LR-N970707, Application for Amends to Licenses DPR-70 & DPR-75,providing TS Surveillance Requirements to Codify Existing Procedural Commitments for SW Accumulator Vessels
| ML18102B677 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 11/14/1997 |
| From: | Storz L Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18102B678 | List: |
| References | |
| LCR-S97-17, LR-N970707, NUDOCS 9711250085 | |
| Download: ML18102B677 (13) | |
Text
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 NOV 141997 LR-N970707 LCR S97-17 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 REQUEST FOR CHANGE TO TECHNICAL SPECIFICATIONS CONTAINMENT INTEGRITY AND CONTAINMENT COOLING SYSTEMS SALEM GENERATING STATION NOS. 1 AND 2 FACILITY OPERATING LICENSE DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311 Ladies and Gentlemen:
In accordance with 10CFR50.90, Public Service Electric & Gas (PSE&G) Company requests a revision to the Salem Unit 1 and 2 Technical Specifications (TS).
In accordance with 10CFR50.9l(b) (1), a copy of this submittal has been sent to the State of New Jersey.
The proposed changes provide TS surveillance requirements to codify existing procedural commitments for the Service Water (SW) accumulator vessels.
Surveillance requirements are provided for vessel level, pressure and temperature and discharge valve response time.
These surveillance requirements are included in Containment Integrity Technical Specification 3/4.6.1.1 and Containment Cooling System Technical Specification 3/4.6.2.3.
The Bases sections for these technical specifications are also being expanded to provide supporting information regarding these surveillance requirements..
The SW accumulator vessels and discharge valves were installed in Salem Unit 2 during the past refueling outage.
Installation of the SW accumulator vessels and discharge valves on Salem Unit 1 is in progress and will be completed prior to Salem Unit 1 entry into Mode 4.
Surveillance requirements for Salem Unit 2 vessel parameters have been procedurally implemented as described in PSE&G letter LR-N97268 to the NRC staff dated April 24, 1997.
The Salem Unit 2 discharge valve response time was surveillance tested during post-modification testing.
Salem Unit 2 surveillance procedures will be prepared to complete future discharge valve response time surveillance tests in accordance with their eighteen month frequency.
For Salem Unit 1 these surveillance requirements will be satisfied prior to Salem Unit 1 entry into Mode 4 from the current refueling outage.
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The SW accumulator vessel and discharge valves are part of modifications made to address Generic Letter 96-06 issues.
These modifications were reviewed by the NRC staff as documented in the NRC Safety Evaluation Report (SER) dated June 19, 1997.
This SER was issued with Technical Specification Amendments 196 and 179 for Salem Unit 1 and 2 respectively.
In this SER, the NRC staff required that PSE&G propose ne~ technical specification surveillance requirements for these components within 90 days following entry into Mode 2, "Startup," for each Salem Unit.
This submittal fulfills this commitment for Salem Unit Nos. 1 and
- 2.
The proposed changes have been evaluated in accordance with 10CFR50.91(a) (1), using the criteria in 10CFR50.92(c), and PSE&G has concluded that this request involves no significant hazards considerations.
The basis for the requested changes are provided in Attachment 1.
The 10C.FR50. 92 evaluation with a determination of no significant hazards consideration is provided in Attachment 2.
The marked up TS pages affected by the proposed changes are provided in.
Upon NRC approval of the proposed.changes, PSE&G requests that the amendment for Salem Unit 2 be made effective on the date of issuance, but allow an implementation period of sixty days to provide sufficient time for associated administrative activities.
For Salem Unit 1, PSE&G requests that the amendment be made effective on the date of issuance, and allow for implementation within 60 days of issuance, or within 60 days of Salem Unit 1 entering Mode 4, whichever is later.
Should you have any questions regarding this request, we will be pleased to discuss them with you.
Affidavit Attachments (3)
Sincerely, 95-4933
1..-.
I Document Control Desk
~ LR-N~97 07 07 3
c*
Mr. H. J. Miller, 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 Ms. M. Evans (X24)
USNRC Senior Resident Inspector Salem Generating Station Mr. K. Tosch, Manager IV Bureau of Nuclear Engineering PO Box 415 Trenton, NJ 08625 NOV 141997 95-4933
STATE OF NEW JERSEY COUNTY OF SALEM SS.
REF: LR-N970707 LCR S97-17 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 the 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 I'(
day of /Jri1~er, 1997 My commission expires on BARBARA A. POWELL NOTARY PUBLIC OF NEW JERSEY My Commission Expires Oec. 2, 1998 ID# 2160323
- Document Control Attacluuent 1 LR-N970707 LCR S97-17 SALEM GENERATING STATION UNIT NOS. 1 AND 2 FACILITY OPERATING LICENSES DPR-70 AND 75 DOCKET NOS. 50-272 AND 50-311 CHANGE TO TECHNICAL SPECIFICATIONS CONTAINMENT INTEGRITY AND CONTAINMENT COOLING SYSTEMS REQUESTED CHANGE AND PURPOSE The requested changes provide surveillance requirements for the Service Water Accumulator Vessels.
Surveillance requirements are included for vessel level, pressure and temperature.
These surveillances are proposed to be performed on a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> frequency.
Surveillance requirements are also proposed for the vessel discharge valve time response test to be performed on an 18 month frequency.
These surveillance test requirements are included in Containment Integrity Technical Specification 3/4.6.1.1 and Containment Cooling System Technical Specification 3/4.6.2.3.
The Bases sections for these technical specifications are also being expanded to provide supporting information regarding these surveillance requirements.
The purpose of these additional surveillance requirements is to provide added assurance that the Service Water (SW) accumulator vessels and associated discharge valves.will be maintained in accordance with design criteria to perform their safety function as assumed during accident conditions.
JUSTIFICATION OF REQUESTED CHANGE In LER 272/96-020-00 dated September 18, 1996, PSE&G identified design deficiencies with the containment fan coil unit (CFCU) piping in that this piping may be subject to water column separation waterhammer and two phase flow conditions during an accident.
The applicable accident was a loss of offsite power (LOOP) with or without a loss of coolant accident (LOCA) or main steam line break in containment (denoted as LOOP/LOCA throughout).
The NRC staff subsequently issued Generic Letter (GL) 96-06,
~Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions," requesting further licensee information and action regarding these issues.
As part of the resolution of these GL 96-06 issues at Salem Station, PSE&G modified the CFCU piping on each Salem Unit to include two SW accumulator vessels (tanks) and fast acting tank discharge valves.
A 15,000 gallon capacity water accumulator tank is installed on each of two service water headers to the CFCU inlet piping.
Each tank is pressurized with a nitrogen cover gas (135 to 160 psig).
During a LOOP/LOCA, the service water pumps coast down on loss of power and the CFCU outlet Page 1 of 6
- Document Control LR-N970707 LCR S97-17 valves travel closed.
The CFCU outlet piping is the high point in the service water system.
As the CFCU outlet valves travel closed, the service water inventory drains from the CFCU outlet piping with the potential for water column separation and subsequent waterhammer within the pipe.
To preclude water column separation on a LOOP, each accumulator tank discharges into the associated service water header through parallel tank discharge valves.
The injected inventory maintains sufficient system pressure in the CFCU outlet piping to prevent water column voiding and two phase flow in this piping during accident conditions.
This precludes the potential for waterhammer events that could challenge CFCU pipe integrity and CFCU containment heat removal capability.
After the service water pumps are repowered from vital buses, the tank discharge valves close to isolate each tank from their respective CFCU header.
PSE&G committed to submit a license change request to include tank level, temperature and pressure parameters in technical specification surveillance requirements.
Surveillance requirements for the tank discharge valve time response are also proposed.
PSE&G committed to provide this license change request to the NRC within 90 days of each Salem Unit entry into Mode 2, "Startup."
This submittal fulfills this commitment for Salem Unit Nos. 1 and 2.
The additional surveillance requirements provide added assurance that the accumulator tank level, temperature and pressure will be maintained within the range established by the design to ensure the SW accumulator tanks are capable of performing their design function.
The additional surveillance requirements proposed for tank discharge valve response time testing provide added assurance that the discharge valves are capable of opening within the time requirements assumed in the accident analysis.
As described in letter LR-N97268 dated April 24, 1997, PSE&G has established administrative controls to periodically verify these parameters.
As further stated in that letter, if these parameters are not within specification, the action statement requirements of Technical Specification 3/4.6.1.1, "Containment Integrity," and Technical Specification 3/4.6.2.3, "Containment Cooling System" would be applicable.
The proposed changes therefore add the additional surveillance requirements to both of these technical specifications.
The justification for adding these surveillance requirements to both of these technical specifications is the SW accumulator tanks and discharge valves function to maintain containment integrity and containment cooling following a LOOP/LOCA (as described above).
If the tank parameter and discharge valve response time surveillance requirements are not met, mitigation of conditions discussed in GL 96-06 cannot be assured during a LOOP/LOCA.
The Containment Integrity Limiting Condition for Page 2 of 6
- .-Document Control LR-N970707 LCR S97-17 Operation would therefore not be met and the action statement to iso~ate the affected CFCU pipe penetrations is applicable.
With CFCU's isolated, the Containment Cooling Limiting Condition for Operation is not met, and the action statement and allowed outage time for inoperable CFCUs is applicable.
Maintaining accumulator tank parameters within specification and verifying discharge valve response time is also required to ensure containment cooling during accident conditions.
Therefore the proposed surveillance requirements are included under the Containment Cooling Limiting Condition for Operation.
The Bases section for these technical specifications have been revised to include a supporting discussion identifying these SW accumulator tank and discharge valve support functions.
The discussion also aids operators in the administration of these requirements.
The Bases section is consistent with Salem procedures that implement these surveillance requirements.
10CFR50.36(c) (3) states that technical specification surveillance requirements are requirements for tests, calibrations and inspections that assure the limiting conditions for operation are met.
Monitoring the SW accumulator tank pressure, level and temperature and periodically verifying discharge valve response time provides assurance that the Containment Integrity and Containment Cooling Limiting Conditions for Operation (LCOs) are met.. Therefore it is appropriate. to include these requirements as technical specification surveillance requirements under these LCOs.
The tank parameter ranges identified in the surveillance requirements are design ranges.
Implementing procedures include margin for instrument accuracy, setpoint drift and measurement uncertainty as appropriate to ensure that the indicated parameter is within the design range.
The instrumentation used to monitor tank operational parameters is designated non-safety related based on its function to monitor the pre-event status of the tanks to assure their capability to perform their design basis function.
This instrumentation is designed to meet Seismic Category 2 requirements.
The associated sensors and indicating devices are included in the Salem Station instrument calibration program.
The tank instrumentation outputs are processed by a programmable logic controller for the purpose of generating local and remote alarms and providing local indication.
Redundant sensors, power supplies and indicating channels are provided.
Separate from the indicating panel display, redundant indication is provided for tank level and pressure as an additional operator aid.
This information was previously provided to the NRC staff in support of their review of GL 96-06 for Salem Station (Reference PSE&G letter LR-N97268 dated April 24, 1997).
The basis for each tank parameter range is discussed in the following.
Each parameter range was established based on Page 3 of 6
- Document Control LR-N970707 LCR 897-17 accident conditions and the most limiting single failure.
The bas~s for the discharge valve response time surveillance is also provided.
Accumulator Tank Inventory Temperature:
A nitrogen cover gas pressurizes the accumulator tank inventory.
Nitrogen solubility increases with decreasing inventory temperature.
When the tank inventory discharges into the CFCU piping, the water pressure will decrease as the fluid travels through the CFCU piping and the nitrogen will come out of solution and be entrained in the flow.
The minimum tank inventory temperature of 55°F has been established to ensure that the amount of nitrogen that may come out of solution will not significantly affect the CFCU heat removal function.
The upper temperature limit of 95°F inventory temperature was established to maintain the CFCU containment heat removal capability within the design requirement as the inventory is injected into the service water header to the containment fan coil units.
Accumulator Tank Nitrogen Pressure:
The minimum tank nitrogen pressure of 135 psig was established to be sufficient to accelerate the tank inventory and piping fluid through the open tank discharge valves and maintain CFCU fluid pressure above saturation during LOOP/LOCA conditions.
The minimum tank pressure includes consideration for single failures that affect CFCU outlet valve closure.
The maximum nitrogen pressure of 160 psig in each tank is established to prevent the entire tank inventory from injecting into the CFCU piping.
This includes allowance for a single failure of a tank discharge valve to close after SW pump restart and inventory injection.
The upper limit on nitrogen pressure also ensures the CFCU heat exchanger tubing will not be overpressurized during inventory injection.
Accumulator Tank Inventory Level:
The minimum accumulator tank level of 226 inches is established to maintain a sufficient inventory in each tank to supply the CFCUs until service water pumps are repowered from vital buses.
This includes consideration for a single CFCU outlet valve failing in the open position, such that the affected CFCU outlet piping continues to drain during a LOOP/LOCA.
The minimum tank level also provides adequate inventory to prevent complete draining of a tank if the tank discharge valve fails open.
The Page 4 of 6
.Document Control LR-N970707 LCR S97-17 maximum tank level of 252 inches is established low enough such that the nitrogen pressure change during inventory injection with decreasing tank level is not significant.
This helps ensure the tank pressure remains sufficient to drive flow into the CFCU piping during injection.
Accumulator Tank Discharge Valve Response Time Surveillance:
The discharge valve response time is critical to assuring the tank inventory injection occurs on a LOOP prior to the CFCU header pressure decaying below the saturation pressure associated with normal operating conditions.
As part of modifications to address GL 96-06 issues, redundant undervoltage relays were installed on the three 4KV vital buses.
During an undervoltage condition on the three vital buses (LOOP), undervoltage signals from these relays combine in a three out of three logic to energize the solenoid valves associated with the tank discharge valves.
The energized solenoid valves vent air from the tank discharge valve operators.
The discharge valves stroke open and the tank inventory is discharged into the CFCU headers to prevent CFCU flow column separation and two phase flow conditions during a LOOP/LOCA.
The proposal requires that the tank discharge valve time response on a loss of power signal be verified_to be within limits on an 18 month frequency.
The design analysis requires that on the initiation of a loss of offsite power signal, the tank discharge butterfly valves stroke open to the 45 degree position in less than or equal to 1.5 seconds.
The proposed response time surveillance requirement for these valves periodically verifies the valves meet this design requirement.
The valve installation includes a limit switch instrumented at the 45 degree position to provide for performance of this response time testing.
Surveillance Frequency:
The proposed tank parameter surveillance requirements are to be completed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
This surveillance frequency is consistent with similar and comparable Salem technical specification surveillance requirements for ECCS accumulator level and pressure and is concluded to be sufficient.
Additionally the twelve hour frequency allows for the tank surveillances to be implemented in the existing secondary plant operator log completed during each twelve hour operator shift.
This frequency is more conservative than the "daily" frequency previously committed to in PSE&G letter to the NRC LR-N97268 dated April 24, 1997.
The proposed tank discharge valve time response surveillance requirements are to be completed every 18 months.
This surveillance frequency is consistent with Salem Technical Page 5 of 6
.Document Control LR-N970707 LCR S97-17 Specification surveillance requirements for the Engineered Safety Features which are on an 18 month frequency.
Additionally this proposed frequency is in accordance with the PSE&G commitment
~ade in letter LR-N97268 to the NRC dated April 24, 1997.
CONCLUSION The proposal provides surveillance requirements for the SW accumulator tank and discharge valves.
These surveillance requirements provide added assurance that the accumulator tanks and valves will be maintained capable of performing their design function during accident conditions.
This is a safety gain.
The addition of these surveillance requirements in the containment integrity and containment cooling technical specifications and the supporting discussions in the Bases sections further ensure operator awareness of the technical specification action statement requirements and allowed outage times that are applicable when SW accumulator tanks or discharge valves are inoperable.
This is also a safety gain.
Additionally, this submittal fulfills a commitment previously made by PSE&G to control these tank parameters and discharge valve response times through establishment of technical specifications.
Page 6 of 6
- -Document Control LR-N970707 LCR S97-17 SALEM GENERATING STATION UNIT NOS. 1 AND 2 FACILITY OPERATING LICENSES DPR-70 AND 75 DOCKET NOS. 50-272 AND 50-311 CHANGE TO TECHNICAL SPECIFICATIONS CONTAINMENT INTEGRITY AND CONTAINMENT COOLING SYSTEMS 10CFR50.92 EVALUATION Public Service Electric & Gas (PSE&G) has concluded that the proposed changes to the Salem Generating Station Unit No. 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 requested change provides surveillance requirements for the Service Water accumulator vessels (tanks).
Surveillance requirements are added for tank level, pressure and temperature.
The requested change also provides surveillance requirements for the response time of the tank discharge valves. These surveillance requirements are included in Containment Integrity Technical Specification 3/4.6.1:1 'and Containment Cooling System Technical Specification 3/4.6.2.3.
The Bases sections for these technical specifications are also being expanded to provide a supporting discussion regarding these surveillance requirements.
BASIS
- 1.
The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed changes provide surveillance requirements for the Service Water accumulator tank level, pressure and temperature parameters and the discharge valve response time test.
Supporting information is included in the Bases section of the applicable technical specifications.
The SW accumulator tank and discharge valve design has been reviewed and approved by the NRC staff as documented in NRC Safety Evaluation Report (SER) dated June 19, 1997.
The proposed surveillance requirements do not alter the design as reviewed by the NRC staff.
The addition of tank parameter surveillance requirements to the technical specifications does not alter the physical plant. arrangement or the installed monitoring instrumentation.
The proposed addition of tank discharge valve response time surveillance requirements to the technical specifications does not alter the method of performing these surveillance requirements.
Page 1 of 3
- .*Document Control LR-N970707 LCR S97-17
' Therefore the proposed changes do not increase the probability of an accident.
The surveillance requirements provide additional controls for ensuring the SW accumulator tanks and discharge valves will be maintained within the design parameters assumed in the safety analysis. This provides added assurance that the accumulator tanks and discharge valves will be capable of performing their required design function during accident conditions.
There is no change to the performance requirements of these components in preventing two phase flow conditions and water column separation waterhammer vulnerabilities identified in GL 96-06.
Therefore, the proposed changes do not involve an increase in the 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 provide surveillance requirements for Service Water Accumulator tank level, pressure and temperature and discharge valve time response.
Supporting information is included in the Bases section of the applicable technical specifications.
The SW accumulator tank and discharge valve design has been reviewed and approved by the NRC staff as documented in NRC Safety Evaluation Report (SER) dated June 19, 1997.
The proposed surveillance requirements do not alter the design as reviewed by the NRC staff.
The proposed surveillance requirements do not alter the plant configuration.
Installed instrumentation will be used to accomplish the tank surveillance requirements.
The current plant installation also provides for completion of the discharge valve response time surveillance utilizing test equipment in accordance with plant procedures and configurations.
Therefore the performance of these surveillance requirements does not create the possibility of a new or different kind of accident from any accident previously evaluated.
The Service Water Accumulator Vessels and discharge valves were installed to address the Generic Letter 96-06 issues of column separation waterhammer and two phase flow in the containment fan coil unit (CFCU) piping during an accident involving loss of offsite power. This design has been reviewed and approved by the NRC staff as documented in NRC Safety Evaluation Report (SER) dated June 19, 1997.
The proposed surveillance requirements do not alter the design as reviewed by the NRC staff.
By providing added assurance that these components are capable of performing their specified safety function as assumed in the safety analysis, Page 2 of 3
- *Document Control LR-N970707 LCR S97-17 the additional surveillance requirements assure system operability to further minimize the possibility of waterhammer and two phase flow in the CFCU piping during accident conditions.
The proposal therefore minimizes the possibility of a new or different kind of accident from those previously evaluated accidents.
- 3.
The proposed change does not involve a significant.reduction in a margin of safety.
The additional surveillances provide added assurance that the margin of safety assumed in the containment integrity and containment cooling technical specifications will be maintained.
The additional surveillance requirements further ensure that in the event the SW accumulator vessels are out of specification or the discharge valves do not meet their response time requirements, corrective actions will be completed in accordance with the existing containment integrity technical specification allowed outage time to restore containment integrity.
The surveillance requirements further ensure that in the event the SW
.accumulator vessel or discharge valves do not meet these requirements, corrective actions will be completed in accordance with the containment cooling technical specification allowed outage time to restore the full complement of containment cooling fan coil units to operability.
Since the proposal maintains the margin of safety provided in the containment integrity and containment cooling technical specifications, there is no 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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