ML16138A702

Safety Evaluation Supporting Corrected Amends 182,182 & 179 to Licenses DPR-38,DPR-47 & DPR-55,respectively

ML16138A702
Person / Time
Site:	Oconee
Issue date:	04/25/1990
From:	Office of Nuclear Reactor Regulation
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ML16138A703	List: ML16138A702 ML16293A750
References
NUDOCS 9005140014
Download: ML16138A702 (10)

Text

'UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 182 TO FACILITY OPERATING LICENSE DPR-38 AMENDMENT NO.

182 TO FACILITY OPERATING LICENSE DPR-47 AMENDMENT NO.

179 TO FACILITY OPERATING LICENSE DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 DOCKETS NOS. 50-269, 50-270 AND 50-287

1.0 INTRODUCTION

By letter dated August 31,

1989, Duke Power Company (the licensee) requested various changes to Technical Specification (TS) 3.7, "Auxiliary Electrical Systems," for the Oconee Nuclear Station, Units 1, 2 and 3. A January 24 1990, letter from the licensee superseded the August 31 letter in its entirety except for the technical justification and "no significant hazards consideration" evaluation which remain valid.

The changes would clarify operability requireme~nts of Emnergency Power Switching Logic (EPSL) functional units, provide more explicit operability requiremrents for specific electrical comp~onents and flowpaths, and update the operability requiremrents for the 125 VOC instrumentation and control batteries.

Va riou s administrative changes were also proposed.

2.0 EVALUATION The licensee proposed the following editorial type changes which we find acceptable on the basis that they add clarity and conciseness to the plants' TSs:

CHANGE 1:

Under Specification 3.7.1(b)2, delete "second" and substitute "other (redundant)"

in the first line.

Delete "; through the overhead path and breaker PCB9" and substitute "and breaker PCB-9" in the second line.

CHANGE 2:

Under Specification 3.7.1(e), add "I(XS1, XS2, XS3)" before shall be energized" in the last line.

9005140014 906425 FR ADOCK 05000269 F'

PDC

-2 CHANGE 3:

Under Specification 3.7.2(b), add "Except for the allowable conditions defined in Specifications 3.7.2(a), 3.7.2(c),

3.7.2(i), 3.7.4, 3.7.6 and 3077 to the beginning of the first sentence.

Add "Beyond the conditions allowed by 3.7.2(b)(1) and (2)," to the beginning of the second paragraph. Delete "If" and substitute "In" as the first word of the last paragraph to correct a typographical error.

CHANGE 4:

Under Specification 3.7.2(e)2, delete the reference to the footnote and the footnote regarding the installation of the ne batteries which has already occurred.

This editorial change was also proposed in the licensee's letter dated July 28, 1987, and included in Amendments Nos. 178, 178, and 175 dated November 29, 1989.

Also delete "Keowee" in the fourth line and substitute "the Keowee 125VDC Power System."

CHANGE 5:

Under Specification 3.7.2(g)3, delete the current paragraph and substitute the following:

"Each unit's 125VDC Instrumentation and Control Power System, provided that only one battery more than the number allowed to be inoperable per 3.7.1 (f) (5) for the station is removed from service under this paragraph."

CHANGE 6:

Under Specification 3.7.2(h), add "(KRA)"

after "System" in the last sentence.

CHANGE 7:

Under Specification 3.7.4(c), delete "of" and substitute "to" in the second line to correct a typographical error.

CHANGE 8:

In the Bases under "Capacity of AC Systems," add "4kV" before "auxiliaries of two units" in the first line.

Delete "6.OMVa" and substitute "6.2Ma" in the first line.

Delete "activated by ESG signal in the other unit (4.8MVa) require a total AC power capacity of 16.8MVa" from the first sentence and substitute "of one unit with a LOCA (7.8MVa) require a total AC power capacity of 20.2MVa.'

Delete "201Va" and substitute "22.4MVa" in the fourth and eighth lines of the first paragraph and the second line of the second paragraph.- Delete "(limited by CTe or CT2)"

and substitute "(limnited by CTI, CT2, or CT3)" in the fifth line of the first paragraph.

Tlhese changes provide consistency with the plants' Final Safety Analysis Report (FSAR).

3 CHANGE 9:

In the Bases under "Capacity of DC Systems" add "for the service test" after "tabulation" in the fifth sentence of the first paragraph.

Also make the following substitutions to reflect actual battery capacities and loads in lieu of the current "bounding" values utilized:

Battery XCA or XCB Capacity

- 825 in lieu of 600 ampere-hours Inrush 709 in lieu of 1160 amps.

(2 sec.)

566 in lieu of 506 armps. (next 59 min.)

Total Load

- 568.4 in lieu of 516.9 ampere-hours Battery SY-1 or SY-2 Capacity 160 ampere-hours each in lieu of 14.4 ampere-hours Keowee Battery No. 1 or No. 2 Capacity 975 ampere-hours each in lieu of 20 ampere-hours Inrush 775.5 in lieu of 1031 amps.

(14 sec.)

114.7 in lieu of 179.4 amps. (next 59 min.)

Total Load

- 125.7 in lieu of 193.6 ampere-hours CHANGE 10:

In the Bases under "Redundancy of DC System" in Section A in the last sentence, delete "CA or CB" and substitute "XCA or XC8 to reflect consistent designations. In Section 8, delete the second and third sentences from the first paragraph and substitute "All safety-related equipment and the relay house in which it is located are seismic Category I design" to reflect the current design.

In Section C, insert a comma between "battery" and "charger" in the last sentence.

CHANGE 11:

At the end of the Bases, add the following new section entitled "Reporting Requirements" which provides a discussion of the reporting requirements contained in Specification 3.7.9:

"Specification 3.7.9 includes reporting requirements in the event there is degradation beyond Specifications 3.7.2, 3.7.4, 3.7.5, 3.7.6, 3.7.7, or 3.7.8.

The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> report to Region II is accomplished by 10 CFR 50.72 notification of the NRC operations center. The 5 day written report has been established to provide the NRC the results of safety evaluations in the event the degraded condition will be ongoing."

-4 The licensee proposed the following changes which we find acceptable on the basis that they add conservatism by providing explicit operability requiremrents for specific electrical components/flowpathsg CHANGE 12:

Under Specification 3.7.1(b)I, delete "and to one 4160 V standby bus" and Substitute "through the Keowee standby bus feeder breakers (SKI and SK2) to two standby buses; and capable of supplying emergency power throu h the standb bus to main feeder bus breakers (SI and s2t."

CHANGE 13:

Under Specification 3.7.1(b)2, add "; and capable of supplying emergency power through the startup transformer to main feeder bus breakers (El and E2)" to the end of the first sentence.

CHANGE 14:

Under Specification 3.7.1(f)5, delete the current operability paragraph for the 125 VOC instrumentation and control batteries and substitute the following:

"5. The 125 VDC Instrumentation and Control (I&C) batteries with associated chargers shall be operable per all the following conditions:

(a) Each unit, when in a cold shutdown condition, shall have at least one of that unit's I&C batteries operab le; (b) For operation of two or more units, five of the six batteries shall be operable; (c) For operation of Unit 1, three of the following four batteries shall be operable: ICA, ICB, 2CA, and 2CB.

For operation of Unit 2, three of the following four batteries shall be operable: 2CA, 2CB, 3CA, and 3CB.

For operation of Unit 3, three of the following four batteries shall be operable: 3CA,

3CS, ICA, and ICB."

CHANGE 15:

Under Specification 3.7.1, add the following:

"(j) The Keowee station auxiliary transformers (IX and 2X and the Keowee station backup auxiliary transformer (CX) shall be operab le."

CHANGE 16:

Under Specification 3.7.2(a),

numb~er the existing paragraph as "(1)" and add the following new paragraphs:

-5

"(2) Both Kewowee station auxiliary transformers (1X and 2X) may be inoperable for periods not exceeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for test or maintenance, provided that the backup auxiliary transformer (CX) and its associated underground power path from Oconee switchgear 1TC is operable; (3)

Keowee backup auxiliary transformer (CX) and its associated underground power path from Oconee switch gear 1TC may be inoperable for periods not exceeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for test or maintenance, provided that the Keowee main set-up transformer and both auxiliary transformers (lX and 2X) are operable; (4)

Keowee auxiliary transformer (IX) may be inoperable for test or maintenance provided that Keowee Unit 2 is aligned to the overhead path; (5)

Keowee auxiliary transformer (2X) may be inoperable for test or maintenance provided that Keowee Unit 1 is aligned to the overhead path.

CHANGE 17:

Under Specification 3.7.2(i)1, delete one 4160 V standby bus" and substitute "two 4160 V standby buses" in the third line.

CHANGE 18:

Under Specification 3.7.8 in the first paragraph, delete all the words preceding "the reactor may be heated..." and sub stitute the following:

"In the event that all conditions in Specification 3.7.1 are met except that any one of the following is expected to be unavailable for longer than the test or maintenance period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, as allowed by 3.7.2(a):

1. Keowee Main Set-up Transformer (including both Keowee Auxiliary Transformers);

2. Both Keowee Auxiliary Transformers (lX and 2X);

3.

Keowee Backup Auxiliary Transformer (CX);"

Under (a) delete "the Keowee Main Set-up Transformer" from the third line and substitute the following:

"any one of the following:

1.

Keowee Main Set-up Transformer (including both Keowee Auxiliary Transformers);

2.

Both Keowee Auxiliary Transformers (1X and 2X);

3.

Keowee Backup Auxiliary Transforemr (CX);n

-6 Also delete "and" between "off-site" and "non-safety" in the last sentence.

Under (c) delete "underground feeder circuit" and substitute:

"overhead if using this Specification due to Keowee Backup Transformer (CX) unavailability.

Generation to the system grid shall be prohibited except for periods of test.

If the overhead path is unavailable, the remaining Keowee Widro Unit must be operable and shall be available to the underground feeder circuit."

CHANGE 19:

In Table 3.7-1, delete Functional Units 8 through 10 in their entirety, renumber Functional Unit 7 as Functional Unit 8, and add the following:

"7. Retransfer to Startup Circuits 2

1 (Channels A and B)"

Delete footnote

• in its entirety and substitute:

"The trip coils and associated trip circuitry for the NI and/or N2 breaker(s) are not required to be operable if the breaker(s) are in the tripped position."

Also add an "*" to Ni in Functional Unit 8.

Delete the existing sentence under Note b and substitute "2 trip coils and associated trip circuitry for each breaker."

Also delete the existing sentence under Note c and substitute "1 trip coil and associated trip circuitry for each breaker."

These changes are consistent with Changes 12 and 13 above.

CHANGE 20:

In the Bases under "Redundancy of AC Systems," delete standby bus" and substitute "standby buses" at the end of the third sentence in the first paragraph.

Add the following new paragraph after the first paragraph:

"Under normal unit auxiliary power system alignment, the main feeder buses shall be capable of receiving power automatically from:

1. The Keowee Unit aligned to the underground, through transformer CT-4, and through both standby buses; and

• 7 0

2.

The redundant Keowee Unit, aligned through the overhead path; and through the respective Unit's startup transformer."

Also delete "bus" and substitute "buses" in the line following the above new paragraph.

Add the following new paragraph at the end of the section:

"In order to meet the single failure criteria for certain design basis scenarios, both standby buses (for the under ground flow path), and both El and E2 breakers (for the overhead path) must be operable for the respective flow path to be considered operable."

In the Bases add "to CT-4" to end of the fifth sentence in the first paragraph on Page 3.7-11 (existing).

Also follow this with the following new sentence:

"Credit can be taken for the operability of the SK and S breakers per the routine surveillance test."

These changes are consistent with Changes 12, 13, and 17 above.

CHANGE 21: In the Bases on Page 3.7-11 (existing) in the first sentence of the fifth paragraph, add "both Keowee Auxiliary Trans formers (IX and 2X), or Keowee Backup Auxiliary Transformer (CX)1 after "main step-up transformer."

Also add the following after the last paragraph on that page:

"The power system of the Keowee Iydro station is designed to allow the alignment of each of the two units to the Oconee emergency power systems through either the underground feeder or the overhead path via the main step-up transformer.

During an emergency start one of the Keowee units will be aligned to the underground feeder and the other to the overhead path.

Each Keowee unit's 600VAC auxiliaries are powered from the unit's generator through a 750KVA auxiliary transformer.

Each auxiliary transformer is capable of handling auxiliary loads of both units.

Unit's auxiliaries can be aligned to receive power from either transformer by a manual transfer capability at the load center level.

A backp 75K A auxiliary transformer (Cx) is provided and powered from Oconee 4KV switchgear 1TC through an underground feeder.

Transformer CX is capable of backing up one or both units auxiliary transformers.

"Each Keowee unit has a generation capacity of 87.5 MVA and the main step up transformer is rated for 230 MVA.

This poer capacity exceeds the Oconee emergency power requirements" These changes are consistent with Changes 15, 16, and 18 abov e.

CHANGE 22:

In the Bases under "Emergency Power witch Logic Circuits",

add "on the EPSL"1 after "maintenance" in the last sentence of the second paragraph.

Delete the existing third paragraph and substitute the following two new paragraphs:

"Emergency power system components (transformers, buses, Keowee I dro Units, etc.) which become inoperable for testing or maintenance cause their associated circuitry (functional units) of the EPSL to become ineffective.

Therefore, the operability of these associated functional units is irrelevant and not required.

In these cases the controlling Technical Specification for the LC will be the one associated with the inoperability of the emergency power system components(s).

However, all other functional units unaffected by the inoperability of the emergency power system component(s) must meet the requirements of Table 3.7-1 to ensure the operability of the remai'ning emergency power system.

"In the event a 125 VOC instrumentation and control power pane lboard becomes inoperable (for planned or unplanned reasons) as allowed by Technical Specification 3.7.2(e)(4),

circuits or channels of more than one functional unit of the EPSL may become inoperable.

In this case, continued operation is alled under the LCD of T.S. 3.7.2(e) (4), provided that no functional units' circuits, etc., addressed by Table 3.7.1 are out of service, which would not have been out of service due to inoperability of the panelboard.

This assures that no functional unit of Table 3.7.1 is degraded beyond the requirements for degraded operation, and that the EPSL is capable of performing its intended function."

Delete "until the EPSI is returned to a normal operational status" from the first sentence of the existing fourth paragraph and substitute:

nunless the return to criticality is permitted by controlling Technical Specification for an emergency power system component(s).

However, all functional units of the EPSL not affected by the inoperability of the emergency power system component(s) must be operable prior to return to criticality."

Also add the following new paragraph to the end of this section:

"The normal source breakers (NI and N2) provide power to the main feeder busses from the auxiliary transformer under normal power operation of the plant.

Under accident conditions the normal breakers open to allow an emergency power flowpath to the main feeder busses.

Since there is no emergency closing function, the Ni and N2 breakers may be opened and control circuitry deenergized without degrading the capability of the EPSL to perform its intended safety function.

Therefore, while the NI and N2 breakers are open, Technical Specification 3.7.2(b) is considered to be satisfied with respect to Ni and N2 functional units of the EPSL."

These changes are consistent with other changes above.

The licensee has proposed the following change which we find acceptable on the basis that it adds conservatism by providing for additional surveillance testing (at the licensee' s option):

CHANGE 23:

Under Specification 3.7.2(g) add "or performance test" to the end of the last line.

Also in the Bases under "Capacity of DC Systems" add the following two new paragraphs which provide a discussion of the allovable outage times and surveillance testing for the 125 VDC systems:

"A single string or component of the 125 VOC safety related distribution system may be inoperable for periods not exceeding 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> as described in Specification 3.7.2(e).

In the case of the annual discharge test required by Specification 4.6.10 and the battery performance test (per IEEE Standard 450), a longer time period of up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed for the required equalizing charge.

"In addition to the service test, the battery performance test may be conducted every 5 years (per IEEE Standard 450), unless there are signs of degradation.

Degradation is indicated when the battery capacity drops more than 10 percent of rated capacity from its average on previous performance tests, or is below 90 percent of manufacturer's rating.

If there is degradation per above definition, the test should be conducted annually until the battery is replaced or until tests prove the battery is not in a degraded state."

3.0 ENVIRONMENTAL CONSIDERATION

These amendments involve changes in requirements with respect to the installation or use of facility compronents located within the restricted area as defined in 10 CFR Part 20. We have determined that the amendments involve no significant increase in the amounts, and no significant change in the types,

--10 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, 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 these ahmendments.

4.0 CONCLUSION

The Commission's proposed determination that the amendments involve no significant hazards consideration was published in the Federal Register (55 FR 8223) on March 7, 1990. The Commission consulted with the State of outh Carolina. No public comments were received, and the State of South Carolina did not have any comments.

We have 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, 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 or to the health and safety of the public.

Principal Contributor: F. Burrows, SELB/DST Dated:

April 25, 1990