Re: TMI Root Causes

[Mike Grissom <mikeg@SLAC.Stanford.EDU>]

Radsafers,

As Harald noted in his post, you really wouldn't have wanted to
be an operator at TMI-2 on that fateful March 1979 day!

To me, the water level indicator device fault was a real killer
from the RO's (reactor operator's) point of view.  But as Harald
and others have noted, there were many contributing factors (the
known problem with the PORV sticking "open" being just a nastier
one for creating a very difficult inside containment environment
early on that made recovery a very long, tedious process--even
without considering the fuel damage done).

I felt after walking through the TMI-2 Control Room later in
1979, while the post-accident recovery process was still going
on, that the deck was stacked against the ROs in many ways.  For
example, some critical devices required going around stacks of
instrument modules to be properly checked--and then to discover
that critical devices/back-up systems were tagged out of service,
etc.!  Time, at the critical point, was not a luxury to be
wasted...

Regarding the Nuclear Navy relationship, it is true that Jack H.
(the resident nuke Manager of Nuclear Operations in the famous
black trailer) got much of the operating utility's blame, but I
can guarantee that not all of the events leading up to the
accident were in his realm of empowerment and few individuals
could have worked harder to mitigate the situation afterwards.
Being a dedicated engineer with a total sense of ownership is not
always good enough...no one can really do everything at a large
nuclear facility by themselves.

Clearly, my opinions on a now distant historical event.

May you never lose the bubble!

S.,

MikeG.

At 02:15 PM 3/12/98 -0600, you wrote:
>Please consider the following in assessing the actions and attitudes at
TMI-2 on
>March 28, 1979.
>
>Notification of the sticking problem with the PORV had been submitted to
NRC for
>distribution and was stagnant somewhere at NRC in Washington that morning.
 The
>TMI-2 operators had not been alerted.
>
>All training for PWRs emphasize the catastrophic potential consequences of
>having a solid condition (no bubble in the pressurizer) in a PWR.
>
>Among all the lights and bells on that morning, the perssurizer level
indicated
>high and the PORV position indicator indicated that the valve was closed.
These
>in combination indicated that the system was either solid or very nearly
so. Due
>to poor design, both indications were wrong.
>
>When the High Pressure Injection system actuated as it should have, the other
>indications said it might be injecting into a solid primary system-this would
>lead to the worst possible accident. The HP Injection was secured causing the
>core to be uncovered and the fuel to melt.
>
>It's too easy to second guess and lay blame but I for one am glad I didn't
have
>to face that situation that morning.


Michael P. Grissom
Asst Dir (ES&H)
SLAC MS-84
Phone: (650) 926-2346
Fax:   (650) 926-3030
E-mail: mikeg@slac.stanford.edu