ML20128F435
| ML20128F435 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/01/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20128F409 | List: |
| References | |
| NUDOCS 9302110389 | |
| Download: ML20128F435 (5) | |
Text
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/'o ng,4*t UNITED STATES 8
NUCLEAR REGULATORY COMMISSION
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.I W ASHINGT ON. D. C. 20%$
SAFETY EVALVAT10ft BY THE OFFICE OF NVCLEAR REACTOR RECVLATIQ!{
RELATED TO AMEf4D11ENT NO.135 TO FACILITY OPERATING LICENSE f1PF-2 afELAtiM0!iMT NO.117 TO FACILITY OPERATING _J.lCENSE NPF _17 DELfqWER COMPANY MCGUIRE NUCLEAR STATION. UNITS 1 AllD 2 D.QCKET NOS. 50-369 AflD 50-370
1.0 INTRODUCTION
By letter dated February 10, 1989, as supplemented April 30, November 16, and December 10, 1992, Duke Power Company (tie licensee), submitted proposed changes to the McGuire Nuclear Station, Units 1 and 2 Technical Specifications (TS).
The TS changes proposed by the licensee involve changes to the 18-rnonth emergency diesel generator (DG) surveillance recuirements and are to provide greater flexibility regarding the scheduling anc performance of the subject DG surveillance tests.
The April 30, November 16, and December 10, 1992, letters provided clarifying information and corrections which were not outside the scope of the original federal ((Lq11t3I notice and did not Uange the initial proposed no significant hazards consideration determination.
The changes proposed by the licensee are evaluated below.
2.0 EVALVATION The proposed TS change involves Surveillance Requirement (SR) 4.8.1.1.2.e.
which includes 15 individual SRs, 4.8.1.1.2.e.1 through 4.8.1.1.2.e.15.
SR 4.8.1.1.2.e includes the term "during shutdown."
This restriction is imposed on all 15 individual surveillances and requires that the unit be in shutdown before any of the SRs can be performed.
This mode restriction creates scheduling problems which the licensee proposes to ease with the i
proposed TS changes.
The following is the staff evaluation of the proposed I
changes to the individual SRs.
The evaluation is keyed to the individual SR numbers.
SR 4.8.1.1.2.e The licensee proposes to delete the term "during shutdown" from this SR.
The i
staff finds this acceptable because the term and the associated mode l
restriction are selectively included in the subsequent SRs, as applicable.
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. 1R 4.8.1.1.2.e.1, 4.8.1.1.2.e.2, 4.8.1.J.2.e.3, 1 4 1.1.2.cd 4.8_.l.l.2.e.6 (al, 4.8.1.1.2.e.6 (bl, 1 1 L I.2.e.10, 4.8.1.1.2.e.ll, and 4 J. l. l. 2. e.15 The term "during shutdown" is included in these SRs.
The staff finds this acce) table because performance of the SRs is.itill limited to when the unit is in slutdown, for these SRs, there is effectively no chango.
SR 4.8.1.1.2.e.S The shutdown mode restriction is deleted from this SR.
The staff finds this acceptable because starting a DG using an engineered safety feature (EST) signal is an acceptable method for the monthly SR, which is required to be performed with the unit at power.
Therefore, inclusion of a shutdown restriction is contradictory.
In addition, the design of the DG control systems at McGuire is such that starting the DG on an ESF signal in no way compromises the capability of the DG to fully respond to an actual design basis event.
SR 4.8.1.1.2.e.6)c)
The term "during shutdown" is added to this SR.
The staff finds this acceptable because performance of the SR is still limited to when the unit is in shutdown. However, a footnote is added to this SR which allows the SR to be performed with the unit at power, if it is done in conjunction with a periodic preplanned preventive maintenance activity.
The footnote includes a restriction that performance of the SR can not increase the time the DG would be inoperable for the preventive maintenance activity alone, it is the staff's view that preventive maintenance can increase DG reliability and that the increase in reliability more than offsets the limited risk of having a DG inoperable to perform the maintenance, if this SR were to be performed in parallel with the scheduled maintenance activity, and not increase the total inoperability time or associated risk, the staff finds nc reason why it couldn't be done. Additionaily, performance of this SR in conjunction with a preventive maintenance activity would result in a net increase in DG availability.
Therefore, the statf finds the proposed footnote to be acceptable.
Implicit in the staff's funding is that the licensee has knowledge of how long the maintenance activity should take and will make the appropriate provisions to ensure that conducting the SR in parallel will not increase this time.
SR 4.8.1.1.2.e.7 The licensee proposes to delete the loss-of-offsite power ESF actuation (LOOP /LOCA) test portion of this SR entirely and to relocate the hot restart portion of the SR to SR 4.8.1.1.2.e.8.
Elimination of the LOOP /LOCA test is consistent with what the staff has allowed for other licensees and what has been approved for the Technical Specification Improvement Program (TSIP).
The staff has concluded that the primary purpose of this SR is to demonstrate the ability of the DG to restart shortly after being shutdown following prolonged operation at or near full power (hot restart).
Requiring a LOOP /LOCA test in s
b
. conjunction with a hot restart imposes a strain on multiple systems / components without measurable benefit and should be eliminated.
Therefore, the licensee's proposal to delete the LOOP /LOCA test from this SR is acceptable.
Relocation of the hot restart test to SR 3.8.1.1.2.e.8 is acceptable for the reasons provided in the staff evaluation for that SR.
With the deletion of the LOOP /LOCA test from this SR, and the relocation of the hot restart to another SR, this SR is deleted.
The staff finds this acceptable.
SR 4.8.1.1.2.e.8 The term "during shutdown" is added R t v 9.
The staff finds this acce> table because performance of the a O w il limited to when the unit is in slutdown.
Effectively, there is no u,e o with respect to when the SR is to be performed.
However, the term "to gr6ater than or equal to" as it applies to DG load has been deleted in two placas. A footnote is added which, in part, states a load range for the two parts of this SR.
The load range is intended to preclude overloading of the DG with the resultant DG degradation.
It is the staff's view that a DG that operates at greater than 90% of rated capacity with no abnormal indications provides more than adequato indication 95-100% of rating and are, therefore, acceptable. pro)osed load ranges are11e proposed foo that the DG can produce 100% of its rating.
The includes a statement to the effect that momentary excursions outside the load range do not invalidate the test.
The staff recognizes that the load on a DG can increase or decrease as a function of grid voltago, which is beyond the control of the DG operator.
in the staff's view, these load variations are acceptable for short periods of time provided the operator takes action to restora the load to within the range.
This second part of the footnote is, thereforo, acceptable, in addition to the above, this SR is also modified by adding the requirement to conduct a hot restart of the DG within 5 minutes of completing the 24-hour DG endurance run.
Performance of this test at the conclusion of the 24-hour run is appropriate ' ecause the DG will be as hot as it will get in normal operation.
Therr',re, the staff concludes that the addition of the hot restart test te.his SR is acceptable.
This SR is further modified by a footnote that allows the hot restart test to be performed prior to completing the 24-hour run provided the DG has operated for at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at or near full load.
This footnote is included to address the possibility of a test failure during the 24-hour run.
It precludes excessive testing of a DG simply to achieve operating temperature.
Operation at load fcr at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> will achieve an acceptable temperature for conducting the hot restart test. The staff concludes, therefore, that the footnote tn this SR is acceptable.
SR 4.8.1.1.2.e.9 The licensee proposes to delete the mode restriction from this SR. The staff finds this acceptable because the SR involves only a calculation and as a result has no direct impact on unit operation or safety.
l
1; 1 SR 4.8.1.1.2.e.12 The licensee proposes to delete Mode restrictions from this SR.
The SR involves manual realignment of the day tanks to the fuel oil storage tanks to denionstrate that each day tank can be supplied from each storage tank.
The SR does not involve any DG starts or require the DG to be rendered inoperable, and during the test the day tanks remain full.
Based on this, the staff concludes that deleting the Mode restriction from this SR is acceptable.
The staff acceptance is predicated on the licensee implementing appropriate QA procedures to ensure the DG fuel system is realigned for proper automatic operation following performance of the SR.
SR 4.8.1.1.2.e.13 The licensee )roposes to delete Mode restrictions from this SR.
The rationale provided by tie licensee in support of this deletion is that the DG systems at McGuire Units 1 and 2 are designed for this type of on-line testing. The DG remains fully functional during the test, and any valid actuation signal (LOOP or LOCA) received would override the test mode enabling the DG to carry out its intended function. Any valid actuation signal would also reset the sequencer. The staff has conducted an extensive review of the design of the sequencer circuits, including the applicable schematic diagrams. As a result of this review, the staff agrees that this SR can be conducted safely with the associated unit at power.
The staff concludes, therefore, that the licensee's proposal to delete mode restrictions from this SR is acceptable.
SR 4.8.1.1.2.e.14 The term "during shutdown" is added to this SR. The staff finds this acceptable because performance of the SR is still limited to when the unit is in shutdown. However, a footnote is added to this SR which allows the SR to be performed with the unit at power if it is done in conjunction with a periodic preplanned maintenance activity.
The footnote includes -a restriction that performance of the SR can not increase the time the DG would be inoperable for the preventive maintenance activity alone.
It is the staff's view that preventive maintenance can increase DG reliability and that the increase in reliability more than offsets the limited risk of having the DG inoperable to aerform the maintenance.
If this SR were to be performed in parallel with t1e scheduled maintenance activity,'and not increase the total inoperability time or associated risk, the staff finds no reason why it could not be done. Additionally, performance of this SR in conjunction with a preventive maintenance activity would result in a net
~ increase in DG availability.
Therefore, the staff finds the proposed footnote to be acceptable.
Implicit in the staff's finding is that the licensee has knowledge of how long the maintenance activity should take and will make the appropriate provisions to ensure that conducting the SR in parallel will not increase this time.
1 t
. hiti The licensee has added a Bases discussion of the proposed footnote to allow SR 4.8.1.1.2.e.6)c) and SR 4.8.1.1.2.e.14 to be conducted in conjunction with DG outages for > replanned preventive maintenance instead of being performed with the unit slut down.
The discussion emphasizes that the footnote is only applicable during preolanned maintenance periods, that performance of the SR should not increase the time the DG would be inoperable, and that the footnote shall not be utilized for operational convenience. The staff agrees with the proposed Bases addition, it is, therefore, acceptable.
The staff concludes that the TS changes to DG surveillance as proposed by the licensee, including the proposed footnotes and Bases discussions, are acceptable.
3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the North Carolina State official was notified of the proposed issuance of the amendments.
The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change requirements with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements.
The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (54 FR 9583 dated March 7, 1989). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not 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 the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
Ed Tomlinson Date: February 1, 1993
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