ML082620151
| ML082620151 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 07/30/2008 |
| From: | Tallman D Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| References | |
| MPC&D 08-064 F8130101 | |
| Download: ML082620151 (23) | |
Text
{{#Wiki_filter:Rancho Seco Final Status Survey Summary Report June 11, 2008 AB -20' Corridor Room 10 floor and lower walls Survey Unit F8130101 Prepared By: Dan A. Tallman Date: June 11, 2008 FSS Engineer Reviewed By:______ __ Date: q!loq/g Lead'FSS Engineer Approved By: Date:_______ Dismantlement Superintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit: F8130101, AB -20' Corridor Room 10 floor and lower walls Survey Unit
Description:
Operating History: The Auxiliary Building is a reinforced concrete structure that contained the RadWaste processing and supporting systems. The building contained six main elevations. Residual radioactive material was known to be present on all levels of the interior of the building. Operating records and the HSA document several events with the potential for a release of radioactivity inside this structure. Site Characterization: Direct measurements were made of each of the interior elevation surfaces as well as the exterior surfaces of the structure. These measurements confirmed the presence of plant-derived radionuclides. Direct measurements on the -20' elevation showed a mean gross activity level of 247,831 dpmr/100 cm 2 and a maximum value of 10,080,000 dpm/100 cml. Based on the classification procedure (DSIP-0020) and levels of gross activity reported, the lower walls and floor of room 10 in the interior of the auxiliary building was determined to be a Class 1 area. HSA Events: HSA Report pg. 63. 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 57.4 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 F8130101
Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area: F813 AB -20' Corridor Room 10 floor and lower walls Survey Unit: 0101 Structure Surface Class: 1 LTP Table 5-4 SU Area (m2): 57.4 Evaluator: D.A.Tallman DCGL (dpm/100 cm 2): 43000 Gross Activity DCGL Area Factor: 5.7 Class 1 Design DCGLemc 246390 Class 1 2 (dpm/100 cm ): LBGR (dpm/100 cm 2): 21500 Default = 50% DCGL Design Sigma (dpm/100 cm 2): 12035 Type I Error: 0.05 Type II Error: 0.05 Predominant Nuclide: Cs-137
.Sample Area (m2): 3.37 Class 1 Scan Area (m2): 57.4 Scan Coverage (%): 100% Class I Zl_, : 1.645 Zl-0 :
1.645 Sign P: 0.96407 Calculated Relative Shift: 1.78 Relative Shift Used: 1.7 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: 17 Class 1 Grid Spacing L: 1.8 Class 1 Page 3 of 8 FSS Summary Report F8130101
Survey Results: A total of 20 direct measurements were made in F8130101. 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 2793 to 79976 dpm/100 cm2 , 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 Activity (dpm/100 cm F8130101-COOOIBD 3792 F8130101 -CO002BD 2194 F8130101-CO003BD 2739 F8130101-CO004BD 2272 F8130101-COOO5BD 2215 F8130101-CO006BD 2339 F8130101-CO007BD 1515 F8130101-C0008BD 2184 F8130101-CO009BD 1349 F8130101-CO01OBD 1592 F8130101-CO011BD 1644 F8130101-CO012BD 3564 F8130101-CO013BD 1359 F8130101-CO014BD 1385 F8130101-CO015BD 1499 F8130101-CO016BD 1328 F8130101-CO017BD 1795 F8130101-CO018BD 1826 F8130101-CO019BD 1494 F8130101 -CO02OBD 1395 Mean: 1974 Median: 1720 Standard Deviation: 712 Range: 1328-3792 Page 4 of 8 FSS Summary Report F8130101
Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2) F8130101COOOISM 9.38 F8130101 C0002SM -0.95 F8130101COOO3SM 6.8 F8130101C0004SM 4.22 F8130101C0005SM 2.93 F8130101C0006SM 15.84 F8130101C0007SM 0.34 F8130101 C0008SM 15.84 F813010iCO009SM 4.22 F8130101CO010SM 9.38 F8130101CO011SM 2.93 F8130101CO012SM 50.71 F8130101CO013SM 1.64 F8130101C0O014SM -2.24 F8130101CO015SM 0.34 F8130101CO016SM 2.93 F8130101CO017SM 11.97 F8130101CO018SM 9.38 F8130101CO019SM -3.53 F8130101CO020SM 0.34 Mean: 7.12 Median: 3.57 Standard Deviation: 11.69 Range: -3.53 to 50.71 Page 5 of 8 FSS Summary Report F8130101
Survey Unit Data Assessment: The survey design required 20 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 F8130101
Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/100 cm2): N/A Ambient Background Used (dpm/IO0 cm2): N/A Average Ambient BKG = 0 Actual Direct Measurements (N): 20 Median (dpm/100 cm 2): 1720 Mean (dpm/100 cm 2): 1974 Direct Measurement Standard Deviation 712 (dpm/100 cm 2): Total Standard Deviation (dpm/100 2 cm ): 712 Based on samples and backgrounds. Maximum (dpm/100 cm 2): 3792 Material Type: N/A Background Subtract Not Applied Sign Test Final N Value: 20 S+ Value: 20 Critical Value: 14 Sufficient Samples Collected: Yes Maximum Value < DCGL: Yes Median Value < DCGL: Yes Mean Value < DCGL: Yes Maximum Value < DCGLemc: Yes Class I 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 F813.0101
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 unit average 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. Therefore the EMC criterion was met.
== Conclusion:==
The FSS of this survey unit was properly designed as a Class 1 survey based on Table 5-4 of the LTP not withstanding the design sigma value usage described on page two. 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/l100 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 F8130101 meets the release criteria of 10CICR20.1402. Page 8 of 8 FSS Summary Report F8130101
Attachment 1 Maps. June 10, 2008 Survey Unit F8130101
IQ 00 Ndo, wal 6o General Surface Area Estimates oar Ceiling- 0.0 M22 Walls- 30.1 m2 Stairs 0.0
- Floor- 27.3 m2 Total - 57.4 n 2 00 Scale Feet 0 3.= 1'-0. AUXILIARY BUILDING EL. -20 ROOM 10 0 AND STAIRWELL 56 Scale Meters SURFACE AREA ESTIMATE SACRAMENTO MUNICIPAL 0 1 2 3 UTILITY DISTRICT F81 30101 -M 1
I -d1Hq! I H' H 11H- -H---H- - H-I - T + = CD
,3 I! H -H111,441--1444-iAH+H H.I+ :_H +-+4+f4+ 4+f+H4l---14 -f4 -h4ijHA +/-- -. H1 ft -H-f4++ H--H+fHj1H1tl: 1 +--fH~
-:-----f-------+-,h-TP~-- +f1H I -T-.
00
. ... ... .. I . . . ..
1 : .. .... ..... . ..... **....
. ..: .......... n :
U' -I-.-
,-If.f-H-Iu,-f-+/-f-H-{---*l +/-H+/-.H-H +f-f-f-, -H 4-I-I-fI-f-i 4 -- 4HIH IH-HH 14l -I-.--H- -,--- -F -- 4--. H ..- .4 -T- .
..1.1. . . .+/- .. .l !' ". 1: : l ; : ' l : ' : : ; l : -" ! , , ', :l ...... :, il ; : : l : :: ...... ;! l l
, :. :. Sr
',',I III
' I ' ,IiII IA I 4+ I I lH H I * **',* *l. . .. . .. . .. " , ',
- J ,* ' ' ' "* * ' '
. . d t Yf , -Hf -. . . - ."H'.-
Lii ++H-4 L A.
-+F81010 H H1 IIiIIiIII1 4H : + +:4M 4 111 +.HG 4H
+/-
H + 4H IH H I H - 41 HH 1 i
~~
,,, ,, ~
,,,,,, ~
,: .. ~
. . . ~
H. . . .. .. .. ......... . . . ....... ...... 00 w> 6... 1~0ll t AUXILIARY BUILDING EL. -20'
- t T2 1 d ii
........ I....... , . . . . . . . .. . -,
aAMOE SACRAMENTO MUNICIPAL ROOM 10 RANDOM START BETA DIRECT/ REMOVABLE SURFACE POINTS
+2 UTILITY DISTRICT F8130101 -M2 PF* 813OOO02e qHT I OF '1 T C HILL F~E 8130002e SHTIOFI TCHILL 0 1 2 3 1 0 9 'o 11 !2 *3 U4 15 1 a 11
0 00 Norh Wall East Wall
'CI Looking Eras.-
West Wall 00 Scale Feet 81"= 1'-0" AUXILIARY BUILDING EL. -20 ROOM 10 w AND STAIRWELL 56 BETA DIRECT/ Scale Meters LOOSE SURFACE MEASUREMENT POINTS SACRAMENfTO MUNICIPAL 0 1 2 3 UTILITY DISTRICT F81 30101 -M2
/' / / // / ///'/y/'/ / / / /. //
/ / / //~///
<~ 7' ;/ .. / /
(JI 7/; / ~ .~ / ~1< 7 / /// 7 7 '7 <6 / 00 Scale Feet 3,= 1,-0. Scale Meters 012345
-10' Floor 00 Scale Feet w* AUXILIARY BUILDING EL. -20 ROOM 10 81-= 1,-0" AND STAIRWELL 56 BETA DIRECT/ '
Scale Meters LOOSE SURFACE MEASUREMENT POINTS SACRAMENTO MUNICIPAL UTILITY DISTRICT F81 30101 -M2 0 1 2 3 FILE 81300.02a SHT 3 OF3 TCHILL
0D 00 zll fr I I North Wall East Wall w West Wall 00 Scale Feet AUXILIARY BUILDING EL. -20 ROOM 10 AND STAIRWELL 56 BETA SCAN Scale Meters
- Smup SACRAMENTO MUNICIPAL MEASUREMENT LOCATIONS 0 1 2 3 UTILITY DISTRICT F8130101 -M3 FLE 81300.020 SHTI OF2 T CHILL
C0 0 Scale Feet 3" 1-6 Scale Meters 0 1 2345
-10' Floor 00 Scale Feet w
81"=1-0 AUXILIARY BUILDING EL. -20 ROOM 10 0* AND STAIRWELL 56 BETA SCAN Scale Meters COO SMUn MEASUREMENT LOCATIONS SACRAMENTO MUNICIPAL UTILITY DISTRICT F81 30101 -M3 0 1 2 3 rLE 813000a U i*ut*.v*a I~rnrq T CHILL
(D 00 0 00
-0 North Wall East Wall West Wall 0-0 Scale Feet 00 AUXILIARY BUILDING EL. -20 ROOM 10 AND STAIRWELL 56 Scale Meters
*smu SACRAMENTO MUNICIPAL UTILITY DISTRICT JUNCTURE BETA SCANS F8130101-M4 0 1 2 3 FIi 813G0.02a SHT 1 OF 1 T C HILL
Attachment 2 Instrumentation June 10, 2008 Survey Unit F8130101
Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No. Model; Serial No. (dpm/100 cm2) (dpm/100 cm 2 ) M2350; 175834 43-68B; 148634 433 1033 M2350; 175834 43-116-1B; 190642 49 1A 739 A Tennelec; 0401171 N/A 6 dpm a, 12 dpmf3 N/A A Juncture - concrete Table 2-2. Investigation Criteria and DCGL Value Parameter (dpm/100 cm 2 ) Investigation Criteria - Direct 43000 B Investigation Criteria - Scan 223802 DCGLw 43000 DCGLEMc 223802 Investigation Level set conservatively at DCGLW within instruction. Page 2 of 2 Att. 2 Instrumentation F8130101
Attachment 3 Investigation June 10, 2008 Survey Unit F8130101 (none required)
Attachment 4 Data Assessment June 10, 2008 Survey Unit F8130101
C F81301 01 Gross Activity Sample Results Quantile Plot 0 DCGL = 43000 dpm/1 00cm2 4,000-3,500 3,000 2,000 2 >En> 2,500 1720 I** Dd1,00 1,000 500 0 0 20 40 60 s0 100 Pe rcentile 0* Dict Measurements (dprn/1O0cr2) median - -75th Percentile - - - - 50th Percentile
0* P8130101 B Gross Activity Sample Results Scatter Plot DCGL =43000 dpm1l00cm2 4500 4000 - -- - - a a - a 4110 0 0 3500 0 8 3000-
>0 0 r 2500 0 E 0 0 0 0 CL2000 - _ 0 0 1974 V 0 00 > S1500 -0 0*
00 0 0 0 0 0
.*1000 CD
-500
-500 0 M aaa aM iM a 93 iMW in aaa M I m a
im a Ms
)
M ,M a3 a M a) 0 a M M/ a 13i w- M Q m aa M a M 0 Mt a a U U UU U U U UU U U U U U U Measurement Locations 0 Gross Activity - Average - - "+3StDev" - "-3StDev"-
0 F8130101 Gross Activity Frequency Plot DCGL = 43000 dpm/1 00cm 2 17 16 15 14 13 12 11 10 LL 9 tzý 0 8 7 6 5 4 3 2 1 0 T- (\4 CO) 00 Bins - Upper End Value (dpm/1 00cm2)}}