ML20217A699
| ML20217A699 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/18/1998 |
| From: | Sen G VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BVY-98-42, IEB-96-003, IEB-96-3, NUDOCS 9803250171 | |
| Download: ML20217A699 (2) | |
Text
VERMONT YANKEE
,_y NUCLEAR POWER CORPORATION
' 185 Old Ferry Road, Brattleboro, VT 05301-7002 (802) 257-5271 March 18,1998 BVY 98-42 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington,DC 20555
References:
(a) Letter, USNRC to VYNPC, NRC Bulletin 96-03, NVY 96-86, dated May 6, 1996 (b) Regulatory Guide 1.82 Revision 2, USNRC, Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident, dated May 1996 (c) BWROG, Utility Resolution Guidance (URG) for ECCS Suction Strainer Blockage, NEDO-32686, dated November 20,1996 (d) Letter, VYNPC to USNRC, VY 180-day Response to Bulletin 96-03, BVY 96-135, dated October 31,1996
Subject:
Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)
Plans for Installation of Larger ECCS Suction Strainers in Accordance With NRC Bulletin 96-03 This letter provides Vermont Yankee's response regarding the resolution of the subject bulletin's concerns. Vermont Yankee has determined that replacement of the current ECCS suction strainers with larger, higher deluis capacity, stacked disk strai ers is the best option for Vermont Yankee. In a letter dated October 31,1996, Vermont Yankee committed to provide a submittal describing a plan and a schedule to resolve NRC Bulletin 96-03 following approval of the Utility Resolution Guidance (URG), Reference (c). Although the staff has not formally approved the URG, Vermont Yankee is providing the following updated information regarding our suction strainer plans.
- Vermont Yankee's approEch to resolve this issue is to install new, higher debris capacity, passive strainers which will have a significantly larger straining surface area. The proposed design and analysis is consistent with Section 2.3 of Reference (b). The input to strainer head loss provided by various debris source terms contained in Reference (c) will be employed.
9803250171'980318 PDR ADOCK 05000271 Q
VERMONT YANKEE NUCLEAR POWER CORPORATION
,s.*
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. BVY 98-42 Page 2 0f 2 Evaluations of the types and categories of debris sources present have been addressed. One category can be classified as ' Fixed Debris Sources'. Fixed debris sources includes piping -
insulation' materials in the drywell and paint on drywell surfaces, which must be impacted by the
- LOCA jet or blowdown forces in order to become debris capable of transport to the ECCS strainers. Another category can be classified as ' Transient Debris Sources'. Transient debris sources includes dust, dirt, and any miscellaneous loose fibrous materials present within the
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drywell or the suppression pool. They generally result from normal plant operations, and are present in a transportable form prior to the postulated LOCA.
Vermont Yankee is currently re-calculating the Containment Analysis taking into account factors -
that are more consistent with current criteria for such an analysis. Once the containment analysis Lis finalized and the NRC has issued the final methodology for maintaining compliance with
- Reference (b), then Vermont Yankee will notify the Staff ofits compliance with the regulatory criteria contained in Reference (b).
As discussed in the letter issued October 31,1996, Vermont Yankee will replace the strainers during the refueling outage currently scheduled to begin this month.
As you are aware, Vermont Yankee will be meeting with members of your staff on March 24, 1998 to discuss strainer replacement in more detail.
Sincerely,
,VIRMONT YANKEE NUCLEAR POWER CORPORATION Ah Gautam Sen Licensing Manager
~
- cc
USNRC Region 1 ' dministrator.
A USNRC Project Manager-VYNPS USNRC Resident inspector-VYNPS Vermont Department of Public Service.
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