RBG-46250, Supplement to Amendment Request License Amendment Request (LAR) 2001-43, High Energy Line Break Analysis Method
| ML041040749 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 04/07/2004 |
| From: | King R Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RBG-46250 | |
| Download: ML041040749 (5) | |
Text
Entergy Entergy Operations, Inc.
River Bend Station 5485 U. S. Highway 61N St. Francisville, LA 70775 Fax 225 635 5068 RBG-46250 April 7, 2004 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
REFERENCES:
River Bend Station, Unit 1 Docket No. 50-458 Supplement to Amendment Request License Amendment Request (LAR) 2001-43, "High Energy Line Break Analysis Method" (1) Letter RBG-45940 to USNRC from P. D. Hinnenkamp dated May 14, 2002 (2) Letter RBG-45985 to USNRC from R. J. King dated June 27, 2002 (3) Letter RBG-46124 to USNRC from R. J. King dated July 9, 2003
Dear Sir or Madam:
By letter (Reference 1), Entergy Operations, Inc. (Entergy) proposed a change to the method of analysis for the High Energy Line Breaks in the subcompartments inside and outside of containment. The change submitted for NRC review and approval involved the use of the GOTHIC code for this analysis.
Reference (2) was in response to discussions with the NRC during June 2002.
Reference (3) was in response to discussions with the NRC during January of 2003.
During January and February of 2004, Entergy and the NRC staff discussed the information provided in the Entergy letter of July 2003. In that letter Entergy provided an additional GOTHIC analysis in response to NRC question number 18. The additional analysis provided results without the drop-liquid conversion option of GOTHIC, and compared them to the effects of this option in the proposed analysis of record for the Reactor Water Cleanup System (RWCU) line break.
_A L)
RBG-46250 Page 2 of 3 The liquid-drop conversion option was only used in the original submittal for the RWCU Filter/Demineralizer Room 8 inch line break where it provided additional margin (i.e.,
resulted in lower room pressure) in the room. The results of the reanalysis without the drop-liquid conversion option remained within acceptable limits.
During further conversations with the NRC staff, it was determined that when using the guidance in the Standard Review Plan'Section (SRP) 6.2.1.2, for breaks involving highly subcooled fluid, the results could be non-conservative. To address these issues, RBS while performing high energy line break analyses, will assume homogenous equilibrium conditions and 100% water entrainment for all breaks. The exception will be when it is more conservative to not employ these assumptions as in the case of breaks involving fluid which is initially highly subcooled. This analysis will be accomplished by disabling the forced equilibrium (i.e., enabling thermal hydraulic non-equilibrium model) and enabling the drop-liquid conversion model in GOTHIC.
Through the use of these assumptions, additional conservatism with respect to the analysis using SRP guidance is expected (i.e., higher room pressure) for applicable breaks. This will be considered as the 'Analysis of Record" for the River Bend Station High Energy Line Break methodology licensing basis The original no significant hazards considerations included in Reference 1 is not affected by the information contained in this supplemental letter. The commitment stated above is listed in the Attachment to this letter.
If you have any questions or require additional information, please contact Barry Burmeister at 225-381-4148.
I declare under penalty of perjury that the foregoing is true and correct. Executed on April 7,2004.
Sincerely, R. J. King Director - Nuclear Safety Assurance BMB
Attachment:
Commitment cc:
U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 NRC Senior Resident Inspector P. 0. Box 1050 St. Francisville, LA 70775
RBG46250 Page 3 of 3 Mr. Michael K. Webb U.S. Nuclear Regulatory Commission M/S OWFN 0-7 D1 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Prosanta Chowdhury Louisiana Dept. of Environmental Quality Office of Environmental Compliance Surveillance Division Radiological Emergency Planning & Response Unit P.O. Box 4312 Baton Rouge, LA. 70821-4312
Attachment RBG-46250 List of Regulatory Commitments
I RBG-46250 Attachment Page I of I List of Regulatory Commitments The following table identifies those actions committed to by Entergy in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.
TYPE SCHEDULED (Check one)
COMPLETION COMMITMENT ONE-TIME CONTINUING DATE(If ACTION COMPLIANCE Required)
In performing high energy line break analyses, RBS will assume homogenous equilibrium conditions and 100% water entrainment for all breaks unless it is more conservative to not employ these assumptions as in the case of breaks involving fluid which is initially highly subcooled. This analysis will be accomplished by disabling the forced equilibrium (i.e., enabling thermal hydraulic non-equilibrium model) and enabling the drop-liquid conversion model in GOTHIC.
x Within 60 days of amendment issuance