ML043290353
| ML043290353 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 11/17/2004 |
| From: | Pillsbury G Maine Yankee Atomic Power Co |
| To: | NRC/FSME |
| References | |
| FD-0500-01, Rev 0 | |
| Download: ML043290353 (20) | |
Text
MAINE YANKEE FINAL STATUS SURVEY RELEASE RECORD FD-0500 CIRCULATING WATER PIPING SURVEY UNIT 1 Date:
Prepared By: _4-
.lfX Engine /nature Prnted Name Reviewed By: I FSS Spce ffstslinature AiR~Lr i'-OZ(C Printed Name Date:
Reviewed By: -,
iiiSdendent'cviewer -
Signature p~intedc~f jSignature XPrinted Name/
Date:
Approved By: __ 03;4 4inteTOP - Signature Printed Name
MAINE YANKEE FINAL STATUS SURVEY RELEASE RECORD FD-0500 CIRCULATING WVATER PIPING SURVEY UNIT 1 A. SURVEY UNIT DESCRIPTION FD-0500 Survey Unit 1, the Circulating Water Piping, consists of the interior portions of the four inlet pipes that brought condenser cooling water into the Turbine Building. The pipes were 72" ID metal lined concrete. The remnant of each pipe is approximately 27 feet long.
The total survey unit comprises approximately 189 m2 of interior pipe surface. The survey unit is located at 407520 N and 624140 E using the Maine State Grid System (see Maps FDO500-01 and FD0500-02, Attachment 1). While the survey area was located inside the Industrial Area of the site, it was outside of the plant's radiologically restricted area (RA).
B. SURVEY UNIT DESIGN INFORMATION FD-0500 Survey Unit I was designated a Class 3 survey unit per the LTP (Table 5-4E).
The survey unit design parameters are summarized in Table 1. A minimum of 30 direct measurements were required in accordance with the LTP, Attachment SA. The start point for the direct measurement locations was the 0 degree point (top of pipe) when facing the pipe opening. Direct measurements were also taken at 90, 180 and 270 degree positions in each end of each pipe. The sample points were located as shown in the attached maps (FDO500-03 and FDO500-04, Attachment 1).
A 1% to 10% scan coverage of the area was required.' Scan areas were typically 0.3 m wide bands around the inner circumference of the pipe openings, as shown on survey maps FD0500-03 and FD0500-04, (Attachment 1). The total scan area was approximately 14 m2 (7% area coverage).
The survey instruments used, their MDC values, and alarm setpoints are provided in Attachment 2. As shown in the Attachment, the scan MDC is less than the scan investigation level in all cases, thus providing high confidence (95% or greater) that an elevated area would be detected in the scan process.
Background values were established, for each particular instrument probe application based on ambient background values in the survey unit. These background values, listed in Table 1, were used to establish net activity for direct measurements, scan alarm setpoints, and to confirm the scan MDCs used were appropriate.
LTP Table 5-3 FD-0500-01, Revision 0 Page 2 of 20
TABLE 1 SURVEY UNIT DESIGN PARAMETERS Survey Unit Design Criteria Basis Area 189 m2 Based on pipe length and ID.
LTP, Attachment 5A Number of Direct Based on LBGR of 4900 dpm/l00 Measurements Required Minimum of 30 cm2 , sigma 2 of 295 dpm/100 cm2 ,
and relative shift of 3.0 Type I = Type II = 0.05 Sample Area N/A Class 3 Area Sample Grid Spacing N/A Class 3 Area 0.3 m wide bands Scan Grid Area around circumference Class 3 Area of pipe opening, east and west ends Area Factor N/A Class 3 Area Scan Survey Area 14 m2 Class 3 Area- 7.3%
Background - i.?rHiL 43-68 Direct and Scan 2 l (flat surfaces) 654 dpn/100 cm Ambient Scan Investigation Level Background plus 25% EC 009-01 (Reference 1) of DCGL DCGL 9800 dpm/100 cm2 LTP, Rev. 2 (Reference 2)
Design DCGLEMc N/A Class 3 Area C. SURVEY RESULTS The direct measurement results are presented in Table 2 below. All direct measurements were less than the DCGL.
No alarms were received during scanning; therefore, no investigations were required.
2 LTP Attachment 2B FD-0500-01, Revision 0 Page 3 of 20
TABLE 2 DIRECT MEASUREMENTS Sample Number Gross Activity Net Activity l (dpm/100 cm2 ) l (dpm/100 cm2 )
FD-0500-1-M017 830 176 FD-0500-1-M018 606 -48 FD-0500-1-M019 890 236 FD-0500-1-M020 640 -14 FD-0500-1-M021 818 164 FD-0500-1-M022 724 70 FD-0500-1-M023 873 219 FD-0500-1-M024 709 55 FD-0500-1-M025 726 72 FD-0500-1-M026 683 29 FD-0500-1-M027 746 91 FD-0500-1-M028 637 -17 FD-0500-1-M029 813 159 FD-0500-1-M030 801 147 FD-0500-1-M031 796 142 FD-0500-1-M032 654 0 FD-0500-1-M033 880 226 FD-0500-1-M034 844 190 FD-0500-1-M035 899 245 FD-0500-1-M036 803 149 FD-0500-1-M037 835 180 FD-0500-1-M038 777 123 FD-0500-1-M039 806 152 FD-0500-1-M040 743 89 FD-0500-1-M041 818 164 FD-0500-1-M042 803 149 FD-0500-1-M043 907 253 FD-0500-1-M044 866 212 FD-0500-1-M045 810 156 FD-0500-1-M046 810 156 FD-0500-1-M047 856 202 FD-0500-1-M048 803 149 Mean 788 134 Median 1 804 150 Standard Deviation f 80 80 Range j 606 - 907 253 FD-0500-01, Revision 0 Page 4 of 20
D. SURVEY UNIT INVESTIGATIONS PERFORMED AND RESULTS No investigations were required.
E. SURVEY UNIT DATA ASSESSMENT An analysis of the direct sample measurements, including the mean, median, standard deviation and sample range, is provided in Table 2. Without subtracting background, all of the direct measurements were less than the DCGL. The maximum direct sample result after subtracting background was 253 dpm/Il 00 cm2 .
When adjusted for background, the mean residual activity is 134 dpm/100 cm 2 . This would be equivalent to an annual dose rate of 3.4E-5 mrem/y. 3 F. ADDITIONAL DATA EVALUATION Attachment 4 provides additional data evaluation associated with this survey unit, including relevant statistical information. Based on survey unit direct measurement data, this attachment provides the Sign Test Summary, Quantile Plot, Histogram, and Retrospective Power Curve.
- 1. The Sign Test Summary provides an overall summary of design input (Table 1) and resulting calculated values used to determine the required number (N) of direct measurements (per LTP Section 5.4.2). The Sign Test Summary is a separate statistical analysis that also calculates the mean, median, and standard deviation of the direct measurements.
The critical value and the result of the Sign Test are provided in the Sign Test Summary table, as well as a listing of the key release criteria. As is shown in the table, all of the key release criteria were clearly satisfied for the FSS of this survey unit.
- 2. The Quantile Plot was generated from direct measurement data listed in Table 2. The data set and plot are consistent with expectations for a Class 3 survey unit. All of the measurements are well below the DCGL of 9800 dpm/l00 cm 2 .
- 3. A Histogram Plot was also developed based on the direct measurement values. This plot shows that the direct data were essentially a normal distribution with no outliers.
- 4. A Retrospective Power Curve was constructed, based on FSS results. The curve shows that this survey unit having a mean residual activity at a small fraction of the DCGL has a high probability ("power") of meeting the release criteria. Thus, it can be concluded that the direct measurement data support rejection of the null hypothesis, providing high confidence that the survey unit satisfied the release criteria and that the data quality objectives were met.
3 Annual dose equivalent is equal to the LTP Table 6-1 I dose rate of 2.52E-3 mrem/y times the DCGL fraction.
FD-0500-01, Revision 0 Page 5 of 20
G. CHANGES IN INITIAL SURVEY UNIT ASSUMPTIONS ON THE EXTENT OF RESIDUAL ACTIVITY The survey was designed as a Class 3 area; the FSS results were consistent with that classification. The direct measurement sample standard deviation was less than the design sigma. Thus, no additional measurements were required.
II. LTP CHANGES SUBSEQUENT TO SURVEY UNIT FSS The FSS of Survey Unit I was designed, performed and evaluated in mid 2002. The design was performed to the criteria of the LTP, Revision 2 (Reference 2). Subsequent LTP changes with potential impact to this survey unit were evaluated:
- 1. Establishment of a scan MDC for gas filled detectors (LTP Revision 3, Table 5-4b, References 3, 4 and 5).
This LTP change was evaluated and found to have no impact on results or conclusions of the FSS of FD-0500 Survey Unit 1.
- 1. CONCLUSION The FSS of this survey unit was designed based on the LTP designation as a Class 3 area.
The survey design parameters are presented in Table 1. The required number of direct measurements was determined for the Sign Test in accordance with the LTP. As presented in Table 2, all direct measurements were less than the DCGL of 9800 dpm/l 00 cm2 .
A Sign Test Summary analysis demonstrated that the Sign Test criteria were satisfied. The direct measurement sigma was determined to be less than that used for design, thus indicating that a sufficient number of samples was taken.
The Retrospective Power Curve shown in Attachment 4 confirmed that sufficient samples were taken to support rejection of the null hypothesis, providing high confidence that the survey unit satisfied the release criteria and the data quality objectives were met. Attachment 4 also revealed that direct measurement data represented essentially a normal distribution, with no outliers.
The scan survey design for this survey unit was developed in accordance with the LTP with significant aspects of the design discussed in Section B and Table 1. Scanning resulted in no verified alarms, therefore no investigations were required.
It is concluded that FD-0500, Survey Unit I met the release criteria of IOCFR20.1402 and the State of Maine enhanced criteria.
FD-0500-01, Revision 0 Page 6 of 20
J. REFERENCES
- 1. Maine Yankee Engineering Calculation, EC 009-01
- 3. Maine Yankee License Termination Plan, Revision 3, Maine Yankee letter to the NRC, MN-02-048, dated October 15, 2002
- 4. Maine Yankee License Termination Plan, Revision 3 Addenda, Maine Yankee letter to the NRC, MN-02-06 1, dated November 26, 2002
- 5. NRC letter to Maine Yankee, dated February 28, 2003, Approval of LTP Rev. 3 and Addenda FD-0500-01, Revision 0 Page 7 of 20
Attachment 1 Survey Unit Maps FD-0500-01, Revision 0 Page 8 of 20
Maine Yankee Map ID #:
Decommissioning TemIID500 ADaine Yankee Decommnissiontintg ProjectSutlrey Fo1 rm FDo Survey Type: Characterization Turnover N Final Status Survey I Survey Area Name: Turbine Condensate Inlet piping 623.000 E 623.500 E 624.000 E 624,500 E 625.000 E MN i i I 0 400 800 1200 FD-0500-01, Revision 0 Page 9 of 20
Maine Yankee Ai Yaeoeap ID#:
Decommissioning Team IAanYnkeDecommiissioning ProjectSurvey Fo FDO500-02 Survey Type: 0 Characterization El Tumover
- Final Status Survey I Survey Area Name: Turbine Condensate Inlet piping MN Plan View Of 3)-- >aE N Condenser Inlet Piping Lci Lcz A B C D FD-0500-01, Revision 0 Page IO of 20
Maine Yankee llaitte Yankee Decommissio/ng Project Sure rI Map ID #:
Decommissioning Team AIneYne eomsinn rjc mre'Fr IFD0500-03 Survey Type: L. Characterization L Turnover
- Final Status Survey ISurvey Area Name: Turbine Condensate Inlet piping Turbine Condenser Inlet Piping East End MN Direct and Scan Locations Inside Pipes AME - BIE A4E A2E B4E W B2E T9Q0 L B3E A Scan Area B C DIE C4E C2E D4E ;\r -D2E I 90 g90o C3E D3E C FD-0500-01, Revision 0 Page 11 of 20 D
Maine Yankee Map ID #:
Decommissioning Team l1ahi}e Yankee DecoiwiuissionidngProject Survey Form'-IFDO500-04 Survey Type: L Characterization L Turnover
- Final Status Survey Survey Area Name: Turbine Condensate Inlet piping Turbine Condenser Inlet MN Piping West End N Direct and Scan Locations Inside Pipes
,- Al1W B1W A4W A2W B4W B2W 2700 90 2700 900 1 L A3W\ B3W Scan Area B D1W C4W- C2W D4W \ D2W 2700 900 2700 90O 1 1 C3W D3W C D FD-0500-01, Revision 0 Page 12 of 20
Attachment 2 Survey Unit Instrumentation FD-0500-01, Revision 0 Page 13 of 20
TABLE 2-1 INSTRUMENT INFORMATION I E-600 S/N I Probe SIN (typc) l 1631 1 148936 (43-68) 1631 148932 (43-68)
TABLE 2-2 INSTRUMENT SCAN MDC AND COMPARISION WITH DCGL AND INVESTIGATION LEVEL I Detector 1 43-68 (Flat) I Comments Scan MDC 1832 LTP Table 5-6 (dpm/I00 cm2 )
DCGL 9800 LTP Table 6-11 (dpm/l O0 cm')
Investigation Level 25% of the DCGL plus Alarm Setpoint 3054 background (dpm/l 00 cm2)
FD-0500-01, Revision 0 Page 14 of 20
Attachment 3 Investigation Table (None Required)
FD-0500-OI, Revision 0 Page 15 of 20
Attachment 4 Statistical Data FD-0500-01, Revision 0 Page 16 of 20
Survey Package FD-0500 Unit 1 Surface Sign Test Summary 7--:1-IvaluiCiSnIn utl4 uAVO* Hi; r -
Survey Package: FD-0500 Circulating Water Piping Survey Unit: 01 Evaluator: GP DCGL.: 9,800 DCGLEr: 9,800 LBGR: 4,900 Sigma: 295 Type I error: 005 Type II error 0.05 Total Instrument Efficiency: 33.0%
Detector Area (cm2 ): 126 Choosing 'N/A' sets material Material Type: N/A background to "0"
,^:->, A ' ;ujaedjii uos:: ,, Co inents,.. . ,
1'-.645 1.645 Sign p: ; '0.99865 Calculated Relative Shift: 16.6 Relative Shift Used: - 3.0 Uses 3.0 if Relative Shift >3 N-Value: 11 N-Value+20%: -14
- Ad;`i8;7,S ~Stdti;,-,o'
'tO.'51 .
Data,'a , a l IZN,=>, sy_
Number of Samples: : .. 32 Median: 151 Mean: 135 Net Static Data Standard Deviation: . 80 Total Standard Deviation: i122 SRSS Maximum: 254
,\-,,,,,8'->ie,'i
,~~, ----t s i ,< I n-
.^ , -,--,;,i-,A~><sg Adjusted N Value:
S+Value:l -' '32 Critical Value: 21
- I"CrlteraS'aisifat
- Sufficient samples collected: Pass Maximum value <DCGL.: .Ras Median value <DCGLw: Pass Mean value <DCGLw: Pass P.
Maximum value <DCGLr,,: I -Pass Total Standard Deviation <=Sigma: .'. E Pass e; _ _. _'s' Sign test results: : , Pass hi, £mment The survey unit passes all conditions: U -*Pass ________________
FDo0500-SU1-Surfacesign 1 0121104 11:04 AM FD-0500-01, Revision 0 Page 17 of 20
00 0
0C)
One-Sample T-Test Report Page/Date/Time 2 10/21/04 10:37:44 AM Database C:\Program Files\NCSS97\FDO500SUI.S0 Variable C2 Plots Section Histogram of FD-0500, SU-1 12.000, 4)
E U)
~0 E
z Activity (dpm/1 00 cm2)
FD-0500-01, Revision 0 Page 19 of 20
One-Sample T-Test Power Analysis Page/Date/Time 2 10/21/04 10:39:28 AM Chart Section Retrospective Power Curve 14 A -
a-0 a.
Survey Unit Mean (dpm/100 cm2)
FD-0500-01, Revision 0 Page 20 of 20