ML090900772

From kanterella
Revision as of 14:24, 12 March 2020 by StriderTol (talk | contribs) (StriderTol Bot change)
Jump to navigation Jump to search
Final Status Survey Summary Report for February 26, 2009, Tank Farm - Bwst Pad, Survey Unit F8100043
ML090900772
Person / Time
Site: Rancho Seco
Issue date: 02/26/2009
From: Tallman D
Sacramento Municipal Utility District (SMUD)
To:
NRC/FSME
Shared Package
ML090830613 List: ... further results
References
DPG 09-097
Download: ML090900772 (25)
v • d • e


Text

Rancho Seco Final Status Survey Summary Report February 26, 2009 Tank Farm - BWST pad Survey Unit F8100043 Prepared By: Dan A. Tallman A_______________ Date: February 26, 2009 FSSEngin/eer Reviewed By: & Jt lI.*)kDate:

, -[3(30 Lead FSS Engineer Approved By: t1 Date:

Dismantlement(Superintendent, Radiological

FINAL STATUS SURVEY

SUMMARY

REPORT Survey Unit:

F8100043, Tank Farm - BWST pad Survey Unit

Description:

Operating History: This survey unit consists of the concrete pad that supported the Borated Water Storage Tank (BWST), used to store radioactive liquids. Operating records and the HSA document several events with the potential for a release of radioactivity associated with this survey area. The HSA documented the storage of radioactive material within the area that may have had the potential to contaminate the area.

Several locations adjacent to the designated pad required remediation as did the majority of the pad itself.

Site Characterization: Soil samples surrounding the pad were collected and analyzed for the presence of plant-derived radionuclides. Cs-137 was the primary nuclide of plant origin detected. The BWST pad was surveyed by with a mean activity level of 11,992 2 2 dpm/100 cm 2 and a maximum value of 140,880 dpm/100 cm . Based on the classification procedure (DSIP-0020) and levels of Cs-137 reported, the BWST Pad was determined to be a Class 1 area.

Survey Unit Design Information:

The Survey Unit Design Parameters are presented in Table 1 below. The survey unit and measurement locations are depicted on the maps in Attachment 1. Direct measurement locations were determined using a random-start, fixed grid pattern and 187 m2 were scanned for 100% coverage. Samples of removable contamination were collected at each direct measurement location. The instrumentation used for the survey along with the MDC values are listed in Tables 2-1 and 2-2 in Attachment 2.

Page 2 of 8 FSS Summary Report F8100043

Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area: F810 Tank Farm - BWST pad Survey Unit: 0043 Structure Surface Class: 1 LTP Table 5-4 SU Area (m2): 187 Evaluator: D.A.Tallman DCGL (dpm/100 cm 2): 43000 Gross Activity DCGL Area Factor: 3.5 Class 1 Design DCGLemc 153669 Class I 2

(dpm/100 cm ):

LBGR (dpm/100 cm 2): 21500 Default 50% DCGL Design Sigma (dpm/100 cm 2): 12845 Type I Error: 0.05 Type II Error: 0.05 Predominant Nuclide: Cs-137 Sample Area (m2): 6.9 Class 1 Scan Area (M2): 187 Scan Coverage (%): 100% Class 1 Zl-,, :

1.645 ZI.* :

1.645 Sign P: 0.945201 Calculated Relative Shift: 1.6 Relative Shift Used: 1.6 Uses 3.0 if Relative Shift is

>3 N-Value: 14 Design N-Value + 20%: 17 NUREG-1575 Table 5-5 Design Min Samples N: 27 Class 1 Grid Spacing L: 2.6 Class 1 Page 3 of 8 FSS Summary Report F8100043

Survey Results:

A total of 27 direct measurements were made in F8100043. The results including mean, median, standard deviation and range are shown in Table 2. All direct measurements were less than the DCGL. None of the scan measurements indicated areas of elevated activity. Scan activity ranged from 1754 to 20819 dpm/100 cm 2, based on a surveyor efficiency of 0.5 and no background subtracted. Samples'for removable surface activity were all less than 10% of the DCGL as shown in Table 3. Removable surface activity samples were counted for alpha activity and none was detected at the MDC shown in Table 2-1 of Attachment 2.

Table 2. Direct Measurement Results Measurement ID Gross Activit (dpm/100 cm)

F8100043-CO001BD 1976 F8100043-CO002BD 1940 F8100043-CO003BD 2791 F8100043-CO004BD 2231 F8100043-CO005BD 2007 F8100043-CO006BD 2033 F8100043-CO007BD 2039 F8100043-CO008BD 2158 F8100043-CO009BD 2044 F8100043-COOIOBD 2111 F8100043-COOI1BD 1966 F8100043-C001 2BD 2065 F8100043-CO01 3BD 2023 F8100043-CO014BD 2065 F8100043-CO01 5BD 2080 F8100043-CO01 6BD 2153 F8100043-CO017BD 2065 F8100043-CO018BD 1950 F8100043-CO019BD 2256 F8100043-C0020BD 2033 F8100043-C0021 BD 2054 F8100043-CO022BD 1987 F8100043-CO023BD 2142 F8100043-C0024BD 2158 F8100043-CO025BD 2085 F8100043-C0026BD 2205 F8100043-CO027BD 1779 Mean: 2089 Median: 2065 Standard Deviation: 172 Range: 1779 -2791 Rag:17929 Page 4 of 8 FSS Summary Report F8100043

Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2 )

F8100043C0001 SM -2.88 F8100043C0002SM -0.29 F8100043C0003SM 3.58 F8100043C0004SM 2.29 F8100043C0005SM 2.29 F8100043C0006SM 2.29 F8100043C0007SM 2.29 F8100043C0008SM -2.88 F8100043C0009SM 2.29 F8100043C0010SM -1.58 F8100043C001 1SM -1.58 F8100043C0012SM 1 F8100043C0013SM 2.29 F8100043C0014SM 2.29 F8100043C0015SM -0.29 F8100043C0016SM -0.29 F8100043C0017SM 4.87 F8100043C0018SM 4.87 F8100043C0019SM -0.29 F8100043C0020SM 3.58 F8100043C0021SM 1 F8100043C0022SM 2.29 F8100043C0023SM -0.29 F8100043C0024SM 1 F8100043C0025SM 2.29 F8100043C0026SM 1 F8100043C0027SM 4.87 F8100043C0008SM 6.16 F8100043C0023SM -1.58 Mean: 1.4 Median: 2.29 Standard Deviation: 2.34 Range: -2.88 to 6.16 Page 5 of 8 FSS Summary Report F8100043

Survey Unit Data Assessment:

The survey design required 27 direct measurements for the Sign Test. The critical value and the results of the Sign Test are presented in Table 4. The sample mean and median values were less than the DCGL. The sample standard deviation was less than the design standard deviation so no additional samples were required.

Page 6 of 8 FSS Summary Report F8100043

Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/100 cm 2 ): N/A Ambient Background Used (dpm/O00 cm 2 ): N/A Average Ambient BKG = 0 Actual Direct Measurements (N): 27 Median (dpm/100 cm 2): 2065 Mean (dpm/100 2 cm ): 2089 Direct Measurement Standard Deviation 172 2

(dpm/100 cm ):

Total Standard Deviation (dpm/100 cm 2): 172 Based on samples and backgrounds.

Maximum (dpm/100 cm 2 ): 2791 Material Type: N/A Background Subtract Not Applied Sign Test Final N Value: 27 S+ Value: 27 Critical Value: 18 Sufficient Samples Collected: Yes Maximum Value < DCGL: Yes Median Value < DCGL: Yes Mean Value < DCGL: Yes Maximum Value < DCGLemc: Yes Class 1 Total Standard Deviation <= Sigma: Yes Pass the Sign Test? Yes Reject the Null Hypothesis? Yes Does the Survey Unit Pass All Criteria? Yes Page 7 of 8 FSS Summary Report F8100043

Survey Unit Investigations and Results:

No investigations were required for either direct or scan measurements and no investigation results are reported.

ALARA Statement:

As stated in Chapter 4 of the LTP, as long as the residual activity within the survey unit is less than the DCGL (i.e. the survey unitaverage activity is less than the DCGL and the EMC criterion has been met), the ALARA criterion has been met.

Changes in Initial Survey Unit Assumptions:

The survey unit was designed as a Class 1 structure survey and the sample results are consistent with that classification. The variability of the survey results was less than the characterization data used for survey design. No potential areas of elevated activity were detected.

==

Conclusion:==

The FSS of this survey unit was properly designed as a Class 1 survey based on Table 5-4 of the LTP. The required number of direct measurements was made and the scan coverage met the requirement of Table 5-6 of the LTP. No direct measurements exceeded the DCGL of 43000 dpm/100 cm 2 and none of the removable surface activity measurements exceeded 10% of the DCGL. No investigations were required.

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.

It is concluded that survey unit F8100043 meets the release criteria of 10CFR20.1402.

Page 8 of 8 FSS Summary Report F8100043

Attachment I Maps February 26, 2009 Survey Unit F8100043

DRC ST PAD C)

CST PAD . r

./

r °i 1o 3 H3 EVAP PAD .

1 I BWST PAD C0 Zone 3 Asphalt

,--l.

Zone 1 C)

TANK FARM - CONCRETE PADS GENERAL ARRANGEMENT PLAN VIEW JTI IT"' DISTRI T F8100043-Mi SHEET 1 OF 2

'7 (1NI (D

NJ]

, N j

/ /

.//

/I "7

/7' //

K' /

-ix Vertical Surface Details C11 F 7w.

\, \ K

\

\\ \

(N 7/7 7 N 7,

/

//

.7

\N' BWST PAD 00 Scale Feet 00 Surfaco Aroa Esdmaias t = 1,-0" TANK FARM - BWST PAD C

C) PLAN / ELEVATION VIEW Scale Meters *0 S Mum SURFACE AREA ESTIMATE Tt~ni 187.5w' SAC0AMENTO MUNICIPAL 0 1 2 3 LUTI ITY, DISTR:CT F8100043-Mi SHEET 2 of2

444-'44-li .4 H'4 f44 'I4'414',r iitl44- 44ilWf HA4i +H ++i! C+I + if f 4I1i44~f44 4'44 f ,i- 4*H4 ~j1- ý 44'- 1+4--

T 4+

w a TT w TT T, I +

T- T

++

11 1 44 al....

if.. F'I'~ fHHH 4 . .-- - A H .-

4fHH

~ iiH 011HI iII 4H 4-f- 4-H+I-+

i +-f f: H lif H-1- --+444-H-+H-4 I41 + - 111it 1iH i m

H I--4 hHil 4 H + '--H-+'-'-4+H-[

1 4Hi4--44 I 4 -m w+-4 4-- + H

~4-H.- H+'4-HH+4+

+/-.-+4--' +/-4-+/-4-44-'

-'4+'4-44-P4+rH-4--

-4+-4-H-H4-4,-4--'

P+4--4-- 444T

  • 'H 4-,44--H-+'-T

- +/-4--4-44-44p4+T 4- - 4 4- _ _ _4 7__

4:~w T 1 4

+ -i+ 4- -_-

PAD~~ ~~

TAKFR-BST A TIIE T'

(D (A

0ý Nm / 23d//

C) 24 25 26 27 V22 21~ 20 -'1l7 5,0*13 10 5ý09 08 81-61 ýV7 Isv06

/2\ /~-

7/

0002 03 04/

  • >1 01 00 Scale Feet BWST PAD I -0" TANK FARM - BWST PAD 0 BETA DIRECT Scale Meters MEASUREMENT LOCATIONS WSACRAM"ENTO H' INICIPAL 0 1 2 3 UTILITY( OISTR C' F8100043-M2 SHEET 2 of2

025 026 027 028 029 030 031 032 t03

".N'

,.024 o0 074 1 073 072 071 070 069 068 067 007 066\

0 N F + + F -, F 0 _ 'K \q34 023 C) 065 064 063 \

006 204 195 185 178 168 158 148 062 .

022/'

0568~ ./'59 060 061

.107 211 203 194 : 184 177 167 157 147 -63 54

/021 ___ _____ 50 "62 51/1-176 166 156 146 055 57 126 _,036 078 26 210 202 193 183 056 I ~ + F + F I +/- F 138 192 185 175 165 155 145 145 138 134 130 125 0201 079 215 209 201 144 137 133 129 124 A-038 019 080 214 206 200 191 184 174 164 154 190 183 173 163 153 143 136 132 128 123 018 061 213 207 199 172 162 152 142 135 131 127 122 ý 212 206 198 189 182

,-1 016 083 205 197 188 181 171 161 151 141 121 11 7 015 .~r4Ž~ 108 118 119 04 085 196 187 180 170 160 150 140 105 A48 4\ 107 _--42 109 45 .120 014\ \

\746/ t I 6 103 104 186 179 169 159 149) 139 1o 2

-- ~043 110 F + + F

}~102 > 7 013\ -~

10/ "., " 44 111 112 113 1 117 115 116

_°"_ 0 4 ,ou001 091 092 093 094 095 i096 BWST PAD o4.,, ___ 0987 K irregular surfac es 0___8i

\j I .

010 009 008 007 006 005 004 003 Scale Feet 00 ."= 1'-0" TANK FARM - BWST PAD C)

C)

C) BETA SCAN Scale Meters 6 SINUD MEASUREMENT LOCATIONS SACRAMENrO MUNUICPAL UTILIY DISTRCT F8100043-M3 0 1 2 3 SHEET 1 of4

(tD 0

0 15 <----..

\0 \

014\/

BWST PAD 00 Scale Feet 0 8" 1'-0 TANK FARM - BWST PAD 0

0 BETA SCAN W/ 43-37 Scale Meters MEASUREMENT LOCATIONS SACRAMENTO MUNICIPAL UTILITY DISTRiCT F8100043-M3 0 1 2 3 SHEET 2 of4

025 026 027 028 029" 030 031 032 (D

00 0

0,21 0201 019 018 017 016 BWST 014, BWST PAD 00 Scale Feet 0

TANK FARM - BWST PAD

1-"

0 0*

BETA SCAN W/ ISOCS Scale Meters MEASUREMENT LOCATIONS SACRAMENTO MUNIC PA.

ITY DISTRiCT LJTH F8100043-M3 0 1 2 SHEET 3 of4

N J,.

/

C)

/"

/

/

/ \

I BWST PAD

  • mu Scale Feet.

Lo C)

I......... TANK FARM - BWST PAD CD ISOCS GAMMA SCAN Scale Meters MEASUREMENT LOCATIONS SA i-"WENTO M~UNICIPAL IPSTRICT ORITY F8100043-M3 0 1 2 3 S;IIELET4 of 4

-A

(<N Oq (D~ N N

\X 15 16 I 14

.i/ //

//

17 13 18 12 11 07 08 - 06 09 -0

/72 irregular surfaces

'N indicate location of remaining 'lunctures" BWST PAD 'N/

N' 00 Scale Feet 0 *"= 1-r TANK FARM - BWST PAD 0

0>

JUNCTURE SCAN Scale Meters MEASUREMENT LOCATIONS 0 1 2 3 F8100043-M4 SIHEET of,

Attachment 2 Instrumentation February 26, 2009 Survey Unit F8100043

Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No. Model; Serial No. (dpm/100 cm ) 2 (dpm/100 cm 2)

M2350; 189089 43-68B; 161406 433 1033 M2350; 175834 43-68B; 148634 433 1033 M2350; 203482 43-68B; 148453 433 1033 M2350; 175834 43-116-1B; 190642 796 3258 M2350; 189081 44-159; 238368 5250 N/A Tennelec; 0401171 N/A r3 5 dpm a, 9 dpm N/A Table 2-2. Investigation Criteria and DCGL Value Valuc Parameter (dpm/1,00 cm2)

Investigation Criteria - Direct 152901 Investigation Criteria - Scan 43,0001 DCGLw 43000 DCGLEMC 152901 IL set at DCGLw for conservatism Page 2 of 2 Att. 2 Instrumentation F8100043

Attachment 3 Investigation February 26, 2009 Survey Unit F8100043 (none required)

Attachment 4 Data Assessment February 26, 2009 Survey Unit F8100043

F8100043 Gross Activity Sample Results Quantile Plot 2

DCGL = 43000 dpm/1OOcm 3,000 2,500 2065 2,000 I 1,500 CD2 1,000 500 0

0 20 40 60 80 100 Percentile 00 I

  • Direct Measurements (dpm/100crn2) -median - - -75th Percentile - -- - 50th Percentile I

0*

-O FP100043 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpmll00cm 30C10 C

- - - a a - - - - a a - - a - - - a - a - a - - a - a a a a 2505 S25C0-E 0 0 0 0

0"-- Tr-

--- 0 2-'° "

- 0 0 0 __0 2088 S20C0 - 00C ý0 r C0 IO - V 0 0

7- 0 0 1572 Ln a. 15(

(C 10 ryn

'100 5C10 o o o o o oooo 0O00O0OOO00000000 000000000 Measurement Locations 1 o Gross Activity - Average - - "+3StDev" a a "-3StDev "i (A,

F8100043 Gross Activity Frequency Plot 2

DCGL = 43000 dpm/1 00cm 20-18-C/2 16-14-0i 12-00 10-8-

6 4

2 0 -+

(1..

CA 00 Bins - Upper End Value (dpm/100cm2)

(D

Retrieved from "https://kanterella.com/w/index.php?title=ML090900772&oldid=2564152"