ML18057B492
| ML18057B492 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 01/21/1992 |
| From: | Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-048, REF-GTECI-049, REF-GTECI-NI, TASK-048, TASK-049, TASK-48, TASK-49, TASK-OR GL-91-11, NUDOCS 9201280043 | |
| Download: ML18057B492 (7) | |
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- NllCHlliAN'S PROliRESS Palisades Nuclear Plant:
27780 Blue Star Memorial Highway, Covert, Ml 49043 January 21, 1992 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 GB Slade General Manager DOCKET 50-255 - LICENSE DPR PALISADES PLANT - RESPONSE TO GENERIC LETTER 9I-II, RESOLUTION OF GENERIC ISSUES 48, "LCOs FOR CLASS IE VITAL INSTRUMENT BUSES," and 49, "INTERLOCKS AND LCOs FOR CLASS IE TIE BREAKERS" Generic Letter 9I-II, dated July I8, I99I, was issued following completion of the NRC staff's evaluation of Generic Issues 48 "LCOs for Class IE Vital Instrument Buses," and 49, "Interlocks and LCOs for Class IE Tie Breakers" as part of the resolution of GI-I28, "Electrical Power Reliability." The generic letter requested that licensees provide a response, under oath and affirmation, that they had either implemented procedures conforming to the guidance provided in the enclosure to the generic letter or could provide adequate justification that such procedures were not needed.
Enclosure I to Generic Letter 9I-II provided guidance regarding the development of procedures the NRC staff felt were necessary to implement the requirements of the generic letter. The NRC staff concluded that the licensee procedures should fulfill the following requirements:
I.
Limit the time that a plant is in possible violation of the single-failure criterion with regard to the Class IE vital instrument buses and tie breakers,
- 2.
Require surveillance of these components, and
- 3.
Ensure that, except for the times covered in Item (I}, the plant is operating in an electrical configuration consistent with the regulations and its design bases.
The attachment to this letter is our response to the recommended actions presented in Enclosure I to Generic Letter 9I-II. Based on our review of the generic letter and its enclosure, we believe that we have implemented the appropriate procedures conforming to the guidance provided in the enclosure.
~.4L.--
Gerald B Slade General Manager CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades Attachment
CONSUMERS POWER COMPANY To the best of my knowledge, information and belief, the contents of this submittal are truthful and complete.
By ~~C?
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David P Hoffman, Vic Nuclear Operations Sworn and subscribed to before me this _lQ day of January LeAnn Morse Notary Public Van Buren County, Michigan My commission expires June 6, 1994 Le1\\.HN M0!-=1SE, NOTARY PUBLIC
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ATTACHMENT Consumers Power Company Palisades Plant Docket 50-255 Response to Generic Letter 91-11 January 21, 1992 4 Pages
A restatement of the Recommended Actions and the CPCo Response to the Recommended Actions are provided below.
Note that some of the requirements regarding limiting conditions of operation (LCOs} for electrical equipment, such as Preferred AC buses YlO, Y20, Y30, Y40 and motor control centers (MCCs}
1 and 2 discussed below, are not contained in our current technical specifications but are described in supplementary technical specifications.
These supplementary technical specifications are administratively controlled in Standing Order 54.
These supplementary technical specifications are the result of plant modifications and commitments made to the NRC and are necessary to maintain systems and equipment affected by the changes OPERABLE.
Administratively, all of the requirements included in the supplementary technical specifications are treated as though they were NRC issued technical specifications.
In addition, the supplementary technical specifications may impose surveillance requirements which are also not contained in the NRC issued technical specifications. Since Palisades considers the supplemental technical specifications equivalent to the NRC issued technical specifications, these additional surveillance requirements are incorporated into the technical specifications surveillance program.
RECOMMENDED ACTION 1 Ensure that your plant has procedures that include time limitations and surveillance requirements for (1) vital instrument buses (typically 120V AC buses).
CPCO RESPONSE A.
Administrative Controls The procedures and administrative control for vital instrument buses (Preferred 120V AC power buses YlO, Y20, Y30 and Y40}
include:
- a. Technical Specification 3.7.2.g limits bus inoperability to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
- b.
Standing Order 54, Section 3.7.2.g limits bus inoperability for buses Y20, Y30 and Y40 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
- c. Kirk key interlocks prevent providing power from the bypass regulator to more than one Preferred 120V AC bus at the same time.
- d.
Standing Order 54, Section 3.7.3, states that if YlO is inoperable, then Technical Specification 3.5.3 applies. This may limit inoperability to less than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> unless all auxiliary feedwater requirements are met.
NOTE:
A modification (FC 842) currently planned for the 1992 Refueling Outage will provide a backup power supply to the A and B Auxiliary Feedwater Pump 24V de control logic.
Therefore, the bus inoperability limit for YlO will be 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, similar to Y20, Y30 and Y40.
- e. Standing Order 54, Section 3.7.2.p, allows only one Preferred 120V AC bus to be powered from the alternate source (bypass regulator) and limits this alternate feed to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
B. Surveillance Requirements Surveillance procedures on the Vital Instrument Buses include:
- a. Technical Specifications Surveillance Procedure (TSSP) M0-29, "Engineering Safety Systems Alignment," which verifies the de input breakers to the inverters and inverter output breakers to the vital instrument buses are closed.
- b.
TSSP SH0-1, "Operators Shift Items," which verifies that all 4 channels of several instruments are operable each shift. Since these instruments are powered from the vital instrument buses, the buses are verified to be operable.
C. Conclusion The recommended actions of Generic Letter 91-11 with respect to vital instrument buses are met.
RECOMMENDED ACTION 2 Ensure that your plant has procedures that include time limitations and surveillance requirements for (2) inverters or other on-site power sources to the vital instrument buses.
CPCO RESPONSE A. Administrative Controls Procedures and administrative controls for inverters and other power sources (instrument AC bus Y-01) to the vital instrument buses include:
- a. Technical Specification 3.7.2.e, limits MCC-1 and 2 inoperability to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
(These are power sources to Y-01)
- b.
Kirk key interlocks prevent providing power from the bypass regulator to more than one Preferred I20V AC bus at the same time.
- c. Standing Order 54, Section 3.7.2.p, allows only one Preferred I20V AC bus (YIO, Y20, Y30 or Y40) to be powered from the alternate source (bypass regulator - which is powered from the Instrument AC Bus YOI).
The alternate source power feed is limited to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> per this same Standing Order 54 section. This, in effect, limits inverter inoperability to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
B. Surveillance Requirements Surveillance procedures on inverters and other on-site power sources to the vital instrument buses include:
- a.
TSSP M0-29, "Engineering Safety Systems Alignment," which verifies that the de input breakers and inverter output breakers are closed.
- b.
TSSP M0-29, which verifies that the alternate AC feed (AC input breaker) to the preferred bus is open.
- c.
TSSP M0-29, which verifies the 480V AC power supply to the 480/I20V instrument AC transformer is closed.
C. Conclusion The recommended actions of Generic Letter 9I-II with respect to inverters and other on-site power sources to the vital instrument buses are met.
RECOMMENDED ACTION 3 Ensure that your plant has procedures that include time limitations and surveillance requirements for (3) tie breakers that can connect redundant Class lE buses (AC or DC) at the unit or that can connect Class 1£ buses between units at the same site.
CPCO RESPONSE A. Administrative Controls Procedures and administrative controls for redundant Class IE tie breakers include the following:
- a.
While buses IC and ID are normally supplied from the same power source, the supply breakers provide the Class IE separation for these buses. Therefore, the only tie breakers capable of cross connecting redundant Class IE buses at Palisades are the tie breakers for load centers II and I2 (52-IIIB and 52-I2I7).
- b.
Interlocks prevent closing the tie breakers unless the 2400V/480V incoming breaker to one of the Load Centers is open.
- c. System Operating Procedure SOP-30, "Station Power", Sections 7.3.I and 7.3.2, specify that Load Centers II and I2, respectively, are administratively inoperable if the load centers are cross-connected and powered from the redundant bus.
- d. Technical Specification 3.7.2.d, limits bus inoperability to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for Load Centers II and I2.
- e. If under-voltage is sensed on one of the 2400V AC Class IE buses (IC or ID) then both the tie breakers are opened on a load shed signal.
B. Surveillance Requirements Surveillance procedures on the tie breakers for Class IE redundant buses include TSSP M0-29, "Engineering Safety Systems Alignment," which verifies that the tie breakers 52-IIIS and 52-I2I7 are open.
C. Conclusion The recommended actions of Generic Letter 9I-II with respect to tie breakers for redundant Class IE buses are met.