Deck 1

Question 1

EXPLAIN the conditions requiring entry into the Operability Determination Process as described in NRC Inspection Manual Chapter (IMC) 0326.

Answer 1

– Loss of “Presumption of Operability”
• IMC 0326 Section 6.5
– Many possible sources of information
– Extent of Condition concern for “similarly affected
SSCs”
• Can be handled under original OD, or can be
addressed with a separate OD
• IMC 0326 Section 6.7
• NMP-AD-012 Sections 3.1.4 and 4.3.1.5

Question 2

Definition of Operable/Operability

Answer 2

A system, subsystem, train, component, or device shall be OPERABLE or have OPERABILITY when it is

capable of performing its specified safety functions, and

when all necessary attendant instrumentation, controls, normal or emergency electrical power, cooling and seal water, lubrication, or other auxiliary equipment that are REQUIRED for the system, subsystem, train, component, or device to perform its function(s)

are also capable of performing their related support function(s).

Question 3

Who determines if an Operability Determination is required?

Answer 3

SRO’s responsibility to determine if an OD is required.

Question 4

Timing of Operability Determinations

Answer 4

– No specific guidance is given in IMC 0326 for time allowed to complete an OD other than it should be done “promptly” based on the complete set of information.
– SNC procedure provides more guidance, as we’ll discuss later.

Question 5

What constitutes loss of presumption of operability?

Answer 5

– IMC 0326 Sections 6.2
• Presumption of Operability is lost when it is
“apparent that a condition has been identified that
causes a substantive (i.e. non-trivial) functional
impact during the REQUIRED mission time or would
be expected to have a substantive functional impact
during an event requiring the SSC to perform its
specified safety function.
– SRO is responsible for identifying the loss of presumption of operability.

Question 6

Scope of Determinations

Answer 6

• Limited to SSCs described in Technical Specifications (TS)
– SSCs directly described in TS
– SSCs that provide necessary and required support
functions to SSCs described in the TS
• Focused on Safety
– Includes all actions necessary to assess capability
of SSCs to perform specified safety functions
• Presumes the Design Basis Event occurs
– Fundamental concept
• Operability determines SSCs’ ability to perform specified safety function(s) in response to DBA

Question 7

“Necessary” definition

Answer 7

“Necessary” means it is needed to ensure SSC performs its “specified safety function”.

(In regards to, the Support Systems link to the “Specified Safety Function”.)

Question 8

“Required” definition

Answer 8

“Required” considers the actual conditions while the
Corrective Action occurs.

(In regards to, the Support Systems link to the “Specified Safety Function”.)

Question 9

Operability Determinations procedure at SNC

Answer 9

NMP-AD-012

Question 10

TREC

Answer 10

Three Required Entry Criteria

• Criterion 1
– The deficient condition must affect a TS SSC
installed at an operating unit.
• Criterion 2
– The deficient condition must have a functional
impact on the SSC. This includes the ability to
perform required functions under postulated, off-
normal design conditions.
• Criterion 3
– The functional impact of the deficient condition
must be substantive (i.e. non-trivial)
• This language is directly from IMC 0326
– NMP-AD-012 states that determination of
substantive functional impact should be based on
a simplistic evaluation, and provides two examples.
• Ex. 1 – The deviation from as-designed values is
more than approximately 10%
• Ex. 2 – Closed system leakage greater than 1%
of operating volume per day.

Additional notes:
• In order to challenge operability, deficient conditions must satisfy all of the TREC.
• If any of the criteria are not met, entry into the OD process is NOT REQUIRED.

Question 11

OD time frame

Answer 11

ODs are normally supposed to be completed within 24
hours.
???

Question 12

Where are OD’s documented?

Answer 12

ODs will be documented in the Work Log Tab of the CR describing the deficient condition.
(from V-ES-PP-63012 page 79, slide 86)

Question 13

What information will ODs will generally include?

Answer 13

– The SSC affected by the deficient condition, and the
nature/severity of the deficiency
– Applicable TS, required Mode or Condition of
Applicability
– The SSC specified safety functions (SSF) related to
the deficient condition
– Potential effect of the deficient condition on the
SSC’s ability to perform its SSF for its mission time.
– Description of the extent of condition performed on
similar SSCs
– Whether additional information is needed in support
of the OD.
• The initial OD should document the basis of a
reasonable expectation of operability while the
follow-up information is being prepared.

Question 14

OD’s possible conclusions?

Answer 14

• The OD will yield one of three possible conclusions:
– The SSC is operable, and additional information is
not expected to change the conclusion.
– The SSC is inoperable.
– The SSC maintains a reasonable expectation of
operability while more information is obtained to
confirm the initial determination.

Question 15

???

Answer 15

Timeliness of completing the supporting basis shall be
commensurate with the safety significance of the SSC and
the severity of degradation.
– Often uses the TS completion time as a guide
– Due dates beyond the TS completion time require
Operations Director concurrence.

Question 16

ASME Pressure Boundary Challenges

Answer 16

• When a condition calls into question ASME Class
pressure boundary integrity, specific considerations must be considered
– Per IMC 0326 section 8.13, when ASME Class 1
components have pressure boundary leakage, the
components must be declared inoperable.
• An operability determination cannot conclude
reasonable assurance of operability in these
cases.
– NMP-ES-077, Processing ASME Class 2 and 3
Pressure Boundary Integrity Challenges, provides
specific guidance to assess operability for Class 2
and 3 Pressure Boundary issues.

Question 17

Margin Model ???

Answer 17

???

Question 18

Procedure for pressure boundary integrity issues

Answer 18

NMP-ES-077
(Processing ASME Class 2 and 3 Pressure
Boundary Integrity Challenges.)

Question 19

Procedure for Operability Determination

Answer 19

NMP-AD-012

Question 20

Specified Function/Specified Safety Function (definition)

Answer 20

– IMC 0326, Section 4.10
• The specified safety function in the Current
Licensing Basis
• Must perform as designed, tested, and maintained

Question 21

Support Function(s) (definition)

Answer 21

– IMC 0326 Section 8.10
• Focused on Specified Safety Function(s)
• Necessary support systems
– Technical understanding of relationships is
mandatory

Question 22

Timing of Operability Determinations

Answer 22

• Normally continuous
– Normal Surveillances
• Assessment of Surveillance results
– Surveillance performance required for
Operability of Technical Specification
equipment
– Additional ongoing activities
• Day-to-day operation
• Additional programs such as IST
• Walkdowns and tours
• Control Room Observations
• Quality Assurance Audits and Reviews
• Engineering Design Reviews
• With no adverse indication, normal surveillances are
sufficient basis for continued operability
– “Presumption of Operability” is based upon specific sets of facts
• IMC 0326 Section 6.2

Question 23

Upon discovery of condition that results in the loss of the presumption of operability?

Answer 23

• SRO’s responsibility to determine if an OD is
required.
• Normal surveillance alone is not sufficient
– Repetitive testing with unknown Root Cause not
acceptable
• Must have a “Reasonable Expectation” of operability
to not declare SSC inoperable.

Question 24

What constitutes loss of presumption of operability?

Answer 24

Presumption of Operability is lost when it is “apparent that a condition has been identified that causes a SUBSTANTIVE (i.e. non-trivial) functional impact during the required mission time or would be expected to have a substantive functional impact during an event requiring the SSC to perform its specified safety function.

SRO is responsible for identifying the loss of presumption of operability.

Question 25

Design Basis Event

Answer 25

– Reported in UFSAR
– Credible
   • Within range of assumptions previously considered, 
      examples:
          – Single failure
          – Loss of power

Question 26

Compensatory Actions

Answer 26

– Implemented with the 10 CFR 50.59 process
• Consider only the comp action, not initial condition
– Use of Manual Actions is restricted/limited
• IMC 0326 Section 8.5 for Automatic to Manual
Actions

Question 27

Mission Time (defintion)

Answer 27

The duration of SSC operation that is credited in the design basis for the SSC to perform its Specified Safety Function.
(Mission Times are found in the UFSAR and NMP-AD-012-GL04)
(PRA mission times should NOT be used when evaluating operability)

Question 28

NOED

Answer 28

Notice of Enforcement Discretion (NOED)

“If strict compliance with a Technical Specification would cause an unnecessary action not in the best interest of public health and safety, a Notice of Enforcement Discretion (NOED) can be requested.”