ML17157A325
| ML17157A325 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 09/13/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17157A324 | List: |
| References | |
| NUDOCS 9009270164 | |
| Download: ML17157A325 (8) | |
Text
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 4' k'~'I f"<
I SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.
99 TO FACILITY OPERATING LICENSE NO. NPF-14 AND AMENDMENT NO.
67 TO FACILITY OPERATING LICENSE NO. NPF-22 PENNSYLVANIA POWER 8( LIGHT COMPANY ALLEGHENY ELECTRIC COOPERATIVE INC.
DOCKET NOS. 50-387 AND 50-388 SUS UEHANNA STEAM ELECTRIC STATION UNITS 1
AND 2
1.0 INTRODUCTION
By letter dated September 4, 1990, Pennsylvania Power 5 Light Company requested amendments to Facility Operating, License Nos.
NPF-14 and NPF-22 for the Susquehanna Steam Electric Station, Units 1 and 2.
The proposed amendments would provide a one-time extension of the limiting condition for operation (LCO) in Technical Specifications Section 3.8.1.1, action b
from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 15 days.
During inspection of emergency diesel generator OG501D, the licensee observed heavy scoring of the cylinder liners on engine cylinders and presence of aluminum oxide in the engine.
The aluminum oxide appeared to have been introduced to the engine as residual material from sand blasting performed on the engine intercoolers during maintenance.
A review of engine lube oil samples revealed the presence of increased levels of chrome.
The source of the chrome was found to be the scored cylinder liners.
The spare diesel generator, OG501E,.was substituted for OG501D.
Similar problem of the presence of increased level of chrome in
'lube oil was observed in the emergency diesel generator OG501B.
As a
- result, OG501B was also declared inoperable and Technical Specification Action 3.8.1.1.b was entered on both units.
An immediate inspection was performed and evidence of aluminum oxide was found in the air intake manifold, confirming the existence of the same condition in OG501B as was found in OG501D.
The licensee states that repairs and return OG501B diesel generator to operable status, and additional testing to assure the reliability of the operable diesel generators will require several days.
Therefore, an extension of LCO from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 15 days is needed to obviate a dual unit shutdown.
These amendments were authorized by telephone on September 6, 1990, and confirmed by letter dated September 6, 1990.
2.0 EVALUATION In support of its request, the licensee has proposed to adopt the following compensatory measures:
1.
The spray pond bypass valve on each division will be maintained open to assure availability of diesel generator Cooling.
9009270160 900913 PDR ADOCK 05000387ii'mu
2.
Per Technical Specification 3.8.1.1.1, Action B.2., the licensee is required to perform Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
It is proposed that this surveillance be performed every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> thereafter for the duration of the extended action time.
This will serve to provide additional assurance of the reliability of the three operable diesel generators.
3.
To further reduce the risk of challenges to the offsite power supply, discretionary power changes on both Units 1 and 2 will be avoided.
4.
No discretionary maintenance or modification work will be performed on the following, systems:
ECCS (including the support functions provided by ESW and RHRSW), RCIC, CRD system, dc power systems, and ac power distribution systems.
In addition to the compensatory measures taken by the licensee, the staff has justified granting one time-extension of 15 days for the following additional reasons:
a.
Given loss of diesel generator OG501B, both units can be brought to safe cold shutdown assuming a loss of offsite power coincident with a single failure.
The limiting single failure is the loss of one of the remaining diesel generators.
b.
Probability of occurrence of loss of coolant accident (LOCA) within a period of 15 days is low.
c.
Susquehanna claims to a have a capability to cope with station blackout for a duration of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> without the need of diesel generators.
Based on the above measures, the staff believes that Susquehanna Steam Electric Station, Units 1 and 2, can be operated safely without undue
'risk to the health and safety of the public and there is reasonable assurance that adequate ac power sources will be available to mitigate any credible event that can occur during the period of 15 days and, therefore, this one-time extension should be granted.
3.0 EMERGENCY BASIS The licensee has provided the following basis for existence of an emergency.
Pursuant to 10 CFR 50.91 guidance is provided on what information the NRC.
requires in support of an application for an emergency change.
First, it requires the applicant to justify that an emergency exists, i.e., "... failure to act in a timely way would result in derating or shutdown of a nuclear power plant....".
Both Susquehanna units are currently operating under a waiver of compliance that extends the expiration of LCO 3.8.1.1, Action b, to September 6, 1990 at 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br />.
Restoration of the LCO cannot be accomplished within this time.
Therefore, without the proposed
- change, both Susquehanna units will,be required to be shut down.
s 4:
- Secondly, 10 CFR 50.91 requires a licensee to "... explain why this emergency situation occurred and why it could not avoid this situa-tion...".
PP& L's current belief, as stated earlier, is that the situation occurred due to unanticipated human error during a recent
'aintenance activity.
As soon as the situation was understood, a waiver of compliance was submitted and the appropriate internal processes were begun in support of the application.
The staff agrees with the licensee's basis for concluding that an emergency situation exists and finds that the proposed Technical Specification should be processed on an emergency basis.
4.0 FINAL NO SIGNIFICANT HAZARDS DETERMINATION The Commission has provided standards for determining whether a significant hazards consideration exists (10 CFR 50.92(c)).
A proposed amendment to an operating license for a facility involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not:
(1) involve a significant increase in the probability or consequences of an accident previously evaluated; (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.
The staff has reviewed the licensee's request and concurs with the following basis and conclusion provided by the licensee in its September 4, 1990, submittal.
1.
This proposal does not involve a significant increase in the probability or consequences of an accident previously evaluated.
The three remaining Diesel Generators will be operable.
Therefore Susequehanna will be in a configuration that is bounded by prior deterministic
- analysis, assuming a single failure has occurred.
Furthermore, as described
- above, the risk of total plant damage on an annual basis
~
has increased, but it is not considered significant because:
a.
it. is lower than the total plant damage frequency in the original
- IPE, and b.
the percentage increase is lower than what was accepted by the NRC in a prior safety evaluation to extend the same action items in order to tie in the 'E'iesel generator.
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2.
b.
the percentage increase is lower than what was accepted by the NRC in a prior safety evaluation to extend the same action items in order to tie in the 'E'iesel generator.
This problem does not create the possibility of a new or different kind of accident from any accident previously evaluated.
The evolution involved is one of restoration to acceptable standards.
No change in the operation or function of the Diesel Generators is proposed.
3.
This change does not involve a significant reduction in a margin of safety.
In the unlikely event of a design basis LOCA/LOOP during the extended action time, it is possible to address the safe operation of both units with the three remaining operable Diesel Generators.
In the event of a LOOP only, safe shutdown of both units can be achieved with two of the three operable diesel generators.
Furthermore, compensatory actions'have been proposed to assure the reliability of these diesels and other safety systems which mitigate the risk of an event should one occur.
Based on the above, this does not represent a significant reduction in a margin of safety.
Based on the above considerations, the Commission has determined that the proposed changes involve no significant hazards consideration.
5.0 STATE CONSULTATION
The Commonwealth of Pennsylvania was consulted on this matter and had no comments on the determination.
6.0 ENVIRONNENTAL CONSIDERATION These amendments involve changes to a requirement with respect to the installation or use of a facility component located within the restricted
'area as defined in 10 CFR Part 20.
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 occupa-tional radiation exposure.
The Commission has made a final no significant hazards finding with respect to these amendments.
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.
7.0 CONCLUSION
The Staff has concluded, based on the considerations discussed
- above, that: (1),the amendment does not (a) significantly increase the probability or consequences of an accident previously evaluated, (b) increase the possibility of a new or different kind of accident from any previously
4 evaluated or (c) significantly reduce a safety margin and, therefore, the amendment does not involve a significant; hazards consideration; (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security nor to the health and safety of the public.
Dated:
September 13, 1990 Princi al Contributors:
Narender Trehan and Mohan Thadani
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