ML18102A251
| ML18102A251 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 07/12/1996 |
| From: | Storz L Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18102A252 | List: |
| References | |
| LCR-S96-09, LCR-S96-9, LR-N96188, NUDOCS 9607220284 | |
| Download: ML18102A251 (11) | |
Text
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- Public Service Electric and Gas*
Company Louis F. Storz Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-5700 Senior Vice President - Nuclear Operations JUL 1 2 1996 LR-N96188 LCR S96-09 United States Nuclear Regulatory Commission Document control Desk Washington, DC 20555 EXIGENT REQUEST FOR CHANGE TO TECHNICAL SPECIFICATIONS ENGINEERED SAFETY FEATURES INTERLOCK P-12 SALEM GENERATING STATION NOS. 1 AND 2 FACILITY OPERATING LICENSES DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311 Gentlemen:
In accordance with 10CFR50.90, Public Service Electric & Gas (PSE&G) Company hereby requests a revision to the Technical Specifications (TSs) for the Salem Generating Station Unit Nos. 1 and 2. In accordance with lOCFR50.91(b) (1), a copy of this submittal has been sent to the State of New Jersey.
The proposed TS changes contained herein represent changes to Specification 3.3.2.1 "Engineered Safety Feature Actuation System (ESFAS)" to reflect a revised setpoint for the interlock, designated P-12. This design feature enables certain Safety Injection (SI) actuation inputs into the protection circuitry, based on the average Reactor Coolant System temperature. The P-12 input enables plant startup and allows blocking of the SI inputs during plant shutdown. This change will correct a deficiency outlined in Licensee Event Report 272/96-007-00, (ref.
PSE&G's letter LR-N96176, dated June 21, 1996) by providing consistency between the various instrumentation TSs, the system design basis, and the ESFAS channel setpoints.
The proposed changes have been evaluated in accordance with lOCFR50.91(a) (1), using the criteria in lOCFR50.92(c), and PSE&G has concluded that this request involves no significant hazards considerations.
The basis for the requested change is provided in Attachment 1.
A lOCFR50.92 evaluation with a determination of no significant hazards consideration is provided in Attachment 2. The marked up Technical Specification pages affected by the proposed changes are provided in Attachment 3.
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JUL 12 1996 Document Control Desk LR-N96188 PSE&G committed to implement this License Change Request (LCR) prior to entry into Mode 3 as a result of the conclusions of LER 272/96-007. In order to support startup of Salem Unit 2, PSE&G requests exigent approval of the amendment.
The justification for the exigent request is that the discrepancy between the system design basis and the TS was identified on June 13, 1996, during the preparation of LER 272/96-007. This LCR was developed after necessary technical justification was received from Westinghouse. PSE&G is requesting a three-day implementation period following amendment approval.
Should you have any questions regarding this request, we will be pleased to discuss them with you.
Sincerely, Affidavit Attachments (3) c Mr. T. T. Martin, Administrator - Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. L. Olshan, Licensing Project Manager - Salem U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 14E21 Rockville, MD 20852 Mr. c. Marschall (X24)
USNRC Senior Resident Inspector - Salem Mr. K. Tosch, Manager IV Bureau of Nuclear Engineering 33 Arctic Parkway CN 415 Trenton, NJ 08625 95-4933
- REF: LR-N96188 LCR S96-09 STATE OF NEW JERSEY )
) SS.
COUNTY OF SALEM )
L. F. Storz, being duly sworn according to law deposes and says:
I am Senior 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, Units 1 and 2, are true to the best of my knowledge, information and belief.
Subscribed and Sworn to before me this _Lfd:,l/i_ day of \JU/u , 1996
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Notary Public of New Jersey DELORIS D. HADDEN Notary Public of New Jersey My Commission ~res My Commission expires on 03-29-2000
- Document Control Desk LR-N96188 LCR S96-09 SALEM GENERATING STATION UNIT NOS. 1 AND 2 FACILITY OPERATING LICENSES DPR-7 0 AND DPR-7.5 DOCKET NOS. 50-272 AND 50-311 CHANGE TO TECHNICAL SPECIFICATIONS ENGINEERED SAFETY FEATURES INTERLOCK P-12 BASIS FOR REQUESTED CHANGE REQUESTED CHANGE AND PURPOSE The proposed Technical Specification (TS) changes contained herein represent changes to Specification 3.3.2.1 "Engineered Safety Feature Actuation System (ESFAS)." These changes provide a consistent temperature for the P-12 interlock and the Safety Injection (SI) signal setpoint generated from High Steamline Flow coincident with Low-Low Reactor Coolant System Average Temperature (Tavg)
- This proposed change will align the TS to the ESFAS system design basis and will also provide consistency between Salem TS and the TS Tables provided in the "Standard Technical Specifications for Westinghouse Pressurized Water Reactors," NUREG 0452 (STS).
The requested changes revise the P-12 TS stated interlock setpoints from "~545°F" to "increasing from 543°F (with an allowable setpoint value ~545°F)" and from "<541°F" to "decreasing from 543°F (with an allowable setpoint value
~541°F)." It should be noted that this change does not impact the Low-Low Tavg input to SI actuation setpoint of 543 °F.
Since the bases for the Minimum Temperature For Criticality Limiting Condition for Operation (LCO), B3/4.1.1.5 (U/1) and B3/4.l.1.4 (U/2.), refers to the P-12 setpoint, it is being changed to ref er to the setpoint allowable value for clarification purposes only.
This submittal satisfies*a commitment made in Licensee Event Report 272/96-007-00, (ref PSE&G's letter LR-N96176, dated June 21, 1996).
BACKGROUND On May 24, 1996, a discrepancy was identified between the Low-Low Tavg setpoint for SI actuation contained in TS Table 3. 3-4 and the setpoints for the P-12 interlock provided in TS Table 3.3-3.
During the investigation of the discrepancy on June 13, 1996, it was determined that the existing system design could not satisfy all of the setpoint requirements specified in the two tables.
The existing system design utilizes a single bistable per channel to provide a partial SI signal, High Steam Flow and Low-Low Tavg, Page 1 of 4
- Document Control Desk LR-N96188 LCR S96-09 and the P-12 interlock function. -
The purpose of the P-12 interlock, established in the original plant design, is to provide manual blocking capability of the Low-Low SI Tavg signal and is necessary for performing controlled plant startups and shutdowns, when Tavg is normally below 543 °F, without receiving an unwarranted SI. In accordance with TS Table
- 3. 3-4, the setpoint for the Low-Low Tavg input signal for the SI*
is ~543 °F. TS Table 3. 3-3, footnote ## denotes that the Tavg signal may be bypassed (i.e. , blocked) in Mode 3 if Tavg is below the P-12 interlock setpoint. The P-12 interlock function is further defined in this table based upon whether Tavg is above or below certain temperature setpoints.
Per the existing TS, with two of the four Tavg channels <541°F, P-12 allows manual block of SI actuation. on High Steamline Flow coincident with either Low-Low Tavg or Low steamline Pressure and also blocks operation of the steam dumps to prevent an excessive cool down of the RCS should a malfunction occur in the system.
This same bistable provides for automatic removal of the manual block, or reinstates the same SI signals, on increasing temperatures when three of the four Tavg channels are ~545 °F and allows full operation of the steam dumps on the increasing temperature.
Since there is only a single bistable for each channel, only two setpoints are achievable: trip and reset functions of the bistable. By the current TS, three setpoints are required:
~543°F for SI actuation, ~541°F for allowing manual block, and
~545°F for preventing manual block. With the bistable trip setpoint established in the plant at 543°F, it was discovered that the setpoints for P-12 are not met and could not be met without a design modification.
As noted in LER 96-007, PSE&G determined that the cause of the mismatch in Salem TS values and the actual instrument setpoints was due to improper implementation of the Westinghouse STS for the Salem plants. Since the STS provides only two different setpoints for Tavgr (the Low-Low Tavg SI actuation setpoint and manual block permissive have the same value with the P-12 reset preventing manual block a different value), the use of a single bistable to satisfy system design requirements is appropriate.
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Attachment 1
- Document Control Desk LR-N96188 LCR S96-09 JUSTIFICATION OF REQUESTED CHANGES The intent of the Tavg input to the ESFAS is to ensure diversity in SI signal actuation for accidents which result in a rapid depressurization of the secondary side of the steam generators, such as, Main Steamline and Main Feedwater Line breaks, and stuck open secondary valves. The injection of borated water into the Reactor Coolant System (RCS) as a result_of the SI actuation provides additional protection against a return to criticality from the positive reactivity introduced during the resulting RCS cooldown. The Low-Low Tavg setpoint is below the program Tavg in -
Modes 1 and 2 which appropriately precludes inadvertent actuatiori of a SI during non-accident transient conditions and is high enough to ensure a SI will occur in time to prevent a return to criticality should the secondary system blowdown. In Modes 4, 5, and 6, operability of the SI initiation instrumentation, including the P-12 interlock, is not required since there is .
insufficient energy in the secondary side of the unit to have an accident. In Mode 3, secondary energy and Tavg increase necessitating an interlock such as P-12 for the mode transition.
- Several different steamline break analyses have been performed to support the operation of the Salem units. These analyses were performed to determine the core response to postulated steamline breaks and to calculate mass and energy releases both inside and outside containment. The High Steamline Flow coincident with Low-Low Tavg or Low steamline Pressure protective functions are not modeled in the current licensing basis core response steamline break analysis~ Other SI signals generated from a postulated steamline break are credited in the analysis.
Interlock P-12 is independent of these credited SI signals.
Therefore, .the P-12 related SI signals are considered backup signals providing protection diversity. since the protective function actuation is not credited from Low-Low Tavg or Low Steamline Pressure in Mode 3, a .change to the P-12 setpoint has no impact on the steamline break analysis.
The licensing basis steamline break mass and energy release safety analyses, inside and outside containment, for Salem Units 1 & 2 assumes the availability of the High Steam Flow coincident with Low-Low Tavg or Low Steamline Pressure for the actuation of SI and steamline isolation. However, other SI signals will actuate before this protective function is reached in the analyses. Therefore, credit is not taken in the ana*lyses for actuation of the High Steam Flow coincident with Low-Low Tavg or Low Steamline Pressure SI functions.
PSE&G has determined that there is no safety consequence due to the P-12 interlock enabling the SI function in the range from 543 °F up to 545 °F. The Tavg no-load temperature for Salem is Page 3 of 4
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Document Control Desk LR-N96188 LCR S96-09 547°F, with increasing Tavg for higher power operation. The allowable setpoint value of 545°F as the upper limit for P-12 assures the availability of the SI function at higher temperatures. Therefore, the protective instrumentation operates within its analyzed range.
On decreasing temperature, P-12 permits manual block of SI in both High Steamline Flow coincident with Low-Low Tavg and High Steamline Flow coincident with Low Steamline Pressure. This permits blocking of these SI actuations during a controlled shutdown. With a 2°F allowable deviation from the nominal setpoint, the setpoint of 543°F is adequate to enable the operator to block SI. (As discussed in the TS Bases, the trip setpoints are nominal values at which the bistables are set. Any bistable is considered to be properly adjusted when the "as-left" value is within the band for channel calibration accuracy (i.e.,
+/-rack calibration+ comparator setting accuracy)).
Revision of the P-12 setpoint to enable manual block of SI in the range from 541°F to 543°F does not impact the safety analyses.
The assumption in the analyses is that SI is available at or above the Tavg no-load value of 54 7 ° F, which is consistent with the setpoint for Low-Low Tavg in TS Table 3. 3-4. Retaining the allowable value of 541°F is also consistent with Table 3.3-4.
The change to the Bases for Minimum Temperature For Criticality has no impact on plant operation and makes the bases consistent with the change to P-12. No change to the Minimum Temperature For Criticality is requested or needed.
CONCLUSIONS The proposed changes to TS Table 3.3-3 make the P-12 setpoint 543°F increasing with an allowable value to 545°F and 543°F decreasing with an allowable value to 541°F. These changes are consistent with assumptions in the accident analysis. By making the P-12 interlock setpoint the same value as the Low-Low Tavg setpoint, a single bistable can be used to ensure that the ESFAS circuitry provides the desired protection for secondary side depressurization accidents. These changes bring the TSs into alignment with the system design.
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e Document Control Desk LR-N96188 LCR S96-09 SALEM GENERATING STATION UNIT NOS. 1 AND 2 FACILITY OPERATING LICENSES DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311 CHANGE TO TECHNICAL SPECIFICATIONS ENGINEERED SAFETY FEATURES INTERLOCK P-12 10CFR50.92 EVALUATION Public Service Electric & Gas (PSE&G) has concluded that the proposed changes to the Salem Generating Station Unit Nos. 1 and 2 Technical Specifications (TS) do not involve a significant hazards consideration. In support of this determination, an evaluation of each of the three standards set forth in 10CFR50.92 is provided below.
REQUESTED CHANGE The change is to Salem Units 1 & 2, Technical Specifications, Table 3.3-3, Designation P-12, to include a nominal setpoint, 543°F, along with the appropriate allowable values for the permissive to block, ~541°F, and automatic unblock, ~545°F, of SI on Low-Low Tavg signal. This revision provides consistency between the direction of the allowable value from the nominal setpoint for the high automatic unblock of Safety Injection (SI) and the low permissive to block SI. In addition, consistency with Technical Specification ESFAS Table 3. 3-4, Low-Low T~vg nominal setpoint is maintained. This is necessary since all three actions are controlled with the same bistable or hardware.
Technical Specification Bases B3/4.1.1.5 (U/1) and B3/4.1.1.4 (U/2), Minimum Temperature For Criticality, is being revised to add the word "allowable" in front of the word setpoint when defining the limitations as applicable to the P-12 setpoint.
BASIS
- 1. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
This change to the Technical Specifications does not involve any physical changes to the plant or any procedures changes.
There is no safety consequence to the SI function being enabled at 543°F. The T~~ no-load temperature is at 547°F with increasing Tavg for higher power operation. The allowable- value. of 545°F as the upper limit assures the availabiiity of the SI function, therefore, the protective Page 2 of 2
e Document Control Desk LR-N96188 LCR S96-09 function will perform within its analyzed range. On increasing temperature, P-12 automatically enables SI in both High Steamline Flow coincident with Low-Low Tavg and High Steamline Flow coincident with Low Steamline Pressure.
It also provides an arming signal to the Steam Dump System.
On decreasing temperature, P-12 permits manual block of SI in both High Steamline Flow ,coincident with Low-Low Tavg and High steamline Flow coincident with Low Steamline Pressure.
This permits blocking of the SI below the minimum temperature for criticality during a controlled shutdown.
With a 2 °F allow.able deviation from the nominal setpoint, the setpoint of 543°F is adequate to enable the operator to block SI.
Hardware design of the ESFAS provides that actuation of the SI block, enable, and ESFAS protection system operations are all provided by the same bistables. The analyses were performed supporting the design of the ESFAS system.
Revision of the P-12 setpoint to enable manual block of SI from 541°F to 543°F does not impact the safety analyses. SI is available at or above the Tavg no-load value of 54 7 °F, which is consistent with the setpoint for Low-Low Tavg in TS Table 3.3-4. Retaining the allowable value of 541°F is also consistent with Table 3.3-4. The proposed revisions do not affect the integrity of the fuel assembly or reactor internals such that their function in the control of radiological consequences is affected. In addition, the proposed revisions do not affect any fission product barrier. The proposed revision does not change, degrade, or prevent the response of safety related mitigation systems to accident scenarios, as described in the FSAR.
Therefore the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. The proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed changes to the TS setpoints for P-12 do not create failure modes that could adversely impact safety-related equipment or cause the initiation of any accident.
The P-12 interlock circuit pertains to accident mitigation systems and not accident initiation. Functions of safety related systems and components, which are related to accident mitigation, have not been altered.
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Document Control Desk LR-N96188 LCR S96-09 The proposed TS setpoint change does not cause the initiation of any accident or create any new credible failure in the system. The proposed revisions do not result in any malfunction of equipment previously evaluated.
The proposed revisions do not result in increased probability of equipment failure scenarios previously deemed improbable.
- Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated, the revisions will not create the possibility of a malfunction of equipment important to safety different than previously evaluated in the FSAR.
- 3. The proposed change does not involve a significant reduction in a margin of safety.
Several different steamline break analyses are performed to support operation of the Salem units. Analyses are performed to determine the core response to postulated steamline breaks and to calculate mass and energy releases both inside and outside containment.
In the current licensing basis core response steamline break analysis, the' High Steamline Flow coincident with Low-Low Tavg or Low Steamline Pressure protective functions are not modeled. As such, a change to the SI permissive has no impact on the analysis. Other SI signals generated from a postulated steamline break are credited in the analysis.
Interlock P-12 is independent of these credited SI signals.
Therefore, this change has no impact on the safety analysis.
The licensing basis steamline break mass & energy release safety analyses, inside and outside containment, for Salem Units 1 & 2 assumes the availability of the High Steamline Flow coincident with Low-Low Tavg or Low Steamline Pressure for actuation of SI and steamline isolation. However, no credit -is taken for these trip functions. The noted Technical Specification change is resolving a discrepancy between the permissive P-12 setpoint and the Low-Low Tavg
- setpoint. Even though this Low-Low Tavg function is available in the steamline break mass & energy release analyses, operation is not credited in the analyses.
Page 4 of 4
Document Control D~k LR-N96188 LCR 596-09 There are no new safety analyses or revision to any existing safety analyses as a result of these changes. In addition, the proposed change does not impact any input assumptions or results of any current licensing basis analyses for the design basis events. Therefore, there is no significant reduction in the margin of safety.
CONCLUSION Based on the above, PSE&G has determined that the proposed changes do not involve a significant hazards consideration.
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