liebe project safety aspects of the pb/bi loop target liebe meeting report – wp5a....

LIEBE projectSafety aspects of the Pb/Bi loop target

LIEBE meeting report – WP5 A. Marchix 19/09/2013

Thanks to : AP. Bernardes/EN/STI, J.Blaha/DGS-RP, Richard Catherall/EN/STI, JC.David/CEA/SPhN,

M.Delonca/EN/STI, TM.De Melo Mendonca/EN/STI, A.Dorsival/DGS-RP, P.Lamuth/CEA/DPSN, N.RAXACH/CEA/DPSN, T.Stora/EN/STI and J.Vollaire/DGS-RP…

Isotope inventory


Preliminaries results on isotope inventory obtained with nuclear models

CEA MCNPX (INCL4.6/ABLA07) + CINDER’90 (activation)A. Boudard, J. Cugnon, J.-C. David, S. Leray, and D. Mancusi, “New potentialities of the Liège intranuclear cascade (INCL) model for reactions induced by nucleons and light charged particles.” Phys. Rev. C, 87, 1, 014606 (2013). J.-C. David et al., “Modeling astatine production in liquid lead- bismuth spallation targets.” Eur. Phys. J. A, 49, 3, 29 (2013).

CERN FLUKA (results need to be validated by the FLUKA’s developers)

Isotope inventory


Beam parameters:• 1.4 GeV proton beam• Irradiation time: 8.0E+5 s• Intensity: 1.25E+13 proton/s

FLUKA Geometry MCNPX simulation : Only consider the Pb/Bi target

Target:• 45.5% Pb, 55.5% Bi• Inside a tantalum cylinder (r=1cm, l=20cm) • Filled up to ~70%• m = 547 g

Isotope inventory


Preliminaries results on the total activity:

Decay time AMCNPX (GBq) AFLUKA (GBq) (AMCNPX - AFLUKA)/AFLUKA (%)

0 hour 18218 19010 -4.17

1 day 3105 3218 -3.51

1 month 176 162 8.64

Good agreement between FLUKA and MCNPX (INCL4.6/ABLA07) on macroscopic observables for radioprotection

comparison on the isotope inventory ?

Following comparison is focused only on the main contributor in term of radiotoxicity (>1% of total) defined by the LA (Limit Authorisation, ORaP)

Isotope inventory


Comparison between FLUKA and MCNPX (INCL4.6/ABLA07) within a factor 2 on radionuclides which mainly contribute to radiotoxicity

Radionuclide Half Life AFLUKA (Bq) AMCNPX (Bq) AFLUKA/LA/Σi Ai/LAi (%)

(AMCNPX-AFLUKA)/AFLUKA (%)

206Po 2.9 y 1.50E+10 7.56E+09 44.68 -49.6087Kr 6.2 d 2.30E+09 1.43E+09 6.93 -37.67

197Hg 8.8 d 1.90E+11 1.54E+11 5.72 -18.83114mIn 2.7 d 1.40E+09 2.20E+02 4.17 -100.00

88Kr 9.9 h 1.30E+09 8.90E+08 4.01 -31.57206Bi 3.8 h 1.30E+11 1.12E+11 2.05 -14.1941Ar 74.5 y 6.40E+08 9.38E+08 1.94 46.54

85mKr 29.8 s 5.60E+09 1.52E+09 1.70 -72.84208Po 2.8 h 1.00E+08 1.19E+08 1.55 19.4477Kr 76.3 m 5.00E+08 1.45E+09 1.53 190.6179Kr 35 h 4.70E+09 1.00E+10 1.44 113.05

195Hg 74.3 m 1.70E+11 1.49E+11 1.28 -12.1415O 109.3 m 4.10E+08 2.50E+08 1.26 -39.07

148Gd 122 s 7.30E+06 3.41E+06 1.12 -53.32193Hg 4.5 h 1.80E+11 1.26E+11 1.07 -29.92106Rh 0 s 3.50E+09 5.06E+09 1.06 44.61

Problem known on 114mIn, and usually for metastable radionuclide with INCL4.6/ABLA07

Environmental release


Arbitrary assumptions to obtain an estimate of the radiological impact on public:• All the activity produced in the target is released• Wind: 5 m.s-1

• Normal condition for diffusion• Reference group distance: 1 km from source• Inhalation DCF: Arrêté du 1er septembre 2003 (BO 2003-46)• Air submersion DCF: Federal Guidance n°12• Ground deposition DCF: Federal Guidance n°12

Calculation done on the radiological impact due to an environmental release in order to determine the risk for population (not official methodology for the project)

Official calculations will be done using CERN methodology

Environmental release


Preliminaries results:

Decay time Total activity (GBq)

Inhalation effective dose (µSv)

Air submersion effective dose (µSv)

Ground deposition effective depot (µSv)

Total adult effective dose (µSv)

0 seconds 1,82E+04 35,35 13,29 56,81 105,45

Decay time Total activity (GBq)

Inhalation effective dose (µSv)

Air submersion effective dose (µSv)

Ground deposition effective depot (µSv)

Total child effective dose (µSv)

0 seconds 1,82E+04 33,69 13,29 56,81 103,79

Only a factor 2 between the total effective doses calculated and the CERN nuclear safety objective (same factor than the nuclear models comparison)

If theses calculations are confirmed: only one barrier is needed for the nuclear safety demonstration

CERN nuclear safety objective:In case of failure, the total effective dose must not exceed 200 µSv for the population reference group

Fire prevention course


June 2013 : 3 days course on fire prevention code CDI done by P.LAMUTH and N.RAXACH (CEA/DPSN) at CERN

Participants to the course:• EN/STI• DGS/SEE

Content of the course:• awareness to the fire hazards• presentation of CDI• how to do a fire study• training with CDI on realistic cases

Conclusions- Only preliminaries results on isotope inventory and radiological impact on population (not

official results, only rough estimation)- FLUKA calculations were done but they need to be validated by FLUKA’s developers

Up to now:- Good agreement on nuclear models comparison, within a factor 2 on the radionuclides

which mainly contribute to the radiotoxicity- Only a factor 2 on the radiological impact of an environmental release between the total

effective doses calculated and the CERN nuclear safety objective

- Work ongoing Isotope inventory : comparison to experiment Nuclear safety analysis

Description of the different phases of the process Definition of the normal condition parameters for operation and the monitoring

associated

If theses calculations are confirmed: only one barrier is needed for the nuclear safety demonstration

Defence in depth


Principle to compensate for potential human and component failures to maintain the effectiveness of the barriers by averting damage to

the plant and to the barriers themselves to protect the public and the environment from harm in the event

that these barriers are not fully effective.

Undesirable event

Failure tree

Failure mode of a safety function

Barrier

Failure

liebe project safety aspects of the pb/bi loop target liebe meeting report – wp5a....

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