ML052660225

Callaways Supplemental Response to NRC Bulletin 2003-01, Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors

ML052660225
Person / Time
Site:	Callaway
Issue date:	09/13/2005
From:	Keith Young AmerenUE
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BL-03-001, ULNRC-05205
Download: ML052660225 (4)

Text

AmereniE PO Box 620 Callaway Plant Fulton, MO 65251 September 13, 2005 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop P I-137 Washington, DC 20555-0001 ULNRC-05205 w Amerein Ladies and Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 SUPPLEMENTAL RESPONSE TO NRC BULLETIN 2003-01, "POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS" Ref: 1. ULNRC-04884, dated August 8, 2003

2. ULNRC-04966, dated March 25, 2004

3. ULNRC-05026, dated July 9, 2004 In accordance with 10 CFR 50.54(f), enclosure I to this letter supplements the Union Electric Company (AmerenUE) response contained in reference 3 to NRC Request for Additional Information Related to Bulletin 2003-01 response transmitted by references I and 2.

In addition, AmerenUE is revising its response to Bulletin 2003-01 contained in reference 1. In response item 1, it states that Callaway wvould administratively control the minimum Refueling Water Storage Tank (RWST) level to a nominal level of 97%. During operation this has caused a problem with resetting the main control board overhead RWST high level alarm. To resolve this issue the RWST nominal level will be changed from 97% to 96.3%. This will allow the high level alarm to reset and will reduce the inadvertent alarms resulting from slight variations in nominal RWST levels. The change in the RWST administrative limit continues to provide assurances of additional capacity above the Technical Specification 3.5.4.2 minimum required level of 93.6% and is still above the current low alarm level of 95.3%.

1 C)

S This letter does not contain newv commitments.A u

a subsidiaq of Ameren Corporation

I Al ULNRC-05205 September 13, 2005 Page 2 If you have any questions concerning this matter, please contact Mr. Keith Young at (573) 676-8659, or Mr. Dave Shafer at (314) 554-3104.

I declare under penalty of perjury that the foregoing is true and correct.

Sincerely, Executed on: September 13, 2005 4t5iA49e&.

Keith D. Young Manager - Regulatory Affairs Callaway supplemental response

ULNRC-05205 September 13, 2005 Page 3 Mr. Bruce S. Mallett Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Jack N. Donohew (2 copies)

Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 7E1 Washington, DC 20555-2738 Missouri Public Service Commission Governor Office Building 200 Madison Street PO Box 360 Jefferson City, MO 65102-0360 Mr. Ron Reynolds Director Missouri State Emergency Management Agency P.O. Box 116 Jefferson City, MO 65102

ULNRC-05205 Page 1 of 1 Callaway's Supplemental Response to Request for Additional Information -

Bulletin 2003-01, "Potential Impact of Debris Blockage on Emergencv Sump Recirculation At Pressurized-Water Reactors" A phone call between NRC and Callaway was held on 7/7/2005 concerning a question on Callaway's July 9, 2004 Response to Request for Additional Information related to Bulletin 2003-01. NRC requested that Callaway provide information on which portions of WCAP 16204 Rev. 1, "Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations," Candidate Operator Action (COA) 6 that had been implemented. In addition, the NRC requested that Callaway clarify which lineups, based on COA 6, exist in the Sump Blockage Control Room Guidelines (SBCRG). Note that Callaway implemented the SBCRG in Emergency Operating Procedure ECA-1.3.

Based on a review of COA 6 of WCAP 16204, the following methods are available to inject more than one RWST volume into containment:

1. Injection from a Refilled RWST

2. Injection from Alternate Source (Bypassing RWST)

Item 1 above is implemented in Step 8 from ECA-1.3, "Try to establish High Head Pressure SI with Suction from the RWST". Step 8 begins the injection of water left in the RWST following the CTMT Spray swapover and any water that has been added from steps initiated in ES-1.3, "Transfer to Cold Leg Recirculation".

Item 2 above is implemented in Steps 28 and 34 from ECA-1.3. These steps attempt to establish normal charging via VCT makeup. These are the only steps within ECA-1.3 that attempt to establish RCS injection from alternate sources.

These two items were implemented with the incorporation of the SBCRG (COA 9).

The SBCRG was implemented in Callaway Emergency Operating Procedure ECA-1.3, "Sump Blockage Mitigation".