.

Fiber Push/Pull Rods, Fish Tape and Measuring Tape D.

Appropriate sized NaI/CsI radiological detectors E.

Radiological data logger (single channel analyzer) F.

Field communications equipment G.

Flexible radiological sources and/or point sources H.

Appropriate sized clean pipe I.

3.) Decommissioning activities having the potential to contaminate the interior

surface of the pipe to be surveyed must be completed prior to the initiation

of FSS.

4.) Prior to inserting a radiological detector into a pipe, ensure by remote video

that the pipe is free of obstructions and is as dry as possible.

5.) Instruments and/or detectors shall be inspected daily for mechanical damage

prior to and following field use. These inspections are documented on

Attachment 3, “Pipe Interior Radiological Survey Form” by circling “Sat” or

“Unsat.”

6.) Prior to using any survey instrument, the current calibration must be

verified.

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7.) The efficiency factor for each detector and data logger pairing used for FSS

pipe surveys shall be determined in accordance with Section 4.1 upon

receipt after calibration, as directed by the FSS Supervisor, or following any

repair or maintenance.

8.) A response and background check will be performed in accordance with

Section 4.2 for each detector and data logger pairing daily prior to use (Pre-

Test) and daily upon completion of surveys (Post-Test).

Records 3.4.

3.4.1 Attachment 1, Pipe Detector Efficiency Determination

3.4.2 Attachment 2, Daily Pipe Survey Detector Control Form

3.4.3 Attachment 3, Pipe Interior Radiological Survey Form

4. PROCEDURE

Efficiency Factor Determination 4.1.

NOTE

The maximum length of the detector cable used will not exceed the length of

the cable that was used during the calibration of the detector and data logger

pairing. The length of cable shall not exceed 150 feet.

4.1.1 Select the detector and data logger pairing, as well as the length of cable to be

used. Ensure the detector and data logger pair have been response checked in

accordance with LC-FS-PR-011, “Operation of the Ludlum 2350-1 Data Logger

and Associated Detectors” (Reference 2.8).

4.1.2 Record the pipe size, instrument/detector type, serial numbers, calibration date,

calibration due date and the detector cable length for the detector and data logger

pairing on Attachment 1, “Pipe Detector Efficiency Determination.”

4.1.3 Ensure that the parameters settings for the data logger (e.g., voltage, etc.) are set

to the values specified for the primary radionuclide to be surveyed per the

certificate of calibration for the paired detector.

4.1.4 Connect the detector to the data logger using the appropriate cable length with the

data logger de-energized.

NOTE

Ensure to the extent practical that the area selected to determine instrument

background is free of residual radioactive contamination and, that any

radiological sources stored in or near the area are properly shielded to mitigate

any influence to background.

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4.1.5 Set the scaler count time for background determination. The minimum count time

for background determination is 600 seconds or 10 minutes. Longer background

count times may be used.

NOTE

A separate background determination must be determined for each size and

type of pipe that will be surveyed with the detector and data logger pairing.

4.1.6 Install the selected detector into the clean pipe commensurate with the internal

diameter size of the pipe to be surveyed, allow the detector to stabilize and record

the size of the pipe applicable to this efficiency factor determination on

Attachment 1.

4.1.7 Initiate a background count.

4.1.8 Record the background counts on Attachment 1.

1.) Calculate and record the result of the background count.

2.) Establish an acceptable background range of +20%.

4.1.9 Set the scaler count time for source counts. The minimum count time for

efficiency factor determination is 60 seconds or 1 minute. Longer source count

times may be used.

4.1.10 Insert the flexible NIST traceable radiological source into the pipe interior by

placing the source into the interior surfaces of the pipe.

1.) Ensure the exposure surface of the source is secured to the pipe by use of

magnets or other means.

2.) If there is overlap in the area of the source, then ensure (to the extent

practical) the overlap is positioned at the bottom of the pipe.

3.) Mark the source edges within the pipe to ensure the source is positioned in

the same geometry for all subsequent efficiency factor determinations.

NOTE

A separate efficiency factor determination must be determined for each size of

pipe that will be surveyed with the detector and data logger pairing.

Efficiencies determined for larger piping diameters may be utilized for piping

of a smaller diameter and construction material.

4.1.11 Initiate source counts at each of the following nine positions:

1.) Position 1: Detector positioned with the detector crystal centerline -7 inches

back of the source centerline. (See Attachment 5)

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5.) Position 5: Detector positioned with the detector crystal centerline 0 inches










4.1.12 Record the source counts on Attachment 1.

1.) Divide the gross counts by the count time to derive gross cpm.

2.) Subtract the mean background count from each gross cpm value to derive

net cpm.

4.1.13 Calculate the mean net cpm and the standard deviation (σ) for the seven

background corrected source counts (net cpm for positions 2 through 8),

determine a +2σ response range, and record this information on Attachment 1.

NOTE

The mean source count is recorded in units of cpm. The Surface Emission

Rate (SER) of a source is typically presented in units of activity. To calculate

the efficiency factor, the SER units must be converted to units of dpm (1 Ci =

3.7E+10 dps = 2.22E+12 dpm). Position 5 may solely be utilized as the

efficiency determination position at the discretion of the FSS Manager.

4.1.14 Ensure the detector and data logger pair have been post-work response checked in

accordance with LC-FS-PR-011, “Operation of the Ludlum 2350-1 Data Logger

and Associated Detectors” (Reference 2.8).

4.1.15 Forward the completed Attachment 1 to the FSS Supervisor for approval.

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Pre-Use and Post-Use Operational Response and Background Check 4.2.

4.2.1 Select the detector and data logger pairing, as well as the length of cable to be

used, for the pipe size to be surveyed as documented on Attachment 1. Ensure the

detector and data logger pair have been response checked in accordance with LC-

FS-PR-011, “Operation of the Ludlum 2350-1 Data Logger and Associated

Detectors” (Reference 2.8).

4.2.2 Record the pipe size, instrument/detector type, serial numbers, calibration date,

calibration due date and the detector cable length for the detector and data logger

pairing on Attachment 2, “Daily Pipe Survey Detector Control Form.”

4.2.3 Ensure the parameters settings for the data logger (e.g., voltage, etc.) are set to the

values specified for the primary radionuclide to be surveyed per the certificate of

calibration for the paired detector.

4.2.4 Connect the detector to the data logger using the appropriate cable length with the

data logger de-energized.

NOTE

A background count and a response check will be performed twice per day for

each detector and data logger pairing applicable to each pipe size surveyed,

daily prior to use (Pre-Test) and daily upon completion of surveys (Post-Test).

4.2.5 Set the scaler count time for background determination. The background count

time should be the same as the count time used to determine the acceptable range

for background on Attachment 2 (typically 600 seconds or 10 minutes). Longer

background count times may be used.

4.2.6 At the same location where background was determined for the detector and data

logger pairing as documented on Attachment 2, install the selected detector into

the clean pipe commensurate with the ID size of the pipe to be surveyed and

allow the detector to stabilize.

4.2.7 Initiate one background count.

4.2.8 Record the pre-use background count on Attachment 2.

4.2.9 Verify that the observed pre-use background count is within the +20%

background range established during efficiency factor determination for the

selected detector and pipe ID (documented on Attachments 2 & 6).

1.) If the pre-use background count falls within the established +20%

acceptable background range, then the result of the single count is used as BR

for the detector and no additional background counts are required.

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2.) If the pre-use background count falls outside of the established +20%

acceptable background range, then initiate three additional background

counts.

3.) If the mean of the three additional background count results fall within the

established +20% background range, then record the mean value as BR for

the detector and continue with the pre-use operational response check.

4.) If the mean value falls outside the established +20% acceptable background

range, then discontinue the pre-use operational response check and

investigate the reasons for the change in background.

5.) Note the results of recounts, investigations and conclusions in the

“Comments” section on Attachment 2.

4.2.10 Using the value established for pre-use background (BR), calculate the Minimum

Detectable Count Rate (MDCR) for the detector using the following equation:

s

b

s

sR

static t

t

ttB

MDCR

)1(29.33

Where: MDCRstatic = Minimum Detectable Count Rate (cpm)

BR = Background Count Rate (cpm)

tb = Background Count Time (min)

ts = Sample Count Time (initially assumed to be 1 min)

4.2.11 Record the MDCR on Attachment 2.

4.2.12 At the completion of the FSS performed in accordance with section 4.3, repeat

steps 4.2.5 through 4.2.9 for the post-use background check and record the results

on Attachment 2.

NOTE

If a detector/data logger pairing fails a post-use source response check, then

notify the FSS Manager. An assessment must be made to determine the

validity of the data acquired by that detector/data logger pairing and whether

or not the data acquired may be reported as FSS data or if the survey must be

repeated.

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NOTE

CsI detectors may become saturated when exposed to high activity. If a CsI

detector has become saturated during the performance of a survey, then a

delay time may be necessary to allow the luminescence characteristic to return

to ground state. In this case, the FSS Manager may authorize a delay in

performing the post use response check until the beginning of the next daily

shift.

4.2.13 Following completion of the post-use background check in accordance with the

previous step, perform a post-use source check in accordance with LC-FS-PR-

011, “Operation of the Ludlum 2350-1 Data Logger and Associated Detectors”

(Reference 2.8).

4.2.14 Forward the completed Attachment 2 to the FSS Supervisor for approval.

Acquiring FSS Data in Pipe Interiors with NaI/CsI Detectors 4.3.

NOTE

The process of collecting data in pipe interiors assumes that a valid efficiency

factor has been determined for the detector and data logger pairing in

accordance with section 4.1 and a satisfactory pre-use response and

background check has been performed in accordance with section 4.2. If an

efficiency is not available for the size of piping to be surveyed, efficiencies

from larger diameter piping of the same construction may be used.

4.3.1 Record the date, time, location, elevation, a description of the access point to the

pipe, the system, pipe size, pipe identification # (if available), instrument/detector

type, serial numbers, calibration date, calibration due date and the detector cable

length for the detector and data logger pairing on Attachment 3, “Pipe Interior

Radiological Survey Form.”

4.3.2 Examine the overall mechanical condition and operability of the detector/data

logger assembly.

4.3.3 Ensure that the parameters settings for the data logger are set to the values

specified for the primary radionuclide to be surveyed per the certificate of

calibration for the paired detector (as applicable).

4.3.4 Initially set the scaler count time to 60 seconds (1 minute).

NOTE

Notify the FSS Supervisor if the sample count time (ts) is adjusted to achieve

an acceptable Minimum Detectable Concentration (MDC). Sample count

times greater than 10 minutes shall not be used without the approval of the

FSS Manager.

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4.3.5 Using the MDCR established for the detector in step 4.2.10 and the efficiency

factor from step 4.1.13, calculate the MDC for the detector using the following

equation:

MDC= MDCREfficiency Factor⁄

NOTE

The MDC is reported in units of dpm per foot of pipe. In order to compare the

MDC to the action level for buried pipe, the MDC must be converted to units

of dpm/100cm2 (buried pipe). The conforming source has an active surface

area of 3050 cm2, which will be used for all piping greater than 13 inches in

diameter. For 10 inch piping, use 2432 cm2, which is the surface area of one

foot of 10 inch piping. If the field of view is increased using means such as

detector vertical position, the area utilized for conversion may be altered with

approval of the FSS Manager.

1.) Ensure that the MDC calculated is lower than the action levels and/or

DCGL applicable to the pipe to be surveyed.

2.) If the MDC is not sufficient, then adjust the sample count time (ts) in step

4.2.10 as necessary to produce a MDCR which will result in an acceptable

MDC.

3.) If the sample count time (ts) was adjusted to achieve an acceptable MDC,

then set the scaler to the new required count time.

4.3.6 Record the MDC and the sample count time (ts) on Attachment 3.

NOTE

Typically, the optimum start position is with the detector inserted completely

to the end of the pipe to be surveyed with the end of the detector housing flush

with the end of the pipe or butted up against the limiting obstruction (i.e., the

bend or obstruction that prevents further travel into the pipe from the opening

or water). In almost all cases, it is preferable to survey from the maximum

extended position back toward the surveyor. This is not always possible in all

configuration scenarios and adjustments may be made as necessary.

4.3.7 Determine a start location for the survey and mark the position on the

measurement tape as position “zero.”

4.3.8 Initiate a scaler count for the sample count time (ts). This may be performed

utilizing the recycle function of the 2350-1 and observing when the scaler counts

initiate in the first section of piping to be surveyed.

1.) Record the gross counts in the appropriate column on Attachment 3.

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2.) Divide the gross counts by the count time to derive the gross measurement

activity in cpm and record in the appropriate column on Attachment 3.

3.) Subtract the daily background cpm from the gross measurement to obtain

net measurement activity and record in the appropriate column on

Attachment 3.

4.) Divide the net measurement activity in cpm by the efficiency factor to

convert the net measurement activity to units of dpm and record in the

appropriate column on Attachment 3.

5.) Calculate the “Activity/Area” in units of dpm/100cm2 for the measurement

and record in the appropriate column on Attachment 3 using the following

equation:

𝐴𝑑𝑝𝑚100𝑐𝑚2⁄

=

(

(dpm)

(𝐴𝑒𝑓𝑓

100⁄ )

)

Where: A dpm/100cm2 = Activity per Area in units of dpm/100cm

2

dpm = Net measurement activity in units of dpm (from step

4.3.8 (3)

Aeff = Effective Area of the Measurement in m2 (3050 cm

2

for all piping greater than 13 inches in diameter.

For 10 inch piping, use 2432 cm2)

NOTE

The efficiency factors are based on a “worst case” geometry of the bottom of

the piping and distance from source to detector assuming a survey in one foot

increments.

4.3.9 Record the increment frequency on Attachment 3.

4.3.10 Retract or advance the detector as applicable to position “one” and repeat step

4.3.8.

4.3.11 Retract or advance the detector at the required increments and take a measurement

at each location until the survey of the pipe length is completed. Record the

locations and results in the appropriate columns on Attachment 3.

NOTE

If a survey measurement taken on the interior of a buried pipe indicates

radiological concentrations in excess of the applicable DCGL, then notify the

FSS Manager.

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4.3.12 Compare each measurement to the DCGLs established for each type of pipe

(DCGLs for buried pipe types are presented in Attachment 4).

4.3.13 Remove the detector from the pipe when the survey has been completed, or when

an obstruction is present that prevents further travel of the detector through the

pipe. Denote the date and time of survey completion on Attachment 3.

1.) Wipe the cables and detector using a damp rag during extraction.

2.) Examine the overall mechanical condition and operability of the

detector/data logger assembly.

3.) Record the total length of pipe surveyed and the total number of bends

encountered during the survey on Attachment 3.

4.) Denote any unexpected conditions encountered during the survey of the pipe

on Attachment 3. Items to denote include but are not limited to:

Pipe configurations contrary to system drawings

Standing or running liquid in the pipe

Unanticipated obstructions

Indications that the pipe integrity has been compromised

5.) Denote whether the equipment worked properly and as expected. If

problems were encountered with the equipment, then record on

Attachment 3.

6.) Summarize the radiological conditions observed inside the pipe, including

average radiological results and any location(s) encountered which exceed

the Operational DCGLs.

4.3.14 Denote completion of the survey by the signature of all persons involved in

obtaining measurements and forward the completed Attachment 3 to the FSS

Supervisor for review.

4.3.15 Following completion of the last survey using a particular detector, or at the end

of a work shift, perform a post-use source check in accordance with LC-FS-PR-

011, “Operation of the Ludlum 2350-1 Data Logger and Associated Detectors”

(Reference 2.8).

4.3.16 Forward all forms to the FSS Supervisor for data validation and data assessment

in accordance with LC-FS-PR-008, “Final Status Survey Data Assessment”

(Reference 2.6).

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5. ATTACHMENTS

Attachment 1, Pipe Detector Efficiency Determination 5.1.

Attachment 2, Daily Pipe Survey Detector Control Form 5.2.

Attachment 3, Pipe Interior Radiological Survey Form 5.3.

Attachment 4, DCGLs for FSS of Buried Pipe 5.4.

Attachment 5, Pipe Source Efficiency Positions 5.5.

Attachment 6, Example of Source Efficiency and MDCStatic 5.6.

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Attachment 1 - Pipe Detector Efficiency Determination

Detector Type: Serial No.: Cal Date: Cal Due Date:

Data Logger Type: Data Logger Serial No.: Cal Date: Cal Due Date:

Pipe Size: Cable Length: Background Location:

BACKGROUND DETERMINATION

Count Time (tb)

(minutes)

counts cpm

Mean Background cpm (BR) Mean Background

+20%

cpm Mean Background -20% cpm

EFFICIENCY FACTOR DETERMINATION

Source information Isotope: Serial No: Activity

Location

#

Count Time

(min)

Gross

Counts

Gross cpm Net cpm

1

2

3

4

5

6

7

8

9

Efficiency Factor Determination

Mean

Net cpm

Standard Deviation +2σ value -2σ value Source SER

(dpm)

Efficiency Factor

(Mean Net cpm/dpm)

Performed by:

Date:

Approved by:

Date:

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Attachment 2 - Daily Pipe Survey Detector Control Form

PRE-WORK Date:____________ Time:____________

Detector Type: Serial No.: Cal Date: Cal Due Date:

Data Logger Type: Data Logger Serial No.: Cal Date: Cal Due Date:

Pipe Size: Cable Length: Background Location:

PRE-WORK BACKGROUND CHECK Acceptable Background Range (from Attachment 1) +20% cpm -20% cpm

Initial Background Count Additional Background Counts (if necessary)

Count # Count Time (tb)

(min) counts cpm (BR)

Count #

Count Time (tb)


Initial 1 1. Is pre-work background within the

acceptable range? Yes No If no, initiate three additional

background counts) 2

3 2. Is mean pre-work background within the

acceptable range? Yes No (If no, stop and investigate reasons

for change in background) Mean Background (BR)

MINIMUM DETECTABLE COUNT RATE (MDCR):

s

b

s

sR

static t

t

ttB

MDCR

)1(29.33

Comments:

BR = ________cpm ts = ________min tb = ________min MDCRstatic = ________cpm (ts will initially be set to 1 minute)

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Attachment 2 - Daily Pipe Survey Detector Control Form

POST-WORK Date:____________ Time:____________

POST-WORK BACKGROUND CHECK Acceptable Background Range (from Attachment 1) +20% cpm -20% cpm

Initial Background Count Additional Background Counts (if necessary)

Count # Count Time (tb)


Count #

Count Time (tb)


Initial 1 1. Is post-work background within the

acceptable range? Yes No If no, initiate three additional

background counts) 2

3 2. Is mean post-work background within the

acceptable range?

Yes No (If no, stop and investigate reasons

for change in background) Mean Background (BR)

Comments:

Detector/Data Logger Assembly Physical Inspection: Satisfactory Unsatisfactory Technician: __________________ Date: _______ Time: ______

Pre-Work Detector Background Determination: Satisfactory Unsatisfactory Technician: __________________ Date: _______ Time: ______

Pre-Work Instrument Response Check Satisfactory Unsatisfactory Technician: __________________ Date: _______ Time: ______

Post-Work Detector Background Determination: Satisfactory Unsatisfactory Technician: __________________ Date: _______ Time: ______

Post-Work Instrument Response Check Satisfactory Unsatisfactory Technician: __________________ Date: _______ Time: ______

Approved by:

Date:

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Attachment 3 - Pipe Interior Radiological Survey Form (Page 1)

Date: Time:

Survey

Unit:

Access Point Area:

System: Pipe Diameter: Pipe #:

Detector: Detector ID #:

Cal Date: Cal Due Date:

Data Logger: Data Logger ID #:

Cal Date: Cal Due Date:

Cable Length: Pre Use:( Sat / Unsat ) Post Use:( Sat / Unsat )

MDCRstatic cpm (taken from Attachment 2)

Efficiency Factor for Pipe Diameter (taken from Attachment 1)

Effective

Area (cm2)

Background (taken

from Attachment 2):

MDCstatic dpm/100cm2 Sample Count Time (ts) min

Is the MDCstatic acceptable? Yes No (if no, adjust sample count time and recalculate MDCRstatic)

Comments:

Pipe Interior Radiological Survey

Radiological Survey Commenced: Date: ______________ Time: _______________

Radiological Survey Increment Frequency: One measurement for every ____ feet of pipe surveyed

Position

#

Feet into

Pipe from

Opening

Sample

Count Time

(ts)

Gross

Counts

Net

cpm dpm

Effective

Area

Activity/

Area

(min) (cm2) (dpm/100cm2)

Zero

1

2

3

4

5

6

7

8

9

10

11

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Attachment 3 - Pipe Interior Radiological Survey Form

Position

#

Feet into

Pipe from

Opening

Sample

Count Time

(ts)

Gross

Counts

Net

cpm dpm

Effective

Area

Activity/

Area

(min) (cm2) (dpm/100cm2)

Page ___ of ___

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Pipe Interior Radiological Survey Log

Date Time Comment Initial

Page ___ of ___

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Pipe Interior Survey Completion

Radiological Survey Completed: Date ____________ Time: ____________

Length of Pipe Surveyed and the Number of Bends

Unexpected Conditions Encountered (Specify any obstructions encountered or other results that may impact

future work):

Did the equipment work properly? Yes No (if “no”, explain below)

Summary of Radiological Conditions (include average radiological results and any hot spot location(s)

encountered):

Survey Completed By: (Print Name) (Signature) (Date & Time)

(Print Name) (Signature) (Date & Time)

(Print Name) (Signature) (Date & Time)

Survey Reviewed By: (Print Name) (Signature) (Date & Time)

Page ___ of ___

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Attachment 4 - DCGLs for FSS of Buried Pipe

Buried Piping DCGL Adjustments for ROC Mixture

Cs-137 Adjustment for Sr-90

Utilizing Equation 4-1 from MARSSIM:

𝐷𝐶𝐺𝐿𝐶𝑠,𝑚𝑜𝑑 = 𝐷𝐶𝐺𝐿𝐶𝑠 ∗𝐷𝐶𝐺𝐿𝑆𝑟

[(𝐶𝑆𝑟𝐶𝐶𝑠) ∗ 𝐷𝐶𝐺𝐿𝐶𝑠] + 𝐷𝐶𝐺𝐿𝑆𝑟

And given from Tables 4 and 12 of LC-FS-TSD-002, Rev. 2:

For Circulating Water Discharge Pipe:

Circulating Water Discharge Base Case and Operational

DCGLs (dpm/100cm2)

ROC DCGLBC DCGLOps

Cs-137 3.30E+05 6.94E+04

Sr-90 7.55E+05 1.58E+05

For Remainder Buried Pipe Group:

Buried Pipe Group Base Case and Operational DCGLs

(dpm/100cm2)

ROC DCGLBC DCGLOps

Cs-137 3.18E+05 6.68E+04

Sr-90 5.16E+05 1.08E+05

RS-TD-31319-001 Rev. 5 states in Table 40 a Sr-90/Cs-137 ratio of 0.502 to 1.

This results in the following DCGLs for Cs-137

Modified Cs-137 DCGLOps Accounting for Sr-90 (dpm/100cm2)

DCGL Buried Pipe Group Circulating Water

Discharge Pipe

DCGLBC 2.42864E+05 2.70621E+05

DCGLOps 5.0973E+04 5.6862E+04

Utilizing the modified DCGLs for Cs-137, equation 4-4 from MARSSIM is utilized:

𝐺𝑟𝑜𝑠𝑠 𝐴𝑐𝑡𝑖𝑣𝑖𝑡𝑦 𝐷𝐶𝐺𝐿 =1

(𝑓1

𝐷𝐶𝐺𝐿1+

𝑓2𝐷𝐶𝐺𝐿2

+. . .𝑓𝑛

𝐷𝐶𝐺𝐿𝑛)

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For LACBWR, this equation for gamma emitters becomes:


(𝑓𝐶𝑜−60

𝐷𝐶𝐺𝐿𝐶𝑜−60+

𝑓𝐶𝑠−137𝐷𝐶𝐺𝐿𝐶𝑠−137

+𝑓𝐸𝑢−152

𝐷𝐶𝐺𝐿𝐸𝑢−152+

𝑓𝐸𝑢−154𝐷𝐶𝐺𝐿𝐸𝑢−154

)

Utilizing Table 42 from RS-TD-31319-001 Rev. 5, the equation becomes:


(0.0714

𝐷𝐶𝐺𝐿𝐶𝑜−60+

0.919𝐷𝐶𝐺𝐿𝐶𝑠−137

+0.00609

𝐷𝐶𝐺𝐿𝐸𝑢−152+

0.00311𝐷𝐶𝐺𝐿𝐸𝑢−154

)

Utilizing the following gamma emitting DCGLBC from Table 4 of LC-FS-TSD-002, Rev. 2:

ROC Buried Pipe Group

(dpm/100cm2)

Circulating Water Discharge

(dpm/100cm2)

Co-60 7.50E+04 7.75E+04

Cs-137 2.42864E+05 2.70621E+05

Eu-152 1.64E+05 1.67E+05

Eu-154 1.52E+05 1.56E+05

Utilizing the following gamma emitting DCGLOps from Table 12 of LC-FS-TSD-002, Rev. 2:

ROC Buried Pipe Group

(dpm/100cm2)

Circulating Water Discharge

(dpm/100cm2)

Co-60 1.57E+04 1.63E+04

Cs-137 5.0973E+04 5.6862E+04

Eu-152 3.44E+04 3.51E+04

Eu-154 3.20E+04 3.27E+04

The following can then be calculated:

Gross Gamma DCGLs (dpm/100cm2)

DCGL Buried Pipe Group Circulating Water

Discharge Pipe

DCGLBC 2.08611E+05 2.28645E+05

DCGLOps 4.3761E+04 4.8225E+04

Cs-137 was not adjusted for the 0.8512 emission rate due to the calibration source being composed of Cs-137.

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Attachment 5 - Pipe Source Efficiency Positions

Illustration of Source Positions for Efficiency Determination

1 2 3 4 5 6 7 8 9 10 11 12

Flexible Conforming Source

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Attachment 6 - Example of Source Efficiency and MDCStatic

60" Steel Pipe

Small Cart - 5.5" verticle from pipe base to center of detector

Distance From Center of Source -7 -6 -4 -2 0 2 4 6 7

Background Counts Per Minute 3632

Gross Counts Per Minute 26848 28333 30935 33098 35198 33747 31671 27987 23874

Net Counts Per Minute 23216 24701 27303 29466 31566 30115 28039 24355 20242

Percentage of Center Response 0.735474878 0.782519166 0.864949629 0.933472724 1 0.95403282 0.888265856 0.771558005 0.641259583

Average (12") 27935

Background Count Time 10 Efficiency 0.002873971

Sample Count Time 1

Background CPM 3632

MDCR 210.9529858

MDC (dpm) 73401.21791

MDC (dpm/100cm2) 2406.597309

0

5000

10000

15000

20000

25000

30000

35000

-8 -6 -4 -2 0 2 4 6 8

Ne

t cp

m

Distance from Center of Source

60" Steel Pipe