ML043290369

Final Status Survey Release Record FR-0910 Fire Pond (Pump House Slab) Footprint Survey Unit 2

ML043290369
Person / Time
Site:	Maine Yankee
Issue date:	11/17/2004
From:	Vanags U Maine Yankee Atomic Power Co
To:	NRC/FSME
References
FR-0910-02, Rev 0
Download: ML043290369 (20)

Text

MAINE YANKEE FINAL STATUS SURVEY RELEASE RECORD FR-0910 FIRE POND (PUMP HOUSE SLAB) FOOTPRINT SURVEY UNIT 2 Prepared By: o k/ aL Date: JJ/z~f toFSS ~inserSignature Printed Name/

Reviewed By: - Date: 11-_3 -Olt_

InpSe SdnReialisve- Signature Printed Name Reviewed By: Date: /,

independent Review- Signature

'Printed Ne Approved By: _Date:.o/sq

,8'tu~pG'fntender(,SFSi ature 1Printed Name Approved By:  ::us,< D ate: ,/~7

'TSS, MOP - Signature Printed Name Revision 0

MAINE YANKEE FINAL STATUS SURVEY RELEASE RECORD FR-0910 FIRE POND (PUMP HOUSE SLAB) FOOTPRINT SURVEY UNIT 2 A. SURVEY UNIT DESCRIPTION FR-0910 Survey Area includes the Fire Pond footprint and the adjacent Fire Pond Pump I-ouse concrete slab, located about 700 feet northwest of the plant (Maine State Grid Coordinates 623500 N and 408250 E) as shown on map FR-0910-01 (Attachment 1). Water for firefighting was stored in a man-made water storage pond, constructed of concrete and gravel, and rubber-lined. The pond was 278 feet long, 200 feet wide and 15 feet deep, with a capacity of approximately 3.4 million gallons. Makeup water for the pond was supplied from the offsite Montsweag Reservoir, located near the junction of U.S. Route I and Route 144.

Water was drawn from the water storage pond by two fire pumps located in the Fire Pump House. Survey Unit 2 consists of the Pump House Slab, approximately 1 9.3 M2 , which contained a sump and several through-slab penetrations. The concrete slab was all that remained of the Fire Pump House following its demolition. The survey unit was located outside of the plant's radiologically restricted area (RA) and industrial area.

B. SURVEY UNIT DESIGN INFORMATION Survey Unit 2 consists of the Fire Pond Pump House slab foot print and was designated a Class 3 survey unit in accordance with the LTP (Table 5-11B; B-0400 and Table 5-lC; R0900).

The survey unit design parameters are summarized in Table 1. Given a relative shift of 3.0, it was determined that 14 direct sample points were required for the Sign Test. The direct measurement locations were randomly generated and are shown on map FR 0910-06 (Attachment 1). The direct measurements were volumetric concrete samples due to the rough condition of the slab surface. The samples were analyzed with laboratory gamma spectroscopy instrumentation.

A 1% to 10% scan coverage of the area was required.' The scan grids consisted of one-meter square areas in the vicinity of each of the 14 concrete samples, resulting in a scan area of 14 meters square. Scanning locations are shown on map FRO910-07 (Attachment 1). Scans were performed prior to sampling.

As an augmented survey to the 14 concrete samples and scans of the Fire Pump House slab, a survey was conducted of the accessible pipe penetrations on the slab. The location of the 12 pipe penetrations are located on map FR0910-07a in Attachment 1. Scans wvere conducted with a SHP 360 and accompanying-smears were obtained on the accessible portion of the penetrations. The final status surveys for the piping systems will be surveyed elsewhere as required by the LTP.

The survey instruments used, their MDC values, and alarm setpoints are provided in Attachment 2.

LTP Table 5-3 FR-0910-02, Revision 0 Page 2 of 20

Background values were established, for each particular instrument probe used to scan concrete (i.e., 43-68), based on background values in the survey unit. These background values were used to establish scan alarm setpoints and to confirm the scan MDCs used were appropriate.

TABLE 1 SURVEY UNIT DESIGN PARAMETERS Survey Unit Design Criteria Basis Area 119.3 m2 No limit for Class 3 Area Based on an adjusted LBGR of e o17,049 dpm/100 cm2 , sigma22 Measurements Required 14 of 317 dpm/100 cm 2 , 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 Scan Grid Area Approximately 1 m x I m Class 3 Area Area Factor N/A Class 3 Area Scan Survey Area 14 ml Class 3 Area: 1% - 10%

Background ;e J, *i, .. 't.-e.

43-68 Scans (flat surfaces) 2821 dpm/100 cm' Ambient and Material Scan Investigation Level See Table 2-2 LTP Revision 3 DCGL 18,000 dpm/100 cm' LTP Revision 3 Design DCGLEMC N/A Class 3 Area C. SURVEY RESULTS As required, 14 concrete samples were obtained from the Fire Pump House slab. The resulting concrete volumetric sample measurement data, converted to surface activity in dpm/I00 cm2 , are presented in Table 2. All direct measurements were below the DCGL.

No scan alarms occurred within this survey unit scan location. Therefore, no investigations were required.

2 LTP Table 5-lB, B0400, Fire Pump House FR-0910-02, Revision 0 Page 3 of 20

TABLE 2 DIRECT MEASUREMENTS Sample SmlNubrCs-137 Number (dpmn/100 cm22Co-60

) (dpmr/100 cm2 )

FRO910-02-3-COOl <18.4 <21.6 FRO910-02-3-C002 <21.9 <24.6 FRO910-02-3-C003 <18.8 <22.6 FRO9 1-02-3-C004 < 25.4 FRO910-02-3-CO05 <25.4 <26.1 FRO910-02-3-C006 <21.9 <26.0 FR0910O-02-3-C007 <21.1 < 25.0 FR0910-02-3-C008 <25.6 <23.9 FR0910-02-3-C009 <24.3 <28.3 FRO910-02-3-CO10 <27.6 <34.7 FRO910-02-3-CO1 <125.0 <25.5 FRO910-02-3-CO12 <29.8 <34.3 FRO910-02-3-C013- <27.3 <29.2 FRO910-02-3-C014 <23.8 <29.6 Mean 23.8 D 26.9 Median 24.0 25.7 Standard Deviation 3.3 3.9 Range 18.4 to 29.8 21.6 to 34.7 NOTES:

1. Sample collected over an area of 6 by 9 inches or 348.4 cm2 .

2. Table 2 represents volumetric results converted to surface activity.

3. "<" indicates values at the MDA prior to conversion.

D. SURVEY UNIT INVESTIGATIONS AND RESULTS Scanning results of the concrete slab did not produce any alarms; therefore, no investigations were conducted.

E. SURVEY UNIT DATA ASSESSMENT An analysis of the direct sample measurement results, including the mean, median, standard deviation, and sample result range, are provided in Table 2. The concrete sampling results yielded no positive indications of plant-derived nuclides. The sample results were converted to surface activity as indicated in Table 2. The mean and median activities were a small fraction of the DCGL(18,000 dpm/l 00 cm 2 ). The maximum direct sample result for combined Cs-137 and Co-60 activity was 64.1 dpm/100 cm2 .

The combined mean residual contamination level is 50.7 dpm/l 00 cm 2 . This is equivalent to an annual dose of 8.48E-04 mrem/y. 3 3 This annual dose equivalent is based on LTP Table 6-11 which shows the contaminated concrete dose contribution (for surfaces contaminated at the DCGL) to be 0.301 mrem/y.

FR-0910-02, Revision 0 Page 4 of 20

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.

I. 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 18,000 dpm/l 00cm2 .

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 one outlier.

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.

As mentioned in Section B, the entrances of 12 pipe penetrations were scanned with a SHP 360 and smeared to check for loose alpha and beta activity. The maximum penetration scan value was 200 c/m which was equivalent to 8023 dpm/l 00 cm2 gross activity. The net result after subtracting ambient background is 6458 dpm/100 cm2 . The smear results were less than the alpha MDA of 3.2 dpm/100 cm2 and the beta MDA of 3.5 dpm/l 00 cm2 (except two smears that were positive for beta but were below 5 dpm). These results demonstrate that the pipe penetrations do not pose a risk to the final status survey results for FR-0910 Survey Unit 2.

FR-0910-02, Revision 0 Page 5 of 20

C. CHANGES IN INITIAL SURVEY UNIT ASSUMPTIONS ON 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.

H. LTP CHANGES SUBSEQUENT TO SURVEY UNIT FSS The FSS of Survey Unit 2 was designed, performed, and evaluated in late 2002. The design was performed to the criteria of the LTP, Revision 2. The only subsequent change with the potential to impact this survey unit was the establishment of a scan MDC for gas filled detectors (Reference 2).

This LTP change was evaluated and found to have no impact on the results or conclusions of the FSS of FR-0910 Survey Unit 2.

I. 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 18,000 dpm/l 00 cm .

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 one outlier.

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 FR-09 10, Survey Unit 2, met the release criteria of IOCFR20.1402 and the State of Maine enhanced criteria.

FR-0910-02, Revision 0 Page 6 of 20

J. REFERENCES

1. Maine Yankee Engineering Calculation, EC-009-01

2. Maine Yankee License Termination Plan, Revision 3, Maine Yankee letter to the NRC, MN-02-048, dated October 15, 2002

3. Approach for Dealing with Background Radioactivity for Maine Yankee Final Status Surveys, Attachment E to Maine Yankee Procedure, FSS Data Processing and Reporting, PMP 6.7.8

4. Maine Yankee License Termination Plan, Revision 3 Addenda, Maine Yankee letter to the NRC, MN-02-061, dated November 26, 2002

5. NRC letter to Maine Yankee, dated February 28, 2003, Approval of LTP Rev. 3 and Addenda

6. MY letter to the NRC, MN-03-049, dated September 11, 2003, "Proposed Change:

Revised Activated Concrete DCGL and More Realistic Activated Concrete Dose Modeling"

7. NRC Letter to Maine Yankee, dated February 18, 2004, Approval of Activated Concrete Amendment

8. MY letter to the NRC, MN-03-009, February 26, 2003 FR-0910-02, Revision 0 Page 7 of 20

Attachment 1 Survey Unit Maps FR-0910-02, Revision 0 Page 8 of 20

Maine Yankee Map ID#:

Decommissioning Team I Mlabie Yanikee DecoyiuissioninhgProjectSurvey Forin FR-0910-0 Survey Type:- Characterization _ Turnover

• Final Status Survey I Survey Area Name: Fire Pond 623,000 E 623,500 E 624,000 E 624,500 E 625,000 E C) °J °0 X) (<

PIb  : 0 P 0 00C 0 o o 0 0 0> 0 z z Z Z Z Z SCALE MN 0 400 800 1200 1--- SD: N FR-0910-02, Revision 0 Page 9 of 20

Maine Yankee AlieYtkeDcmnsitii ProetSun'e ForuilI Map ID#:

Decommissioning Team lAine YankFee roject uel FRIeconussiomng 0910-06 Survey Type: -1 Characterization = Turnover

• Final Status Survey ISurvey Area Name: Fire Pump House I

Fire Pump House Foot Print FR 0910 Survey Unit 02 Concrete Sample Locations Fire Pump House

%6( -

_Or

-IA I -LIU c-mmnlita OI I IFICaL I fjrnfin

- JuJ1LIJI A Starting At The Northeast Corner Of The Fire Pump House Footprint

, reem Q1,rnmrndei I nrntinn 'rrnrtrin:ntfc In mfrirz (..

Nortneast Corner Of C002 C001 Fire Pump 1101(6,1) 3 (3,1) House (0,0)

C003 C005 1101(6,3) 0009 (7,4)110 C004 (1,5) x (6,4) x C006 C008 (8,5) C007 (3,6) 80 (6,7)

CO01 0 010 C 120 (5,9) 1101(2,9) 0012 (5,10)0 0013 C014 (1,12)0 30(6,13)

FR-0910-02, Revision 0 Page 10 of 20

Maine Yankee Mainte Yankee DecommissioitigProject Survey orin Map ID #:

Decommissioning Team DeoIsiigSre For FIR 0910-07 Survey Type: -Characterization = Turnover N Final Status Survey Survey Area Name: Fire Pump House Fire Pump House Foot Print FR 0910 Survey Unit 02 I Concrete Scan Locations Fire Pump 3K - Concrete sample Location NJ House n - Concrete Scan Location (.85 square meter)

C002 Cool C003 C005 C004 C009 C006 11C008 C007 coi1l 0C010 C012 C013 XC014 Total Area: 119.3 Sq Meters 14 Scan Areas - .84 SQ meters FR-0910-02, Revision 0 for a total of 11.9 SQ meters Page II of 20 scanned in this area.

Maine Yankee liMap ID#:

Decommissioning Team MIneYne eomisoigPoecIuvyFr FIR 0910O-07a Survey Type: 0 Characterization E Turnover U Final Status Survey I Survey Area Name: Fire Pump House Fire Pump House Foot Print FR 0910 Survey Unit 02 Piping Penetration Locations

© 6" Raw Water Line I

© 6" Raw Water Line

© 8" Raw Water from Montsweag 4" Floor Drain (I] -r 4" From 13-5 Discharge To f loor Drainage ©

)12" Yard Fire L op Sump '

- A4 From P-5 l2l 4" Floor Drain CO 9 H,eeat Exchanget -

DiTo Floor Drainage f)1 2" Yard Fire Lc DP 4" Floor DrainT Su I

4" From P-4 Discharge To Floor Drainage ©

©4" Floor Drain CO FR-0910402, Revision 0 Page 12 of 20

Attachment 2 Survey Unit Instrumentation FR-0910-02, Revision 0 Page 13 of 20

TABLE 2-1 INSTRUMENT INFORMATION I E-600 SIN Probe S/N (type) l 1619 1 148117 (43-68) 1647 467 (SHP360) JJ HPGc Detectors for Lab Analysis of Volumetric Samples I Detector Number I MDC (pCi/g) I I DET 2 1 0.05 - 0.13 l DET 3 l 0.05 - 0.13 l TABLE 2-2 INSTRUMENT SCAN MDC, DCGL, AND INVESTIGATION LEVEL Detector 1 43-68 (Flat) J Comments Scan MDC 1,832 LTP Table 5-6 (dpm/l 00 cm 1 DCGL 18,000 LTP Revision 3 (dpm/I00 cm 2 )

Investigation Level (Alarm Setpoint) 9,000 - 50% DCGL (dpm/100 cm 2)

FR-0910-02, Revision 0 Page 14 of 20

Attachment 3 Investigation Table (None Required)

FR-0910-02, Revision 0 Page 15 of 20

Attachment 4 Statistical Data FR-0910-02, Revision 0 Page 16 of 20

Survey Package FR-0910 Unit 2 Surface Sign Test Summary Ealuation Inpu' alues+/- n' ___.__________ ': Cmm Survey Package: FR-0910 Fire Pond Pump House Survey Unit: 02 Evaluator: GP DCGLw: 18,000 DCGL,mc: 18,000 LBGR: 9,000 Sigma: 317 Type I error: m0.05 Type II error: 0.05 Total Instrument Efficiency: 13.0%

2 Detector Area (cm ): 126 Choosing 'NIX sets material Material Type: N/A background to "0' Z: .1.645 Z1 , 1.645 Sign p: 0.99865 Calculated Relative Shift: 28.3 Relative Shift Used: 3.0 Uses 3.0 if Relative Shift >3 N-Value: - ' 11 N-Value+20%: ,, i4

jt,^Statc Data -a ues ,- . - .14 omme Number of Samples

14 Median: . 51 Mean: '51 Net Static Data Standard Deviation: 7 Total Standard Deviation: 7 SRSS Maximum: , 64 ha.>.Pt.AfSr<.. Ts Re~ijltstt ign6i m-'li Adjusted N Value: 14 S+ Value: . .14 Critical Value: 10 Sufficient samples collected: ; - Pass Maximum value <DCGLW: Pass Median value <DCGL,: Pass Mean value <DCGL,: Pas's Maximum value <DCGL,,: Pass Total Standard Deviation <=Sigma: Pass_

Sign test results: "'Pass The survey unit passes all condiios:oassj FR-0910SU2-urfaceSign FR-0910-02, Revision 0 11/1504 11:48 AM Page 17 of 20

FR-0910 SU-2 Quantile Plot 70 60 E 50 0 .

TIl 0lar

• Activity (dpm/100 cm2) 40 30 - Median (dpm/100 of0 0

0W 4.-.O cm2)

._ 20 A:

10 0 -I 0 25 50 75 100 Percent

One-Sample T-Test Report Page/Date/Time 2 11/15/04 11:49:42AM Database C:\Program Files\NCSS97\FrO9l0C.SO Variable C2 Plots Section Histogram of FR-0910, SU-2 (0

C.

E zu Activity (dpm/100 cm2)

FR-0910-02, Revision 0 Page 19of20

One-Sample T-Test Power Analysis Page/Date/Time 2 11/15/04 11:52:43 AM Chart Section Retrospective Power Curve 1.0

, I 0.8 .. I I I I a) 0.6 I@ \ I I'\ I I 0 II \ I I a- I I Il I 0.4 I I I I I l III \I I I I \I 0.2 I I I \I I I I \ I I I I I 0.0 l l ^ l C 5000 100oo 15600 20600 Survey Unit Mean (dpm/100 cm2)

FR-0910-02, Revision 0 Page 20 of 20