ML20134J655

Proposed TS Change 203 to License DPR-36,revising TS Pages 3.12-1,3.12-2 & 3.12-3 Re 115 Kv Offsite Power Requirements

ML20134J655
Person / Time
Site:	Maine Yankee
Issue date:	02/07/1997
From:	Frizzle C Maine Yankee
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20134J659	List: ML20134J655 ML20134J664
References
CDF-97-23, MN-97-29, NUDOCS 9702120240
Download: ML20134J655 (8)

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. MaineYankee  ;

, Hill AHL E E L[ C T RICIT Y SINCE 197?

329 Bath Road Charles D. Fnzzle Brunswick. Maine 04011 President and Chief Executive Officer (207) 798-4100

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1997  !

MN-97-29 February 7, CDF-97-23 l

Proposed Change No. 203 l l

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UNITED STATES NUCLEAR REGULATORY COMMISSION Attention: Document Control Desk  :

Washington, DC 20555 t Referer.ce: (a) License No. DPR-36 (Docket No. 50-309)

(b) USNRC Letter to Maine Yankee dated January 30, 1997.

Confirmatory Action Letter (No. 1-96-015, Supplement No. 1) ,

(c) NUREG-1432, Rev. O of September 1992 - Standard Technical Specifications for Combustion Engineering Plants.

Subject:

Proposed Technical Specification Change No. 203 - 115 kV Offsite Power Requirements .

Gentlemen:

Maine Yankee hereby submits, pursuant to 10.CFR 50.90, this application to amend Specification 3.12, Station Service Power of the Maine Yankee Technical l Specifications. This application is meant to address the actions agreed to in l Reference (b) commitment no. 1.

The proposed change is to modify Technical Specification 3.12 as follows:

l a. Requires both 115kV incoming lines to be operable when the reactor is critical.

b. Allows continued operations for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with one 115kV incoming line inoperable.

c. Allows continued operations for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with both 115kV incoming lines inoperable.

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d. Applies the increased operability requirements described above to another affected remedial action. }

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. e. Incorporates some minor editorial changes to uniformly apply the usage 1 l

of the term " operable." l l

} i. Changes the basis section to be consistent with the above proposed l changes.

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} 9702120240 970207 i PDR ADOCK 05000309 P PDR g

120005 i

. MaineYankee UNITED STATES NUCLEAR REGULATORY COMMISSION MN-97-29 Attention: Document Control Desk Page Two These changes are consistent with Reference (c) and are considered acceptable since they place more restrictive operability requirements and shorter time limits on continued operation with inoperable configurations of offsite power.

These restrictions will result in the increased assurance that station service power will be available when required and that offsite power will be restored under greater urgency.

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 in the probability or consequences of an accident previously analyzed, nor does it create the possibility of a new or different kind of accident from any accident previously evaluated. 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 and 3.12-3 are included as Attachment B.

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 are requesting that the NRC review this application under 10 CFR 50.91(a)(6) as an " exigent" Technical Specification change. Exigent circumstances exist because this Technical Specification change is being requested in accordance with the commitments documented in Reference (b) as a condition of starting up the plant. Therefore, this Technical Specification is being treated as a potential critical path for startup. Treatment of this Technical Specification change under this procedure is appropriate since the change consists of increased restrictions on existing operating practices.

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. MaineYankee UNITED STATES NUCLEAR REGULATORY COMMISSION MN-97-29 Attention: Document Control Desk Page Three We request this proposed change be made immediately effective upon issuance.

Please contact us should you have any questions regarding this matter.

Very truly yours, 2

Charles D. Frizzle.

President and Chief Executive Officer MAW /mwf c: Mr. Hubert J. Miller Mr. J. T. Yerokun Mr. P. J. Dostie Mr. Clough Toppan Mr. Uldis Vanags Mr. D. H. Dorman STATE OF MAINE Then personally appeared before me. Charles D. Frizzle, who being duly sworn did 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 and on behalf of Maine Yankee Atomic Power Company, and that the statements therein are true to the best of his knowledge and belief.

M1lCle N

[NotaryPublic Men:en , .r r . 1,

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ATTACHMENT A Descriotion of Prooosed Chances Soecification 3.12 r On January 30, 1997 Maine Yankee committed to propose Technical Specification changes to Specification 3.12. This commitment is documented in Reference (b).  !

A description of each proposed Technical Specific; tion change is provided below:

a. Technical Specification 3.12.B.1 is proposed to r, quire both 115 kV incoming lines to be operable when the reactor ".s critical. Since j initial licensing of the plant, Maine Yankee'a licensing basis for the Offsite Power Systems has been two red'.ndant 115 kV incoming lines, and a 345 kV line available within s,x hours, with only one i of the two redundant 115 kV lines required to be operable, by the Technical Specifications. The proposed Technical Specification will require both 115 kV incoming lines to be operable and will result ia an increased assurance that station service power will be available when required. This proposed Technical Specification assumes that both 115 kV incoming lines are independently capable of suppling the plant auxiliary power requirements.

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b. Technical Specification 3.12.B Remedial Action No.1 is proposed to '

allow continued operations for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with one 115kV incoming line inoperable. This remedial action statement in conjunction with Technical Specification 3.12.B.1, described above. I is a new requirement. The current Technical Specifications do not i limit the time allowed for one 115 kV incoming line to be inoperable. The proposed Technical Specification Remedial Action statement will result in an increased assurance that station service l power will be available when required. If upon the completion of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> time period, the inoperable 115 kV incoming line is not restored to service, the unit will proceed to shutdown in accordance with Technical Specification 3.0. A. Sufficient time prior to the initiation of the shutdown is available to assess the availability of remaining equipment required to accomplish safe shutdown or to seek NRC relief, if appropriate. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> remedial action time takes into account the capacity and capability of the remaining AC power sources, a reasonable time for repairs, and the low probability of a design basis accident occurring during this period.

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c. Technical Specification 3.12.B Remedial Action No 2 is proposed to

- allow continued operations for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with both 115kV incoming lines inoperable. This remedial action statement is

similar to the existing Remedial Action No.1. Currently, seven days are allowed to restore one 115 kV incoming line to service.

This restoration time has been reduced to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to be consistent with Standard Technical Specifications (Reference (c)). If upon

completion of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time period, one 115 kV incoming line is not restored to service, the unit will proceed to shutdown in i

i accordance with Technical Specification 3.0.A. Sufficient time prior to the initiation of the shutdown is available to assess the availability of remaining equipment required to accomplish safe shutdown or to seek NRC relief. if appropriate.

The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> notification requirement has been removed. Notification

. to the NRC of significant events is covered separately under 10 CFR 50.72 & 73.

I The proposed Technical Specification remedial action statement will

] result in an increased urgency to restore one 115 kV incoming line i to service. Following the restoration of one 115 kV incoming line

to service, continued operation would be allowed for up to the i remainder of the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (subtracting the portion of the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> j used under proposed Remedial Action No. 2) while the remaining 115

kV incoming line is restored to service under proposed Remedial

! Action No. 1. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> remedial action time takes into account

the risks associated with performing a shutdown without 115 kV j 1 offsite power and the risks associated with remaining at power to l j perform repairs. With both 115 kV incoming lines inoperable. l sufficient onsite AC sources are redundantly available to supply i

power to all required engineered safeguards loads.

I d. The increased operability requirements described above are applied to proposed Technical Specification 3.12.B Remedid Action No. 4 and the Basis section. The existing remedial action statement (No. 3) i is equivalent to both 115 kV incoming lines and one Diesel Generator (DG-1A or DG-1B) becoming coincidentally inoperable. In this configuration, continued operation is currently allowed by the ,

Technical Specification for up to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The Standard Technical '

Specifications do not permit continued operation under this configuration and would require the commencement of an immediate shutdown since the configuration constitutes a severe degradation and any further losses in the AC electrical power system would cause a loss of function.

The proposed Technical Specification 3.12.B Remedial Action No. 4 4 applies to a postulated configuration where one 115 kV incoming lines and one Diesel Generator (DG-1A or DG-1B) are coincidentally inoperable. In this configuration, continued operation is allowed for up to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Although the individual redundancy for each of the onsite and offsite power source. is removed. the diversity of power sources providing AC electrical power is maintained. The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> remedial action time takes into account the capacity and A-2

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capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a design basis accident i occurring during this period.

e. Some minor editorial changes are made to uniformly apply the usage of the term " operable." The term available/ unavailable is replaced with the term operable / inoperable in proposed Technical Specification 3.12.B Remedial Action Nos. 3 and 4 and the Basis section. This proposed change will provide for greater consistency since the term " operable" is defined in the Technical Specification Definitions Section.

f. Changes to the basis section are proposed consistent with the above proposed changes.

These proposed Technical Specification changes meet the commitments documented in Reference (b) and are consistent with the Standard Technical Specifications (Reference (c)).

Sionificant Hazards Evaluation These proposed changes are requested in order to revise Station Service Power requirements of the Maine Yankee Technical Specifications. As such, these 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.B do not involve a physical change to the plant or the maintenance of the plant. The proposed changes increase the operating requirements associated with i the operability of the 115 kV incoming lines beyond that currently i required by Technical Specifications. For those accidents  !

previously evaluated the more restrictive operability requirements  !

associated with maintaining both 115 kV incoming lines operable and  ;

the more restrictive remedial action times result in increased assurance that station service power will be available when required. This increased availability will be achieved because elective maintenance on the offsite power system will be significantly restricted and the restoration of inoperable 115 kV incoming lines will be treated with greater urgency. The increased assurance of availability will result in a decrease in the probability or consequences of these postulated accidents.

However, the more restrictive remedial action times decrease the restoration period and consequently increase the possibility that successful restoration may not be achieved. given an outage of the 1 115 kV power system. A unit shutdown without offsite power would I then be commenced. This evolution would involve a unit shutdown without the availability of equipment such as the reactor coolant pumps, condensate pumps and main feedwater pumps. Although none of these components are credited as available for the mitigation of the consequences of accidents previously evaluated the probability of the occurrence of certain accidents is increased without them.

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, Although the combination of these considerations could involve an ,

increase in the probability of accidents previously evaluated, the  !

increase would not be significant due to the low probability of  !'

independent failures or common cause failures of both of the 115 kV incoming lines. There is no increase in the consequences of any accident previously evaluated as a result of these proposed Technical Specification changes. The proposed Technical t

Specification changes are consistent with the Standard Technical  :

1~ Specifications (Reference (c)) approved by 'the NRC. The proposed '

changes, therefore, will not involve a significant increase in the j probability or consequences of an accident previously evaluated.

$ 2. Create the possibility of a new or different kind of accident from

any previously evaluated.

The proposed Technical Specification change does not involve a change to the physical plant or to the physical configuration of the offsite power system. The effect of the proposed change will be to

, increase the availability of the offsite power system when required.

! In addition, the proposed change will increase the possibility of a j

unit shutdown without offsite power operable. However, the accidents previously evaluated assume a simultaneous loss of offsite

power. design basis accident and worst case single failure as part of the design basis. The proposed changes do not result in the

creation of a unique operating condition or a configuration that has not been previously evaluated. Therefore, the proposed change does not create the possibility of a new or different kind of accident

from any accident previously evaluated.

j 3. Involve a significant reduction in the margin to safety.

This proposed change modifies Technical Specification 3.12 to be consistent with the Standard Technical Specifications (Reference (c)). The proposed Technical Specification change maintains the i current margin of safety which is based upon supplying power to j engineered safequards. Adequate sources of power remain available i for the operation of the engineered safeguards equipment.

Therefore, the proposed change would not involve a significant reduction in a margin of safety.

Based on the discussion above, it is concluded that there is reasonable assurance that operation of the Maine Yankee plant, consistent with the proposed Technical Specifications, will not endanger the health and safety of the public. Maine Yankee has concluded that the proposed change to the Technical Specifications does not involve a significant hazards consideration as defind by 10 CFR 50.92.

Information Concernina an Environmental Assessment An Environmental Assessment is not required for the Technical Specification changes proposed by this Proposed Change because the requested changes to the Maine Yankee Technical Specifications meet the criteria for " actions eligible for categorical exclusion" as specified in 10CFR51.22(c)(9). The requested changes will have no impact on the environment. The changes do not involve a Significant Hazards Consideration as discussed in the preceding section. The requested changes do not involve a significant change in the types or significant increase A-4

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. in the amounts of any effluent that may be released off-site. Also, the l requested changes do not involve a significant increase in individual or i cumulative occupational radiation exposure.  !

Conclusion ,

Therefore, based upon the reasoning presented above, Maine Yankee has determined  !

that the requested change does not involve a significant hazards consideration.  !

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