radiation protection aspects lss1/5 tans
DESCRIPTION
Radiation Protection aspects LSS1/5 TANs. Cristina Adorisio, Kurt Weiss (CERN - DGS/RP). Outline. Residual dose rate measurements February 2012 (Xmas Shutdown): TAN+ZDC detector Evolution of activation Prediction for 2012 and LS1 Conclusions. Thanks to: K. Weiss (CERN DGS/RP). - PowerPoint PPT PresentationTRANSCRIPT
RADIATION PROTECTION ASPECTSLSS1/5 TANSCristina Adorisio, Kurt Weiss (CERN - DGS/RP)
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2OUTLINE
Residual dose rate measurements February 2012 (Xmas Shutdown): TAN+ZDC detector
Evolution of activationPrediction for 2012 and LS1
Conclusions
TAN- LSS1L
1.5µSv/h 6.3µSv/h
2.1µSv/h
5µSv/h 1.2µSv/h
6.7µSv/h
6.4µSv/h
5.4µSv/h155µSv/h @ vacuum chamber
RP measurements done on February 1st 2012All values at contact
585µSv/h @ vacuum chamber 879µSv/h @ vacuum chamber
Thanks to: K. Weiss (CERN DGS/RP)
1
1
2 3 54To ARC To IP1
CR-0
0161
7
CR-0
0161
6
CR-0
0161
5
CR-0
0161
8
450 µSv/h 550 µSv/h 603 µSv/h 500 µSv/h 125 µSv/hValues measured after removal of the ZDC, at the bottom of the TAN crack
310 µSv/h 300 µSv/h
180 µSv/h
150 µSv/h
2.6 µSv/h(left)
1.3 µSv/h (right)
2 µSv/h (back)
1.3 µSv/h(front) 2
440 µSv/h70 µSv/h@10cm13 µSv/h@40cm
320 µSv/h
200 µSv/h
215 µSv/h
2.6 µSv/h 1.6 µSv/h
1.6 µSv/h
1.7 µSv/h
3
330 µSv/h 270 µSv/h
370 µSv/h
245 µSv/h
5
460 µSv/h 80 µSv/h
180 µSv/h
170 µSv/h
TREC identifiers
Thanks to: K. Weiss (CERN DGS/RP)
TAN- LSS1R
4µSv/h
2.7µSv/h6µSv/h
6µSv/h
1.6µSv/h
5µSv/h
1.6µSv/h
1.7µSv/h (*)
10µSv/h
(*)
RP measurements done on Febuar 17 th 2012All values at contact
438µSv/h @ vacuum chamber
84µSv/h @vacuum chamber
Thanks to: K. Weiss (CERN DGS/RP)
1
1
2 3 54To IP1 To ARC
CR-0
0167
0
CR-0
0166
8
CR-0
0166
9
CR-0
0166
7
77µSv/h 312 µSv/h 423 µSv/h 450 µSv/h 360 µSv/hValues measured after removal of the ZDC, at the bottom of the TAN crack
90 µSv/h 107 µSv/h
180 µSv/h
180 µSv/h
1.6 µSv/h(left)
1.6 µSv/h (right)
2.2 µSv/h (back)
1.6 µSv/h(front) 3
320 µSv/h34 µSv/h@10cm5 µSv/h@40cm
310 µSv/h
260 µSv/h
300 µSv/h
2.0 µSv/h 1.7 µSv/h
2.0 µSv/h
1.7 µSv/h
4
270 µSv/h 230 µSv/h
220 µSv/h
180 µSv/h
5
270 µSv/h 180 µSv/h
144 µSv/h
150 µSv/h
TREC identifiers
1.7 µSv/h 1.7 µSv/h
1.7 µSv/h
1.4 µSv/h
1.3 µSv/h 1.6 µSv/h
1.3 µSv/h
1 µSv/h
Thanks to: K. Weiss (CERN DGS/RP)
TAN- LSS5L
1.4µSv/h 8µSv/h
2.1µSv/h
9µSv/h
1.3µSv/h
8µSv/h
540µSv/h @ buttom of crack
3.3µSv/h
8µSv/h
RP measurements done on February 6 th 2012All values at contact
Thanks to: K. Weiss (CERN DGS/RP)
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1
32To ARC To IP5
340 µSv/h 590 µSv/h 340 µSv/h 340 µSv/h 140 µSv/hValues measured after removal of the ZDC, at the bottom of the TAN crack
3 µSv/h (back)
2 µSv/h(front)
3
100 µSv/h @ sides
150 µSv/h
90 µSv/h
3 µSv/h (back) 2 µSv/h (back)
3 µSv/h(front)
2 µSv/h(front)
200 µSv/h (back) 520 µSv/h (back) 180 µSv/h (back)
270 µSv/h(front)
130 µSv/h(front)
130 µSv/h(front)
100 µSv/h @ side
Thanks to: K. Weiss (CERN DGS/RP) RP measurements done on February 6 th 2012All values at contact
ZDC detector (5L)
TAN- LSS5R
8µSv/h
4µSv/h11.5µSv/h
8µSv/h
1.5µSv/h
9.5µSv/h 0.5µSv/h
1.7µSv/h (*)
8.3µSv/h
(*)
RP measurements done on February 6 th 2012All values at contact
573µSv/h @ buttom of crack
Thanks to: K. Weiss (CERN DGS/RP)
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2EVOLUTION OF ACTIVATION
Year of operation 2010 2011 2012
Number of days physics 39 129 210
Energy (TeV) 3.5 3.5 4.0
Fraction of nominal beam intensity 13% 50% 50%
Number of bunches 368 1320 1320
Peak luminosity (cm-2s-1) 1.0×1032 3.5×1033 6×1033
Integrated luminosity (fb-1) 0.05 5.7 15
Source: M. Lamont
The measurements could be used to estimate the residual dose rate during the TS in 2012 and the LS1
Referring to Feb. 2012 detailed measurements done on TANs and on the detectors, the scaling factors are:
8 for 2012 TS4 (Oct. 2012) → essentially driven by the peak luminosity (factor of 2 with respect to the last TS in 2011) and derived from the different cooling time (factor 4 from 3 months cooling time to 1 week cooling time)
3 for LS1 → essentially driven by the integrated luminosity
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2FUTURE SITUATION – 2012 TS4 AND LS1
Residual dose rate (maximum values) on contact (mSv/h)
LSS5February 6th
2012
TS4October 22nd
2012 (Feb.2012 x fact
8)
LS1February 2013
(Feb.2012 x fact 3)
TAN (top) 11.5 92 35
TAN (side) 2.1 17 6
ZDC 520 4160 1560
LSS1February 6th
2012
TS4October 22nd
2012 (Feb.2012 x fact
8)
LS1February 2013
(Feb.2012 x fact 3)
TAN (top) 10 80 30
TAN (side) 2.1 17 6
ZDC 460 3680 1380
→ Higher values are expected for the Cu/SS bars
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2
A B C D E
Pos.Distance
to IP5 (cm)
Ambient dose equivalent rate in µSv/h for the cooling time
1 hour 8 hours 1 day 1 week 1 month 4 months
A 3045 1819 ±2% 872 ±2% 603 ±3% 315 ±3% 167 ±3% 78 ±4%
B 4515 702 ±3% 423 ±5% 323 ±5% 198 ±5% 117 ±5% 56 ±5%
C 6015 660 ±3% 264 ±5% 155 ±6% 59 ±9% 30 ±8% 16 ±10%
D 9825 21 ±12% 8 ±21% 6 ±26% 3 ±36% 2 ±43% 0.7 ±41%
E 14145 972 ±2% 526 ±3% 392 ±3% 239 ±3% 155 ±3% 64 ±4%
FUTURE SITUATION – LHC NOMINAL M. Fuerstner et al., EDMS 1006918 Calculation done considering 109 7 TeV pp/s for 180 days
(~1 year @ nominal beam energy and intensity)
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2FUTURE SITUATION – LHC NOMINAL
~ 0.6 mSv/h ~ 0.2 mSv/h
Calculation done considering 109 7 TeV pp/s for 180 days are very conservative, scaling the results to a more realistic scenario:
TANLSS5
February 6th 2012
TS4October 22nd
2012 (Feb.2012 x fact
8)
LS1February 2013
(Feb.2012 x fact 3)
Last TS 2015
Residual dose rate
(mSv/h)
2.1 17 6 90
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2CONCLUSIONS
The residual dose rate measurements show No differences from L to R Comparable values in IR5 and in IR1 ZDC detectors values confirm the need of a remote
handling tool also in IR5 to manage the exchange ZDC/bars
The evolution of the activation can be estimated Based on the simulation results Based on the evolution of the operational parameters
The residual dose rate expected in the last TS in 2012 is 8 times higher than in Feb. 2012
The residual dose rate in LS1 (3 months of cooling) is 3 times higher than in the last Xmas stop
THANK YOUFOR YOUR ATTENTION!
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2ALARA
Optimization is a legal requirement if accumulated individual dose exceeds 100 μSv/year (ALARA)
Optimization includes
• work coordination• work procedures• handling tools• design • material
requiredoptional
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2WORK PLANNINGAt present, sharepoint-based RP tool for work approval In future directly linked to the overall LHC work planning approval and access permission tools