ML13036A298
| ML13036A298 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 02/01/2013 |
| From: | Beltz T Plant Licensing Branch III |
| To: | Millen M Point Beach |
| References | |
| TAC ME8792, TAC ME8793 | |
| Download: ML13036A298 (4) | |
Text
1 NRR-PMDAPEm Resource From:
Beltz, Terry Sent:
Friday, February 01, 2013 9:17 AM To:
Michael.Millen@nexteraenergy.com Cc:
'Hanneman, Harv'; Carlson, Robert; Jackson, Christopher; Parks, Benjamin; Woodyatt, Diana
Subject:
Point Beach Nuclear Plant, Units 1 and 2 - Request for Additional Information re: Review of 10 CFR 50.46 30-Day Report TCD Impact on ASTRUM ECCS Evaluation (TAC Nos.
ME8792 and ME8793)
Attachments:
Request for Additional Information (TAC Nos. ME8792 and ME9793).docx
Dear Mr. Millen:
By letter dated May 30, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12152A101), NextEra Energy submitted a report for the Point Beach Nuclear Plant, Units 1 and 2, describing the nature of an error associated with thermal conductivity degradation in its ASTRUM [Automated Statistical Treatment of Uncertainty Method] emergency core cooling system evaluation. Due to the error, the estimated effect on the predicted peak cladding temperature (PCT) is 151 °F for Unit 1 and 285 °F for Unit 2.
Considering this error correction, the currently reported PCTs are 2126 °F and 2095 °F for Units 1 and 2, respectively.
The NRC staff from the Reactor Systems Branch of the Office of Nuclear Reactor Regulation has determined that additional information is required to complete its evaluation. The request for additional information is provided in the attached document.
You may accept this as a formal request for additional information and respond to the question by March 8, 2013. Alternatively, you may request to discuss the content of this RAI with the NRC staff in a conference call, including any change to the proposed response date.
Please let me know if you have any questions or concerns.
Sincerely, Terry A. Beltz, Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation (301) 415-3049 Terry.Beltz@nrc.gov
Hearing Identifier:
NRR_PMDA Email Number:
598 Mail Envelope Properties (Terry.Beltz@nrc.gov20130201091700)
Subject:
Point Beach Nuclear Plant, Units 1 and 2 - Request for Additional Information re:
Review of 10 CFR 50.46 30-Day Report TCD Impact on ASTRUM ECCS Evaluation (TAC Nos. ME8792 and ME8793)
Sent Date:
2/1/2013 9:17:24 AM Received Date:
2/1/2013 9:17:00 AM From:
Beltz, Terry Created By:
Terry.Beltz@nrc.gov Recipients:
"'Hanneman, Harv'" <Harv.Hanneman@nexteraenergy.com>
Tracking Status: None "Carlson, Robert" <Robert.Carlson@nrc.gov>
Tracking Status: None "Jackson, Christopher" <Christopher.Jackson@nrc.gov>
Tracking Status: None "Parks, Benjamin" <Benjamin.Parks@nrc.gov>
Tracking Status: None "Woodyatt, Diana" <Diana.Woodyatt@nrc.gov>
Tracking Status: None "Michael.Millen@nexteraenergy.com" <Michael.Millen@nexteraenergy.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 1520 2/1/2013 9:17:00 AM Request for Additional Information (TAC Nos. ME8792 and ME9793).docx 20203 Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received:
REQUEST FOR ADDITIONAL INFORMATION REGARDING THE REVIEW OF THE POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 REPORT SUBMITTED PURSUANT TO 10 CFR 50.46(a)(3) CONCERNING A SIGNIFICANT EMERGENCY CORE COOLING SYSTEM EVALUATION MODEL ERROR RELATED TO THE EFFECT OF FUEL THERMAL CONDUCTIVITY DEGRADATION NEXTERA ENERGY POINT BEACH, LLC DOCKET NOS. 50-266 AND 50-301 (TAC NOS. ME8792 AND ME8793)
By letter dated May 30, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12152A101), NextEra Energy submitted a report for the Point Beach Nuclear Plant, Units 1 and 2, describing the nature of an error associated with thermal conductivity degradation in its ASTRUM [Automated Statistical Treatment of Uncertainty Method] emergency core cooling system evaluation. Due to the error, the estimated effect on the predicted peak cladding temperature (PCT) is 151 °F for Unit 1 and 285 °F for Unit 2.
Considering this error correction, the currently reported PCTs are 2126 °F and 2095 °F for Units 1 and 2, respectively.
=
Background===
In the letter, the licensee stated as follows:
In accordance with 10 CFR 50.46, NextEra will conduct a re-analysis following approval by the NRC of a revised LBLOCA evaluation model, with explicit treatment of thermal conductivity degradation (TCD), if the model used for the impact of TCD in this 30-day report is determined to be non-conservative with respect to the new approved model.
Regulatory Basis The regulations in 10 CFR 50.46(a)(3)(ii) state that licensees shall include, with an error report pursuant to 10 CFR 50.46(a)(3)(ii), a proposed schedule for providing a re-analysis or taking other action as may be needed to show compliance with [10 CFR 50.46] requirements.
In the Statements of Consideration accompanying the 1988 revision to 10 CFR 50.46, the reporting requirements are explained in greater detail (53 Federal Register 35996): the final rule revision also allows the NRC to determine the schedule for re-analysis based on the important to safety relative to other applicant or licensee requirements.
Issue The NRC staff is unable to determine that the above re-analysis statement provided by the licensee satisfies the statement in 10 CFR 50.46. Although the staff notes that the estimate has been based on rigorous analysis using calculational tools that incorporate the effects of TCD, the staff also notes that the estimate is based on re-execution of a very limited (about 25-percent) subset of cases from the original ASTRUM run set. Based on the high predicted PCTs and on the apparent limitations of the current analysis, the staff determined that additional information is necessary to determine whether this report satisfies the re-analysis requirement.
Request for Additional Information Please supplement the May 30, 2012, report pursuant to 10 CFR 50.46(a)(3)(ii) for the Point Beach Nuclear Plant, with a proposed schedule for either providing a re-analysis or taking other action as may be needed to show compliance with 10 CFR 50.46 requirements.