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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)
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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.
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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.
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
6
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
8
The aim of RaDoM is to improve the estimation
of the dose delivered to the lung by
reproducing the energy deposition on the lung
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
9
Silicon DetectorMesh
Screen
System
Mixed cellulose
Filter
Alpha Particles
from
Radon Decay
Products
A New Concept
of Radon Dose Monitoring
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
11
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
12
Evolution
PUMP
OUTLET
AIR
INLET
AIDA PoC / MAPF
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
13
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
14
• 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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
15
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
16
Electronics
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
18
RaDoM calculates the Effective Dose from a measurement of
the PAEC of short lived radon daughters attached to the filter
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
19
Results: test in real fieldOngoing measurements in a water
reservoir in Switzerland (Grenchen)
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
20
ELECTRONIC
BOARD
Connectivity
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
21
FixIntegration in
smart buildings
Real-time
monitoring
integrated in
smart systems
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
22
Driving ventilation systems
Wi-Fi
Lora
Ethernet
LTE
Internet
Intranet
Wi-Fi
Ethernet
PCLs 0-10V, 4-20 mA,
or digital connection
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
23
And now a live demo
https://radom.nextome.net/login
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
24
Additional slides
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
25
Cloud interface
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
26
Cloud interface
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
27
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
29
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
31
Particle stopped by the mesh screen as a function of the mesh thickness
(50% probability). Different lines correspond to different air speed.
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
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
M. Silari, CERN AIDA meeting, Bologna, 26 April 2018
33