ML073330684

EP-1.15, Nasa, Survey Unit Release Record

ML073330684
Person / Time
Site:	Plum Brook
Issue date:	11/12/2007
From:	US National Aeronautics & Space Admin (NASA)
To:	NRC/RGN-III/DNMS/DB
References
EP-1.15
Download: ML073330684 (15)

Text

Survey Unit Release Record 2) EP 1.15 is a Class 1, Group 1 survey unit as per the PBRF Final Status Survey Plan (FSSP) and Technical Basis Document (TBD)-06-004.

Survey Unit #(s) 3) Surveys in EP 1.15 were performed using a scintillation detector optimized to measure gamma energies representative of Co-60.

Sample #EP 3-9 from Survey Request (SR)-13 was referenced for this decision.

Page 1 of 4 Design # 1.15 1) Embedded Pipe (EP) Survey Unit 1.15 meets the definition of embedded pipe for Plum Brook Reactor Facility (PBRF). Description

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.

EP-1.15 5) Instrument efficiency determinations are developed in accordance with the BSI/LVS-002, WEP 05-006, these determinations are appropriate for the types of radiation involved and the media being surveyed.

6) This pipe is a drain for the exterior sheath encasing the primary coolant supply and return piping. This is a closed system with only one opening. Historical assessments indicate that this system was not subjected to radioactive contaminated liquids during plant operations or anytime during shutdown.

Only the last four feet of the approximate overall length of sixty feet of this pipe was accessible for final survey. However, the four feet of this pipe that was surveyed is the only access to this pipe as well as the low point for the system. It is reasonable to assume that if any radioactive liquid was present in this pipe, it would have accumulated at this point. Subsequently, 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.

I Revision # Approval Signatures Original I Date: FSS/Characterization Engineer I I 11/08/2007 1 FSSICharacterization Manager

- -, FSS Design

1. EP 1.15 Revision # Original Page 2 of 4 - Survey Unit: 1.15 1.0 HistoryDescription 1.1 The subject pipe system is a 2" system line. Access to this pipe is located in the Sub Pile Room. This pipe is the drain for the exterior sheaths surrounding the primary coolant supply and return piping. 1.2 EP 1.15 is approximately 60 feet in length. Approximately four feet in from the access, a series of mitered, 90" elbows prevent the travel of radiological detectors past that point. Subsequently, only four of the approximate 60 feet of total length for this pipe was accessible for survey.

2.0 Survey

Design Information 2.1 EP 1.15 was surveyed IAW Procedure

1. BSI/LVS-002.

2.2 The accessible portion of the 2" ID pipe was surveyed by static measurement at one foot increments, for atotal of 4 survey measurements.

2.3 Surface

area for the 2" ID piping is 486 cm2 for each foot of pi ing, B corresponding to a total 2" ID piping surface area of 1,944 cm (0.2 mZ) for the entire accessible length of (4') of 2" piping. 3.0 Survey Unit Measurement Locationsmata 3.1 Pipe interior radiological survey fonns are provided in Attachment 2 of this release record. 4.0 Survey Unit Lnvestigations/Results 4.1 None 5.0 Data Assessment Results 5.1 Data assessment results are provided in the EPBuried Pipe (BP) Survey Report provided in Attachment

1. 5.2 Only the last four feet of the approximate overall length of sixty feet of this pipe was accessible for final survey. However, the four feet of this pipe that was surveyed is the only access to this pipe as well as the low point for the system. It is reasonable to assume that if any radioactive liquid was present in this pipe, it would have accumulated at this point. 5.3 All measurement results from the four feet of accessible pipe are less than the Derived Concentration Guideline Level WGL) for radionuclide specific EP that corresponds to the 1 mrem/$ dose goal established in Table 3-3 of the FSSP. 5.4 Background was not subtracted ftom the survey measurements and the Elevated Measurement Comparison (EMC) was not employed for the accessible portion of this survey unit.

.J - FSS Design

1. EP 1.15 Revision # Original Page 3 of 4 Survey Unit: 1.15 5.5 In addition to the four 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 radiological conditions represented by the four final survey measurements are representative of the entire length of pipe.

5.6 A scan survey was performed using a beta-gamma GM detector on the exterio~ of the access point for this pipe system. The survey is documented as survey no. NASA-07-2331 performed in support of RWP PB-07-116. The scan survey results indicated activity <1,000 dpm per direck frisk. In addition, smear surveys were taken inside of the pipe opening and on the surrounding wall. No loose radiological contamination greater than 1,000 dpm/lOOcmZ was detected.

5.7 A screw auger was inserted into the pipe to a distance of 20 feet. The auger was able to transit past the first set of mitered elbows to the second set of elbows, where additional penetration into the pipe was blocked. A large area smear was attached to the auger on two penetration attempts, ow to 20 feet and the other to 15 feet. Following extraction from the pipe, the large area smears were surveyed using a beta-gamma GM detector. The survey results were documented on surveys RWP PB-07-233 1 and NASA-07-2607 performed in support of RWP PB-0100. No detectable loose radiological contamination was present on either of these smears. 5.8 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 1.15 demonstrates c~mpliance with the DCGL values, as prksented in Sections 3.3,7.5 and Attachment C of the PBRF FSSP.

5.9 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 &t that is constituted by EP 1.15 passes FSS Y- L FSS Design

1. EP 1.15 Revision # Original Page 4 of 4 Survey Unit: 1.15 5.10 Statistical Summary Table 6.0 Documentation of evaluations pertaining to compliance with the unrestricted use limit of 25 mremlyr 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 review of the survey results has shown that the dose contribution for the accessible portion of EP 1.1 5 to be less than 1 mrem/yr. The dose contribution is estimated to be 0.021 mredyr based on the average of the actual gross counts.

7.0 Attachments

Attachment 1 - BSI EPJBP Survey Report Attachment 2 -Pipe Interior Radiological Survey Form & Radiation Protection Survey Forms Attachment 3 - DQA Worksheet Attachment 4 -Disc containing RR for EP 1.15 & Spreadsheet SECTION 7 ATTACHMENT 1 2 PAGE(S) -

BSI EPlBP SURVEY REPORT -44 el. Sub Pile Room Detector-Sled

1. 44-62 2127011121 Detector EfAclency LUES NOT BACKGROUND CORRECTED RP Engineer I Date 1118/2007 EP 1.15 2" Pipe TBD 06-004 Group 1 Co-GO activity (dpm1100cm2) 7,195 P - I c: g I ncpm 2 : 1 Co-80 activity (total dpm) gcpm 14 I I ~-~~ ~ 7: 35,000 2 81 ~ ---.- i i Cs-137 activity Eu-152 activity 4 ~- 1.950 --- / , 518 60 14 0.012 (dpm1100cmZ) 2j 10,000 Unity 3 4 I Eu-154 activity / Nb-91 activity Ag-1OBm activiiy (dpml100cm2)

~- 285 ~ 2,056 -~ ---- ! - - MEAN i 0.021 ~- ~ - MEDIAN / 0.017 ..~ - STD DEV 1 0.016 I !!!AX_-- ! 0.043 MIN / 0.006 2 7 (dpmllOOcm2) 6,825 ; 1,814 210 50 0.043 (dpmllOOcm2) (dpm1100cm2)

~ 975 i ~. 259 - 30 7 0.006 3,413 j 907 105 ~ ~ ~ 0.021 ~ - 1' 5,000 1,028 -- 41 143 3.5 17,500 , 3,598 SECTION 7 ATTACHMENT 2 4 PAGE(S) -

Pipe Interior Radiological Survey Form Revision 4 Date: 2. 3/- fl L' Time: /j&- Pipe ID#: . /, 157- Pipe Diameter:

Access Point Area: Jda fi /cz Building:

2% Elevation:

7-G- Sptm: %sfl\+ 3e-J Type of Survey Investigation Characterization - Final survey other J Gross - C06O J cs - Detector ID# I Sled ID# qq- 6 2 / 2 /2 7 ot I /A/ DetectorCalDate:

/7-yJo6-o<

Detector Cal Due Date: / 7- ,dd (- fi L Instrument:

5x33 - 1 Instrument ID #: 3/.73;5.3 Jnstnunent Cal Date: 17 - /\lo ,' - o. 4 F Instrument Cal Due Date: , 7 - /d s.i - 0 G From the Daily Pipe Survey Detector Control Form for the selected Detector Background Yalue 3 cpm MDCRe,uc /"a 4" cpm Efficiency Factor for Pipe Diameter C) 0 0 0 2/ (&om detector efficiency determination)

MDCmhc ad Is the h4DCsad, acc (if no, adjust sample comt time and recalculate MD&) Comments: Technician Signature

+ Pipe Interior Radiological Survey REFERENCECOPY 0 Package Page 1 of 2 Attachment 3, Page 1

RArrLATION PROTECTION SURVEY POhdI Page 1 of 1 I t - General ma dose rah *Contad30em dose rats 0 -Smear location LAS-lsrgcarsarmcar unless othawise noted yi~- Radblogisal boundary x-x-x- Cmfatinatcd lrca wa5 I I Rev. 0 SECTION 7 ATTACHMENT 3 1 PAGE(S) -