1. Malfunction with a Different Result
DM Result - 1
Malfunction with a Different Result
Different
Malfunctions
What constitutes a malfunction with a different result?
© 2006 L.A. Grime, PE

2. Malfunction with a Different Result
Would the activity create the possibility for a malfunction of an SSC important to safety with a different result than any previously evaluated in the UFSAR?

3. Identifying Different Accidents
NEI 96-07, 4.3.6, Rev 1, Does the Activity Create a Possibility for a Malfunction of an SSC Important to Safety with a Different Result?
Review malfunctions from failure analysis
Include licensing basis required malfunctions

4. Different Results Demonstration
NEI 96-07, 4.3.6, Rev 1, Does the Activity Create a Possibility for a Malfunction of an SSC Important to Safety with a Different Result?

5. Different Malfunction Result Example
NEI 96-07, 4.3.6, Rev 1, Does the Activity Create a Possibility for a Malfunction of an SSC Important to Safety with a Different Result?
A substantial modification or upgrade to control station alarms, controls, or displays that are associated with SSCs important to safety that creates a new or common cause failure that is not bounded by previous analyses or evaluations would be a malfunction with a different result.

6. Different Malfunction Result Justification
No adverse effects possible
Equivalent to existing acceptable condition
Hypothesized different malfunction results lack credibility
beyond licensing basis requirements
malfunction result probability, if calculated, is less than 1E-7 or 1E-6/year in some cases
Bounded by existing malfunction results
Example: If a component meets seismic criteria, the seismically induced failure of the component is considered incredible.

7. Different Malfunction Result Analysis
NEI 96-07, 4.3.6, Rev 1, Does the Activity Create a Possibility for a Malfunction of an SSC Important to Safety with a Different Result?
Consider if malfunctions were analyzed at the system or component level in the UFSAR
Determine if malfunctions that were considered incredible would become credible

8. Different Malfunction Logic
DM Result - 8
Different Malfunction Logic
Could activity initiate any non-UFSAR-described malfunction results? No
NO, not a different malfunction result
Are malfunction results credible?
Yes No
Yes
Are results beyond the bounds of existing malfunction results? No
YES, a different malfunction result
Yes
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9. DM Result - 9
Points to remember...
Keep the different malfunctions focus on the malfunction results.
If the activity could initiate a non-UFSAR-described malfunction result, it is a different malfunction result, unless the result is incredible or bounded by a UFSAR-described malfunction result.