October 12, 2006 EURISOL
Radiological Safety for the J-PARC Project
Hiroshi Nakashima J-PARC
J-PARC Facility Materials and Life Science Experimental Facility
Hadron Beam Facility
Nuclear Transmutation
500 m
Neutrino to Kamiokande
Linac (350m)
3 GeV Synchrotron (25 Hz, 1MW)
50 GeV Synchrotron (0.75 MW)
J-PARC = Japan Proton Accelerator Research Complex
Joint Project between KEK and JAERI
Secondary particles from high energy proton reaction
Nuclear & Particle Physics at 50 GeV
R&D toward Transmutation at 0.6 GeV
Materials & Life Sciences at 3 GeV
T2K Experiment Intense neutrino beam by 100 times at KEK 12 GeV PS
T2K = Tokai to Kamioka
Muon neutrino beam J-PARC
(Kamioka)
ντ νe
Change to Change to
νµ νµ
(Tokai)
Disappearance of νµ ↔ High Statistics T2K （Five year data at KEK-PS can be measured within a few weeks at J-PARC ） Detection of νe at Super Kamiokande↔ Totally new experiment
Materials and Life Science Experimental Facility Neutron and Muon
Neu tro
Building dimension : Width : 70m n Sc
atte ri n
Target remote handling room
Length : 146m g Fa cilit
y
1M W
Height : 30m Exp. Hall Height : 22m Spa llati o
Cooling systems (Basement)
n Ta r ge
Mu
t St atio
on
Sci
Pro
n
en c eF
acil it
ton b
eam
y
Sp alla
Ex per ime
23 neutron beam lines will be Installed in experimental halls under present design.
tion tar Merc get ury
n ta l ha
line
3GeV, 1MW proton beam
ll
Mu Sc rap
er
on
pr o duc tion
ta r get
Transmutation Experimental Facilities TEF-P: TEF-P: Transmutation TransmutationPhysics PhysicsExperimental ExperimentalFacility Facility TEF-T: TEF-T:ADS ADSTarget TargetTest TestFacility Facility
10W Critical Assembly
200kW
Laser Charge Exchange
Shield
Pb-Bi Target
Characteristics of J-PARC from the view point of safety Characteristics ・High beam power (up to 1MW) ・High beam energy (up to 50GeV) ・Large-scale accelerator complex (about 3.2 km in length) Radiation problems ・Widely distributed radiation source ・Thick shield ・Activation etc…
Safety issues Design method is basically simplified method, Detailed method for complicated geometry.(1) Confinement of activated air during operation. (2) Ventilation after cooling-down. Closed cycle for cooling water and mercury. Release after measuring T activity. Underground(3) Design criteria for soil should have been decided. Target issues(4) Nuclear heating, Activation, Radiation damage, Pressure wave
Design Criteria ・ Controlled Area: 12.5µSv/h 1/2 of regulation (1mSv/40h:1week) ・ In-site： 0.25µSv/h 1/2 of regulation (250µSv/500h:3 months） ・ Site boundary Radiation: 50µSv/ year 1/20 of regulation (1mSv/year ） ・ Gasious waste: Regulation Concentration and total amount by government and local government ・ Liquid waste: Regulation Concentration and total amount by government and local government ・ Soil activation: 5mSv/h No regulation.
Assumption of beam loss distribution 50GeV Dump： ： 7.5 kW
Collimator： ： 4 kW Septum： ： 1 kW Beam Dump： ： 1 kW Analize r： ： 0.35kW
3-50BT Scraper ： 450 W
Septum： ： 1 kW Beam Dump： ： 4 kW
Extraction： ： 1.13 kW
5 0 GeV Dump ： 750 kW
D400-4a: 2 kW D400-4b:5.4 kW
T1 target： ： 225 kW Neutron Facility ：1 MW
Injection ：135 W
S62-1: 11 W S72-1: 19 W D200-1: 0.11 kW
Extraction： ： 7.5 kW
D400-2: 4 kW D450-1:0.6 kW D400-3a:0.6 kW D400-3b:5.4 kW
Planed beam loss
Scraper： ： 450 W
Dump:3 kW Muon Facility T1 target： ： 37 kW ： 37 kW Scraper： T2 target： ： 37kW BeamTransport： ： 37kW
1 nA/m 0.5 W/m 1.0 W/m ＞2.3 W/m
Criteria of hands on maintenance
(1) Simplified methods For bulk shielding ・ Moyer model (KEK parameter: H0, λ)[＞1GeV] ・Tesch’s equation[20MeV, Ei>1MeV i=p, pion, meson) Neutron source for low energy calculation
Nuclear decay data set Neutron flux Particle flux 2nd-γ−ray
Nuclear decay DCHAIN-SP 2001 Nuclear Production X’sect
Low-energy particle flux MCNP (En W NMTC/JAM Free NNCS NMTC/JAM Inmedium NNCS MCNPX+LA150 MARS -7 10 -1 0 1
10
10
10
102
Neutron Energy (MeV)
103
Comparison of neutron skyshine dose attenuation among simplified and detailed methods
（ Dose equivalent（
／source neutron） ） Sv／
1E-11
3GeV Monte Carlo 3GeV SHINE-III 3GeV Stapleton 600MeV Monte Carlo 600MeV SHINE-III 600MeV Stapleton
1E-12 1E-13 1E-14 1E-15 1E-16 1E-17 0
500
1000
1500
Distance from source（ （ m） ）
Agreement within a factor of two
2000
J-PA R C Co nstruc tio n S c hed ule Y e ar Item s
JFY 2 00 1
J FY 20 02
JFY 2 00 3
JFY 200 4
J FY 20 05
E P o wer Fe ed Ac c. Inst B uild ing D esig n
Linac
J FY 20 07
B e am Co m m issio ning
Eq uip m ent Dra w ing, Fab ric a tion, Inst al la tion
B uild ing D esig n Eq uip m ent De sign
B uild ing D esig n
H adro n
O p era tion
B ea m
B uild ing C onstruc tio n
Eq uip m ent Dra w ing, Fab ric a tion, Inst al la tion
(Ma te ria ls & L if e)
B ea m
B uild ing C onstruc tio n Eq uip m ent Dra w ing, Fab ric a tion, Inst al la tion
B ea m
B uild ing C onstruc tio n Eq uip m ent Dra w ing, Fab ric a tion, Inst al la tion B uild ing D esig n
Eq uip m ent Dra w ing, Fab ric a tion, Inst al la tion
Infrastruc tu re Sa lt F arm A sse ts
B ea m
B uild ing C onstruc tio n
Neu trino De sign
20 09 ~
B ea m
Eq uip m ent Dra w ing, Fab ric a tion, Inst al la tion
B uild ing D esig n
M LF
JFY 2 00 8
B uild ing C onstruc tio n
Eq uip m ent De sign
50 Ge V M R
JFY 2 00 6
B uild ing C onstruc tio n
Eq uip m ent De sign
B uild ing D esig n
3G eV RC S
Fe b. 27 2 00 6
Dra w ing, Fab ric a tion, Inst al la tion In ve st iga tio n, B o oking
C urre nt
B ea m
