marco silari the radom€¦ · radon dose monitor (radom) m. silari, cern aida meeting, bologna, 26...

The RadoMMarco Silari

Alessandro Curioni

Natalie Heracleous

Francesco La Torre

Stefano Romano

HSE-RP

M. Silari, CERN AIDA meeting, Bologna, 26 April 2018

1

Funding: 135k CHF

Aida-2020 PoC (January 2017) – 50%

CERN Medical Applications (March 2017) – 50%

Radon Dose Monitor (RaDoM)


2

Sources

of Natural

Exposures in

Switzerland

Radon is considered the

first cause of death bylung cancer after

smoking

Radon

57%

Medicine

22%

Water and food

6%

Cosmic and

Terrestrial

13%

Industry and

Research

2%M. Silari, CERN AIDA meeting, Bologna, 26 April 2018

3

Radon map of Switzerland (Risk assessment 2009)

Source: Swiss Federal Office of Public Health (National Action Plan concerning Radon 2012 – 2020)

< 50 Bq/m3

50-100 Bq/m3

> 100 Bq/m3

STRONG INTEREST FROM OFSP in RaDoM


4

Radon gas is the most important source of ionizing radiation

among those of natural origin.

Currently the dose is estimated by measuring

radon and/or radon progeny concentrations.

In the dose estimation, lots of parameters are taken as default,

such as the aerosol size, the equilibrium factor, particle density

and shape, etc, leading to significant uncertainties.


5

222Rn

3.82 d

α

α6.0

MeV

7.7

MeVα

218Po

3.05 min

214Pb

26.8 min

214Bi

19.7 min

214Po

164 μs

210Pb

22 y

β β

The effective dose to the lung is obtained by

assuming an equilibrium factor between

radon and its progeny.

The dose conversion factor

of radon decay products may

vary with particle size and

shape.


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Contribution of the unattached and attached fraction of radon

progenies to the dose

The unattached fraction:

Radon decay products attach to ambient molecules and become neutralized by the

recombination. This is defined as unattached fraction with a particle diameter ranging

from 0.5 to 5 nm.

The attached fraction:

Clusters attach to aerosol particles and have a particle diameter up to 100 μm,

forming the attached fraction of radon progeny.

A. M. Mohamed et al, Ultrafine fraction and aerosol attached

activity size distribution of radon progeny in living room, Journal

of Physical Science and Application 2(2012) 205–215


7

Particles with different size, unattached and attached fractions,

deposit in different sections of the human respiratory tract:

• Lower nose

• Upper nose

• Bronchi

• Bronchioles

• Alveoli


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The aim of RaDoM is to improve the estimation

of the dose delivered to the lung by

reproducing the energy deposition on the lung


9

Silicon DetectorMesh

Screen

System

Mixed cellulose

Filter

Alpha Particles

from

Radon Decay

Products

A New Concept

of Radon Dose Monitoring


10

Penetration of particles through a mesh screen is a

function of particle size, air velocity, mesh wire

diameter, total thickness of mesh system, diffusion

coefficient


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RaDoM uses one or more mesh screens to select

particles of given diameter

CUT OFF 1CUT OFF 2

Particles attached to the mixed

cellulose filter mimic particles

attached to human respiratory

track

ET1: lower nose

ET2: upper nose

BB: bronchi

bb: bronchioles

AL: alveoli


12

Evolution

PUMP

OUTLET

AIR

INLET

AIDA PoC / MAPF


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Radon chamber at CERN

Microcontroller

Associated analogic

Electronic

Pump

Sensor

• RaDoM prototype: evolution from a breadboard to an integrated system with microcontroller

• Detector testing in a home-made radon chamber and comparison with commercial radondetectors

• Contract given to Nuclear Instruments for the production of 5 electronics boards ready fortesting in December 2017. Current status: latest firmware upgrade and 4G GSM module bythe end of April 2018.

• Contract given to Nextome for development, including communication and cloud: a prof-of-concept version ready by December 2017. Beta version currently under testing.

RaDoM - Product development


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• The RaDoM project was selected from 450 applicants as one of the 75 finalists forthe MassChallenge2017 Accelerator Programme in Switzerland and passed the VentureKickPhase 1 selection for funding

• More than 30 classes on business development attended by at least one team member

• A total of 64 meetings with stakeholders and potential customers

• Several partners/distributors identified: Airfox AG, Kueger AG, Econs SA, Miam, Vortice

• A 30-page business plan ready for investors

• Pilot projects:

• March 2018: a pilot of 3 weeks carried out in a primary school in Nennigkofen (CH) and 2 pilots in water plantsin Grenchen (CH)

• April 2018: pilot of 2 weeks started in a school in Rheinfelden (CH) in collaboration with Airfox AG

• May 2018: pilot driving a ventilation system in a water plant in St. Gallen in collaboration with Krueger AG

Business development


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Present version

110 mm

200 mm

High resolution alpha particle spectrometer: radon,

thoron and actinium daughters

External plug-in radon concentration probe

15-minute time resolution

Embedded shock, temperature and humidity sensors

Optional environmental sensors, e.g. CO2

Powered by Linux

LoRa, WiFi, Bluetooth, LTE connectivity

Cloud platform

iOS and android apps


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Electronics


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218Po+212Bi

216Po

214Po

Real time energy

spectrum from alpha

particles attached to

the mixed cellulose

filter

The deposited particles

mimic the bronchial

deposition thanks to

the mesh screen

filtering

Th+Rn from sand


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RaDoM calculates the Effective Dose from a measurement of

the PAEC of short lived radon daughters attached to the filter


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Results: test in real fieldOngoing measurements in a water

reservoir in Switzerland (Grenchen)


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ELECTRONIC

BOARD

Connectivity


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FixIntegration in

smart buildings

Real-time

monitoring

integrated in

smart systems


22

Driving ventilation systems

Wi-Fi

Lora

Ethernet

LTE

Internet

Intranet

Wi-Fi

Ethernet

PCLs 0-10V, 4-20 mA,

or digital connection


23

And now a live demo

https://radom.nextome.net/login


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https://radom.nextome.net/login

Additional slides


25

Cloud interface


26

Cloud interface


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ET1: lower nose

ET2: upper nose

BB: bronchi

bb: bronchioles

AL: alveoli

Total deposition of particles with different size in the human

respiratory tract assuming light work-breathing conditions

unattached attached

Encyclopaedia of Occupational

Health and Safety, 4th Edition,

Part I, chapter 10


28

Bronchial and alveolar dose (mGy/WLM), mouth and nasal breathing

Epithelial cell nasal

breathing

Epithelial cells

mouth breathing

Basal cells nasal

breathing

Alveolar

Unattached

fraction

15.2 47.5 4.2 0

Attached

fraction

4.69 4.69 2.94 0.22

Breathing

Rate [m3/h]

Breathing

Frequency [1/min]

Effective Dose

[mSv/WLM]

0.45 15 7.68

0.78 20 11.77

1.5 20 18.25

3.0 26 34.29

Effective dose (mSv/WLM) in different breathing conditions (ICRP 66)

El-Hussein et al, Radiation Dose to

the Human respiratory tract from

Inhalation of Radon-222 and its

Progeny, Appl. Radiat. Isot, Vol 49,

No. 7 (1998) 783–790


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Penetration of particles through a mesh screen is a

function of particle size, air velocity, mesh wire

diameter, total thickness of mesh system, diffusion

coefficient


30

Why the mesh screens?

𝑃 𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒 𝑠𝑖𝑧𝑒 ∝ exp (𝑢 • 𝑑

𝑠)−0.67• 𝐷(𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒 𝑠𝑖𝑧𝑒)0.67

The penetration of the particles through a mesh

screen, as a function of the particle size:

u: Air velocity

d. Mesh wire diameter

S: Total mesh system thickness

D: Diffusion coefficient as a function of the particle size


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Particle stopped by the mesh screen as a function of the mesh thickness

(50% probability). Different lines correspond to different air speed.


32

How RaDoM calculates the Effective Dose

Effective dose = DCF x Cn x t

DCF = 3 mSv/mJ h/m3 (ICRP137)

Cn = net PAEC of short lived radon daughters attached to the cellulose filter

T = 15 min (integration time of RaDoM)

RaDoM calculates the Effective Dose from a measurement of

the PAEC of short lived radon daughters attached to the filter


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marco silari the radom€¦ · radon dose monitor (radom) m. silari, cern aida meeting, bologna, 26...

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