ML17157A445
| ML17157A445 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/15/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17157A444 | List: |
| References | |
| NUDOCS 9012040124 | |
| Download: ML17157A445 (14) | |
Text
I
~gg RECT v (<
Wp O~
Cy
~
~
4)
C1O
~
0 0
Cy
+>>*<<+
UNITED STATES NUCLEAR R EG ULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.
103 TO FACILITY OPERATING LICENSE NO. NPF-14 AND AMENDMENT NO.
TO FACILITY OPERATING LICENSE HO.
NPF-22 PENNSYLVANIA POWER 5 LIGHT COMPANY ALLEGHENY ELECTRIC COOPERATIVE IHC.
DOCKET NOS. 50-307 AND-50-388 SUS UEHANNA STEAM ELECTRIC STATION UNITS 1
AND 2
1.0 INTRODUCTION
By letter dated March 16, 1990, as revised April 2, 1990, Pennsylvania Power and Light Company requested an amendment to Facility Operating License Nos.
NPF-14 and NPF-22 for the Susquehanna Steam Electric Station, Units 1 and 2.
The proposed amendments would change Section 3/4.8 of the Technical Specifications (TS) for Susquehanna Steam Electric Station (SSES),
Units 1 and 2.
The changes deal primarily with the methodology of diesel generator surveillance testing, and in particular with fast loading of diesel generators during testing.
In its March 16, 1990 letter, the licensee identified current diesel generator testing requirements as a "potential root cause" of the September and October 1989 diesel generator overpressurization
- events, as well as being "a contributor to engine degradation."
In light of this, the licensee requested TS changes to eliminate what they perceive to be a contributor to a problem.
It should be noted that the diesel generator overpressurization events mentioned above are the subject of a separate staff review, and this evaluation does not address the issues related to diesel generator testing as a "potential root cause" of overpressurization events.
However, the staff recognizes that certain aspects of the current SSES diesel generator surveillance requirements are not consistent with good operating practice, and the licensee's requested TS changes have been reviewed on that basis.
The staff is presently evaluating the diesel generator testing methodology on a generic basis.
The staff's positions regarding the diesel generator testing will be summarized in Revision 3 to Regulatory Guide 1.9.
- 2. 0 EVALUATION The following staff evaluation is keyed to the applicable TS sections in which changes have been proposed and is applicable to Units 1 and 2.
k
'V012040124 901 if5 PDR ADOCK 05000387 P
I~gge 0
I l
I On April 4, 1990, the staff granted a temporary waiver of compliance from the provisions of the TS Sections 3.8.1.1 and 4.8.1.1.
The granting of that waiver was contingent upon the licensee's performing certain tests of the refurbished diesel generators in accordance with the licensee's proposals to revise the TS Sections 3.8.1.1 and 4.8.1.1.
The waiver of compliance expires upon issuance of amendments supported by this safety evaluation.
Limitin Condition for 0 eration 3.8.1.1.b The footnote associated with this LCO is modified to include a clarification that, in the event diesel generator E cannot or will not be substituted for any one of diesel generators A-D, the time =limit-for performance of SR 4.8.1.1.1 will commence when an inoperability determination regarding a diesel generator is
- made, The staff has reviewed this proposed change and concluded that it is a clarifica-tion that does not alter the intent of the original specification.
This change is, therefore, acceptable.
Actions 3.8.1.1.a throu h f The most significant change to these actions is the elimination of the single paragraph format for each action, and the substitution of several sub-paragraphs for each action.
The staff considers this restructuring of the TS format to be an administrative change and therefore finds it acceptable.
In addition to the above format change, the licensee has made other changes and added clarifying footnotes to various subparagraphs in several of the above actions.
These are discussed below.
o Actions 3.8.1.1.a.2.a) and 3.8.1.1.b.2.a).
The licensee has added an optional action to the effect that a.diesel generator need not be tested if it has been successfully tested within the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
The licensee indicated in justification of this change that testing an engine 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to the event which caused entrance into the ACTION provides the same level of confidence that the machine will be able to perform its intended safety function.
The staff agrees with the licensee's justification and therefore finds the proposed change to be acceptable.
o Action 3.8.1.1.a.2.
The licensee has added a footnote (++) to the effect that if an offsite power circuit is inoperable because an ESS transformer is inoperable, only the diesel generators associated with that transformer need be tested.
The normal offsite power system arrangement at Susquehanna allows each safety division to have access to two independent offsite power circuits.
Mhen one ESS transformer is out of service, two of the four safety divisions at Susquehanna will t
~
. ~
~
It t
have one versus two independent offsite circuits.
The other two safety divisions will continue to have access to two offsite circuits.
Because two independent offsite circuits remain operable between the offsite grid system and the safety buses, the staff considers the licensee's proposed change to be acceptable.
Also, the staff is considering generically, as part of its review of the Standard Technical Specifi-
- cations, the elimination of diesel generator testing on loss of an offsite circuit.
o Action 3.8.1.1.b.2.
The licensee has proposed a footnote (8) to the effect that if a diesel generator is inoperable due solely to preplan-ned preventative maintenance, there. is no requirement to test the re-maining operable diesel generators.
A primary reason for requiring remaining diesel generators to be tested when one diesel generator becomes inoperable is to ensure that the inoperability is not due to a
common cause.
In the case of preplanned preventative maintenance, it is clear that a
common cause does not exist.
Consequently, testing the remaining diesel generators would add a test cycle without any measurable benefit.
The proposed footnote will eliminate unnecessary starts under these conditions.
The staff finds this consistent with the provisions of GL 84-15.
However, the footnote implies incorrectly that diesel generators may be taken out of service in accordance with operating time limits specified in the technical specification.
The operating time limits should not be construed to include preplanned preventive maintenance activities which require the incapacitation of any required electric power source.
Such activities should be scheduled for performance during cold shutdown and/or refueling activities (reference:
Position C5 of Regulatory Guide 1.93).
Therefore, the proposed footnote is not acceptable.
The staff is considering generically, as part of its review of the Standard Technical Specifications, a resolution of this issue.
If the footnote is revised to remove the above described implication, the staff can conclude that the change is consistent with the generic resolution and is acceptable.
Proposal for revised footnote:
This ACTIOt< is not required to be performed if the absence of common cause for the diesel generator inoperability can be established for the remaining diesel generators.
The above footnote has also been applied to Action 3.8.1.1.c.2.
The staff can find it acceptable for the same reasons as in Action 3.8.1.1.b.2.
o Action 3.8.1.1.c.
This Action addresses the inoperability of one offsite ac source and one diesel generator.
Upon restoration of one of the inoperable power sources, this Action reverts to the Action associated with the remaining inoperable power source.
In the event the diesel generator is restored to operability, the controlling Action would become 3.8.1.1.a.
Under this action, there is a requirement to test the diesel generators.
However, the diesel generators would have already been tested under Action 3.8.1.1.c, and testing again to satisfy the requirements of Action 3.8.1.1.a would serve no useful purpose.
To the contrary, it would require unnecessary diesel generator testing that is in direct conflict with the provisions of GL 84-15.
The same conditions apply if the offsite source is restored first; i.e., Action 3.8.1.1.b applies.
The licensee has proposed adding a footnote (88) to the TS which would allow diesel generator testing under Action 3.8.1.1.c to meet the requirements for diesel generator testing in Actions 3.8.1.1.a.
and 3.8.1.1.b.
The staff finds this footnote to be acceptable on the basis that it will eliminate unnecessary diesel generator testing as recommended in GL 84-15.
The same footnote is applied to Actions 3.8.1.1.e (two offsite sources inoperable) and 3.8.1.l.f (two or more diesel generators inoperable).
Both actions require diesel generator testing.
- However, upon restora-tion of either an offsite source or a diesel generator, the required Action becomes 3.8.1.1.a or 3.8.1.1.b, each with its own diesel gener-ator testing requirements.
As stated
- above, such additional testing serves no useful purpose, and should be eliminated.
Therefore, the licensee's proposal to make the above footnote applicable to Actions 3.8.1.1.e and 3.8.l.l.f is acceptable.
Surveillance Re uirements 4.8.1.1.1 thru 4.8.1.1.3 Surveillance requirements (SR) have been modified to include footnotes for various
- tests, add a load operating range for selected diesel generator surveillances, and to include some editorial changes.
Each of the proposed changes is listed below along with the applicable staff evaluation.
o SR 4.8.1.1.2.
The licensee has added a.footnote (*) to this SR which allows prelubing of the diesel engine prior to any starts for purposes of satisfying these survei llances.
The staff is aware that no, or inadequate, prelube over a period of time has caused catastrophic failure of diesel generators in nuclear service.
There-fore, prelubing of an engine prior to starting is highly recommended in order*to improve reliability.
The staff is also aware that diesel generators will not be prelubed if called upon to operate in an emergency.
However, it has been adequately demonstrated that diesel generators can start as required without prelube.
Therefore, pre-lubing does not raise a question regarding the validity of surveil-lance testing to demonstrate diesel generator operability.
The licensee's proposed footnote regarding prelube is, therefore, acceptable.
o SR 4.8.1.1.2.a.4.
This surveillance was revised to show the gener-ator voltage and frequency as 4160 +400 volts and 60+3.0 Hz within ten seconds after a start signal.
These values are consistent with what is in the remainder of the TS, and the staff considers this to be an administrative change.
The proposed change is, therefore, acceptable.
o SR 4.8.1.1.2.a.5.
This SR is changed to delete the requirement to test diesel generators at equal to or greater than 4000kw, delete the requirement to reach 4000kw in 90 seconds, and to add two footnotes,
(**) and (***)
The requirement to load a diesel generator to equal to or greater than 4000kw can lead to overloading in order to ensure compliance with TS requirements.
In at least one instance, overloading has contributed to catastrophic engine failure.
The 'staff has, therefore, allowed licensees to test diesel generators in a load band within 5 percent of the diesel generator's continuous or overload ratings.
In the staff's view, this will enhance overall diesel. generator reliability.
The licensee's proposal to substitute a load range of 3600-4000kw meets the intent for enhancing diesel generator reliability; however, the load range of 3600-4000kw exceeds the 5 percent band
( i.e.,
3800 to 4000kw) that has been generally accepted by the staff.
The staff is concerned that a load band greater than 5 percent may not ade-quately demonstrate the diesel generator's capability to supply design basis load requirements.
The proposed load band is, there-fore, unacceptable.
And, for similar reasons, the load band of 4100-4400kw (used to simulate the diesel'enerator's capability to supply power when overloaded) is not within 5 percent of 4700kw and is unacceptable.
The proposed change also deletes the requirement to load the diesel generator from 0 to 4000kw in 90 seconds or less.
The staff has determined that this type of fast loading does not simulate the block loading a diesel generator will see 'in an actual emergency, and that fast loading is detrimental to diesel generator reliability.
In light of the negative aspects of fast loading, the staff now recommends that diesel generators be loaded in accordance with vendor recommenda-tions, including a warmup period, as applicable.
A footnote (**) has been added to this SR which contains specific language to allow warmup and loading as recommended by the vendor.
This footnote is acceptable for the above stated reasons.
A second footnote (***) addresses the load range discussed
- above, and contains language to the effect that momentary transients outside the stated load range will not invalidate the test.
The staff finds this acceptable on the basis that allowing some leeway can preclude the necessity for retesting, and that reducing the number of diesel generator tests is consistent with the provisions of GL 84-15.
In addition to the above, this SR has been modified to indicate that the diesel generator is synchronized "with the grid" for loading during test.
The staff considers this to be an administrative or editorial
- change, and concludes that it is acceptable.
o SR 4.8.1.1.2.d.2.
This SR is modified to include footnote (**). This change is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.2.a.5.
, ~
I
~
~
~ i~
I l
o SR 4.8.1.1.2.d.3.
This SR is modified to include footnote (**). This change is acceptable for the reasons stated in the staff evaluation of SR 4;8.1.1.2.a.5.
o SR 4.8.1.1.2.d.7.
This SR has been modified "to greater than or equal to 4700kw" as they relate to diesel generator loading for the first two hours and the remaining 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test, respectively.
The licensee has substituted load ranges of 4100-4400kw and 3600-4000kw for the above two hour and 22 hour2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> loads.
The staff finds this load range substitution to be unacceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.2.a.5.
Footnotes (**) and (*~*).are also added to this SR.
The inclusion of these footnotes is acceptable for the reasons stated in the staff evaluati on of SR 4.8.1.1.2.a.5.
o SR 4.8.1.1.2.d.8.
The SR has been modified to delete the requirement that the diesel be loaded after hot start with permanently connected loads within 10 seconds and operate with shutdown loads for 5 minutes.
The staff is considering generically, as part of its review of the Standard Technical Specifications, the elimination of loading after hot start.
As part of this generic review, the staff has conclu'ded that other tests verify the load carrying capability of the diesel generator and need not be repeated as part of a test whose objective is to demonstrate the hot start capability of the diesel generator.
Loading when the diesel generator is hot is not considered to be a
problem.
On this basis the staff finds the addition of the proposed footnote to be acceptable.
o SR 4.8.1.1.3.
This SR is modified to include footnote (*).
This change is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.2.
o SR 4.8.1.1.3.a.4.
This SR covers the "E" diesel generator.
It is modified to include footnote (¹¹¹).
Footnote (¹¹¹) provides a
clarification that this SR as it applies to diesel generator E can be conducted utilizing the test facility. It is the staff's view that diesel generator operation at load for the minimum required time, regardless of the load source, satisfies this SR.
The proposed foot-note is, therefore, acceptable.
o SR 4.8.1.1.3.a.5.
This SR is modified to include -the load range of 3600-4000kw, footnotes (**) and (***),an editorial change regarding synchronizing with the grid, and footnote (¹¹¹).
The above load range, footnotes (**) and (***),and the editorial change are identical to those included in SR 4.8.1.1.2.a.5.
The load range is unacceptable and the footnotes and editorial changes are acceptable for the same reasons stated in the staff evaluation of SR 4.8.1.1.2.a.5.
'I ~
~
()
Footnote (¹¹¹) is identical to the footnote included in SR 4.8.1.1.3.a.4 and is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.3.a.4.
o SR 4.8.1.1.3.d.2.
This SR is modified to include footnote (¹¹¹) and footnote (**).
Footnote (¹¹¹) is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.3.a.4.
Footnote (**) is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.2.a.5.
(Note - footnote (***)is not applicable to this SR).
o SR 4.8.1.1.3.d.3.
This SR is modified to substitute a load range of 3600-4000kw for the original 40CCkw load rejection, adds footnotes
(**) and (***), and footnote (¹¹¹).
Footnote (**) is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.2.a.5 relative to this SR.
Footnote (¹¹¹) is identical to the footnote included in SR 4.8.1.1.3.a.4 and is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.3.a.4.
The proposed load range of 3600-4000kw is not acceptable because it could allow the load rejection to be conducted at less than 4000kw which would defeat the purpose of the test.
Footnote (***)provides clarification of the load range.
Since it is directly associated with the proposed load range, it is also not acceptable.
o SR 4.8.1.1.3.d.4.
This SR is modified to include load ranges of 4100-4400kw and 3600-4000kw, footnotes (**) and (***), and footnote
(¹¹¹).
The footnotes (**) and (***)are identical to those included in SR 4.8.1.1.2.d.7.
These changes to SR 4.8.1.1.3.d.4 are acceptable for the same reasons stated in the staff evaluation of SR 4.8.1.1.2.d.7.
The load ranges of 4100-4400kw and 3600-4000kw are identical to those included in SR 4.8.1.1.2.d.7.
These changes are unacceptable for the same reasons stated in the staff evaluation of SR 4.8.1.1.2.a.5.
Footnote (¹¹¹) is acceptable for the reasons stated in the staff evaluation of SR 4.8.1.1.3.a.4.
fg
'C
J e
47 n
o Table 4.8.1.1.2-1 This Table is modified to dele'.e the requirement, for diesel generator surveillance testing at 14 day intervals as a function of the number of diesel generator failures.
The revised table will now include surveillance testing at 31 day and 7 day intervals, only.
In addition, the failure criterion is changed and is now based on the last 20 valid tests as opposed to the last 100 valid tests.
The testing frequency will now be 31 days if failures are equal to or less than one, and 7
days if failures are equal to or greater than 2, based on the last 20 valid tests.
Note (STAR) is changed to Note (a),
and is changed to delete reference to the "last 100 valid" tests and substitute "the last 20 valid" tests.
There is also a minor editorial change wherein "last 100 tests" becomes "number of tests."
Note (b) is added to provide guidance regarding how long the 7 day testing interval must be maintained.
The above changes to Table 4.8.1.1.2-1 are consistent with the provisions of GL 84-15 with respect to reducing the total number of diesel generator tests.
They are, therefore, acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve changes to a requirement with respect to the installation or use of a faci lity component located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillance require-ments.
The staff has determined that these 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 these amendments involve no significant hazards consideration and there has been no public comment on such finding.
Accordingly, these 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 nor environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CONCLUSION
The Commission made a proposed determmination that the amendments involve no significant hazards consideration which was published in the Federal Re ister (55 FR 14150) on April 16, 1990 and consulted with the Commonw~ea t o
No public comments were received, and the Commonwealth of Pennsylvania did not have any comments.
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public wi 11 not be endangered by operation in the proposed
- manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of these amendments will not be inimical to the common defense and security nor to the health and safety of the public.
Dated:
November 15, 1990 Princi al Contributor:
J.
Knox
t ~'I
'4
'C'