1. Daniela Kiselev, Ryan Bergmann, Polina Otiougova, Vadim Talanov, Michael Wohlmuther : Paul Scherrer Institut
Total radioactive waste of decommissioning the high intensity proton accelerator (HIPA) facility at PSI
SATIF13, Dresden, Germany,

2. Motivation
Authority (NAGRA) requires an estimate of the amount of the radioactive waste after the final shutdown of the proton accelerator facility (HIPA)
 input for the planning of the final repository
Exemption limits in Switzerland will change (~ 2018)
Switzerland will follow Euratom Basic Safety Standards Directive (BSS)
 New cost estimate for the decommisioning required
Side remark:
Nowadays an estimate of total rad. waste volume is required
for the operational approval of a facility in Switzerland.

3. New and old exemption values in Switzerland
Nuclide
LE present regulation [Bq/g]
LL future regulation [Bq/g]
LE/LL
H-3
200
100 2
Co-60 1
0.1 10
Ni-63 70
0.7
Eu-152 7
Eu-154 5 50
Most of the limits for important isotopes (steel, concrete) are considerably reduced
Nuclide
LE [Bq/kg]
artificial
LL [Bq/kg]
natural
K-40
2000
1000
10000
Ra-228 10
100
Th-232 50 6
U-238
200
400

4. Applied technique for waste estimate
Monte Carlo particle transport program : n,p,g,a,p,d,3H....
Input: dedicated geometry, material compositions,
cross sections: for n<20MeV ENDF-B, otherwise Bertini-Dresner
Output: n-fluxes (E<20 MeV), residual nuclei production rates
with rnucs-card (former active htape) in *.o file
- avoids huge histp file (can be several GB)
- developed by F. Gallmeier & M. Wohlmuther
- patch in the Cinder2008 release on RSICC
MCNPX2.7.0
activation script
M. Wohlmuther et al.,
Proc. AccApp 2007,
Pocatello, p. 226.
F.X. Gallmeier, dito, p. 207
Cinder or
SP-Fispact + EAF2010 or
Orihet3
+ c.s. library
+ irradiation history
 nuclide inventory
clearance index for each cell in script sum_nuclides,
summing up volumes

5. Clearance index Clearance index:
LE = limit de exemption
LL= limite de libération
CI > 1 (after 30 y cooling time)  radioactive waste
Influence of U, Th and daughters Ra-228 on the CI for concrete is
non-negligible (depending on geometry and activation) for
longer storage times of 75 y, 100 y
But:
Natural and artificial isotopes have different exemption limits!

6. Material definition(s)
Some trace elements are particular important due to large neutron capture cross section
For cooling times > 30 years in concrete and steel:
Eu-152 (T1/2 = 13.5 years), Eu-154 (T1/2 =8.6 years) ,Co-60 (T1/2 = 5.3 years)
Values as used for the calculation of the nuclide inventory of operational waste (PWWMBS), mainly conservative.
Element
Steel
Concrete Co
170 ppm
1 ppm Eu
3 ppm
Material Munich initiated by NAGRA
Element
Steel (St52.3)
Steel (St37)
Concrete Co
140 ppm
110 ppm
4 ppm Eu -
<0.007 ppm (?)
0.5 ppm
Amount of concrete waste volume is sensitive on Eu content
 analyses on more samples needed

7. NAA @ SINQ (Spallation source at PSI)
3 capsules irradiated at the same time:
MCNPX simulation:
D2O
PNA
Fly ash from NIST for calibration:
Eu: 4.67 ppm +/- 0.07%
Sample
Sample
NAA
20% agreement between measured and calculated Eu-152n (T1/2 = 9.3h)

8. Samples and Results
Sample
Eu (ppm)
shielding block exp. hall #1
/- 7.0%
roof Ring machine bunker
0.52 +/ %
p-channel around MHC5 #4
/ %
Ring EEC
0.25 +/ %
Ring
0.27 +/- 6.7 %
shielding block exp. hall #1, 3 stones
0.53 +/- 4.8 %
shielding block exp. hall #1, milled
0.26 +/- 7.4 %
p-channel around MHC5 #4, milled
0.40 +/- 5.4 %
Weighted mean
0.34 +/- 2.6 %
shielding block exp. hall #1: the same as measured by NAGRA
Eu: /- 6.2%
 0.5 ppm Eu was assumed in the material definition of concrete

9. PSI Proton Accelerator Facilities
SINQ
OPTIS
Injector 1
Target E
Gantry 3
Injector 2
OPTIS 2
Ring cyclotron
590 MeV
Target M
Gantry 2
at present:
Nominal 2.2 mA (approval for 2.4 mA)
Max. integral charge/year: 10 Ah
UCN
Gantry 1
PROSCAN
Comet: 250 MeV
Length scale: Target M to beam dump = 35.5 m

10. Main Loss points in the 590 MeV areal
Accelerator:
72 MeV Injector2 + transfer line
590 MeV Ring and AHA %
( nA)
- p-channel: 590 MeV beam line:
Target M rebuild in %
Target E rebuild in %
KHE2/ rebuild in %
Beam dump rebuild in <= %
>= % * 70 %
- Spallation neutron production targets:
SINQ: thermal neutrons (~ 25 meV)
cold neutrons (< 5 meV) >= %
UCN: ultra cold neutrons (~ meV)
pulsed operation with 1 % duty cycle >= %
Page 10

11. The geometry: From CAD to MCNPX
Conversion process:
CATIA-V model  step file SuperMC/MCAM
developed by Institute of Nuclear Energy Safety Technology (INEST), China
Post-editing: simplification, removing of gaps, double lines
of step file usually necessary
 ANSYS SpaceClaim is a good tool
(also for modification of existing geometry)
Restriction in MCAM, McCAD: 1000 cells
 combination of several parts possible
Loss of information about the material def. in CATIA
 solved by an additional material list + Python script

12. Example: Tg M region CAD (SpaceClaim) Model in MCNPX
modeled in SpaceClaim
CAD (SpaceClaim)
in CATIA-V
modeled region
Model in MCNPX
also done (partly)
for TgE-Region
Page 12

13. The need for biasing methods
Built-in methods in MCNPX:
importances:
- based on cells  fine structure needed!
- have to be adjusted by hand  tedious work in large regions
weight windows: (ww ~ 1/importances)
- meshed (or cell) based
- energy dependend
- semi-automatic, optimization on 1 direction (= tally, detector)
For activation calculations: Biasing in every cell, not only 1 direction  global variance reduction
Otherwise 6 different runs for one geometry (done for UCN)
Applied technique: convert neutron flux to weight windows
weight windows(E) ~ neutron flux(E) ~ 1/importances
UCN geoemtry: 6 different runs for each direction one

14. Target M to Target E region
Loss points with and without magnetic field in the tripletts:
TgM C1 C C C4 C C TgE
Losses from % 1.0% %
beam dynamics
Losses (no
magnetic field) 1.5% 0.45% % 2.7% % %
Total losses are 1000 times smaller with magnetic field
 1000 times smaller activity

15. FLUKA simulation
for estimating the effect of the magnetic field in the Triplett after Target M:
horizontal plane
vertical plane
Beam losses evaluated in FLUKA
in MCNPX: After triplett:
neutron/proton fluxes are scaled down according to FLUKA & TURTLE results

16. Results for Target M to Target E region
colored:  radiactive waste
LE-values:
steel
LL-values:
concrete
Vadim Talanov

17. Target E to Beam dump The geometrical model: set to «void» to
speed up the calculation
The geometrical model:
concrete
steel/cast iron
GC009
GC007
heavy concrete
Conditioned Container
filled with accelerator waste
Polina Otiougova

18. The Ring Cyclotron 8 sector magnets, each more than 400 t
Injection: 72 MeV
Extraction: 590 MeV

19. The Ring: a special case
Approach:
Measurement of the neutron dose rates on Ring bunker roof
LB6411: MeV
Wendi-II: 0 – 5 GeV
Relative distribution:
Adjustment of the relative strength of the sources
in the MCNPX model
Remark:
Implementing the response function of LB6411 and Wendi-II
into MCNPX compared to applying actual
neutron dose conversion factors has negligible effect

20. Dose rate measurements on bunker roof
0.7
6.6/11.3
2.0
1.4
3.9
5.7
3.8/6.2
3.2/5.5
5.1
0.4
Results in mSv/h:
LB6411/Wendi-II
Extraction
Injection
Measurements on the roof!
 Source of loss point is few meters shifted

21. Distribution of the sources
adjusted to match the measured dose rate distribution
AHA
Kav1
EEC
Kav4
Kav5
Kav3
ZS2
Kav2
Quelle
Stärke in MCNPX
AHA
0.5
EEC
0.14
Kav1
0.74
Kav2
0.1
ZS2
0.05
Kav3
Kav5
Kav4
main losses

22. Relative dose rate distribution on bunker roof
Energy range: 0 – max.
(~ Wendi-II)
Distribution up to 20 MeV
looks similar
(~LB6411)
Measured
DR(Wendi-II)
DR(LB6411)
~ 1.7
Calculated
DR(0-max.)
DR(0-20MeV)
~ 2.5
Reduction of H-content
(0.1% to 0.05%) 
DR(0-max.)
DR(0-20MeV)
~ 2.0

23. Proton and Neutron distribution at beam plane
Protons
Neutrons
Sample2 EEC
Sample1 AHA
Sources: Protons scattering on metal piece
Effective Thickness of the piece determines the neutrons per proton
Adjustment by absolute total loss, measured dose rates &
measured activity from 3 samples

24. Comparison to samples
Sample 1 AHA
Sample 2 EEC
Sample 3 roof (AHA+EEC)
Bq/g
Data
MCNPX
Meas/Calc
Be7
1.22
2.61
0.47
0.88
1.52
0.58
0.32
Na22
2.46
1.17
2.11
1.09
0.76
1.43
0.19
Na24
8.21
5.08
1.62
3.13
4.48
0.70
3.46
Sc46
0.05
9.29
0.49
0.03
14.70
0.01
Sc47
0.07
0.38
0.16
0.06
Cr51
0.34
0.43
0.79
0.21
Mn54
0.31
0.92
0.29
0.30
0.95
0.11
Fe59
0.20
0.17
1.21
0.26
0.14
1.84
Co60
0.72
0.48
1.50
1.14
0.41
2.79
0.82
2.60
Cs134
0.35
0.09
3.87
6.55
Eu152
1.63
0.78
2.09
3.08
0.69
0.57
0.55
1.03
Eu154
0.25
2.89
5.18
Measured activities in sample is factor 2-3 larger than calculated

25. Beam losses in Ring .Likely explanation:
In year 2015, where the dose rates were measured, total losses
were small (100 nA).
In previous years much larger losses ( nA) in ring.
2013
600
400
200
loss current [nA]
Nominal operation
Test-operation: 2.4 mA
2015
600
400
200
loss current [nA]
2014
600
400
200
loss current [nA]
Problems
with
Kav.5
We hope that the losses will
stay small in the future
(needed for increasing beam current)

26. Wir schaffen Wissen – heute für morgen
Monte Carlo based estimate for the expected radioactive waste for
the final repository after the shutdown of the HIPA facility including
SINQ and UCN.