ML082620101
| ML082620101 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 05/29/2008 |
| From: | Tallman D Sacramento Municipal Utility District (SMUD) |
| To: | NRC/FSME |
| References | |
| MPC&D 08-064 | |
| Download: ML082620101 (25) | |
Text
Rancho Seco Final Status Survey Summary Report May 29, 2008 Aux. Bldg. Elev. #2 (Rm 129, 221, & 346)
Survey Unit F8132051 Prepared By: Dan A. Tallman '.'O-Date:
May 29 2008 n;/
Reviewed By:
z Date:.fZ/
Lead FSSEngineer Approved By:
7 Date:
7__ _
9__
Dismantlen r*kuperintendent, Radiological
FINAL STATUS SURVEY
SUMMARY
REPORT Survey Unit:
F8132051, Aux. Bldg. Elev. #2 (Rm 129, 221, & 346)
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. Characterization scan measurements on the interior of the elevator shaft at grade elevation showed a maximum gross activity level of 5,070 dpm/100 cm'. Based on the classification procedure (DSIP-0020) and levels of gross activity reported, the interior of the auxiliary building non-controlled elevator was determined to be a Class 3 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 randomly determined and 12 m2 were scanned for approximately 6%
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 F8132051
Table 1. Survey Unit Design Parameters Survey Design Value Comment Parameter Survey Area:
F813 Survey Unit:
Class:
SU Area (m2):
Evaluator:
DCGL (dpm/100 cm2):
Area Factor:
Design DCGLemc (dpm/100 cm 2):
LBGR (dpm/100 cm 2):
Design Sigma (dpm/100 cm 2):
Type I Error:
Type II Error:
Predominant Nuclide:
Sample Area (m):
Scan Area (M2):
Scan Coverage (%):
Zj-P :
Sign P:
Calculated Relative Shift:
Relative Shift Used:
N-Value:
Design N-Value + 20%:
Design Min Samples N:
Grid Spacing L:
20511 3
195.6 D.A. Tallman 43000 N/A N/A 21500
. 261 0.05 0.05 Cs-137 N/A 12 6%
1.645 1.645 0.99865 82.3 3
11 14 14 N/A Aux. Bldg. Elev. #2 (Rm 129, 221, & 346)
Structure Surface LTP Table 5-4 Gross Activity DCGL Class 3 Class 3 Default = 50% DCGL Class 3 Class 3 Uses 3.0 if Relative Shift is
>3 NUREG-1575 Table 5-5 Class 3 Class 3 Page 3 of 8 FSS Summary Report F8132051
Survey Results:
A total of 14 direct measurements were made in F8132051. The results including mean, median, standard deviation and range are shown in Table 2. All direct measurements were less than the DCGL. The scan measurement acquired using the'ISOCS indicated no areas of elevated activity. The Scan activity observed was 338 dpm/100 cm2 (Cs 137).
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/l00 cm)
F8132051-COOOIBD F81 32051 -C0002BD F8132051-CO003BD F8132051-CO004BD F8132051 -CO005BD F8132051-CO006BD F8132051-CO007BD F8132051-CO008BD F8132051-CO009BD F8132051-COOIOBD F8132051-CO011BD F8132051-CO012BD F8132051-CO013BD F8132051-CO014BD Mean:
Median:
Standard Deviation:
Range:
1509 1473 1416 1395 1416 1546 1556 1608 856 1447 1634 1406 1613 1012 1421 1460 224 856-1634 Page 4 of 8 FSS Summary Report F8132051
Table 3. Removable Surface Activity Results Measurement ID Surface Beta Activity (dpm/100 cm 2)
F8132051C0001SM
-2.24 F8132051C0002SM 0.34 F8132051C0003SM
-3.53 F8132051C0004SM
-0.95 F8132051C0005SM
-2.24 F8132051 C0006SM
-0.95 F8132051C0007SM
-3.53 F8132051C0008SM
-4.82 F8132051C0009SM
-4.82 F8132051C0010SM
-2.24 FB132051 CO01ISM
-4.82 F8132051CO012SM 0.34 F8132051C0013SM
-4.82 F8132051C0014SM
-4.82 Mean:
-2.79 Median:
-2.88 Standard Deviation:
1.94 Range:
-4.82 to 0.34 Page 5 of 8 FSS Summary Report F8132051
Survey Unit Data Assessment:
The survey design required 14 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 F8132051
Table 4. Data Assessment Results Survey Results Parameter Value Comment Material Background Used (dpm/lO0 cm2):
N/A Ambient Background Used (dpm/100 cm2):
N/A Average Ambient BKG = 0 Actual Direct Measurements (N):
14 Median (dpm/I00 cm 2):
1460 Mean (dpm/100 cm2):
1421 Direct Measurement Standard Deviation 224 (dpm/100 cm2):
Total Standard Deviation (dpm/100 cm2):
224 Based on samples and backgrounds.
Maximum (dpm/100 cm 2):
1634 Material Type:
N/A Background Subtract Not Applied Sign Test Final N Value:
14 S+ Value:
14 Critical Value:
10 Sufficient Samples Collected:
Yes Maximum Value < DCGL:
Yes Median Value < DCGL:
Yes Mean Value < DCGL:
Yes Maximum Value < DCGLemc:
N/A Class 3 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 F8132051
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), the ALARA criterion has been met.
Changes in Initial Survey Unit Assumptions:
The survey unit was designed as a Class 3 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.
==
Conclusion:==
The FSS of this survey unit was properly designed as a Class 3 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 F8132051 meets the release criteria of 10CFR20.1402.
Page 8 of 8 FSS Summary Report F8132051
Attachment I Maps May 29, 2008 Page 1 of 10 Att. I Maps F8132051
(~Z7 1 AT
~'.
L-Zr N.
L
- ' -NS ELEVATIO
- ELLY,
!W SQ. KIM Page 2 of 10 Att. 1 Maps F8132051
- i. ii f i
i...........
.I-
.+-
H ~ -~
f+ - *H 4 H
i-1 H-H- I-H I-.
-HI I +H1 HI TI
+
H
- H-I I
t : + +
H-+H - i l -
H*i i -i i H-+
i
-H-i
+
. i H -I+ :H-I +
T T/T I
T' I-HHH--H I H-HH-Hhh HH-HH-I-H--H-H
-+H TIHI-H--HI il-Hl-HH-4 H--IH-1-H-H iH--H !.-111HH 11 H-+1 -
H-H.......
+
x
+
T
-H:H H -
H H-H-H-H-'+FH-H"HHt..
H+.t1.4.H H'H-IH H
H+I.H H+H,
+-
+-
HIHH----
IH
.H.H.
T I H -
H.
++H fIll 1
-1 1
II fIII 1
I I
l i 1
1 I I I
I Il x
t----t OI..
-T p
- +
'1,,
'M ' r H-H++-HH HI-H-::
+H-H I H-÷
-IHH -
H-H
- <~......
I H
0.
I H-I-HI-I-H-HH-++'
'H
-" +4 + 1-H-'I-H
-HH I-H ---
HHHI-I
-H-"M I-I+ H-II-HI-
"---II H-I-I-IH-HI H-------
IIHIII-H H-I-H-I-I-I-H-I-0..
Page 3 of 10 Att. I Maps F8132051
7 Z
Cm 1`1~'
QD st-0-f.l V) m C
oC CIE~
00r z
FriVm Cpr Z' I' c0 m
0 m
m
>1
- a~
cxj r'Q-<
0"-
z ELEVATION LOOKING NORTH ELEVATION LOOKING EAST AT COL R.1 MIDWAY TO COL. 9.7 Page 4 of 10 Att. I Maps F8132051
t0 00 4..L EL, 0-0*"
KEY PLANS PLAN EL. O'O-REFLECTED CEILING PLAN EL 59'-5*+/-
NOTES:
- 1. AT TIME OF FSS MAP DEVELOPMEN" ELEVATOR EQUIPMENT, PIPING. LIGHTS.
AND CONDUIT REMAINED IN PLACE.
SCAN MEASUREMENT LOCATIONS MAY NEED TO BE ADJUSTED IN THE FIELD TO o~mom,*cOATE
,NSaTU EQPmENT.
3 1,
a 2 3
SCALE METERS AUXILIARY BUILDING -ELEVATOR
- 2 RM 129, 221 & 346 WALL ELEVATIONS
.BETA DIRECT/REMOVABLE ACTIVITY MEASUREMENT LOCATIONS F8132051 -M2
, PA 00 a4
0 z
III rfl
-,151 rF 0
C: C Ln Co K:t -P<
Li Ul 00) 0>~
mo
> ril N0> m i0" z
U)*
z1 0
ELEVATION LOOKING NORTH MIDWAY TO COL 9.7 ELEVATION LOOKING EAST AT COL.. K.1 Page 6 of 10 Att. I Maps F8132051
0 A
C mm Z
MI v)*-
-6in Fi ;I>
-4 0
-- m in F
(O Icm
-a m1
-T]
70 Ct <Nz, c
z1 0
ELEVATION LOOKING SOUTH AT COL 10.3 ELEVATION LOOKING EAST MIDWAY TO COL K Page 7 of 10 AAtt. I Maps F8132051
00) c:
EL. O'-0" KEY PLANS PLAN EL 0*-0' REFLECTED CEILING PLAN EL 59'-5'+/-
Of NOTES:
- 1. AT TIME OF FSS MAP DEVELOPMENT ELEVATOR EQUIPMENT. PIPING. LIGHTS, AND CONDUIT REMAINED IN PLACE.
SCAN MEASUREMENT LOCATIONS MAY NEED TO BE ADJUSTED IN THE FIELD TO ACCOMMODATE INSITU EQUIPMENT.
SMU*
SACRAMENTO MUNICIPAL lUL)Tf DISTRICT AUXILIARY BUILDING -ELEVATOR
0 O0 0
1 CL 2
.3 METERS
09 sp m
14>
-z 7-c' z
FrI M
C 1.4 "m
K) A1 U) 0)C 02>
m z
r 01 (Ao t,,.
ELEVATION LOOKING NORTH z
--4 ELEVATION LOOKING EAST AT COL K.1 MIDWAY TO COL 9.7 Page 9 of 10 Att. I Map F8132051
m.p:
Z 0
0 m
T 1 EEII w
- 00 I-U FO U
ic
-Z~C m
>1/2 CcJ
ý;z r-r (A m
>ZO ELEVATION LOOKING SOUTH AT COL 10.3 ELEVATION LOOKING EAST MIDWAY TO COL. K Page 10 of 10 Att. I Maps F8132051 Instrumentation May 29, 2008 Survey Unit F8132051
Table 2-1. Survey Unit Instrumentation Instrument Detector MDC Static MDC Scan Model; Serial No.
Model; Serial No.
(dpmll00 cm2 )
(dpm/100 cm 2 )
M2350; 142509 43-68B; 160699 433 1033 180 (Cs137)
ISOCS 1983920 NA 140 Co60)
Tennelec; 0401171 N/A 6dpm a, 12 dpm P N/A Table 2-2. Investigation Criteria and DCGL Value Parameter Val ue cm2)
(dpmll00 c2 Investigation Criteria - Direct 21500 Investigation Criteria - Scan 43000 DCGLw 43000 DCGLEMC N/A Page 2 of 2 Att. 2 Instrumentation F8132051 Investigation May 29, 2008 Survey Unit F8132051 (none required)
Data Assessment May 29, 2008 Survey Unit F8132051
0n Cn 00 C)
F8132051 Gross Activity Sample Results Quantile Plot DCGL = 43000 dpm/1 00cm2 Im 1,800 1,600 1,400 1,200 1,000 800 600 1460 400 200 0
0 20 40 60 80 100 Percentile
_Direct Measurements (dpm/100cm2)
-median
- 75th Percentile....
50th Percentile
aQ 0
F8132051 Gross Activity Sample Results Scatter Plot DCGL = 43000 dpmI100cm" En cjn CD 0n 2500 E 2000-a S1500-.
E
~b1000~
Soo.0-w
= o w M a w w w -
= w = ft IN
-w -
= M -
n w w = -
- 1 2092 1'
0~
p 0~-~
0 o
02
-tNe W
-0 00 1421
-¸ -
-m w "
w w
m
-me - m
"
- 1 750 I.
I f8,o N oo 4 0
00C 0
aC 0t0 0
0L0t0 0
C 0
a 0- C~
t Measurement Locations I o Gross Activity -
Average -
"+3StDev" -
"%3StDev"
CD
-0
~r1 00 F8132051 Gross Activity Frequency Plot DCGL = 43000 dpm/1 00cm2 1
1 1
1 0
U-3 2
1 0
9 8
7 6
5 4
3 2
1 0
Bins - Upper End Value (dpm/100cm2)