ML20138L066
| ML20138L066 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/10/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20138L063 | List: |
| References | |
| NUDOCS 9702200350 | |
| Download: ML20138L066 (4) | |
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4 UNITED STATES s
j NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 300SHWD1
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0. 213 TO FACILITY OPERATING LICENSE NO. NPF-3 TOLEDO EDISON COMPANY CENTERIOR SERVICE COMPANY m
j THE CLEVELAND ELECTRIC ILLUMINATING COMPANY j
DAVIS-BESSE NUCLEAR POWER STATION. UNIT NO. 1 l
DOCKET NO. 50-346 I
l.0 INTRODUCTION i
By letter dated August 7,1996, Toledo Edison Company, Centerior Service Company, and The Cleveland Electric Illuminating Company (the licensees),
submitted a request for changes to the Davis-Besse Nuclear Power Station i
(DBNPS), Unit No.1, Technical Specifications (TS) as a cost beneficial licensing action. The requested amendment would revise TS 1.0, " Definitions,"
by defining a refueling interval to be s 730 days; and would revise TS 3/4.0,
" Applicability," TS 3/4.6.2.1, " Containment Systems - Depressurization and Cooling Systems - Containment Spray System," and TS 3/4.6.3.1, " Containment i
Systens - Containment Isolation Valves," to reflect performing surveillance tests during a refueling interval rather than every 18 months.
2.0 EVALUATION i
DBNPS has proposed increasing surveillance intervals from 18 months to s 730 days based on an increased fuel cycle. The licensees propose to add a i
definition of a REFUELING INTERVAL as s 730 days in TS 1.0, " Definitions," and 4
l change the 18-month interval to REFUELING INTERVAL. The licensees plan to submit the changes to accommodate a longer refueling interval in several submittals to ease preparation and review. These proposed changes are submitted as cost beneficial licensing actions. The first submittal addresses adding the j
definition of REFUELING INTERVAL, modifies the interval for TS 3/4.6.2.1,
" Containment Systems - Depressurization and Cooling Systems - Containment Spray i
System," TS 3/4.6.3.1, " Containment Systems - Containment Isolation Valves," and adds a change to the TS Bases to address the longer refueling interval.
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Generic Letter (GL) 91-04, " Changes In Technical Specification Surveillance Intervals to Accommodate a 24-Month Fuel Cycle," provides guidance on changing i
TS to accommodate a longer fuel cycle. As discussed in the GL, the TS that specify an 18-month surveillance interval could be changed to state that these d
surveillances are to be performed once per refueling interval. The GL states 9702200350 970210 PDR ADOCK 05000346 P
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that the notation for surveillance intervals would then be changed to include the definition of a " Refueling Interval" for surveillances that are generally performed during a refueling outage. The GL addresses the provision to extend surveillances by 25 percent of the specified interval to extend the time limit for completing these surveillances from the existing limit of 22.5 months to a maximum of 30 months. Therefore, the proposed changes to add a definition of REFUELING INTERVAL of s 730 days and to allow the continued application of TS 4.0.2, which allows surveillance intervals to be increased up to 25% on a l
non-routine basis (nominally 30 months) is in accordance with the GL. The l
licensees propose to add a paragraph to Bases 4.0.2, consistent with GL 91-04, that ensures that surveillances are performed consistent with safe plant operation. This TS Bases section already includes clarification that the allowable tolerance not be used as a convenience to repeatedly schedule the l
performance of surveillances at the allowable tolerance limit. The licensees l
have not included a proposed change to TS Table 1.2, " Frequency Notation," which currently defines "R" as at least once per 18 months.
The "R" notation which is used in the GL to refer to refueling interval will be included in a later amendment request that addresses changes to instrumentation surveillance frequencies.
In addition, the GL requests the licensee to perform an evaluation of each change of surveillance interval. This evaluation entails reviewing the l
historical maintenance and surveillance test data at the bounding surveillance l
interval limit, supporting a determination that a 24-month surveillance test l
interval would not invalidate any assumption in the plant licensing basis, and that the effect on safety is small.
TS Surveillance Requirement (SR) 4.6.2.1.b requires that each Containment Spray System (CSS) shall be demonstrated OPERABLE at least once per 18 months, during shutdown, by performing the activities listed in SR 4.6.2.1.b.1 and SR 4.6.2.1.b.2.
SR 4.6.2.1.b.1 requires that each automatic valve in the flow path be verified as actuating to its correct position on a containment spray test signal. The CSS containment isolation valves open on a Safety Features Actuation System (SFAS) Incident Level 2.
The containment spray pumps start on an SFAS Incident Level 4.
The licensees evaluated the 18-month TS surveillance test data for the CSS automatic valves CS 1530 and CS 1531 and CSS pumps CS 1-1 and CS 1-2 for the period since 1985. This period was selected as most representative of current operating condition since many changes occurred after the loss of feedwater event in 1985. The duration includes five refueling outages and four operating cycles of test results. No test failures for these components occurred over the period reviewed.
The licensees reviewed the maintenance history of CS 1530, CS 1531, CS 1-1, and CS 1-2.
Although several instances of bearing wear were noted, the bearing wear did not render the pumps inoperable. A modification was made to the coupling hubs for CS 1-1 and CS 1-2 during the last refueling outage to ensure long-term reliability.
The licensees concluded that based on the historical good performance of CSS components, the low potential for significant increases in failure rates under a longer test interval, and the introduction of no new failure modes that it was acceptable to increase the surveillance test interval from every 18 months to every REFUELING l
INTERVAL. The staff has reviewed this information and concludes that the licensee has adequately analyzed the effect of the changes on safety.
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i TS 4.6.3.1,2 requires that each isolation valve shall be demonstrated OPERABLE during the COLD SHUTDOWN or REFUELING MODE, at least once per 18 months by performing the activities listed in SR 4.6.3.1.2.a and SR 4.6.3.1.2.b.
Surveillance Requirement 4.6.3.1.2.a requires verification that on a containment isolation test signal, each automatic isolation valve actuates to its isolation position. Surveillance Requirement 4.6.3.1.2.b requires verification that each l
purge and exhaust automatic valve actuates to its isolation position on a containment purge and exhaust isolation test signal. The licensees propose to change "during COLD SHUTDOWN or REFUELING MODE at least once per 18 months" with "each REFUELING INTERVAL." Technical Specification 4.0.2 would continue to apply which would allow increasing the new surveillance interval on a non-routine basis from 24 months to 30 months. The licensees provided a list of the specific valves in these two categories. The staff reviewed the list against Updated Safety Analysis Report Table 6.2-23, Containment Vessel Isolation Valve Arrangements, and determined that the scope of valves included in the license amendment application was complete. The licensees' review of surveillance test data and maintenance history discovered four test deficiencies since 1935. None of the deficiencies indicated any programmatic concern with valve maintenance or operation.
In general, unless plant conditions or other circumstances prohibit valve stroking at power, containment isolation automatic valves are stroke-tested quarterly in accordance with ASME Section XI Inservice Testing Program.
The containment purge and exhaust automatic isolation valves are maintained closed with control power off in Modes 1 through 4.
The licensees conclude that L
the potential impact on safety is small since no additional failure modes are l
introduced and the potential for significant increases in failure rates of these components under a longer test interval is low. The staff has reviewed this information and concludes that the licensee has adequately analyzed the effect I
of the changes on safety.
Since the proposed changes are consistent with the guidance in GL 91-04, the staff finds these proposed changes acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Ohio State official was notified of the proposed issuance of the amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
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This amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or changes a surveillance requirement. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent that may be released offsite, j
and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a i
proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (61 FR 52970). Accordingly, the amendment meets the eligibility criteria for i
categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to l
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4-l 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not l
be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
L. Gundrum i
Date:
February 10, 1997 i
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