Re: [TUHS] Death by bug

[Ralph Corderoy <ralph@inputplus.co.uk>]

Hi Jon,

> So I'm kind of wondering what sort of bug may blow up a refinery or
> chemical plant and cause enough loss of life and damage to make people
> take notice.

I see, a ‘big bang’ disaster, like Bhopal, rather than a gradual
sniping.

There's the Battery Management System software which controls the
charging and discharge of Lithium-ion batteries.  I don't mean a burning
laptop causing an airliner to go down, more a shipping container stuffed
full of the things going up.

There is an interesting recent paper on the flaws in ‘Battery Energy
Storage Systems’ and defending against the inevitable lithium metal
dendrites.  It assumes the BMS has no flaws but if it did then the same
end effect could occur.  Here's some extracts from the ‘Executive
Summary’.

    Safety of Grid Scale Lithium-ion Battery Energy Storage Systems
    https://www.researchgate.net/publication/352158070_Safety_of_Grid_Scale_Lithium-ion_Battery_Energy_Storage_Systems

    Li-ion batteries are dominant in large, grid-scale, Battery Energy
    Storage Systems (BESS) of several MWh and upwards in capacity.
    Several proposals for large-scale solar photovoltaic (PV) “energy
    farms” are current, incorporating very large capacity BESS.

    Despite storing electrochemical energy of many hundreds of tons of
    TNT equivalent, and several times the energy released in the August
    2020 Beirut explosion, these BESS are regarded as “articles” by the
    Health and Safety Executive (HSE), in defiance of the Control of
    Major Accident Hazards Regulations (COMAH) 2015, intended to
    safeguard public health...

    Li-ion batteries can fail by “thermal runaway” where overheating in
    a single faulty cell can propagate to neighbours with energy
    releases popularly known as “battery fires”.  These are not strictly
    “fires” at all, requiring no oxygen to propagate.  They are
    uncontrollable except by extravagant water cooling.  They evolve
    toxic gases such as Hydrogen Fluoride (HF) and highly inflammable
    gases including Hydrogen (H2), Methane (CH4), Ethylene (C2H4) and
    Carbon Monoxide (CO).  These in turn may cause further explosions or
    fires upon ignition.  The chemical energy then released can be up to
    20 times the stored electrochemical energy.

    “Battery fires” in grid scale BESS have occurred in South Korea,
    Belgium (2017), Arizona (2019) and in urban Liverpool (Sept 2020)...
    A report into the Liverpool “fire” though promised for New Year
    2021, has not yet been released...

    No existing engineering standards address thermal runaway
    adequately, or require measures (such as those already used in EV
    batteries) to pre-empt propagation of runaway events.

And BMS's get a few mentions, e.g.:

    Li-ion batteries are sensitive to mechanical damage and electrical
    surges, both in over-charging and discharging.  Most of this can
    however be safeguarded by an appropriate Battery Management System
    (BMS)...

-- 
Cheers, Ralph.