NL-15-0964, Response to Request for Additional Information Regarding SNC License Amendment Request for TSTF-523, Revision 2

Response to Request for Additional Information Regarding SNC License Amendment Request for TSTF-523, Revision 2

ML15167A279
Person / Time
Site:	Hatch
Issue date:	06/16/2015
From:	Pierce C Southern Co, Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-15-0964
Download: ML15167A279 (6)

Text

' Charles R. Pierce Regulatory Affairs Director Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295 Birmingham, AL 35201 Tel 205.992.7872 Fax 205.992.7601 s JUN 1 6 2015 Docket Nos.: 50-321 NL-15-0964 5.0-366 U. S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant - Units 1 and 2 Request For Additional Information Regarding SNC License Amendment Request for TSTF-523. Revision 2

References:

1. SNC Letter NL-14-1349, Edwin I. Hatch Nuclea r Plant- Units 1 and 2 License Amend ment Request to Revise Technical Specifications Regarding Generi c Letter 2008-01, Managing Gas Accumulation in accordance with TSTF-523, Revision 2, Using the Consolidated Line Item Improvement Process (CLIIP), dated January 13, 2015, ML15014A411.

2. NRC Letter, Edwin I. Hatch Nuclea r Plant, Units 1 and 2- Request for Additio nal Information (TAG NOS. MF557 9 AND ('AF5580), dated May 18,201 5.

Ladies and Gentlemen:

On January 13, 2015, in accordance with the provisions of 10 CFR 50.90 Southern Nuclear Operating Company (SNC) submitted a request for an amend ment to the technical specifications (TS) for Edwin I. Hatch Nuclear Plant (HNP), Units 1 and 2 (Reference 1).

The proposed amendment would modify TS requirements related to Generi c Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray systems," as described in TSTF-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation."

Following the submittal of the HNP License Amend ment Request, SNC received a request for additional information by the NRC on May 18, 2015 (Refere nce 2). The enclosure provides the requested information.

U.S. Nuclear Regulatory Commission

, NL-15-0964 Page2 This letter contains no new NRC commitments. If you have any questio ns, please contact Ken McElroy at (205) 992-7369.

Mr. C. R. Pierce states he is Regulatory Affairs Director of Southern Nuclea r Operat ing Company, is authorized to execute this oath on behalf of Southern Nuclea r Operat ing Compa ny and, to the best of his knowledge and belief, the facts set forth in this letter are true.

Respectfully submitted, t.ft~

C. R. Pierce Regulatory Affairs Director CRP/GLS/Iac Sworn to and subscribed before me this ik_ day of 9.uvJ? ,2015.

Notary Public My commission expires: / 6I/r JZC>t1 I

Enclosure:

Response to Request for Additional Information - TSTF-523 cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bost, Executive Vice President & Chief Nuclear Officer Mr. M. D. Meier, Vice President - Regulatory Affairs Mr. D. R. Vineyard, Vice Presid ent- Hatch Mr. D. R. Madison, Vice Presid ent- Fleet Operations Mr. B. J. Adams, Vice Presid ent- Engineering Mr. G. L. Johnson, Regulatory Affairs Manag er- Hatch RType: CHA02.004 U. S. Nuclear Regulatory Commission Mr. V. M. McCree, Regional Administrator Mr. R. E. Martin, NRR Senior Project Manag er- Hatch Mr. D. H. Hardage, Senior Resident Inspec tor- Hatch State of Georgia Mr. J. H. Turner, Direct or- Environmental Protection Division

Edwin I. Hatch Nuclear Plant - Units 1 and 2 Request For Addition al Informat ion Regarding SNC License Amendment Request for TSTF-523, Revision 2 Enclosure Response to Request for Additional Information - TSTF-523

Enclosure to NL-15-0964 Response to Request for Additional Informa tion- TSTF-523 Page E-1 The NRC staff has reviewed the Edwin I. Hatch, Units 1 and 2 license amend ment request and determined that additional information is necessary as noted below.

RAI1:

An acceptable surveillance must include allowance for gas accumulation until the next surveillance is scheduled. How is this requirement satisfied by the following:

a. Satisfactorily operati ng a system or subsystem such as a residual heat removal shutdown cooling subsyst em?

b. Monitoring Reactor Core Isolation Cooling pump suction pressur e?

c. Use of a procedure designe d to initially ensure that piping is adequately filled and vented?

SNC Response to RA1:

a. The current systems under GL 2008-01 have been reviewed and the operatin g

procedures for these systems ensure that the system is properly filled and vented after any maintenance activity that could induce gas voids in the system and before being placed in standby or in service to reduce voids upon system operatio n

initiation. Once the system is placed in service, operating parameters are monitored to ensure the capability of the running system is meeting its system requirements and the presence of gas voids is not detected during running. Erratic pump operation, including suction pressure, discharge pressure, and flow oscillations, as well as unusual vibration levels, can be indicative of air or gas accumulation in the system piping. Actions will be taken to document, via Condition Report (CR), and investigate the potential gas intrusion as needed.

If a system is currently running and the 31 day frequency should occur, monitoring the system running parameters, as discussed above, ensures that the system is meeting its system requirements for the required surveillance. If the system is in standby, then the conventional gas accumulation monitoring process will be performed per the required surveillance frequency control program.

b. As stated above, erratic pump operation, including suction pressure, discharg e

pressure, and flow oscillations, as well as unusual vibration levels, can be indicative of air or gas accumulation in the system piping. During the Reactor Core Isolation Cooling (RCIC) pump operability tests, RCIC pump suction pressure is monitored and recorded. Depending on the reason for the RCIC pump operation, a 0.5% accuracy calibrated Test Pressure Gauge (30" Hg vacuum to 100 psig range) is installed for the test to ensure accuracy. The value is compared to an acceptance range and if outside the acceptance range a CR would be written and the abnormal indication would be investigated. Possible reasons investigated would include the possibility of voids in the RCIC system. Also, per the RCIC system operating procedure, outlet pressure of the RCIC Pump is similarly

Enclosure to NL-15-0964 Response to Request for Additional Informa tion- TSTF-523 Page E-2 recorded and the RCIC pump differential pressure is calculated with an acceptance range verified.

The RCIC gas accumulation program also ensures proper filling and venting and ultrasonic testing of the system suction piping when the RCIC system is placed in standby readiness. Empirical data suggests that the 31 day frequency for monitoring gas voids in the suction piping is adequate, as no voids have been discovered that exceed the allowable value.

c. As the systems are placed in standby readiness, the operating procedures either include steps to perform actions (e.g. fill and vent) to ensure voids found in the system are removed or provide references to procedures to perform ultrasonic testing to ensure void size is below analyzed limits to ensure the capability of the system is assured. As the systems are manually initiated, vulnerable system piping locations, such as changing suction alignment, may require special actions to ensure the piping is properly filled as part of the operating procedure. If any voids are left in the system, they will be analyzed and verified to be acceptable to ensure they are not degrading the capability of the system.

RAI2:

Please describe the monitoring of other system parameters that could identify a change that could introduce gas into piping between surveillance intervals.

SNC Response to RA2:

Residual Heat Removal (RHR) and Core Spay (CS) systems currently have keep fill systems that have annunciator alarms installed which provide operator information that the respective system water level is low. If this alarm is not clear it may indicate that voids are present and the respective piping system may need to be filled and vented to ensure the system is cleared of gas accumulation. When these Emergency Core Cooling Systems (ECCS) are placed in standby operation readiness, it is verified by steps in the operating procedures that the annunciator alarm is clear.

Also, the operating procedures that perform system valve operability and could potentia lly induce voids during valve cycling, require the appropriate portion of the system piping affected to be filled and vented when that system's valve cycling is complete.

RAI3:

What are representative surveillance frequencies that exist under the Surveillance Frequency Control Program that differ from the TSTF-523 example of 31 days and what is the basis for those changes?

Enclosure to NL-15-0964 Response to Request for Additional Inform ation- TSTF-523 Page E-3 SNC Response to RA3:

When this TSTF-523 Technical Specification change is issued all values for the gas accumulation surveillance requirements (SRs) will be 31 days as per the recommendation in the implementation guidance of this license amendment change. These surveill ance frequencies will then be controlled by the Surveillance Frequency Control Program change process going forward.