Status and Radiological Safety Issues on 100 MeV Proton Linac of PEFP/KAERI

Joint Meeting of SAFERIB and Task 5 LMU, Muechen, Germany Oct. 12/13, 2006 Young-Ouk Lee Korea Atomic Energy Research Institute

Outline

I. Current Status of PEFP II. Future Extension Options III. Radiological Safety Issues

Project Goals of PEFP


Project Name : Proton Engineering Frontier Project (PEFP) 21C Frontier Project, Ministry of Science and Technology
Project Goals : 1st : Developing & constructing a proton linear accelerator (100MeV, 20mA) 2nd : Developing technologies for the proton beam utilizations & accelerator applications 3rd : Promoting industrial applications with the developed technologies
Project Period : 2002.7 – 2012.3 (10 years)
Project Cost : 128.6 B Won (about 130M$) (Gyoungju City provides the land, buildings & supporting facilities)

3

Project Schedule 1st Step(’ Step(’02~’ 02~’05) Major Subject

‘02.702.7‘03.6

‘03.703.7‘04.6

‘04.704.7‘05.6

20 MeV

2nd Step(’ Step(’06~’ 06~’08) ‘05.705.7‘06.3

‘06.406.4‘07.3

‘07.407.4‘08.3

3rd Step(’ Step(’09~’ 09~’12) ‘08.408.4‘09.3

Accelerator Installation (at Site.)

Site Selection

‘10.410.4‘11.3

‘11.411.4‘12.3

100 MeV

60 MeV

Accelerator Development

‘09.409.4‘10.3

20Mev 20Mev Beam Beam

100Mev 100Mev Beam Beam

Const. Licensing Conventional Facilities

Construction

• • • • •

Basic Design

Detail Design

Accelerating Tunnel, Gallery

Project milestones of the accelerator development & construction. A 20MeV accelerator has been assembled and tested in the 1st step. The 2nd step goal is to build the 60MeV accelerator and to construct buildings & conventional facilities. After completion of them, the 20MeV accelerator will be moved to a new site and commissioned. A 20MeV beam can be provided by 2009, a 100MeV beam by 2011 4

Summary of Recent Project Progress (2006. 9) § Accelerator Development - Beam test of the 20MeV accelerator : 1mA Peak at 50us, 0.1Hz. (Aug. 2006) - Tests of the LLRF and the Beam diagnostics. - Option studies for a future extension of the project.

§ Accelerator Construction - Basic design technical documents of the conventional facility were reviewed by international experts. (Oct. 14, 2005) - Site was selected by Gyeongju city. (Feb. 2006) - Set up a cooperation organization between Gyeongju city and KAERI. (March. 2006) - Geological survey of the site was done. (Aug. 2006) - Detail design of conventional facilities is continued.

§ Beam Utilization - Design of the 20/100MeV proton beam lines is under way. - Proton and Ion beam services for the PEFP users continues. (Number of users & samples increase about 2 fold) - 7 subprojects for proton beam utilization are continued in 2006 - 18 small projects in user program are selected and conducted.

Basic Accelerator Parameters

§ Particle

: Proton

§ Beam Energy

: 100 MeV

§ Operational Mode

: Pulsed

§ Max. Peak Current

: 20 mA

§ RF Frequency

: 350 MHz

§ Repetition Rate

: 15 Hz / 60Hz*

§ Pulse Width

: < 1 ms / 1.33ms*

§ Max. Beam Duty

: 1.5% / 8%* * ) Modified Parameters (06.2)

6

PEFP Accelerator and Beam Lines 100 MeV Future Extension HEBT

20 MeV

DTL(2)

DTL(1)

MEBT

Duty : 8%

AC

3 MeV

RFQ

Duty : 24%

50 keV Injector LEBT

AC Degrader Collimator Energy Filter Wobbler

BL102 BL104

BL105 BL101 BL103

• 102 : ST, BT • 104 : LEPT, Medical Application • 105 : Neutron Science • 101 : RI • 103 : Material Science

BL25

BL23

BL22

BL24

BL21

• 25 : Material Science, Industrial Application • 23 : IT, Semiconductor • 22 : BT/ST, Medical Application • 24 : Neutron Science • 21 : RI

• The PEFP Accelerator compose of 50keV Proton Injector, 3MeV RFQ and 100MeV DTL. • It can extract protons at 20MeV and 100MeV. • AC magnets to distribute beams for each beam line simultaneously. • It has energy degraders & filters to change and select proton energy. 7

Status of PEFP - 20MeV Proton Linac • Front of 100MeV PEFP accelerator Klystron for RFQ 350MHz 1MW CW

Proton Injector 50keV 40mA

Klystron for DTL 350MHz 1MW CW

Waveguide WR2300

LEBT 2 Solenoids

3MeV RFQ 350MHz 4 Vane Brazed Structure

Beam Dump 100kW

20MeV DTL 4 Tank 150 Drift tube Electroplated Tank Pool type Electromagnet

8

Site Map □ Geoncheon, Gyeongju (Area; 440,000 m2)

Site

Site Gyeong-Bu Expressway (No.1)

Facility

Express way Load

highway

Start Point

Dist.

Gyeong-bu

Gyeongju IC

4.3km

#4

Kwang myeong Inters.

1.0km

#7

Palwoojung Inters.

7.8km

#20

Railway

Eastsea nambu KTX

Geoncheon

6.9km

Angang Sta.

20.0km

Nawon Sta.

9.5km

(actual)

Gyeongju Sta.

8.0km

(plan)

New Gyeongju Sta.

1.5km

(plan)

Express Railway & Station (KTX)

9

Site Preparation Plan for the 100MeV Facility q Site Arrangement for Phase I 450m M 0 . 0 9 . L E

⑤

① Accelerator Tunnel & Klystron Building ② Beam Application Building ③ Ion Beam Application Building

⑩

G N IA KE RR AA P

M 5 . 2 8 . L E

④

⑦

⑥

① ⑤ M 0 . 8 7 . L E

400m

② ③ G NA I KE RR AA P

⑫

G AN I EK RR AA P

⑧

⑨

Elevation

EL

4 0m

EL

0m

①

④ ②

⑥

⑦

⑩

③

⑧ ⑪

⑫ ⑨

M 0 . 4 7 . L E

M 0 . 4 7 . L E

⑪

④ Utility Building ⑤ Power Supply Facility ⑥ Cooling Tower

⑦ Water Retaining Tank ⑧ Main Office Building ⑨ Regional Cooperation Building ⑩ Dormitory Building ⑪ Information House ⑫ Sanitary Water transfer and Treatment Facility

EL

2 5m

EL

0 0m

Area : 400m(W)× ×450(L) = 180,000㎡ ㎡ 10

Layout of Accelerator and User Beam Lines

2nd Step 1st Step 3rd Step

100MeV

103

101

20MeV 25

21 24

105 100

102

104

1st Step ’02 02 ’04 04 Design of t e 20MeV ser Facility Development of Core Tec nologies Development peration of Test Facilities 2nd Step ’05 05 ’0 0 Contruction of t e 20MeV Beam Line Components peration of Test Facilities

20

23

22

3rd Step ’0 0 ’11 11 Construction of t e 100MeV ser Facility peration of t e 20MeV 100MeV ser Facilities 11

Layout of the 20 MeV Beam Lines DTL 45 deg. dipole

A C

: Horizontal bending magnet : Vertical bending magnet

B

B

C D

Target Room BL 23

25 ms

E

D

C

Programmable Power Supply

45 deg. dipole

Target Room BL 21

-20 deg. dipole AC magnet

45 deg. dipole 45 deg. dipole

FODO Lattice 20 deg. dipole

Beam Dump [BL20]

Common beam line

Target Room BL 25

45 deg. dipole 90 deg. dipole

Individual beam Target Room BL lines 22

Vertical Beam

Target Room BL 24

Beam Optics of TR 25

12

20 MeV Beam Lines for User Facilities Beam Line No.

Energy

Max. Irrad. Dia.

Avg. Current

Irrad. Condition

-

100mm

- RI Production

BL20

20MeV

~4.8mA

Horizontal Vacuum

BL21

20MeV

120µ µA ~1.2mA

Horizontal Vacuum

Application Field - Beam Dump - Material Test - with High Current Beam

BL22

3~20MeV

10nA ~60µ µA

Vertical External

300mm

- BT, ST - Detector Test - Space Radiation Effect - Liquid, Powder Sample Available

BL23

3~20MeV

60µ µA ~1.2mA

Horizontal External

300mm

- Power Semi. Device Development - Semiconductor Application

BL24

20MeV

120µ µA ~1.2mA

Horizontal Vacuum

100mm

- BNCT - Low Energy Neutron Source

BL25

20MeV

120µ µA ~1.2mA

Horizontal Vacuum

300mm

- Industrial Application for Mass Production 13

Layout of the 100 MeV Beam Lines 45 deg dipole

Doublet Lattice

Horizontal bending magnet

45 deg dipole

Vertical bending magnet

DTL2

Target Room BL 103

Target Room BL 101

20 deg dipole AC magnet

45 deg dipole 45 deg dipole

Beam Dump [BL100]

Common beam line

F D Lattice

20 deg dipole

Target Room BL 105

45 deg dipole

Individual beam lines

0 deg dipole

Target Room BL 102 Vertical Beam

Target Room BL 104

Beam Optics 14

100 MeV Beam Lines for User Facilities Energy

Avg. Curre nt

Irrad. Condition

BL100

100MeV

~1.6m A

Horizontal Vacuum

BL101

33,45,57, 69,80,92, 103MeV

30~ 300µ µA

Horizontal Vacuum

BL102

33,45,57, 69,80,92, 103MeV 20 ~103MeV

~10µ µA (10nA)

Vertical External

BL103

20~ 103MeV

30~ 300µ µA

Horizontal External

300mm

BL104

20~ 103MeV

10nA ~10µ µA

Horizontal External

- Low Energy Proton Therapy 300mm - Medical Applications - Pencil Beam Available

103MeV

30~ 300µ µA

Horizontal Vacuum

- Neutron Source 100mm - Nuclear Material Test - Nuclear Data Measurement

Beam Line No.

BL105

Max. Irrad. Dia. -

Application Field - Beam Dump - Material Test with High Current Beam

100mm - RI Production - BT, ST, Medical Application - Detector Test 300mm - Space Radiation Effect - Liquid, Powder Sample Available - Industrial Application for Mass Production

15

Construction Milestone for the100MeV Accelerator

Milestone

Major Activities

2006. 4

Project contract between Gyeongju and PEFP/KAERI, Site work start

2007. 6

Purchasing the land and receive the construction Licensing

2007. 7 2008. 7 2009. 12 2011. 12 2012. 3

Construction start - Ground Breaking, excavation, utility & building etc.

Start of 20MeV Accelerator Installation Extraction of 20MeV Proton Beam 100MeV Accelerator Installation and Commissioning Completion of PEFP project 16

Possibility of Future Extension of PEFP

Option I : Spallation Neutron Source Option II : Nuclear /High Energy Physics Experiments Option III : Radio-Isotope Production Option IV : Accelerator Driven System Experiment

17

Option I : Spallation Neutron Source q Survey • Typical Machine Parameters Energy : 0.5 – 3 GeV Duty : 0.1 - 1 Power : 100kW - MW Accelerator : Cyclotron, Linac + Synchrotron Linac + Ring • Applied Technology for Utilization Neutron Scattering Neutron Diffraction • Current Status in the World ISIS (800MeV, 250kW, in operation) SINQ (590MeV,1.5mA In operation) SNS (1GeV, 1MW in commissioning) J-Parc (3GeV, 1MW in construction) CSNS (1GeV, 150kW in developing) Indian SNS (1GeV, 100kW in planning)

q Environment in Korea • Potential Users in Korea - Material Science & Nano Technology - Life Science & Bio Technology - Others • Strength - Pulsed Neutron Source in Korea - Complementary with Reactor Neutron Source (HANARO) & Light Source (PLS) - Expansion of Korean Neutron Users (150) & Photon Users (400) - Easy Transfer Neutron Instrument Technology (Ex, SANS, Cold NS) • Weakness -Two Neutron Sources in Korea - Small number of Current Neutron User - Little Experiences and Interest in the BT field

Option II : NP of HEP Experiments q Survey • Typical Machine Parameters Energy : 0.15 – 50 GeV Current : a few nA – tens of A Duty : ~1 Power : kW - MW Accelerator : Linac + Synchrotron • Applied Fields for Utilization Radio Nuclei Beam Hyper Nuclei Exp Kaon Physics (CP/Rare Decay) Neutrino Production • Current Status in the World - CERN, DESY - FNAL, BNL - TRIUMP - DA NE (Italy), IHEP (Russia) - J-Parc (Japan, 50GeV, 15uA)

q Environment in Korea • Potential Users in Korea - Nuclear Physics - High Energy Physics - Others • Strength - 1st Large NP/HEP Facility in Korea - Promote & encourage the NP/HEP Users - Cultivate Young Scientists in the Fields • Weakness - Limited Number of Users (40-50) - Fund Issue to build Detectors - Hard to find Good Research Subjects - Tough Competition against Existing Facilities

Option III : RI Production q Survey • Typical Machine Parameters Energy : 10 – 200MeV Current : 30 – 300 uA Duty : 1 Power : 0.5 – 5kW Accelerator : Cyclotron • Applied Technology for Utilization RI Production RI Compounds • Current Status in the World - LANL (100MeV, 250uA) - BNL (200MeV, 120uA) - INR (160MeV, 100uA, Moscow) - iThemba(66MeV, 120uA, South Africa)

q Environment in Korea • Potential Uses in Korea - Medial RI Production - Industrial RI Production • Strength - No RI Production Facility over 50MeV in Korea - Production of New RI’s (Ge-68, Na-22, Sr-82 Cu-67, Pd-103) - Movement to develop a High Power Target with International Collaboration under IAEA - Initiative for New RI Business in Korea • Weakness - Premature of Commercial Uses for New RI’s - Limited Number of Specialists in Korea

Option IV : ADS Experiment q Survey • Typical Machine Parameters Energy : 0.5-1.5GeV Current : 10 – 50 mA Duty : 1 Power : MW Accelerator : Linac • Applied Technology for Utilization - High Flux Neutron Production - Transmutation of Nuclear Waste • Current Status in the World - J-Parc (Japan, 0.6 GeV in Planning) - CADS (China, 1GeV in Planning) - Indian ADS (India, 1GeV in Planning )

q Environment in Korea • Potential Users in Korea - Nuclear Power Industry • Strength - Originally developed a CW linac technology - Interests in Neighbor Asian Countries (Japan, China, India) - Good opportunity of an international collaboration - Neighbor with Korean Nuclear Waste Site • Weakness - Little Interests in USA & EU - Exclude from Gen IV Nuclear Energy System - Huge Costs for Construction & Operation - Resistance from Environmentalists - No more intentions of the KAERI transmutation group.

Proposed Extension Options for PEFP • Proposed Option (Option I + Option III) - Spallation Neutron Source + RI Production • Proposed Extended Machine Parameters - Energy : 1GeV - Current : 20 - 40mA peak - Duty : 8 -10 % - Power : 300kW – 1MW - Accelerator : 100MeV NC Linac + 1GeV Synchroton 1GeV Linac + GeV Accumulation Ring - 100MeV Beam Extraction : for RI Production • Proposed Machine Parameters of the 20-100MeV - Current : 20 - 40mA peak - Duty : 8-10 % - Frequency : 350MHz (700MHz for SC Linac) - Accelerator : NC Linac to 100MeV or NC Linac to 80MeV + SC Linac to 100MeV - 100MeV Beam Extraction

Radiological Safety Issues •Design requirements, concept and strategies •Benchmarks : TTY and streaming •Bulk shielding of beam line and beam dump •Source terms from 3D MCNPX Model •Beam loss analyses : Accident and normal operation •Radioactivity in the air (Ar-41) •Shielding of beam line facility hall •Activation products in accelerator components (20 MeV)

23

Design Requirements •For site boundary: •For public area: •For controlled area: •For groundwater activation:

1 mSv/y (by law, subject to change) 0.25 Sv/h 12.5 Sv/h below acceptable limits (JPARC: 5/11 mSv/h)

•Accident Scenario : A full beam loss dose rate < 100 mSv/h and system must be capable of aborting the beam in a time short enough that the integral dose caused by such an incidental condition remains negligible (CERN) •Radiation Sources: Normal operation beam losses: < 1 W/m 3x1011 protons m-1 s-1 at 20 MeV 6x1010 protons m-1 s-1 at 100 MeV Beam Dump: 4.8 mA at 20 MeV, 1.6 mA at 100 MeV 24

Sources of Radiation 10 MeV

20 MeV

50 MeV

DTL(I)

100 MeV

DTL(II)

Beam Loss

4.8/1.6 mA < 1 W/m 1 W/m Beam Facility A

Beam Facility B

Up to 2mA (600 A) 25

Design Concept and Strategies Design Concept •LINAC is shielded in underground concrete tunnel •Beam facilities are locally shielded with movable shielding blocks •Air activation is mitigated by cooling and ventilation •Beam dump is locally shielded if necessary

Design Strategies •Preliminary assessment by using Line-of-sight model •MCNPX with simplified 3D geometry for source terms and decay coefficients •MCNPX 3D models for important regions •Streaming and skyshine by semi-empirical models such as DUCT-III, SKYSHINE with source terms from MCNPX 26

Benchmarks: TTY of Cu target 1400

0.25

nat

1200

Cu(p,non)

1000 800 600 400 200

Present Work LA150 LAHET Kirkby (66) Pollock (65) Wilkins (63) 20

40

60

80

100

120

140

Incident proton energy (MeV)

Absolute number of neutron produced depends on the non-elastic cross section

p+ Cu neutron yield Neutron multiplicity (n/p)

Reaction cross section (mb)

nat

0.2 0.15 Ryder (82) Nakamura (83) Broome (83) MCNPX-Bertini MCNPX-CEM MCNPX-LA150 MCNPX-KAERI

0.1 0.05 0 20

40

60

80

100

120

140

160

Incident proton energy (MeV)

TTY simulation gives a better agreement on n/p

27

Benchmarks: NIMROD

•Monte Carlo: MCNPX 2.5e •Deterministic: KATRIN •JENDL-HE library (2004 version) •LA150 library

•7 GeV proton on copper target •Target room surrounded by iron wall •11-m bent tunnel •Low energy: 197Au(n,γ)198Au •High energy: 12C(n,2n)11C •Each tunnel is 2.3m x 2.3m 28

Benchmarks: NIMROD 10

1

1st leg

2nd leg

Attenuation factor

100 10-1 10-2 10-3

197

Au(n,γ)198Au

10-4 MCNPX with JENDL-HE MCNPX with LA150 Exp. KATRIN

10-5 10

-6

0

5

10 Distance (m)

15

20 29

Benchmarks: NIMROD 101

1st leg

2nd leg

Attenuation factor

100 10-1 10-2 10-3

12

C(n,2n)11C

10-4 MCNPX with JENDL-HE MCNPX with LA150 Exp. KATRIN

-5

10

10-6

0

5

10 Distance (m)

15

20 30

Benchmarks: TIARA

•Monte Carlo: MCNPX •JENDL-HE library (2004 version) •LA150 library

•68 MeV proton on copper target •Target room surrounded by concrete •29-m three-legs labyrinth •Bonner ball counter and TLD

31

-1

-1

Neutron Dose Equivalent Rate (µSv h µA )

Benchmarks: TIARA 106

JENDL-HE ENDF/B-VI Exp.

105 104 103 102 101 100 1st leg

-1

2nd leg

3rd leg

10

0

5

10

15 Distance (m)

20

25

30 32

Beam Line and Dump Shielding (Simplified Model) •Beam power •Beam loss •Conc. density •Public area

4.8mA 1W/m 2.35 g/cm3 < 0.25 Sv/h

208cm concrete

120cm iron 3 MeV

Injector

RFQ

10 MeV

DTL(I)

20 MeV

50 MeV

100 MeV

DTL(II)

20m

70m Beam dump

Beam dump 33

Beam Line Shielding

34

3D MCNPX model [mSv/hr] 155 m

1.0E+5

1.0E+1 9.5 m

1.0E-3

35

Sources from 3D MCNPX model

Particle flux [#/cm3-sec]

Injector

10

5

1E-4

1E-3

0.01

0.1

1

10

Energy [MeV]

36

Sources from 3D MCNPX model

Particle flux [#/cm3-sec]

RFQ

10

5

1E-4

1E-3

0.01

0.1

1

10

Energy [MeV]

37

Sources from 3D MCNPX model

Particle flux [#/cm3-sec]

DTL Part 1

10

6

10

5

10

4

10

3

10

2

1E-4

1E-3

0.01

0.1

1

10

Energy [MeV]

38

Sources from 3D MCNPX model

Particle flux [#/cm3-sec]

DTL Part 2

10

6

10

5

10

4

10

3

10

2

1E-4

1E-3

0.01

0.1

1

10

Energy [MeV]

39

Sources from 3D MCNPX model

Particle Flux [#cm2-sec]

DTL Part 3

10

7

10

6

10

5

10

4

10

3

10

2

1E-4

1E-3

0.01

0.1

1

10

Energy [MeV]

40

Sources from 3D MCNPX model

Particle flux [#/cm3-sec]

DTL Part 4 10

6

10

5

10

4

10

3

10

2

1E-4

1E-3

0.01

0.1

1

10

Energy [MeV]

41

Sources from 3D MCNPX model Dump

Particle Flux [#/cm2-sec]

1E12

3

1E11

1

1 2 1E10

1E9

1 1E-4

1E-3

0.01

0.1

1

2

3

3 2 10

Energy [MeV]

42

Beam Loss Accident: 20 MeV In the Accident at the MEBT § Beam Losses from MEBT assuming accident - In the magnetic field for beam extraction,

10

11

10

10

2

Neutron Flux [#/cm sec]

- 20 MeV proton beam with 4.8 mA losses

10

9

1E-4

1E-3

0.01

0.1

1

10

100

Energy [MeV]

eutron Spectrum

MEBT Model

Bending Magnet Model

43

Beam Loss Accident: 20 MeV Beam Losses from the MEBT in the 20 MeV full beam loss accident Design model and beam loss position

Bending Magnet

Dose distribution in the accelerator tunnel building 1

.

0

0

0

E

5

9

.

0

0

1

E

4

8

.

0

0

2

E

4

7

.

0

0

3

E

4

6

.

0

0

4

E

4

5

.

0

0

5

E

4

4

.

0

0

6

E

4

3

.

0

0

7

E

4

2

.

0

0

8

E

4

1

.

0

9

E

4

1

0

0 0

.

0

44

Beam Loss Accident: 20 MeV Beam Losses from the MEBT in the 20 MeV full beam loss accident

Bending Magnet( beam loss point) DTL 1

Dose calculation from beam loss at the MEBT

DTL 2

45 B M

P1

QM

45 BM

P2

Calculation point

P1

P2

Dose [μ μSv/hr]

826

23

2 2 .5 B M

QM

QM

S w itc h in g M ag n et

20 B M QM QM 10 B M

10 BM

2 2 .5 B M

20 BM

If the beam is cut within 1 sec, the integrated dose equivalent is 0.23 Sv, which is totally acceptable considering DER for public area: 0.25 Sv/h based on annual dose equivalent 1 mSv

Transport line for 20 MeV beam extraction 45

Beam Loss Accident: 100 MeV In the Accident at the end of the beam line Beam Losses at the end of the 100 MeV beam line

§

10

11

10

10

2

Neutron Flux [#/cm sec]

- 100 MeV proton beam with 4.8 mA loss

10

9

1E-4

1E-3

0.01

0.1

1

10

100

Energy [MeV]

eutron Spectrum

DTL Model

Design of t e 100 MeV beam transport

46

Beam Loss Accident: 100 MeV Beam Losses from end of the beam Line Design model and beam loss position 100 MeV` Beam Transport

Dose distribution in the accelerator tunnel building 1

.

0

0

0

E

5

9

.

0

0

1

E

4

8

.

0

0

2

E

4

7

.

0

0

3

E

4

6

.

0

0

4

E

4

5

.

0

0

5

E

4

4

.

0

0

6

E

4

3

.

0

0

7

E

4

2

.

0

0

8

E

4

1

.

0

0

9

E

4

1

0

0

.

0

Dose at the concrete wall of the building : 3024 mSv/hr

•If the beam is cut within 100 ms, the integrated dose equivalent is 84 Sv. • DER for public area: 0.25 Sv/h based on annual dose equivalent 1 mSv 47

Beam Loss : Normal Operation Beam Losses from the beam line in the normal operation

Design model for accelerator tunnel building

Dose distribution in the accelerator tunnel building

48

Radioactivity produced in the air Production depends on : operation mode of accelerator volume and ventilation capacity of the room Estimation depends on: estimated neutron spectrum and relevant nuclear data Radionuclide

Half life

Production reactions

Neutron threshold energies

H-3

12.26y

C-12 (n,t) B-10 N-14 (n,t) C-12 O-16 (n,t) N-14 Ar-40 (n,t) Cl-38

18.93 MeV 4.02 MeV 14.48 MeV 12.12 MeV

C-11

20.4m

C-12 (n,2n) C-11

18.72 MeV

N-13

9.96m

N-14 (n,2n) N-13

10.55 MeV

O-15

122s

O-16 (n,2n) O-15

15.66 MeV

Ar-41

1.83hr

Ar-40 (n, γ) Ar-41

1/v law 49

Radioactivity produced in the air 1000 C-12(n,x))H-3

Moszynski (94) KAERI JENDL-HE

1000 N-14(n,t)C-12

100

σ [mb]

σ [mb]

100

10

Shaimi (88) Shaimi (78) JENDL-HE ENDF/B-VI KAERI

10

1 1

0.1 10

100 Neutron Energy [MeV]

C-12(n,x)H-3 •JENDL-HE and present evaluation underestimate measurements •Recommended: •Present evaluation factored by 1.5

0.1 10

100

Neutron Energy [MeV]

N-14(n,t)C-12 •ENDF/B-VI and present work agree well with measurements •Recommended: •ENDF/B-VI for En < 10 MeV •Present evaluation for En > 10 MeV 50

Radioactivity produced in the air 1000 O-16(n,t)N-14

Ar-40(n,x)H-3 100 σ [mb]

σ [mb]

100

1000

Shibata (96) Qaim (78) JENDL-HE KAERI ENDF/B-VI

10

Qaim (78) KAERI Recommanded JENDL-3.3

10

1

1

0.1

0.1 10

100

10

100 Neutron Energy [MeV]

Neutron Energy [MeV]

O-16(n,t)N-14 •ENDF/B-VI agrees well for En < 30MeV Present work agrees well for En > 30 MeV Recommend: ENDF/B-VI for En < 30 MeV Present evaluation for En > 30 MeV

Ar-40(n,x)H-3 •Only present work available for En > 20 MeV •Measurement needed •Recommended: •Present evlaution factored by 2 51

Ar-41 production MCNPX calculation setup

•Operation mode •Concentration limit •Discharge limit

2

10

1

RI concentration (Bq/cm3)

• Proton energy : 20 MeV, 100 MeV • Beam current : 300 μA, 600 μA • Target size : 5 cm long, 6 cm in diameter • Target room size : 30x3x3 m3, 10x10x5 m3 • Irradiation time : 10 hours

10

Target : tantalum Proton energy : 100 MeV Beam current : 600µA 3 Target room : 10x10x5 m

0

10

-1

10

3

no ventilation 3 500m /h 3 1000m /h

-2

10

1500m /h 3 2000m /h 3 2500m /h

-3

10

0

1

2

3

4

5

6

7

8

9

10

Elapsed time (hour) 52

Ar-41 in the Accelerator Tunnel -2

3

Ar-41concentration after shut down [Bq/cm ]

1.0x10

Ar-41 concentration with operation time

-3

8.0x10

-3

6.0x10

-3

4.0x10

-3

2.0x10

0

2

4

6

8

10

Operation Time [hr]

In the Case of the Operation with 20 MeV Beam Line and Beam Dump 10

In the Case of the Operation of the 100 MeV Beam Line without Beam Dump 10

2

-3

lim it

lim it

12 hr operation

0

3

10

Ar-41concentration [Bq/cm ]

10

1

3

Ar-41concentration [Bq/cm ]

1 2 h r o p era tion

10

-1

10

-2

10

-3

10

-4

0

2

4

6

C ooling T im e [hr]

8

10

10

-4

10

-5

10

-6

0

2

4

6

C ooling Tim e [hr]

8

10

53

Ar-41 in Target Rooms in the Beam Experiment Hall

Ar-41 Conentration [Bq/cc]

The concentration of the Ar-41 in the each target room after shut down

10

2

10

1

10

0

5 .0 E -2 B q /c c 5 .0 E -4 B q /c c

10

-1

10

-2

2 0 M e V -B e 2 0 M e V -C 2 0 M e V -C u 1 0 0 M e V -A g

10

-3

10

-4

10

-5

1 0 0 M e V -C 1 0 0 M e V -S i-0 1 1 0 0 M e V -S i-0 2 1 0 0 M e V -S i-0 3 1 0 0 M e V -W

0

2

4

6

8

10

C o o lin g T im e [h r]

54

Ar-41 conc. in the Target Rooms and the Accelerator Tunnel

§

10

1

5 .0 E -2 5 .0 E -4

10

0

1 2 h r o p e r a tio n

3

§

As the concentration of the Ar-41 is very high in the target rooms, required cooling time exceeds more than a few tens of hour. To avoid such situation, it is proposed that the air in the accelerator tunnel building and in target rooms in the beam experiment hall be mixed before discharged. In Korea, the limit for radiation workers is 5.0 10-2 Bq/cc and the limit for discharge is 5.0 10-4 Bq/cc

Ar-41 concentration [Bq/cm ]

§

10

-1

10

-2

10

-3

10

-4

10

-5

0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

C o o lin g T im e [h r ]

55

Shielding of Beam Lines and Target Rooms

Accelerator Tunnel Building

20 MeV Beam Line

100 MeV Beam Line TR 103

TR 25

TR 101

TR 21 TR 23 TR 105

TR 100 TR 102

TR 104

TR 20

TR 24 TR 22

Beam Experiment Hall

56

Design and Model of Beam Line Facility Hall MCNPX Model of the Beam Line Facility Hall

20 MeV Beam Line

TR 101

TR 105

TR 104

TR 102

TR 103 TR 100

100 MeV Beam Line

57

The Characteristics of the Target Rooms and BTL Room Number

Beam Energy [MeV]

Beam Current [mA]

Target Material

TR 20

20

4.8

C (Dump)

TR 21

20

1.5

Cu

TR 22

20

0.05

Si

TR 23

20

0.05

Si

TR 24

20

1.5

Be

TR 25

20

1.5

Si

TR 100

100

1.6

Cu (Dump)

TR 101

100

0.3

Ag

TR 102

100

0.01

Si

TR 103

100

0.3

Si

TR 104

100

0.01

Si

TR 105

100

0.3

W

BTL-I

20

1 W/m loss

TR 105

100

1 W/m loss 58

Radiation Source in the Beam Line Facility Hall The Neutron Spectra from Each Target 1E15 1E14

Neutron Flux [#/sec]

1E13 1E12 1E11 1E10 1E9 1E8 1E7 10

-3

10

-2

10

-1

20MeVCu1.5mA

20MeVC4.8mA

20MeVBe1.5mA

100MeVSi300uA

100MeVSi10uA

100MeVC1.6mA

100MeVAg300uA

100MeVW300uA

10

Energy [MeV]

0

10

1

10

2

59

Radiation Source in the Beam Line Facility Hall

10

6

10

5

10

4

10

3

10

2

20 MeV BTL 100 MeV BTL

2

Neutron Flux [#/seccm ]

The Neutron Spectra from Each BTL

10

-9

10

-8

10

-7

10

-6

10

-5

10

-4

10

-3

10

-2

10

-1

10

0

10

1

10

2

Energy [MeV]

60

Concrete Thickness of the Target Rooms and BTL Calculations of the Concrete Thickness for Each Target Room

ICRP-74 Ambient Dose [uSv/hr]

10

10

10

9

10

8

10

7

10

6

10

5

10

4

10

3

10

2

10

1

10

0

10 uSv/hr 2 uSv/hr W Be

0

50

100

150

200

250

300

Concrete Thickness [cm]

61

Concrete Thickness of the Target Rooms and BTL Shielding Test for materials § §

In the case of using only one kind of shield material, generally “Low Z Materials” are good for neutron shielding. In PEFP, additional shield material beside concrete are required to reduce total shield thickness, because the neutron spectrum is harder. 1E-8 STS-304

The additional shied material which makes neutron spectrum softer is effective when used with concrete

Steel

High Z Materials

1E-9

Sv/hr/source neutron

§

Polyethylene paraffin Lead Borat-Parraffin

1E-10

1E-11

“Shield efficiency is more lower more thicker” 1E-12

Low Z Materials 1E-13 0

10

20

30

40

50

Thickness [cm]

62

Concrete Thickness of the Target Rooms and BTL Shielding Test for materials

1E-4

1E-4

1E-5

1E-5

1E-5

1E-7

5 10 15

1E-9

1E-7

Thickness [cm]

2

Thickness [cm]

1E-8

1E-6

20

5

1E-8

10 15

1E-9

20

1E-10

25

40

10

-8

10

-7

10

-6

10

-5

10

-4

10 20

1E-12 10

-3

10

-2

10

-1

10

0

10

1

10

2

10

-8

10

-7

10

-6

10

-5

10

-4

10

-3

10

-2

10

-1

10

0

10

1

10

2

1E-7

Thickness [cm]

2

2

Thickness [cm]

1E-6

5 10 15 20

5

1E-8

10 15

1E-9

20

1E-10

25

1E-11

40

10

10

10

10

10

10

-5

-2

Energy [MeV]

10

-1

10

0

10

1

10

2

-8

10

-7

10

-6

10

-5

10

-4

-4

10

-3

10

-2

-1

10

-1

10

10

0

10

1

10

0

10

1

10

2

10 15

1E-9

20 25 30

40

10

10

5

1E-11

35

1E-12 -3

10

Thickness [cm]

1E-8

30

35

10

1E-7

1E-10

25

30

-4

-6

1E-6

2

1E-6

Flux [#/cm /neutron]

1E-5

Flux [#/cm /neutron]

1E-4

-5

10

Lead

1E-5

-6

-7

STS-304

1E-5

-7

10

Energy [MeV]

1E-4

-8

-8

Energy [MeV]

1E-4

1E-12

40

10

1E-3

1E-11

35

1E-12

1E-3

1E-10

25 30

40

Steel

1E-9

15

1E-9

1E-3

1E-8

5

1E-11

35

Energy [MeV]

1E-7

Thickness [cm]

1E-8

30

1E-11

35

1E-12

1E-7

1E-10

25

30

1E-11

1E-6

2

1E-6

Flux [#/cm /neutron]

1E-4

Flux [#/cm /neutron]

1E-3

1E-10

Flux [#/cm /neutron]

Polyethylene

Borate Paraffin 1E-3

2

Flux [#/cm /neutron]

Paraffin 1E-3

35 40

1E-12 10

-3

10

-2

Energy [MeV]

10

-1

10

0

10

1

10

2

10

-8

10

-7

10

-6

10

-5

10

-4

10

-3

10

-2

10

2

Energy [MeV]

63

Concrete Thickness of the Target Rooms and BTL Shielding Test for Steel

64

Concrete Thickness of the Target Rooms and BTL Concrete Shield thickness Considering Additional Steel Shield

1 W/m of Beam Losses

0.2 W/m of Beam Losses 3

3

10

2

10

2

10

Ambient dose [uSv/hr]

Ambient dose [uSv/hr]

10

1

10

10uSvhr iron10cm iron20cm iron30cm

0

10

1

10

10uSvhr iron10cm iron20cm iron30cm

0

10

-1

-1

10

10

20

40

60

Thickness [cm]

80

100

20

40

60

80

100

Thickness [cm]

65

Ambient Dose Distribution from Neutrons Mapping of the Ambient Dose Distribution in the Beam Experiment Hall Operation of 5 target rooms from 100 MeV BTL

66

Activation Products in the Accelerator Chain (20 MeV) §

Considering external exposure during an overhaul, dose due to residual gamma-ray from the 20 MeV accelerator chain was evaluated - Source particle: proton beam and secondary neutrons - Using PHITS code and previous computational model (MCNPX) LEBT

Injector § § §

Materials S S 304 Copper Proton Energy 50 keV eutron spectrum from t e source term calculation

§ § §

Materials Steel S S 304 Copper Proton Energy 50 keV eutron spectrum from t e source term calculation

§

Produces o Radio nuclide

§

Produces o Radio nuclide

RFQ

DTL Tank

§ § §

Materials S S 304 Copper Proton Energy 50 keV 3 MeV eutron spectrum from t e source term calculation

§ § §

Materials STPA21 Steel Proton Energy 3 20 MeV eutron spectrum from t e source term calculation

§

Produces o Radio nuclide

§

Produces Radio nuclides

67

Activation Products in the Accelerator Chain § Decay of the radio-nuclides in the DTL § Effective Dose is about 1.817 10-3 uSv/hr from DTLs during the operation 10

1

52-Mn 51-Cr

10

54-Mn

0

56-Co

Activity [Bq]

57-Co 58-Co

10

-1

10

-2

10

-3

10

-4

0

20

40

60

80

100

120

140

160

180

200

Time [hr]

68

Residual radiation from activation products of beam dump (100 MeV, 4.8mA) Radiation protection options from residual radiation of beam dump 6

6

10

10

5

10 10

4

3

10

10

2

Dose equivalent rate(µSv/h)

Dose equivalent rate(µSv/h)

180 hours(7.5days) needed to cool down to the 12.5µSv

105

4

10

1

10

0

10

-1

10

-2

10

-3

10

-4

10

4.8mA, 10cmapart, noshielding Cu-63(n,a) Cu-63(n,g), Cu-65(n,2n) Cu-63(n,p) Cu-65(n,a)

-5

10

-6

10

-7

10

-8

10

Cu-63(n,2n) Cu-65(n,g) Cu-65(n,p) Total

3

10

2

10

1

10

0

10

-1

10

4.8mA, 10cmapart, no shielding 4.8mA, 200cmapart, no shielding 4.8mA, 10cmapart, 11cm-thick lead shielding 300µA, 100cmapart, no shielding

10-2 -3

10

-4

10

-9

10

-5

10

-10

10

0

10

20

30

40

Cooling time (hour)

50

60

70

0

10

20

30

40

50

60

70

Cooling time (hour) 69

Further Works

n

Finalize key operation parameters (duty factor, beam loss, target power, etc)

n

Detailed design with source terms from 3D MCNPX model • •

n

Duct streaming (20/100 MeV) Activation of components, cooling water and air (100 MeV)

Site selection • • •

Skyshine and groundwater activation Dose rate at site boundary Other site-dependent issues

70