ML18100A983
| ML18100A983 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 03/28/1994 |
| From: | Hagan J Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18100A984 | List: |
| References | |
| LCR-93-10, NLR-N94007, NUDOCS 9404060083 | |
| Download: ML18100A983 (8) | |
Text
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Public Service Electric and Gas Company Joseph J. Hagan Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1200 Vice President - Nuclear Operations MAR281994 NLR-N94007 LCR 93-10 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
REQUEST FOR LICENSE AMENDMENT SALEM GENERATING STATION UNIT NOS. 1 AND 2
.FACILITY OPERATING LICENSE NOS. DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311 In accordance with the requirements of 10 CFR 50.90, Public Service Electric and Gas Company (PSE&G) hereby submits a request for amendment of Facility Operating Licenses DPR-70 and DPR-75 for Salem Generating Station Unit Nos. 1 and 2, respectfully.
This proposed change would revise the Sustained Degraded Voltage Trip Setpoint and Allowable Value due to changes in the switchyard configuration.
A description of the requested amendment, supporting information and analyses for the change and the basis for a no significant hazards determination are provided in Attachment 1.
The Technical Specification pages affected by the proposed change are marked-up in Attachment 2.
PursQant to the requirements of 10 CFR 50.91(b) (1), PSE&G has provided a copy of this amendment request to the State of New Jersey.
Since the proposed amendment to the Sustained Degraded Voltage trip setpoint and Allowable Value limits are within the range presently allowed by the Technical Specification, changes to the trip setpoint and allowable value have been implemented by PSE&G in accordance with 10CFR50.59 prior to placing the Salem Unit 1 switchyard modifications into service.
Although the proposed changes for Salem Unit 1 have been implemented as part of the switchyard modification, PSE&G requests that the Salem Unit 1 amendment be made effective upon issuance, but shall be implemented within 60 days to provide sufficient time for any remaining administrative activities.
9404060083 940328 PDR ADOCK 05000272 p
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Document Control Desk NLR-N94007 MAR28 7994 It is requested that the proposed amendment to the Salem Unit 2 Technical Specifications.be made effective upon issuance, but shall be implemented prior to startup following the next Unit 2 refueling outage.
Should you have any questions on this submittal, please contact us.
Attachments (2)
Mr. T. T. Martin, Administrator - Region 1
- u. s. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. J. Stone, Licensing Project Manager
- u. s. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. c. s. Marschall (S09)
USNRC Senior Resident Inspector Mr. Kent Tosch, Manager, IV NJ Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625
STATE OF NEW JERSEY COUNTY OF SALEM
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REF:
NLR-N94007 SS.
J. Hagan, being duly sworn according to law deposes and says:
I am Vice President - Nuclear Operations of Public Service Electric and Gas Company, and as such, I find the matters set forth in the above referenced letter, concerning Salem* Generating Station, Unit Nos. 1 and 2, are true to the best of my knowledge, information and belief.
Subscribed and swor~ef ore me
. ', ', this 9(?_-&lz day of fld£l.JL, 1994
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Jersey I
KIMBERL y JO BROWN My Commission expires on ~~----J~NO~T~A-RY~P~U~Bl~IC~O=F_N~E~W~J~ER~S~E~Y~
Mr 6ommisslon Expires April 21, 1998
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ATTACHMENT 1 LCR 93-10 NLR-N94007 PROPOSED TECHNICAL SPECIFICATION CHANGES REQUEST FOR LICENSE AMENDMENT SALEM GENERATING STATION UNITS 1 AND 2 FACILITY OPERATING LICENSE NOS. DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311
I.
Description of Change
'R 93-10 NLR-N94007 This amendment request proposes to revise Technical Specification 3/4.3.2, Table 3.3-4, Item 7b, Sustained Degraded Voltage for Salem Generating station Units 1 and 2.
The amendment proposes to change the Sustained Degraded Voltage Trip Setpoint from
~91.6% of bus voltage for~ 13 seconds to >94.6% of bus voltage for ~ 13 seconds, and the Allowable Value for Sustained Degraded Voltage from ~ 91% of bus voltage for ~ 15 seconds to ~ 94% of bus voltage for < 15 seconds.
II.
Reason for Proposed Change PSE&G has implemented modifications to the Unit 1 switchyard configuration that consists of new 500/13KV station power transformers, new 13KV circuit breakers, and 13/4KV station power transformers.
This new equipment will continue to provide the two offsite sources of power to the 3 vital buses as well as power to a new non-vital 4 KV bus.
Similar design changes are planned to be implemented for Salem Unit 2 during the next refueling outage scheduled for the Fall, 1994.
In support of these modifications, calculations have been performed to determine the minimum vital bus voltage necessary to maintain vital loads within their voltage ratings without having to transfer these loads to the emergency diesel generator.
These calculations also determined the minimum bus recovery voltage subsequent to a transient that would reset the undervoltage relay, and prevent unnecessary transfers to the emergency diesel generators.
The results of these calculations concluded that a Sustained Degraded Voltage Trip Setpoint of ~ 94.6% and an Allowable Value of > 94% will ensure that the vital bus electrical loads operate at or above their minimum operating voltage based upon the completed switchyard modifications.
This LCR also addresses a related issue that was identified as part of a PSE&G self-initiated electrical engineering assessment.
A review of Engineering Calculation ES-15008(Q), "Salem Unit 1 and 2 Degraded Grid Study", determined that the present Technical Specification Sustained Degraded Voltage Trip Setpoint of 91.6%
may not fully protect loads served by the 4160 vital busses should the bus voltage degrade to less than 93.2% but greater than 91.6%.
A detailed description of this issue has been submitted to the NRC under Licensee Event Report (LER) 93-014-00 dated August 20, 1993.
As part of this LER, PSE&G committed to implement a design change to revise the Sustained Degraded Voltage Trip Setpoint.
Although further evaluation of this issue concluded that the existing trip setpoint of 91.6% would provide adequate protection of 4KV, 460V and 230V vital electrical loads under degraded voltage conditions, it was concluded that maintaining the grid voltage at no less than 93.2% will enhance the level of performance and provide a greater margin of reliability for these loads.
The proposed setpoint changes PAGE 1 OF 3 ATTACHMENT 1
'R 93-10 NLR-N94007 therefore address the LER commitment to protect these loads.
Changes to the Unit 1 Sustained Degraded Voltage Trip Setpoint have been implemented by PSE&G in accordance with 10CFR50.59 since the proposed setpoint and allowable value limit are more restrictive than allowed by the present Technical Specification.
Similar changes to the Unit 2 setpoint will be implemented prior to startup following the next refueling outage currently scheduled for Fall, 1994.
III. Justification for the Proposed Change Undervoltage protection for the loads served by the 4160 V vital buses is provided in two levels.
The first level uses one undervoltage relay per vital 4 KV bus to sense the loss of offsite power.
The Second Level of Undervoltage Protection System (SLUPS) was provided to comply with the requirements of an NRC letter dated June 2, 1977.
The second level trip function (2 out of 3 logic) ensures that a minimum voltage is maintained at the vital buses. If for any reason the bus voltage decays below the specified setpoint for greater than the prescribed time, the bus is isolated from its offsite power source by tripping the infeed breaker and is automatically aligned to the associated emergency diesel generator.
The present Technical Specifications require a setpoint for Sustained Degraded Voltage of ~ 91.6% of bus voltage for ~ 13 seconds based on an Allowable Value of ~ 91% of bus voltage for <
15 seconds.
Reanalysis of the Sustained Degraded Voltage Trip Setpoint has been performed in support of modifications to'the Salem Unit 1 switchyard as discussed in Section II above.
Calculations have been performed to determine the optimum setpoint for this trip function based on the response to various transients including a LOCA, degraded grid voltage, transformer failure and starting of the largest electrical load in accordance with the existing design basis.
In addition, the optimum setpoint was determined based on the requirement that (1) all vital loads will operate satisfactorily at or above the setpoint, and (2) following a transient, the bus voltage recovers above the reset value of the second level undervoltage relay thus preventing unnecessary loading of the emergency diesel generators.
The calculations have determined that a Sustained Degraded Voltage Trip Setpoint of ~ 94.6% of bus voltage for ~ 13 seconds is the optimum setpoint with an Allowable Value of > 94% of bus voltage for ~ 15 seconds to meet the current design requirements.
IV.
Significant Hazards Consideration PSE&G has, pursuant to 10CFR50.92, reviewed the proposed amendment to determine whether our request involves a significant PAGE 2 OF 3 ATTACHMENT 1
IR 93-10 NLR-N94007 hazards consideration.
We have determined that operation of Salem Units 1 and 2 in accordance with the proposed change:
- 1.
Will not involve a significant increase in the probability or consequences of an accident or malfunction of equipment important to safety previously evaluated.
The proposed amendment will increase the minimum voltage available at the vital buses and maintain vital loads within their voltage ratings under degraded voltage conditions.
The change to the Sustained Degraded Voltage Trip Setpoint also considered the* minimum bus recovery voltage following a transient that would reset the undervoltage relay to prevent unnecessary transfers to the emergency diesel generators.
Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated in the UFSAR.
- 2.
Will not create the possibility of a new or different kind of accident from any previously evaluated.
The proposed amendment to the Sustained Degraded Voltage Trip Setpoint ensures a higher minimum voltage is available to all vital loads during any electrical transient, and is sufficient to operate these loads within their voltage rating.
Therefore, the proposed amendment does not create the possibility of a new or different kind of accident from any previously evaluated.
- 3.
Will not involve a significant reduction in a margin of safety.
The proposed amendment will increase the minimum voltage available at the vital buses and maintain vital loads within their voltage ratings.
This ensures that the minimum voltage for any vital load will continue to be available including under degraded voltage conditions.
Calculations have determined that a Sustained Degraded Voltage Trip Setpoint of ~ 94.6% of bus voltage for ~ 13 seconds is the optimum setpoint with an Allowable Value of ~ 94% of bus voltage for ~ 15 seconds to meet the current design requirements.
The.Se values provide sufficient margin based on the minimum voltage of 93.2% required to ensure that vital loads will operate within their designed voltage range.
Therefore, the proposed amendment does not involve a significant reduction in a margin of safety.
Conclusions Based on the above, PSE&G has determined that the proposed amendment does not involve a Significant Hazards Consideration.
PAGE 3 OF 3 ATTACHMENT 1
ATTACHMENT 2 LCR 93-10 NLR-N94007 TECHNICAL SPECIFICATION MARKED-UP PAGES REQUEST FOR LICENS~ AMENDMENT SALEM GENERATING STATION UNITS 1 AND 2 FACILITY OPERATING LICENSE NOS. DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311