ML052450030

Summary of a Telephone Conference Call Held on August 10, 2005, Between the NRC and Nuclear Management Company, LLC (NMC) to Discuss Follow-Up Items Regarding the Severe Accident Mitigation Alternatives RAI Responses for Monticello Plant

ML052450030
Person / Time
Site:	Monticello
Issue date:	09/01/2005
From:	Jennifer Davis NRC/NRR/DRIP/RLEP
To:	Nuclear Management Co
Davis J A, NRR/DRIP/RLEP 301-415-3835
References
TAC MC6441
Download: ML052450030 (9)

Text

September 1, 2005 LICENSEE:

Nuclear Management Company, LLC FACILITY:

Monticello Nuclear Generating Plant

SUMMARY

OF A TELEPHONE CONFERENCE CALL HELD ON AUGUST 10, 2005, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND NUCLEAR MANAGEMENT COMPANY, LLC (NMC) TO DISCUSS FOLLOW-UP ITEMS REGARDING THE SEVERE ACCIDENT MITIGATION ALTERNATIVES (SAMA) REQUEST FOR ADDITIONAL INFORMATION (RAI) RESPONSES FOR MONTICELLO NUCLEAR GENERATING PLANT (TAC NO. MC6441)

On August 10, 2005, the U.S. Nuclear Regulatory Commission (NRC or the staff) and its contractor from Information Systems Laboratory (ISL) conducted a conference call (teleconference) with representatives from NMC to discuss the Monticello Nuclear Generating Plant (Monticello) SAMA RAI responses (see ADAMS Accession No. ML052130197). The SAMA RAI responses were submitted to the NRC on July 27, 2005. The teleconference was held to clarify these RAI responses. Enclosure 1 provides a listing of the teleconference participants.

The NRC staff asked for clarification regarding RAI 1.d, 1.e, 2.b, and 5.b. NMC staff provided information to help clear up those questions. No staff decisions were made during the teleconference. Enclosure 2 contains an email response from NMC clarifying their response to RAI 5.b.

/RA/

Jennifer Davis, Project Manager Environmental Section License Renewal and Environmental Impacts Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket No.: 50-263

Enclosures:

As stated cc w/encls: See next page

ML052130197). The SAMA RAI responses were submitted to the NRC on July 27, 2005. The teleconference was held to clarify these RAI responses. Enclosure 1 provides a listing of the teleconference participants.

The NRC staff asked for clarification regarding RAI 1.d, 1.e, 2.b, and 5.b. NMC staff provided information to help clear up those questions. No staff decisions were made during the teleconference. Enclosure 2 contains an email response from NMC clarifying their response to RAI 5.b.

/RA/

Jennifer Davis, Project Manager Environmental Section License Renewal and Environmental Impacts Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket No.: 50-263

Enclosure:

As stated cc w/enclosure: See next page DISTRIBUTION: See next page ADAMS Accession No.: ML052450030 DOCUMENT NAME: E:\\Filenet\\ML052450030.wpd OFFICE PM:RLEP:DRIP LA:RLEP:DRIP SC:RLEP:DRIP NAME JDavis YEdmonds RFranovich DATE 08/31/05 08/31/05 09/01/05

DISTRIBUTION: Letter to Nuclear Management Company dated September 1, 2005 ADAMS Accession No.: ML052450030 PUBLIC D. Matthews/F. Gillespie (RidsNrrDrip)

P.T. Kuo (RidsNrrDripRlep)

R. Franovich J. Davis D. Merzke A. Hodgdon, OGC L. M. Padovan S. Imboden R. Schaaf J. Flemming A. Stone, RIII B. Burgess, RIII J. Adams, RIII R. Orlikowski, RIII P. Lougheed, RIII Jan Strasma, OPA RLEP R/F C. Quinly (LLNL)

LIST OF PARTICIPANTS TELECONFERENCE WITH NUCLEAR MANAGEMENT COMPANY, LLC AUGUST 10, 2005 Names Affiliations Jim Holthaus Nuclear Management Company, LLC (NMC)

Doug Johnson NMC Britta Johnson NMC Anthony Sarrack NMC Rick Loeffler NMC Steve Callis NMC Jennifer Davis U.S. Nuclear Regulatory Commission (NRC)

Robert Palla NRC Jason Flemming NRC Robert Schmidt Information Systems Laboratory From: "Holthaus, James J." <James.Holthaus@nmcco.com>

To:

<JXD10@nrc.gov>

Date: 8/12/05 10:28AM

Subject:

Supplement SAMA RAI 5b To supplement Response to Request for Additional Information Regarding Severe Accident Mitigation Alternates for Monticello Nuclear Generating Plant (TAC NO. MC6441), dated July 27, 2005 (Accession Number ML052130197) and telecon on August 10, 2005.

NMC provides herein clarifying information for our response to NRC SAMA RAI 5.b regarding SAMA 37 (Manual Reactor Core Isolation Cooling (RCIC)

Operation) and combined impact of recommended SAMAs:

Given a prolonged station blackout (SBO), SAMA 37 (Manual RCIC Operation) alone does not provide a success path for preventing core melt, because containment heat removal and containment venting are both unavailable. This eventually results in containment rupture due to overpressure, precluding operators from occupying the RCIC room to support manual operation of the system. In addition, RCIC would eventually deplete the condensate storage tank (CST) inventory and would overheat if torus water (saturated conditions) was used as the suction source.

For these reasons, RCIC only shifts risk dominant sequences from leading to core melt in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after batteries deplete) to 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> (a few hours after containment ruptures or CST inventory is depleted). This has competing effects on risk. The delay allows an increased probability of recovering offsite power or power from an emergency diesel generator, which reduce risk. At the same time, it also increases risk because the additional time allows containment to heat up and pressurize.

The risk reduction gained by allowing an increased probability of power recovery (ending SBO) is far outweighed by the increase in risk due to shifting to more severe consequences of failing a pressurized reactor vessel into a pressurized containment at saturated conditions. However, SAMA 37 is highly effective at mitigating risk if other supporting SAMAs are also implemented to assure its viability and reliability. Those supporting SAMAs are summarized as follows:

SAMA 28 (Refill CST) establishes the use of the fire protection system to ensures RCIC has a long-term suction source.

SAMA 12 (Additional Diesel Fire Pump for Fire Service Water System) improves the reliability of the fire protection system, especially during SBO scenarios. This dramatically improves the suction source reliability for RCIC since CST is filled from fire protection system).

SAMA 2 (Enhanced DC Power Availability) provides power to solenoid valves, allowing containment to be vented during prolonged SBO

scenarios, preventing RCIC failure.

SAMA 36 (Divert Water from Turbine Building 931-Foot Elevation East) improves RCIC reliability by preventing flooding of supporting batteries before enough time is available to establish manual RCIC operation.

If you have any questions regarding this information please contact Jim Holthaus, Monticello License Renewal, at (763) 295-1309.

James J. Holthaus Monticello Nuclear Generating Plant License Renewal Environmental Lead Nuclear Management Company 2807 West County Road 75 Monticello, Minnesota 55362-9637 CC:

<RLP3@nrc.gov>, <erschmidt@adelphia.net>, "Musolf, David M."

<David.Musolf@nmcco.com>, "Burke, Patrick B." <Patrick.Burke@nmcco.com>, "Sarrack, Anthony G." <Anthony.Sarrack@nmcco.com>

Mail Envelope Properties (42FCB211.01A : 20 : 26)

Subject:

Supplement SAMA RAI 5b Creation Date:

8/12/05 10:28AM From:

"Holthaus, James J." <James.Holthaus@nmcco.com>

Created By:

James.Holthaus@nmcco.com Recipients nrc.gov TWGWPO01.HQGWDO01 RLP3 CC (Robert Palla) nrc.gov owf4_po.OWFN_DO JXD10 (Jennifer Davis) nmcco.com Anthony.Sarrack CC (Anthony G. Sarrack)

Patrick.Burke CC (Patrick B. Burke)

David.Musolf CC (David M. Musolf) adelphia.net erschmidt CC Post Office Route TWGWPO01.HQGWDO01 nrc.gov owf4_po.OWFN_DO nrc.gov nmcco.com adelphia.net Files Size Date & Time MESSAGE 3068 08/12/05 10:28AM TEXT.htm 8652 Mime.822 13891 Options Expiration Date:

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Monticello Nuclear Generating Plant cc:

Jonathan Rogoff, Esquire Vice President, Counsel & Secretary Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 U.S. Nuclear Regulatory Commission Resident Inspector's Office 2807 W. County Road 75 Monticello, MN 55362 Manager, Regulatory Affairs Monticello Nuclear Generating Plant Nuclear Management Company, LLC 2807 West County Road 75 Monticello, MN 55362-9637 Robert Nelson, President Minnesota Environmental Control Citizens Association (MECCA) 1051 South McKnight Road St. Paul, MN 55119 Commissioner Minnesota Pollution Control Agency 520 Lafayette Road St. Paul, MN 55155-4194 Regional Administrator, Region III U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60532-4351 Commissioner Minnesota Department of Health 717 Delaware Street, S. E.

Minneapolis, MN 55440 Douglas M. Gruber, Auditor/Treasurer Wright County Government Center 10 NW Second Street Buffalo, MN 55313 Margo Askin Head Librarian, Monticello Public Library 200 W. 6th Street Monticello, MN 55362 Commissioner Minnesota Department of Commerce 85 7th Place East, Suite 500 St. Paul, MN 55101-2198 Manager - Environmental Protection Division Minnesota Attorney Generals Office 445 Minnesota St., Suite 900 St. Paul, MN 55101-2127 John Paul Cowan Executive Vice President & Chief Nuclear Officer Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Nuclear Asset Manager Xcel Energy, Inc.

414 Nicollet Mall, R.S. 8 Minneapolis, MN 55401 Mr. James Ross Nuclear Energy Institute 1776 I Street, NW, Suite 400 Washington, DC 20006-3708 Patrick Burke License Renewal Project Manager Monticello Nuclear Generating Plant Nuclear Management Company, LLC 2807 West County Road 75 Monticello, MN 55362-9637 Mr. Douglas F. Johnson Director, Plant Life Cycle Issues Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Amy Wittmann Branch Librarian, Buffalo Public Library 18 Northwest Lake Boulevard Buffalo, MN 55313