ML20135F655
| ML20135F655 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 03/03/1997 |
| From: | Sorensen J NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9703130250 | |
| Download: ML20135F655 (2) | |
Text
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Northern states Power Company 1717 Wakonado Dr. E.
Welch. MN 55089 Telephone 612-388-1121 March 3,1997 U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERALNG PLANT Docket Nos. 50-282 License Nea. DPR-42 50-306 DPR-60 Statement of Intent With Respect to Unit 2 Heat Up to Hot Shutdown (MODE 3)
Reference 1: NRC letter dated November 1,1996 to Mr. E. Watzl, Vice President, Nuclear Generation, from Geoffrey E. Grant, Division of Reactor Safety, entitled, "NRC SPECIAL INSPECTION REPORTS NO. 50-282/96015(DRS); 50-306/96015(DRS)."
Reference 2: License Amendment Request Dated January 29,1997, Amendment of Cooling Water System Emergency Intake Design Bases.
This letter is submitted to clarify Northern States Power Company's (NC")
understanding of the restrictions on Prairie Island Unit 2 operations resulting from the outstanding Unreviewed Safety Question relating to the Cooling Water System.
In Reference 1 the NRC identified an Unreviewed Safety Question associated with post-seismic cooling water system operations. The NRC informed NSP in January 1997 that resolution of this Unreviewed Safety Question is required prior to resumption of power operations following a shutdown of either Prairie Island unit.
On January 25,1997, Unit 2 shutdown for refueling. NSP subsequently submitted Reference 2 to resolve the Unreviewed Safety Question.
I Reference 2 included evaluations and discussions consistent with the plant licensing basis. The NRC, through a Request for Additional Information dated h
i February 21,1997, requested additional evaluations be performed to assist the NRC in completing the review of the intake canal seismic stability discussed in References 1 and 2. The responses to Questions 1,2,4, and 5 and part of the 9703130250 970303 PDR ADOCK 05000306
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answer to Question 3 were presented to the NRC in meetings held on February 24,
' 1997. However, the dynamic finite element analysis requested in Question 3 is significantly more complex in nature and can not be prepared prior to the currently scheduled end of the Unit 2 outage. NSP is pursuing the dynamic finite element analysis and is also considering interim measures to provide resolution of the Unreviewed Safety Question.
NSP's objective is to operate Prairie Island in a manner which protects the health and safety of the public. In order to support the continued progression of the Unit 2 outage, NSP intends to take Unit 2 to MODE 3 (hot shutdown) operation when plant system readiness will support MODE 3 operations. All applicable Technical Specifications will be met as the plant MODE changes occur. When the plant is in MODES 4,5 and 6, the core decay heat is removed by the Residual Heat Removal System which in turn is cooled by the_ Cooling Water System. In MODE 3 the plant is subcritical and no additional decay heat loads are created. Furthermore, the Residual Heat Removal System is removed from service and core cooling is provided by the steam generators. Since the Residual Heat Removal System is not used for cooling, the Cooling Water System loads are reduced. Therefore, NSP believes Unit 2 operations in MODE 3 will continue to maintain the plant in a condition in which the health and safety of the public is protected and operations in MODE 3 meets the NRC's intent of resolution of the Unreviewed Safety Question prior to resumption of power operations. NSP will not place Unit 2 in MODES 1 or 2 until resolution has been reached with the NRC on the Unreviewed Safety Question.
If you have any questions related to this letter, please contact myself or Dale Vincent at 612-388-6758.
h Joel P. Sorensen Plant Manager, Prairie Island Nuclear Generating Plant j
c:
Regional Administrator - 111, NRC NRR Project Manager, NRC Senior Resident inspector, NRC State of Minnesota Attn: Kris Sanda J E Silberg