Root cause analysis at the Savannah River Plant Page: 2 of 6
6 pagesView a full description of this article.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
ROOT CAUSE ANALYSIS AT SAVANNAH RIVER PLANT
By: Mark Paradies
Savannah River Plant
Building 105-C
Aiken, SC 29808-0001
Ph. (803) 557-9887
ABSTRACT
Events (or near misses) provide important information about ways
to improve plant performance. Any particular event may have
several "root causes" that need correcting to prevent recurrence of
the event and, thereby, improve the safety of the plant. Also, by
reviewing a large number of events, one can identify cause trends or
"generic concerns." A method has been developed at Savannah
River Plant (SRP) to systematically evaluate events, identify their
root causes, record the root causes, and analyze the root cause
trends. By providing a systematic method to identify correctable
root causes, the system helps the event investigator ask the right
questions during the investigation. It also provides an independent
safety analysis group and management with statistics indicating
existing and developing trouble spots.
DEVELOPING A ROOT CAUSE ANALYSic SYSTEM
Although events at SRP's reactors were being investigated and
reported in "Reactor Incident" (RI) reports, management and the
independent safety evaluation groups were concerned that RIs didn't
get to a level of detail that would allow correcting the event's root
cause. Also, there was concern that the RI cause coding system
didn't allow analysis of event cause trends for areas of generic
concern. Therefore, in November of 1985, the Reactor Safety
Evaluation Division (RSED) began to study methods to determine
and analyze the root causes of events. We tried to find a system
already in use in the utility industry that would meet our needs.
However, we found little agreement on the definition of a root
cause, much less on an accepted method to analyze it. This was
especially true for root causes that involved human error. Therefore
we created a new system by starting with the best parts of several
systems we had studied.David Busch
Savannah River Laboratory
Building 773-4IA
Aiken, SC 29808-0001
Ph. (803) 725-5261
The first task in creating this new root cause analysis system was to
define a "root cause." Our definition is:
ROOT CAUSE: The most basic cause that can
reasonably be identified and that management has
control toftx.
The three key words in this definition are basic, reasonable, and fix.
To attempt to reach a basic level m an event, the investigator (or
investigating team) keeps asking additional "Why?" questions.
However, there is only a limited amount of time and resources for
any investigation, so the investigator must decide when a reasonable
number of "Why?" questions have been asked. This is where the
word fix plays an important role. When the root cause level is
reached, the fix that will prevent the event from recurring seems
obvious. If an investigation stops before this level is reached (or if
it isn't possible to reach this level due to the type of event) then the
fix will not be obvious and may or may not prevent recurrence of the
event. So if a fix is obvious, then the investigation is both basic
enough and reasonable. If a fix is still uncertain, then the
investigator and management need to decide if continued effort to
find a root cause is worth the benefit of preventing recurrence of the
event.
Providing the investigators with a definition of a root cause was not
enough to ensure that all the root causes were reached in a particular
event. We wanted to give the investigators a fairly inclusive list of
the types of root causes that they could find. We wanted to provide
the list in an easy to understand format that would lead the
investigator to the right answers. Therefore, we developed a root
cause analysis system that starts with Events and Causal Factors
Charting and includes a Root Cause Analysis Tree.Initial Cond
Reactor OnEVENT
itions: -
-Line
Operator Assigned Operator Technician Valve
to Lineup Valves Performs Begins Rx SS-3412-A
for Shutdown Valve Systemn Tops Found Open
System Testing Ltne-up Test !Insteaa o' Snut
OperatorVane Because o! Open
ratord SS-3412-A Lett Valve, Shutdown Signal
tsd Open requiredd position Actuates 2 of 3 Detectors and
u*shut) Causes Trin
dperto sk Technician used
Procedure and properly
CAUS AL performed test
FACTORFIGURE 1: EXAMPLE EVENTS & CAUSAL FACTORS CHART
REASON FOR
INVESTIGATIONundie
had per
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Paradies, M & Busch, D. Root cause analysis at the Savannah River Plant, article, January 1, 1988; United States. (https://digital.library.unt.edu/ark:/67531/metadc1058071/m1/2/: accessed July 16, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.