PNP 2011-070, Response to Request for Additional Information for License Amendment Request to Revise Calculated Peak Containment Internal Pressure (ME6875)
| ML112790383 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 10/06/2011 |
| From: | Vitale A Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PNP 2011-070, TAC ME6875 | |
| Download: ML112790383 (5) | |
Text
Entergy Nuclear Operations, Inc.
.lirit i~ii Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, Ml 49043 Tel 269 764 2000 Anthony J. Vitale Site Vice President PNP 2011-070 October 6, 2011 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Response to Request for Additional Information for License Amendment Request to Revise Calculated Peak Containment Internal Pressure (ME6875)
Palisades Nuclear Plant Docket 50-255 License No. DPR-20
Reference:
- 1. Entergy Nuclear Operations, Inc. letter, License Amendment Request to Revise Calculated Peak Containment Internal Pressure, dated August 16, 2011 (ADAMS Accession No. ML112280430) 2.
NRC e-mail dated September 8, 2011, Request for Additional Information
- Palisades
- License Amendment Request to Revise Calculated Peak Containment Internal Pressure - ME6875 (ML112550406)
Dear Sir or Madam:
In Reference 1, Entergy Nuclear Operations, Inc. (ENO) submitted a proposed license amendment on August 16, 2011, to revise the calculated peak containment internal pressure in the Palisades Nuclear Plant Technical Specifications (TS). TS Section 5.5.14 would be revised by increasing the calculated peak containment internal pressure for the design basis loss of coolant accident from 53 psig to 54.2 psig.
ENO received an electronic request for additional information (RAI) from the Nuclear Regulatory Commission (NRC) concerning the submittal on September 8, 2011 (Reference 2). ENO and the NRC held a conference call on September 22, 2011, to clarify the RAI.
PNP-201 1-070 Page 2 The enclosure contains the ENO response to the RAI.
A copy of this request has been provided to the designated representative of the State of Michigan.
This letter contains no new or revised commitments.
I declare under penalty of perjury that the foregoing is true and correct. Executed on October 6, 2011.
Sincerely, ajv/j~~~~4
Enclosure:
RAI Response on License Amendment Request to Revise Calculated Peak Containment Internal Pressure cc:
Administrator, Region Ill, USNRC Project Manager, Palisades, USN RC Resident Inspector, Palisades, USN RC State of Michigan
ENCLOSURE RAI RESPONSE ON LICENSE AMENDMENT REQUEST TO REVISE CALCULATED PEAK CONTAINMENT INTERNAL PRESSURE Request for additional information (RAI) received by electronic mail on Sertember 8, 2011.
Nuclear Regulatory Commission (NRC) Request 1.
Please provide (1) the name of the computer code that provided the non-conservative LOCA mass and energy release input for the containment response analysis, (2) the name of the containment response computer code.
Entergy Nuclear Operations, Inca (ENO) Response 1.
The computer code that provided the non-conservative loss of coolant accident (LOCA) mass and energy release was the nuclear steam supply system thermal hydraulic response computer code CEFLASH-4A. The Palisades containment response analysis was performed using thermal hydraulic computer code Generation of Thermal-Hydraulic Information for Containments (GOTHIC),
version 7.2a.
NRC Request 2.
Please verify that this issue is not related in any way with the discrepancies recently discovered in the EPITOME computer modeling.
ENO Response 2.
The EPITOME code is not used to perform containment response analyses at Palisades.
NRC Request 3.
Please state whether this error could only have occurred with the Palisades LOCA calculations or whether it is of a nature that it may have occurred in calculations done for other plants using the same calculation methods.
ENO Response 3.
The error occurred due to an incorrect setting in the time step resolution of the CEFLASH-4A code for the blowdown phase of the LOCA event. This value is 1 of 3
established by the code user and could impact calculations at other plants if these calculations were performed with similar time step settings.
Per the Westinghouse letter that notified ENO of the error, the error was discovered by Westinghouse while performing an extended power uprate (EPU) study for another customer. Therefore, the error is known to have impacted at least one other plant.
NRC Request 4.
Please provide a brief description of how the error was discovered.
ENO Response 4.
The error was discovered by Westinghouse while performing an EPU study for another customer. Westinghouse noticed a discrepancy in the integral of mass added to containment between the customers LOCA analysis of record and the EPU study. Westinghouse notified ENO of the error in a formal letter.
NRC Request 5.
Please describe the steps that will be taken following approval of this amendment with regard to Appendix J Type A, B and C testing.
ENO Response 5.
Upon approval of this license amendment, the Palisades Appendix J Type A test procedures will be revised to reflect the revised calculated peak containment internal pressure in the Section 5.5.14 of the Technical Specifications. Type A testing is required by American National Standards Institute (ANSI) 56.8-1994 to be performed at a pressure not less than 0.96 times the calculated peak containment pressure (Pa) and not more than containment design pressure. The Type A test procedures will be revised to incorporate the new 0.96 times Pa value.
Appendix J Type B and C test procedures will not require revision upon approval of this license amendment.
ANSI 56.8 requires that Type B and C testing be performed at a pressure not less than Pa and not more than 1.1 times Pa. Site procedures for Type B and C testing require that testing be performed within a range of pressures that, with the revised Pa, will continue to be within the range of pressures required by ANSI 56.8. Therefore, the Type B and C test procedures will not require revision upon approval of the license amendment.
Upon approval of the license amendment, the required changes to the Appendix J Type A test procedures would be implemented prior to the next performance of a Type A test. The next planned Type A test performance is in 2 of 3
2012. ENO submitted a license amendment request to extend the Type A test frequency from 10 years to 15 years. Upon approval of this amendment request, the next planned performance of a Type A test would be in 2015.
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