ML073400172

From kanterella
Jump to navigation Jump to search
EP-1.42, Nasa, Survey Unit Release Record
ML073400172
Person / Time
Site: Plum Brook
Issue date: 11/29/2007
From:
US National Aeronautics & Space Admin (NASA)
To:
NRC/RGN-III/DNMS/DB
References
EP-1.42
Download: ML073400172 (23)
v • d • e


Text

Survey Unit Release Record I Design # EP-1.42 Revision # Original Page 1 of 4 Survey Unit #(s)

1) Embedded Pipe (EP) Survey Unit 1.42 meets the defdtion of embedded pipe for Plum Brook Reactor Facility (PBRF).
2) EP 1.42 is a Class 1, Group 2 survey unit as per the PBRF Final Status Survey Plan (FSSP) and Technical Basis Document (TBD)-06-004.
3) Surveys in EP 1.42 were performed using a scintillation detector optimized to measure gamma energies representative of Co-60. Sample #EP 2-2 from Survey Request (SR)-13 was referenced for this decision.
4) Survey Instructions for this survey unit are incorporated into and performed in accordance with (IAW) the Babcock Services Incorporated (BSDLVS-002, Work Execution P ~ & ~ ~ ~ ' ( w05-006.

E P ) Survey instmctions des&bed in this Description document constitute "Special Methods" and the survey design used in the acquisition of survey measurements.

5) Instrument efficiency determinations are developed in accordance with the BSULVS-002, WEP 05-006, these determinations are appropriate for the types of radiation involved and the media being surveyed.

Approval Signatures Date:

FSSICharacterization Engineer

FSS Design # EP 1.42 Revision # Original Page 2 of 4 Survey Unit: EP 1.42 1.0 History/Description 1.1 The subject piping described in this report is the 6 inch header from the cooling air system service ring to the drain trench on the Rx Building -25 foot elevation.

1.2 The length of pipe has one vertical 90 degree elbow and is approximately 42 feet in length.

2.0 Survey Design Information 2.1 EP 1.42 was surveyed IAW Procedure #BSI/LVS-002.

2.2 100% of the 6 ID pipe was accessible for survey. The accessible 6 ID pipe was surveyed by static measurement at one foot increments, for a total of 42 survey measurements.

2.3 Surface area for the 6 ID piping is 1,459 cm2 for each foot of piping, corresponding to a total 6 ID piping surface area of 61,291 cm2 (6.1 m2) for the entire length of (42) of 6 piping..

3.0 Survey Unit Measurement Locations/Data 3.1 Pipe interior radiological survey forms are provided in Attachment 2 of this release record.

4.0 Survey Unit Investigations/Results 4.1 None 5.0 Data Assessment Results 5.1 Data assessment results are provided in the EP/Buried Pipe (BP) Survey Report provided in Attachment 1.

5.2 All measurement results are less than the Derived Concentration Guideline Level (DCGL) for radionuclide specific EP that corresponds to the 1 mrem/yr dose goal established in Table 3-3 of the FSSP.

5.3 When implementing the Unity Rule, provided in Section 3.6.3 of the FSSP, and applying the Nuclide Fraction (NF), provided in TBD-06-004, the survey unit that is constituted by EP 1.42 passes FSS.

5.4 Background was not subtracted from the survey measurements and the Elevated Measurement Comparison (EMC) was not employed for this survey unit.

FSS Design # EP 1.42 Revision # Original Page 3 of 4 Survey Unit: EP 1.42 5.5 Statistical Summary Table Statistical Parameter 6 Pipe Total Number of Survey Measurements 42 Number of Measurements >MDC 19 Number of Measurements Above 50% of DCGL 0 Number of Measurements Above DCGL 0 Mean 0.015 Median 0.013 Standard Deviation 0.006 Maximum 0.033 Minimum 0.004 6.0 Documentation of evaluations pertaining to compliance with the unrestricted use limit of 25 mrem/yr and dose contributions from Embedded Pipe and radionuclides contributing 10% in aggregate of the total dose for both structural scenarios and soils.

6.1 A replicate QA survey was performed of this survey unit. Several of the replicate QA static measurements exceeded the acceptance criteria for Relative Percent Difference (RPD) when compared with the original measurement. In accordance with section 12.7 of the Final Status Survey Plan for the Plum Brook Reactor Facility, an investigation was performed.

The investigation concluded that the Final Status Survey data presentedin this report are valid and usable in determining the radiological condition of this survey unit. The investigation documentation is included in attachment 3.

FSS Design # EP 1.42 Revision # Original Page 4 of 4 Survey Unit: EP 1.42 6.2 A review of the survey results has shown that the dose contribution for EP 1.42 to be less than 1 mrem/yr. The dose contribution is estimated to be 0.015 mrem/yr based on the average of the actual gross counts measured.

7.0 Attachments Attachment 1 - BSI EP/BP Survey Report Attachment 2 - Pipe Interior Radiological Survey Form Attachment 3 - Replicate Measurement Comparison & Investigation Attachment 4 - DQA Worksheet Attachment 5 -Disc containing RR for EP 1.42 & Spreadsheet

SECTION 7 ATTACHMENT 1 3 PAGE(S)

BSI EPlBP SURVEY REPORT COMMENTS:

I 1

ACTNlN VALUES NOT BACKGROUND CORRECTED RP Ellgineat Date $1-

EP 1.42 6" Pipe TBD 06-004 Group 2 Measurement #

Co-60 activity Co-60 activity Cs-137 activity Eu-152 activity Eu-154 activity Nb-94 activity Ag-108m activity gcpm ncpm (total dpm) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2)

Unity 1 5 5 25,000 1,713 888 14 10 1 49 0.007 2 9 9 45,000 3,084 1,599 26 18 2 89 0.013 3 11 11 55,000 3,769 1,954 31 22 2 108 0.016 4 8 8 40,000 2,741 1,421 23 16 1 79 0.012 5 14 14 70,000 4,797 2,487 40 28 2 138 0.021 6 8 8 40,000 2,741 1,421 23 16 1 79 0.012 7 9 9 45,000 3,084 1,599 26 18 2 89 0.013 8 6 6 30,000 2,056 1,066 17 12 1 59 0.009 9 7 7 35,000 2,398 1,244 20 14 1 69 0.010 10 9 9 45,000 3,084 1,599 26 18 2 89 0.013 11 14 14 70,000 4,797 2,487 40 28 2 138 0.021 12 3 3 15,000 1,028 533 9 6 1 30 0.004 13 12 12 60,000 4,112 2,132 34 24 2 118 0.018 14 6 6 30,000 2,056 1,066 17 12 1 59 0.009 15 21 21 105,000 7,195 3,731 60 42 4 207 0.031 16 8 8 40,000 2,741 1,421 23 16 1 79 0.012 17 7 7 35,000 2,398 1,244 20 14 1 69 0.010 18 9 9 45,000 3,084 1,599 26 18 2 89 0.013 19 9 9 45,000 3,084 1,599 26 18 2 89 0.013 20 14 14 70,000 4,797 2,487 40 28 2 138 0.021 21 6 6 30,000 2,056 1,066 17 12 1 59 0.009 22 10 10 50,000 3,426 1,777 28 20 2 99 0.015 23 5 5 25,000 1,713 888 14 10 1 49 0.007 24 6 6 30,000 2,056 1,066 17 12 1 59 0.009 25 8 8 40,000 2,741 1,421 23 16 1 79 0.012 26 11 11 55,000 3,769 1,954 31 22 2 108 0.016 27 5 5 25,000 1,713 888 14 10 1 49 0.007 28 14 14 70,000 4,797 2,487 40 28 2 138 0.021 29 12 12 60,000 4,112 2,132 34 24 2 118 0.018 30 10 10 50,000 3,426 1,777 28 20 2 99 0.015 31 10 10 50,000 3,426 1,777 28 20 2 99 0.015 32 8 8 40,000 2,741 1,421 23 16 1 79 0.012 1 of 2

EP 1.42 6" Pipe TBD 06-004 Group 2 Measurement #

Co-60 activity Co-60 activity Cs-137 activity Eu-152 activity Eu-154 activity Nb-94 activity Ag-108m activity gcpm ncpm (total dpm) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2) (dpm/100cm2)

Unity 33 11 11 55,000 3,769 1,954 31 22 2 108 0.016 34 7 7 35,000 2,398 1,244 20 14 1 69 0.010 35 19 19 95,000 6,510 3,376 54 38 3 187 0.028 36 9 9 45,000 3,084 1,599 26 18 2 89 0.013 37 11 11 55,000 3,769 1,954 31 22 2 108 0.016 38 7 7 35,000 2,398 1,244 20 14 1 69 0.010 39 10 10 50,000 3,426 1,777 28 20 2 99 0.015 40 10 10 50,000 3,426 1,777 28 20 2 99 0.015 41 22 22 110,000 7,538 3,909 63 44 4 217 0.033 42 17 17 85,000 5,825 3,020 48 34 3 168 0.025 MEAN 0.015 MEDIAN 0.013 STD DEV 0.006 MAX 0.033 MIN 0.004 2 of 2

SECTION 7 ATTACHMENT 2 3 PAGE(S)

Date:

Building:

System: QW Sled Size Detector:

Cal Date:

i~nstrument:

Cal Date: 2~

n A,

c;-&

6" F'

e In i

Type of Survey Investigation

/ - / b 6 0 6 Time:

2 #@.d//'&/

s&- D C ;

g'3>-0-/

Elevation pipe Diameter:

inch

-6C 9 6 c +- 6 9

- 0

~25 Characterization b"

Pipe Interior R;idiological Survey Form Detector ID #:

Cal Due Date:

Instrument ID #:

Cal Due Date:

From the Daily Pipe Survey Detector Control Form for the Selected Detector l

Access Point Area:

~ n a Survey Pipe ID LL%

80- b c c

--32 o t h e r 7 1'

13 "f 7 3 8 d o - Dgi

./

EN.^^, d

, +a

-ale

-L>G Background Value / cpm MDCRtatic Efficiency Factor for Pipe

/ ? 7 cpm h ,~ a o Z (taken from detector B-eter stahc 33q3 d p m 1 1 ~ ~ ~ ~ 2 Is the MDCstaric NO (ifno; adjust sample count time and recalculate MDc%,titi) c&%@&Ble? 7ii::-

r, x L <* >, q e - /

Pipe Interior Radiological Survey Radiological Survey Commenced: Date: j - /t/ , Time: d m" a REFERENCE COPY Package Page 1 of +&

Attachment 3, Page 1

Pipe Interior Radiological Survey Form (Continuation Form)

.n

~&..ige Page of*

REFERENCE COPY Attachment 3, Page 2

SECTION 7 ATTACHMENT 3

'7Page(s)

Investigation of EP 1.42 regarding Replicate measurements comparisons exceeding the 20% RPD criterion Issue Summary Embedded piping Survey Unit 1.42 was final status surveyed on 01-16-06. On 4-2-07, a replicate measurement survey was performed in accordance with (IAW) section 12.7.1 of the License Termination Plan (LTP). The replicate survey measurements were taken with identical equipment, calibrated several months apart.

A total of forty-two (42) measurements were performed for each of the two (2) surveys.

Of the forty two (42) replicate measurement comparisons, thirty four (34) were found to exceed the maximum allowable RPD criterion of 20% variance. The maxium RPD variance was 157%.

Observations IAW the applicable guidance in section 7.1 of the LTP, it was verified that the correct piping section(s) were replicate surveyed, instructions and procedures followed, and that the instruments were operating properly for each of the surveys.

Several factors were identified as potential contributing factors causing the discrepancy:

  • Background was not subtracted from either data set and varied significantly each between the measurement days.
  • Different technicians operated equipment, and more than a year of piping measurement operations transpired between the collections of the measurement data sets. This creates the possibility that a small change in the position indexing for example, may have introduced minor positioning errors.
  • Due to the 1/r2 source-detector geometry relationship, relatively small systematic positioning error may account for the discrepancies.
  • Both data sets indicated a very low level of contamination in the piping, equating to approximately 3% (or less) of the applicable dose limits.
  • Nineteen (19) of the forty-two (42) original data set was observed to be above the Minimum Detectable Activity (MDA). Eleven (11) of the forty-two replicate measurements exceeded the MDA.

Only two (2) of the forty two (42) comparisons had both input values exceeding the MDA, even in these cases the values exceeded the MDA by only a small multiple.

Conclusion In light of the foregoing, it is recommended that another more appropriate survey unit be selected for replicate survey quality assurance purposes. Further, since the data have consistently demonstrated that Survey Unit EP 1.42 meets the release criterion by a very wide margin, it is deemed to be acceptable for release purposes.

However, statistical comparisons of the results and replicate survey are observed to be largely meaningless due to the very low magnitude of all measurements.

RP Engineer / Date / //-26-07

Survey Unit EP 1.42 QA Worksheet QA ORIG Co-60 Co-60 Co-60 Co-60 Ft into Pipe from activity Ft into Pipe activity gcpm net cpm activity gcpm net cpm activity RPD (%) Unity Value Access (dpm/100cm from Access (dpm/100cm (total dpm) (total dpm)

2) 2) 1 4 4 10,526 721 1 5 5 25,000 1,713 81.5 0.007 2 10 10 26,316 1,803 2 9 9 45,000 3,084 52.4 0.013 3 7 7 18,421 1,262 3 11 11 55,000 3,769 99.6 0.016 4 8 8 21,053 1,443 4 8 8 40,000 2,741 62.1 0.012 5 10 10 26,316 1,803 5 14 14 70,000 4,797 90.7 0.021 6 14 14 36,842 2,525 6 8 8 40,000 2,741 8.2 0.012 7 8 8 21,053 1,443 7 9 9 45,000 3,084 72.5 0.013 8 5 5 13,158 902 8 6 6 30,000 2,056 78.0 0.009 9 15 15 39,474 2,705 9 7 7 35,000 2,398 12.0 0.010 10 8 8 21,053 1,443 10 9 9 45,000 3,084 72.5 0.013 11 13 13 34,211 2,344 11 14 14 70,000 4,797 68.7 0.021 12 6 6 15,789 1,082 12 3 3 15,000 1,028 5.1 0.004 13 6 6 15,789 1,082 13 12 12 60,000 4,112 116.7 0.018 14 8 8 21,053 1,443 14 6 6 30,000 2,056 35.1 0.009 15 13 13 34,211 2,344 15 21 21 105,000 7,195 101.7 0.031 16 7 7 18,421 1,262 16 8 8 40,000 2,741 73.9 0.012 17 10 10 26,316 1,803 17 7 7 35,000 2,398 28.3 0.010 18 5 5 13,158 902 18 9 9 45,000 3,084 109.5 0.013 19 8 8 21,053 1,443 19 9 9 45,000 3,084 72.5 0.013 20 10 10 26,316 1,803 20 14 14 70,000 4,797 90.7 0.021 21 14 14 36,842 2,525 21 6 6 30,000 2,056 20.5 0.009 22 8 8 21,053 1,443 22 10 10 50,000 3,426 81.5 0.015 23 6 6 15,789 1,082 23 5 5 25,000 1,713 45.2 0.007 24 13 13 34,211 2,344 24 6 6 30,000 2,056 13.1 0.009 25 14 14 36,842 2,525 25 8 8 40,000 2,741 8.2 0.012 26 13 13 34,211 2,344 26 11 11 55,000 3,769 46.6 0.016 27 9 9 23,684 1,623 27 5 5 25,000 1,713 5.4 0.007 28 7 7 18,421 1,262 28 14 14 70,000 4,797 116.7 0.021

29 12 12 31,579 2,164 29 12 12 60,000 4,112 62.1 0.018 30 8 8 21,053 1,443 30 10 10 50,000 3,426 81.5 0.015 31 6 6 15,789 1,082 31 10 10 50,000 3,426 104.0 0.015 32 13 13 34,211 2,344 32 8 8 40,000 2,741 15.6 0.012 33 8 8 21,053 1,443 33 11 11 55,000 3,769 89.3 0.016 34 12 12 31,579 2,164 34 7 7 35,000 2,398 10.3 0.010 35 10 10 26,316 1,803 35 19 19 95,000 6,510 113.2 0.028 36 11 11 28,947 1,984 36 9 9 45,000 3,084 43.4 0.013 37 11 11 28,947 1,984 37 11 11 55,000 3,769 62.1 0.016 38 9 9 23,684 1,623 38 7 7 35,000 2,398 38.6 0.010 39 9 9 23,684 1,623 39 10 10 50,000 3,426 71.4 0.015 40 10 10 26,316 1,803 40 10 10 50,000 3,426 62.1 0.015 41 5 5 13,158 902 41 22 22 110,000 7,538 157.3 0.033 42 11 11 28,947 1,984 42 17 17 85,000 5,825 98.4 0.025 NOTE: QA COMPARISONS ARE MADE WITH DIFFICULTY SINCE ALL OF THE MEASUREMENTS WERE ON THE ORDER OF THE MDA.

CONSEQUENTLY, ALL RESULTS CARRY A SIGNIFICANT ERROR RELATIVE TO THE 20% COMPARISON AGREEMENT CRITERION. IN CONSIDERATION OF THE RESULTS COMPARISONS, IT IS IMPORTANT TO NOTE THAT ALL QUALITY ASSURANCE RESULTS DIFFERING BY MORE THAN 20% WERE LESS THAN 4% OF THE DCGL.

BSIlLVSPipeCrawler-002 Revision 4 Pipe Interior Radiological Survey Form Date: /07 Time:

Pipe ID#: 114-2 Pipe Diameter: H Access Point Area:

Building: Elevation: system: - M Q fi/k Type of Survey Investigation Characterization Final Survey other @F?

Gross C06O / Cs Detector ID# I Sled ID# IWl6I Ll/s-/ I 107 Detector Cal Date: 1 1 107 Detector Cal Due Date:

Instrument: 23T0-/ Instrument ID #: /5?9~4e Instrument Cal Date: I 11 0 7 Instrument Cal Due Date: 1 ir Jog From the Daily Pipe Survey Detector Control Form for the Selected Detector Background Value 3 .6 cpm MDcREtauc Efficiency Factor MDC~tahc 2

zobb

,5 cpm Pipe Diameter 0.00 038 (hom detector efficiency determination) m:: cm2

~fno, adjust sample count time and recalculate MDCK-)

Is the IvDC,~,~,acceptable?

comments: 1T - .C~NPLETE Technician Signature Pipe Interior Radiological Survey Package Page 1 of 3 Attachment 3, Page 1

BSIILVSPipeCrawler-002 Revision 4 Pipe Interior Radiological Survey Form (Continuation Form)

//

Date:

Pipe ID#:

  • Pipe Diameter:

' Access Point Area: TEE~d Building: , Elevation: - ~7~ System: Q U ~ Di3 ~ V G I N GPIJ(

Package Page 2bf 7 Attachment 3, Page 2

SECTION 7 ATTACHMENT 4

/ PAGE(S)

Design # I EP 1.42 1 Revision # I Original I I survey unit # I I

EP 1.42 I Release Record

1. Have surveys been performed in accordance wlth survey instructions in the Survey Design? X
2. Is the instrumentation MDC for structure static measurements below the DCGLw for Class 1 and 2 X survey units, or below 0.5 DCGLWfor Class 3 survey units?
3. Is the instrumentation MDC for embeddedlburied piping static measurements below the DCGLw ? X
4. Was the instrumentation MDC for structure scan measurements, soil scan measurements, and embeddedl~uriedpiping scan measurements below the DCGLw,or, if nd. was the need for addiiona X static measurements or soil samples addressed in the survey design?
5. Was the instrumentation MDC for volumetric measurementsand smear analysis < 10% DCGLw ? .'.%

. ,. . ', X

6. Were Me MDCs and assumptions used to develop them appropriate forthe instruments and techniques  :;:'$;: '

used to perform the survey? ,~ ,&

~.li Were the survey methods used to collect data proper for the types of radiation involved and forthe 7.

media being s ~ ~ e y e d ? ,.x.>.

x.:~':

,,- .., ;?

8. Were "Special Methods" for data cdlediin properly applied for the survey unit under review? 1' . . x .1

~.,, I 1

9. Is the data set wmpnsed of qualified measurement results collected in accordance with the survey X* .

design, which accurately refleds the radiological status dthe facility?

. . . . . . i..:... . . : . . ..;,, . i... j,. ..

'..i...~miwdjs&~e&~",:?.

i.. , ; : i .-.r..-,.L ^I..: : .." .>, . . ,A

. .' . . . . . . . .. I . .

"i. ., , .',' . '."".. .. . , ,...

1 1.

( Has a posting plot been created?

! " II II 2. Has a histogram (or other frequency plot) been created?

3. Have other graphical data tools been created to assist in analyzing the data? I X

X II 11 Are all sarn~iemeasurements below the DCGLw (Class 1 & 2). or 0.5 DCGLw (Class 3)7 1.x I I 1 Page i of 1

SECTION 7 ATTACHMENT 5 1 DISC

Retrieved from "https://kanterella.com/w/index.php?title=ML073400172&oldid=2572704"