Loading ...
Sorry, an error occurred while loading the content.

Ramblings on Evidence

Expand Messages
  • richr192220
    The current discussion on why the human psyche takes certain actions, while certainly pertenant to the possibility of helping the individual understand his or
    Message 1 of 2 , Aug 2, 2002
      The current discussion on why the human psyche takes certain actions,
      while certainly pertenant to the possibility of helping the
      individual understand his or her own actions, we must be careful in
      pursuit of this type of root cause. Remember, our job is to prevent
      the next person from making the same mistake. My assumption here is
      that the sharp end will learn sufficiently to prevent their own
      recurrence. The need for root cause is minimal if all we can help is
      the individual who commited the initiating action.

      This brings us back to the system that has the potential to allow the
      action to recur. Certainly if the system you are working in is
      rewarding the initiating action, the desire of someone else to take
      that same action is high indeed. Now, given the confluence of other
      internal and external factors that led to the previous consequence,
      this action may or may not, in and of itself, have a consequence (in
      the context of a significant event).

      Let us examine your "lawn mower" event as if it were significant
      enought (safety or economic consequence) to cause us to spend the
      resources to do a root cause. The function of the root cause is to
      prevent what ever happened to your spouse from happening to you (and
      possibly your kids). In viewing the actions taken by the "light of
      our lives", it is important to question whether others would have
      taken the same action given the same conditions.

      I typically view the human element of an event based on the internal
      and external elements that led to the decision that resulted in the
      intiating action. To my way of thinking it is important to understand
      what caused the person at the sharp end to make the decision and how
      those internal and external factors could be applied to the next
      person. It is in that understanding of how to apply the decision to
      the next person that "root cause" drilling begins.

      To sum all of this up, I subscribe to the theory developed by William
      Powers that: "Our perceptions are the only reality we can know, and
      the purpose of all our actions is to control the state of this
      perceived world."
    • Dr. Bill Corcoran at NSRC
      Richard, Thanks for your posting. Poka-Yoke has not hit the nuclear industry yet. It will be interesting when it does. As to your comments on engineering:
      Message 2 of 2 , Aug 6, 2002
        Thanks for your posting.
        "Poka-Yoke" has not hit the nuclear industry yet. It will be interesting when it does.
        As to your comments on engineering: The engineering logic that it takes to go from a crack to severe RVH degradation is not complex. I outlined it in my article (posted in the files section of the DBRVH e-group).  I have been in many meetings of PORC's and OSSRC's in which comparable scenarios have been rolled out to help decide how far to chase an anomaly. why didn't it happen at D-B?
        Can you explain the term "vital 70"? Does this refer to someone's observation that there are about seventy people who have significant influence on what happens at a nuclear plant? Do you have any links? How should we be applying this idea to the near miss LOCA?
        New topic: Have you thought of the near miss LOCA in terms of process effectiveness? How come so many processes failed?
        Best Regards,
        Bill Corcoran
        W. R. Corcoran, Ph.D., P.E.
        Nuclear Safety Review Concepts
        21 Broadleaf Circle
        Windsor, CT 06095-1634
        860-285-8779 Fax: 702-993-2408
        Mission: Saving lives, pain, assets, and careers through thoughtful inquiry.
        Check out our e-groups  at
        where you will find all back issues of "The Firebird Forum" and at
        where you will find a dialogue on the Davis-Besse near miss LOCA., including photos, polls, files, tables, and links.
        For a complimentary subscription to our e-newsletter on root cause, organizational learning, and safety send a message to firebird.one@...
        Visit our web site at http://pages.prodigy.net/corcoran.nsrc/index.html
        ----- Original Message -----
        Sent: Monday, August 05, 2002 8:53 PM
        Subject: [Root_Cause_State_of_the_Practice] Ramblings on Evidence


        Thank you for the education on "Poka-Yoke". This was a term I had not
        heard and it was interesting reading.

        As to your question on the Davis-Besse near miss LOCA:

        1.  The engineers did not believe that boric acid left on the reactor
        vessel head could result in a significant problem. Since most
        engineers who have been in the industry for a period of time have
        seen such results, this explanation must go an extra step. The
        engineers viewed the condition using the "perfect" environment. That
        is, they did not look for ways in which the boric acid could become
        or remain wetted. So they did not ask, "what would happen if the
        conditions were right for the boric acid corrosion to occur?" Why
        not? We will see that when we get to the management portion of the

             How does this apply outside of the nuclear industry?  Let us
        suppose the next time you are getting ready to fly as you board the
        major airliner you find out that the emergency oxygen system has been
        disabled.  As fate would have it you the engineers are present and
        reassure you by saying that it is a bright sunny day between here and
        your destination and these "perfect" conditions will preclude you
        from needing the system. Would this bother you?  Are there any times
        you drive without a seat belt? Do you use as your excuse that the
        conditions are "perfect" (dry roads, no traffic, etc.) and therefore
        you won't need it? These would be examples of the type of thinking
        that was going on at Davis Besse.

        2.  The failure to fully evaluate the remaining indications stem from
        the belief that "everything else is okay" so this must be just an
        anomaly that will eventually take care of itself. IT WORKS! IT'S JUST
        DIFFERENT. Davis Besse had dealt with other issues in the near past
        (pressurizer safety relief) and although it is unlikely to be
        contributing to the indications in the containment air coolers or the
        radiation element filters, everything else appears to be operating
        okay, so this must just be a situation that has to continue to fix
        itself after the problems we had. One might ask why they didn't
        pursue these conditions and that will take us to the management tone
        that was set for the organization.

        Let us do some none nuclear applications. Have you ever had something
        wrong with you, but waited to go to the doctor? Why? Certainly you
        expected it to go away. I personally waited nine months to find out
        that the growth that I had was not going to go away on its own. In
        fact, it is interesting to note that many illnesses are made much
        more serious by not taking the time to care for them. Or, I had a
        dear friend who found that he could continue to operate his car for a
        period of time after the oil light came on. The car worked, it was
        just different with the light on. He would drive to the gas station,
        add a quart of oil and continue on. After about a year the engine
        seized and he had to replace the whole thing. It is obvious that
        these are everyday occurrences. What makes this situation different
        is that we are talking engineers. By the nature of the profession
        they chose one would expect them to be more curious than the rest of
        us meer mortals. But in this case, apparently not.

        The preceeding represents the front-line. But they were not alone. My
        premise is that management establishes the tone of an organization or
        an activity. A percentage of the people (I use 20%) will go beyond
        the tone established by management to ensure that their tasks and
        activities are done the best they can do them. A percentage of the
        people (I use 2%) will find the way to live strictly by the letter of
        the managment policies and procedures so as to keep their job.
        Finally, the rest of the people (what Jack Welsh calls the "vital
        70") will perform their activities to the best of their abilities to
        meet what they view as the tone of the organization estalished by
        management. I view the group of engineers addressed earlier in this
        discussion as in the "vital 70". So what kind of tone did managment
        present to these employees?

        1.  From the Nuclear Assurance Director: A visual inspection of the
        reactor pressure vessel head is not an NRC commitment.

        2.  When a front-line person requested a modification that would
        allow a rigorous inspection of the reactor pressure vessel head, the
        modification was approved but not funded. Even when it was funded
        four years latter, it was scheduled four years in the future. And
        finally, that modification date was delayed due to reduce the number
        of modifications installed during the outage.

        3.  From a line manager. Nozzle cracking is of cours a significant
        issue. However, at present, the probability of occurrence is
        relatively low. We should remove boron form the reactor pressure
        vessel head as best we can and so as to minimze dose. This will allow
        us to monitor any leakage, should a nozzle crack occur.

        So what is the "tone" being set for the "vital 70". I would argue
        that "boric acid on the reactor head is not a problem." How would you
        respond to that "tone"? Most people, the "vital 70" would not view
        boric acid on the reactor vessel head as a significant problem. And,
        if that is not a problem, then containment air cooler fins and
        radiation elements filters must be just an anomaly that will fix
        themselves given time.

        So there you have have it. A rather long winded answer to a short
        question. The real answer: If you work for a company and you are
        among the "vital 70", know who the 20% are and listen to them. -


      Your message has been successfully submitted and would be delivered to recipients shortly.