ML073400106

EP-RX-138-1, Nasa, Survey Unit Release Record

ML073400106
Person / Time
Site:	Plum Brook  File:National Aeronautics and Space Administration icon.png
Issue date:	11/29/2007
From:	US National Aeronautics & Space Admin (NASA)
To:	NRC/RGN-III/DNMS/DB
References
EP-RX-138-1
Download: ML073400106 (16)

Text

Survey Unit Release Record 1

2) EP Rx 138-1 is a Class 1, Group 1 survey unit as per the PBRF Final Status Survey Plan (FSSP) and Technical Basis Document (TBD)-06-004.

Design #

Survey Unit #(s)

3) Surveys in EP Rx 138-1 were performed using a scintillation detector optimized to measure gamma energies representative of Cod0. Sample #EP 3-9 from Survey Request (SR)-13 was referenced for this decision.

EP-Rx 138-1

/ 5) Instrument efficiency determinations are developed in accordance with the 1

Description BSILVS-002, WEP 05-006, these determinations &e appropriate for the types of radiation involved and the media being surveyed.

Rx 138-1

1) Embedded Pipe (EP) Survey Unit Rx 138-1 meets the definition of embedded pipe for Plum Brook Reactor Facility (PBRF).

Revision #

4) Survey Instructions for this survey unit are incorporated into and performed in accordance with (IAW) the Babcock Services Incorporated (BSI)/LVS-002, Work Execution Package (WEP)05-006. Survey instructions described in this document constitute "Special Methods" and the survey design used in the acquisition of survey measurements.

6) Only the eight feet of the approximate overall length of twenty two feet of this pipe was accessible for final survey. However, it is concluded that the final survey of the accessible portion of this pipe system is appropriate to demonstrate the radiological condition of the entire pipe and the suitability of the pipe for unrestricted release.

Original Technical Reviewer FSSICharacterization Manager Page 1 of 4 Approval Signatures Date:

FSSICharacterization Engineer A

/(- 2 8- 0'7

FSS Design # EP Rx 138-1 Revision # Original Page 2 of 4 Survey Unit: Rx 138-1 1.0 History/Description 1.1 The subject pipe system is a 1 system line. The ends of the piping section are accessible from the Sub Pile Room and Quad D on the -25 elevation of the Reactor Building.

1.2 EP Rx 138-1 is approximately 22 feet in length. The middle portion of the pipe run could not be accessed for survey due to a series of mitered, 90o elbows that prevent the travel of radiological detectors past the access points. Consequently, only eight of the approximate 22 feet of total length for this pipe was accessible for survey.

2.0 Survey Design Information 2.1 EP Rx 138-1 was surveyed IAW Procedure #BSI/LVS-002.

2.2 The accessible portion of the 1 ID pipe was surveyed by static measurement at one foot increments, for a total of 8 survey measurements.

2.3 Surface area for the 1 ID piping is 243 cm2 for each foot of piping, corresponding to a total 1 ID piping surface area of 1,946 cm2 (0.2 m2) for the entire accessible length of (8) of 1 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 Only the eight feet of the approximate overall length of 22 feet of this pipe was accessible for final survey.

5.3 All measurement results from the eight feet of accessible pipe 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.

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

5.5 In addition to the eight final survey measurements taken in the accessible portion of this pipe, additional radiological surveys were performed to the extent possible as allowed by the configuration of this piping. These surveys were performed to provide additional assurance that the

FSS Design # EP Rx 138-1 Revision # Original Page 3 of 4 Survey Unit: Rx 138-1 radiological conditions represented by the eight interior survey measurements are representative of the entire length of pipe.

5.6 Scan surveys were performed for pre and post remediation purposes, using a beta-gamma GM detector on the exterior of the access point for this pipe system. The surveys are documented as survey nos. NASA-07-3204 and NASA-07-3221, performed in support of RWP PB-07-100. Both pre and post surveys showed negligible levels of activity. The scan survey results indicated activity <1,000 dpm per direct frisk. In addition, smear rag was pulled through the length of the piping section. No loose radiological contamination greater than 1,000 dpm/100cm2 was detected.

5.7 Based upon the results of the final survey measurements combined with the results of the operational survey, it is reasonable to conclude that the final survey of the accessible portion of this pipe system is appropriate to demonstrate the radiological condition of the entire pipe. Survey Unit EP Rx 138-1 demonstrates compliance with the DCGL values, as presented in Sections 3.3, 7.5 and Attachment C of the PBRF FSSP.

5.8 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 Rx 138-1 passes FSS.

Statistical Summary Table Statistical Parameter 1 Pipe Total Number of Survey Measurements 8

Number of Measurements >MDC 8

Number of Measurements Above 50% of DCGL 1

Number of Measurements Above DCGL 0

Mean 0.2107 Median 0.1174 Standard Deviation 0.1633 Maximum 0.5146 Minimum 0.0967 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.

FSS Design # EP Rx 138-1 Revision # Original Page 4 of 4 Survey Unit: Rx 138-1 6.1 A review of the survey results has shown that the dose contribution for the accessible portion of EP Rx 138-1 to be less than 1 mrem/yr. The dose contribution is estimated to be 0.211 mrem/yr based on the average of the actual gross counts.

7.0 Attachments - BSI EP/BP Survey Report -Pipe Interior Radiological Survey Form & Radiation Protection Survey Forms - DQA Worksheet -Disc containing RR for EP Rx 138-1 & Spreadsheet

SECTION 7 ATTACHMENT 1 z PAGE(S)

BSI EPIBP SURVEY REPORT Suwey Locatlon Detector-Sled #

Detector Efficiency Survey Unit Classification TBD 06-004 Piping Group SR-13 Radionuclide Distribution Sample Measured Nuclide Area FactorIEMC Used PassiFail FSS MREMNR Contribution 1

1 EP 3-9 Co-60 No Pass

<I COMMENTS:

ACTIVITYVALUES NOT BACKGROUND CORRECTED RP Engineer 1 Date

EP Rx 138-1 1" Pipe TBD 06-004 Group 1 Measurement #

gcpm ncpm Co-60 activity (total dpm)

Co-60 activity (dpm/100cm2)

Cs-137 activity (dpm/100cm2)

Eu-152 activity (dpm/100cm2)

Eu-154 activity (dpm/100cm2)

Nb-94 activity (dpm/100cm2)

Ag-108m activity (dpm/100cm2)

Unity 1

32 32 45,070 18,531 734 17,578 4,673 541 129 0.111 2

28 28 39,437 16,214 643 15,381 4,089 473 113 0.097 3

35 35 49,296 20,268 803 19,226 5,111 591 141 0.121 4

33 33 46,479 19,110 757 18,128 4,819 558 133 0.114 5

29 29 40,845 16,793 666 15,930 4,235 490 117 0.100 6

149 149 209,859 86,284 3,420 81,849 21,759 2,518 601 0.515 7

120 120 169,014 69,490 2,754 65,919 17,524 2,028 484 0.414 8

62 62 87,324 35,903 1,423 34,058 9,054 1,048 250 0.214 MEAN 0.211 MEDIAN 0.117 STD DEV 0.163 MAX 0.515 MIN 0.097 1 of 1

SECTION 7 ATTACHMENT 2 5

PAGE(S)

IBSYE~peC~awler-ti02 Revision 5 Pipe Interior Radiplogical Survey Form ate, i!:J7 : ti7 Tke:

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F m the Daily Pipe Survey Detector C~nbroIBom far the Selected Detector BackgronndValue 78 Cpm M

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tab la cpm Efficiency Pactor for Pipe Diameter 0,'13007/

(firam detecmr efficiency determintion)

Is the MDCrtati, acceptable?

[if no, ad@t sample tart time and recalculate bDCl&dJ GO " D". b 5. k

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(8'-lb Technician Signature Pipe Interior Radiological Survey

\\J REFERENCE COPY package Page I o f 3, Page 1

REFERENCECOPY

RADIATION PRO'I'ECZTON SURVEY FORB4 3 ? a g e L o f L

RADXA3XON PROmGTZON SURTEY FORM I

Page 1 of )

RP-005 / 1 Rev. 0

SECTION 7 ATTACHMENT 3 I

PAGE(S)

FSSlCharaderization Engineer (prinffsign)

CS-0912 Page 1 of 1

SECTION 7 ATTACHMENT 4 1 DISC