United States Nuclear Regulatory Commission - Protecting People and the Environment

Line-Item Improvements in Technical Specifications - Removal of the 3.25 Limit on Extending Surveillance Intervals (Generic Letter 89-14)

 August 21, 1989



TO:       ALL LICENSEES OF OPERATING PLANTS, APPLICANTS FOR OPERATING 
          LICENSES, AND HOLDERS OF CONSTRUCTION PERMITS

SUBJECT:  LINE-ITEM IMPROVEMENTS IN TECHNICAL SPECIFICATIONS - REMOVAL OF THE
          3.25 LIMIT ON EXTENDING SURVEILLANCE INTERVALS (GENERIC LETTER 
          89-14)


Specification 4.0.2 of the Standard Technical Specifications allows surveil-
lance intervals to be extended up to 25 percent of the time interval 
specified.  In addition, this specification limits the combined time interval 
for any three consecutive surveillance intervals to less than 3.25 times the 
specified surveillance interval.

A lead-plant proposal was submitted by Commonwealth Edison for the LaSalle 
Technical Specifications (TS) to modify the 3.25 limitation on extending sur-
veillance intervals.  Based on the review of the Commonwealth Edison proposal, 
the NRC staff concludes that the removal of the 3.25 limit from Specification 
4.0.2 results in a greater benefit to safety than limiting the use of the 25- 
percent allowance to extend surveillance intervals.  The enclosed guidance is 
provided for the preparation of a license amendment request to implement this 
line-item improvement in TS.

Licensees and applicants are encouraged to propose changes to plant TS that 
are consistent with the guidance provided in the enclosure.  Conforming 
amendment requests will be expeditiously reviewed by the NRC Project Manager 
for the facility.  Proposed amendments that deviate from this guidance will 
require a longer, more detailed review.  Please contact the Project Manager if
you have questions on this matter. 

                                        Sincerely,


                                        James G. Partlow
                                        Associate Director for Projects
                                        Office of Nuclear Reactor Regulation

Enclosures: 
1.  Guidance for the Preparation of a License Amendment Request to Remove the 
    3.25 Limit of Extending Surveillance Intervals
2.  List of Most Recently Issued NRC Generic Letters


8908210105
.                                                           Enclosure 1


         GUIDANCE FOR THE PREPARATION OF A LICENSE AMENDMENT REQUEST TO
            REMOVE THE 3.25 LIMIT ON EXTENDING SURVEILLANCE INTERVALS

BACKGROUND

Specification 4.0.2 of the Standard Technical Specifications permits surveil-
lance intervals to be extended up to 25 percent of the specified interval.  
This extension facilitates the scheduling of surveillance activities and 
allows surveillances to be postponed when plant conditions are not suitable 
for conducting a surveillance, for example, under transient conditions or 
other ongoing surveillance or maintenance activities.  Specification 4.0.2 
also limits extending surveillances so that the combined time interval for any 
three consecutive surveillance intervals shall not exceed 3.25 times the 
specified surveillance interval.  The intent of the 3.25 limit is to preclude 
routine use of the provision for extending a surveillance interval by 25 
percent.

Commmonwealth Edison Company (CECo) submitted a lead-plant proposal for the 
LaSalle Technical Specifications (TS) to remove the 3.25 limit for surveil-
lances that are performed during a refueling outage and are specified with an 
18-month surveillance interval.  After discussions with the staff, CECo 
amended the proposal to remove the 3.25 limitation for all surveillances.  The
amended proposal was approved by the staff on a lead-plant basis.  Consistent 
with NRC policy, this Generic Letter provides guidance for license amendment 
requests to implement this line-item improvement in TS.

DISCUSSION

Experience has shown that the 18-month surveillance interval, with the provi-
sion to extend it by 25 percent, is usually sufficient to accommodate normal 
variations in the length of a fuel cycle.  However, the NRC staff has 
routinely granted requests for one-time exceptions to the 3.25 limit on 
extending refueling surveillances because the risk to safety is low in 
contrast to the alternative of a forced shutdown to perform these 
surveillances.  Therefore, the 3.25 limitation on extending surveillances has 
not been a practical limit on the use of the 25-percent allowance for 
extending surveillances that are performed on a refueling outage basis.

The use of the allowance to extend surveillance intervals by 25 percent can 
also result in a significant safety benefit for surveillances that are 
performed on a routine basis during plant operation.  This safety benefit is 
incurred when a surveillance interval is extended at a time that conditions 
are not suitable for performing the surveillance.  Examples of this include 
transient plant operating conditions or conditions in which safety systems are
out of service because of ongoing surveillance or maintenance activities.  In 
such cases, the safety benefit of allowing the use of the 25-percent allowance 
to extend a surveillance interval would outweigh any benefit derived by 
limiting three consecutive surveillance intervals to the 3.25 limit.  Also, 
there is the administrative burden associated with tracking the use of the 
25-percent allowance to ensure compliance with the 3.25 limit.  On the basis 
of these considerations, the staff concluded that removal of the 3.25 limit 
will have an overall positive impact on safety. 

An acceptable alternative to the existing requirements of Specification 4.0.2 
is the following:
.                                     - 2 - 


     4.0.2  Each Surveillance Requirement shall be performed within the 
     specified surveillance interval with a maximum allowable extension not to 
     exceed 25 percent of the specified surveillance interval.

Licensees should also propose changes to update the Bases Section of 
Specification 4.0.2.  Generic Letter 87-09 provided updated Bases for 
Specification 4.0.2.  The following changes to the Bases of Specification 
4.0.2, as provided in Generic Letter 87-09, are shown underlined to reflect 
this change. 

     Specification 4.0.2 establishes the limit for which the specified time 
     interval for Surveillance Requirements may be extended.  It permits an 
     allowable extension of the normal surveillance interval to facilitate 
     surveillance scheduling and consideration of plant operating conditions 
     that may not be suitable for conducting the surveillance; e.g., transient
     conditions or other ongoing surveillance or maintenance activities.  It 
     also provides flexibility to accommodate the length of a fuel cycle for 
     surveillances that are performed at each refueling outage and are spec-
     ified with a 12-[an 18-]month surveillance interval.  It is not intended 
     that this provision be used repeatedly as a convenience to extend 
     surveillance intervals beyond that specified for surveillances that are 
     not performed during refueling outages.  The limitation of Specification 
     4.0.2 is based on engineering judgement and the recognition that the most 
     probable result of any particular surveillance being performed is the 
     verification of conformance with the Surveillance Requirements.  This 
     provision is sufficient to ensure that the reliability ensured through 
     surveillance activities is not significantly degraded beyond that 
     obtained from the specified surveillance interval. 

SUMMARY

This alternative to the requirements of Specification 4.0.2 will remove an un-
necessary restriction on extending surveillance requirements and will result 
in a benefit to safety when plant conditions are not conducive to the safe 
conduct of surveillance requirements.  The removal of the 3.25 limit will 
provide greater flexibility in the use of the provision for extending 
surveillance intervals, reduce the administrative burden associated with its 
use, and have a positive effect on safety.

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