ML20012G328
| ML20012G328 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 02/17/1993 |
| From: | Frizzle C Maine Yankee |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20012G329 | List: |
| References | |
| CDF-93-29, IEIN-89-050, IEIN-89-50, MN-93-19, NUDOCS 9302240020 | |
| Download: ML20012G328 (5) | |
Text
.
MaineYankee REllABLE ELECTRCITY FOR MAINE SINCE 1972 -
l
~
Charles D. Fnzzle Edson Dme
- Presdent Augusta, Maine 04336 FeDruary 17, 1993 (2m s224 ass MN-93-19 CDF-93-29 Proposed Change No. 161 UNITED STATES NUCLEAR REGULATORY COMMISSION Attention: Document Control Desk Washington, DC 20555 a)
License No. DPR-36 (Docket No. 50-309)
(b) USNRC Letter to Maine Yankee dated September 7,1938, Amendment'
Reference:
(
No. 106 to facility Operating License No. DPR-36 (c) USNRC Letter to Maine Yankee dated October 11, 1988, Correction to Amendment No. 106 (d) Maine Yankee Letter to USNRC dated March 31, 1989 (MN-89-42),
Maine Yankee Off-site Power (e) NRC Information Notice No. 89-50, Inadequate Emergency Diesel' dated May 30, 1989 Generator Fuel Supply,f September 1992 - Standard - Technical.
(f)
NUREG-1432, Rev. Oo Specifications for Combustion Engineering Plants.
Subject:
Procosed Technical Specification Change No.161 - Station Service Power and Emergency Power System Periodic Testing Gentlemen:
Maine Yankee hereby submits, aunuant to 10 CFR 50.90, this application to amend Specification 3.12, Station Serv ce Power and Specification 4.5,' Emergency Power System Periodic Testing of the Maine Yankee Technical Specifications.
The first proposed change is to modify Technical Specification 3.12 as follows:
a.
An evaluation -of the emergency diesel. generator loading and fuel consumption in. response to NRC Information Notice 89-50, Reference (e),
has been completed.
The results of this evaluation indicate a need to
~
revise the minimum specified gallons of fuel oil in the fuel oil tanks to a higher number.
Consistent.with Reference (f), a remedial action has been added to address fuel oil tank levels less than the minimum.
b.
Since the 115 KV Surowiec line (Section 69) capacitor bank is now operable, the restriction added by Amendment No. 106 is no longer applicable and is removed by this proposed change.
c.
A change to the remedial action requirements of Specification 3.12.B is proposed consistent with Reference (f) to eliminate the need for alternate train testing-if an emergency ~ diesel generator is taken out of service and.
22005 the cause of it's inoperability does not. apply to the operable diesel-t generator.
In addition, if more than one power supply is inoperabie,.
specific remedial actions for each situation are proposed.
d.
Changes to the basis section are proposed consistent' with the above proposed changes.
The second proposed change is to modify Technical Specification 4.5 to change the ~ emergency diesel generator's monthly surveillance test from maximum expected-emergency loading to its continuous rating (2500 KW) at a unity power factor. This; change also provides for a semi-annual test that demonstrates the emergency diesel g
9302240020 930217 v
L:\\93mn\\9319 pon ApocK 05000309
-ti i
[;
p
^
bIaiDe'Ninhee UNITED STATES NUCLEAR REGULATORY COMMISSION MN-93-19 Attention: Document Control Desk Page 2 generator's capability to supply the maximum expected safeguard loads (resistive and reactive loads). These changes are consistent with Reference (f) and are considered acceptable since design changes are rarely accomplished on the diesel backed, i
and a semi-annual test is safeguards buses (especially during power operations)bility to supply the expected considered adequate to demonstrate diesel generator capa i
safeguards loads.
In addition, an editorial change to Specification 4.5.B is 1
proposed.
A description of the proposed changes and the Significant Hazards evaluation is presented in Attachment A.
As discussed in the attachment, this change does not involve a significant increase % the probability or consequences of an accident or malfunction of equipment important to safety previously analyzed. Nor does it create the possibility of a riew or different kind of accident or malfunction important to safety. Lastly, it does not cause a significant reduction in the margin of safety.
Thus, based on this evaluation, it is concluded that there is reasonable assurance that operation of the Maine Yankee plant, consistent with the proposed Technical Specifications, will not impact the health and safety of the public.
Revised Technical Specification pages 3.12-1, 3.12-2, 4.5-1 and 4.5-2 are included as Attachment B.
l The proposed changes have been reviewed by the Plant Operation Review Committee.
The Nuclear Safety Audit and Review Committee has also reviewed this submittal.
Representatives of the State of Maine are being informed of this request by a copy
)
of this letter.
We request this proposed change be made effective within 30 days after issuance.
Please contact us should you have any questions regarding this matter.
Very truly yours, Charles D. Frizzle, i
President and I
Chief Executive Officer 1
JVW/ jag c:
Mr. Thomas T. Martin Mr. Charles S. Marschall Mr. E. H. Trottier Mr. Patrick J. Dostie Mr. Clough Toppan STATE OF MAINE Then personally appeared before me, Charles D. Frizzle, who being duly sworn did i
state that he is President and Chief Executive Officer of Maine Yankee Atomic Power Company, that he is duly authorized to execute and file the foregoing request in the name cad on behalf of Maine Yankee Atomic Power Company, and that the statements j
therein are true to the best of his knowledge and belief.
- )
D 6fM >
f Notary 'Public
%RBARA J. PADAVANA L:\\93mn\\9319 isol/RY N 9',m i/Aq j
NYColAnsioN cxw;s x,m, au j
l ATTACHMENT A Description of Proposed Chanags Snecification 3.12 a.
The proposed chanae to Specifications 3.12. A and 3.12.B increases the amount of fuel oil required to operate one diesel for the specified duration.
Maine Yankee, in response to NRC Information Notice 89-50, Inadequate Emergency Diesel Generator Fuel Supply (Reference (e)),
completed an evaluation of the emergency diesel generator loading analysis and determined the minimum fuel oil storage requirements.
As emergency diesel generator "B" has more electrical loads and uses more fuel, it became the diesel generator on which the fuel storage requirements were based.
The modified fuel oil reserve specification is the result of reevaluating Maine Yankee's fuel consumption in accordance with current regulatory guidance (ANSI N195-1976; "American National Standard Fuel Oil Systems for Standby Diesel-Generators"). Maine Yankee currently maintains administrative controls requiring the specified fuel oil reserve.
This Technical Specification change is to modify Specifications 3.12.A and B to be consistent with current administrative controls and to add an appropriate Remedial Action to Specification 3.12.B consistent with Reference (f).
b.
Specification 3.12 was revised by Amendment No.106 (References (b) and (c)).
The need for Amendment 106 was stated in the cover letter of Reference (b):
"This amendment modifies Technical Specification 3.12, " Station Service Power," which provides limiting conditions for operation for the electric power system. The change prohibits reliance on the 115 KV Surowiec line unless additional justification is provided to the NRC.
This restriction will remain in effect until a new capacitor bank is placed in operation."
With Reference (d), Maine Yankee informed the NRC that the new capacitor bank was installed during the 1988 refueling outage and that we have concluded that the capacitor bank is fully operational.
Maine Yankee, therefore, proposes to revise Specification 3.12 to remove the restriction placed in effect by Amendmer,t No.106.
c.
A change to Specification 3.12.B, Remedial Action No. 2 is proposed which avoids the need for alternate train testing if it can be determined that the cause of inoperability for one emergency diesel generator is not common to the other diesel generator (DG). If the cause of inoperability for one DG cannot be confirmed not to exist -
the remaining DG, on performance of Specification 4.5.A.1 suffices to provide assurance of continued operability of that DG. According to Generic Letter 84-15, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is reasonable to confirm that the operable DG is not affected by the same problem as the inoperable DG.If the cause of inoperability is common to the other DG, both DGs would be declared inoperable upon discovery and Remedial Action No. 4 would be entered.
Once either DG is repaired, the common cause failure no longer exists and this Remedial Action is satisfied.
d.
A change to Specification 3.12.B, Remedial Action No. 3 is proposed which separates the existing Remedial Action into two Remedial Actions which specifically address the two possible combinations of inoperable power supplies.
L:\\93mn\\9319
j In the proposed Remedial Action No. 3, redundancy is lost in both the offsite electrical power systems (reserve and station service power) and the onsite AC electrical power system.
The reliability of the available power systems in this condition is primarily affected by the susceptibility of this power system configuration to a single bus failure or a plant trip followed by either a switching failure or failure of the available diesel. For example, failure of the emergency power distribution bus that is energized by either the single available offsite circuit or the single available onsite AC supply could render all emergency AC power ineffective.
Based on these considerations, the operating restrictions imposed on this level of degradation are intended to minimize the time period during which an event with a coincident single failure could result in a complete loss of redundant required safety functions.
The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> completion time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a design basis accident occurring during this period.
It also recognizes that there are risks involved with pursuing a shutdown in a degraded condition that have to be weighed against the risks of remaining at power to perform repairs.
With Train A and Train B DGs inoperable (Proposed Remedial Action No. 4),
there are no remaining standby AC sources. Thus, with an assumed loss of offsite electrical power, insufficient standby AC sources are available to power t e minimum required ESF functions.
Since the offsite electrical power system is the only source of AC power for this level of degradation, the risk associated with continued operation for a short time could be less than that associated with an immediate controlled shutdown (the immediate shutdown could cause grid instability, which could result in a total loss of AC power).
However, since any inadvertent generator trip could also result in a total loss of offsite AC power, the time allowed for continued operation is severely restricted. The intent of the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> completion time is to avoid the risk associated with an immediate controlled shutdown and to minimize the risk associated with this level of degradation.
(
e.
The proposed changes to the basis section updates the derivation of the i
fuel requirements for Specifications A and B.
)
Specification 4.5 The proposed change to Specification 4.5. A.1 is to revise the monthly emergency diesel generator testing requirements. The proposed change requires monthly testing at 90 to 100 percent of the diesel generators continuous rating (2500 KW) with a unity power factor when it is operated in parallel with other power sources.
The proposed change also adds a new Specification 4.5.A.3 requiring a semi-annual test demonstrating the emergency diesel generators' capability to supply the maximum j
expected safeguards loads (resistive and reactive loads).
Staine Yankee believes that plant modifications that could impact emergency loading are infrecuent and would most likely occur during refueling shutdowns. The semi-an.ual test " ncludes reactive loads (VARs), and therefore, would confirm that the emeraency diesel generators remain capable of supplying the maximum expected safeguard loads.
The monthly test at continuous rating for at least two hours duration would demonstrate the emergency diesel generators' operability. Also, this amendment to Maine Yankee's Technical Specifications would better reflect the 7
manufacturer's recommendations.
Specification 4.5.8 provides three periodic surveillances of the Station Batteries within one paragraph. For clarity, Maine Yankee proposes to break this one paragraph into three separate outline subparts (1, 2, and 3) of Specification 4.5.B.
e L:\\93mn\\9319
Sionificant Hazards Evaluation These proposed changes are requested in order to revise Station Service Power requirements of the Maine Yankee Technical Specifications. As such, tnese proposed changes would not:
1.
Involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed changes to Specifications 3.12. A and 3.12.8 do not have a direct effect on the physical plant or the maintenance of the physical plant but would improve the safe operation of the plant.
The increased fuel oil storage requirements reflect the emergency diesel fuel requirements to supply power for seven continuous i
days in accordance with ANSI N195-1976. Removing the restriction from the 115KV Surowiec line reflects the increased reliability of this power supply due to the capacitor bank being operable. The change to Remedial Action No. 2 reduces the unnecessary challenges associated with alternate train testing of emergency diesel generators with one train already out of service.
The change to Remedial Action No. 3 provides different but reasonable allowed outage times for the two possible loss of power supply configurations possible.
The change to Specification 4.5.A revises the survei lance requirements for the emergency diesels. The surpose of these l
surveil w.= requirements is to demonstrate on a periodic 3 asis that these diesels remain capable of performing their intended function. The revised surveillance requirements will continue to demonstrate that the diesels are operable.
The change to Section 4.5.B is editorial.
The proposed changes, therefore, will not increase the probability or consequences of an accident previously evaluated.
2.
Create the possibility of a new or different kind of accident from any previouslr evaluated.
In Specification 3.12, increasing the fuel oil storage requirement to ensure operation of the emergency diesel generator for seven continuous days, removal of the 115 KV Surowiec restriction, i
modification of the alternate train testing requirements and the l
clarification of the loss of two power supply requirements does not create the possibility of a new or different kind of accident.
This proposal 2
does not involve any hardware modifications or the creation of a unique operating condition.
Verification of diesel and battery operability in Section 4.5 is maintained while requiring no system configuration changes in order to perform surveillance testing, which could adversely effect system functional performance.
3.
Involve a significant reduction in the margin to safety.
This proposed t
change modifies Technical Specification 3.12 to be consistent with current J
administrative controls which are more restrictive than the current i
specifications. The monthly surveillance of Specification 4.5.A.1 at its continuous rating and the semi-annual surveillance of Specification 4.5. A.3 at maximum expected emergency real (KW) and reactive loads (KVAR) 1 will continue to ensure that the emergency diesel generators are l
operational. The change to Specification 4.5.B is editorial. Therefore, adoption of the proposed change would not involve a significant reduction t
i in a safety margin for the plant.
Based on the discussion above, it is concluded th6 there is reasonable assurance that operation of the Maine Yankee plant, comstent with the proposed Technical Specifications, will not endanger the health rad safety of the public.
4 i
L:\\93mn\\9319 i
.-