ML020100131

Issuance of License Amendments, Technical Specifications Change - Reactor Protection System Instrumentation Scram Discharge Volume Water Level High

ML020100131
Person / Time
Site:	Quad Cities
Issue date:	02/11/2002
From:	Mahesh Chawla NRC/NRR/DLPM/LPD3
To:	Kingsley O Exelon Generation Co, Exelon Nuclear
Chawla, ML, NRR/DLPM/LPD III_2, 415-8371
References
TAC MB2352, TAC MB2353
Download: ML020100131 (14)

Text

February 11, 2002 Mr. Oliver D. Kingsley, President Exelon Nuclear Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

ISSUANCE OF AMENDMENTS - TECHNICAL SPECIFICATIONS CHANGE -

REACTOR PROTECTION SYSTEM INSTRUMENTATION SCRAM DISCHARGE VOLUME WATER LEVEL HIGH FOR QUAD CITIES NUCLEAR POWER STATION, UNITS 1 AND 2 (TAC NOS. MB2352 AND MB2353)

Dear Mr. Kingsley:

The U.S. Nuclear Regulatory Commission (Commission) has issued the enclosed Amendment No. 203 to Facility Operating License No. DPR-29 and Amendment No. 199 to Facility Operating License No. DPR-30 for the Quad Cities Nuclear Power Station, Units 1 and 2. The amendments are in response to your application dated July 6, 2001, as supplemented by your letters dated October 25, 2001, and December 17, 2001.

The amendments revise technical specifications (TS) Section 3.3.1.1, Reactor Protection System Instrumentation, to modify the description for Reactor Protection System (RPS)

Function 7.a, Scram Discharge Volume Water Level - High. This change supports a planned upgrade to the scram discharge volume level instrumentation from Fluid Components International thermal switches to Magnetrol float switches. These float switches are more reliable than the existing thermal switches, which are highly sensitive to a steam environment, since they respond to actual water level increases within the scram discharge volume. These types of Magnetrol float switches are used successfully in various applications at Quad Cities.

A copy of the related safety evaluation is also enclosed. The Notice of Issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely,

/RA/

Mahesh Chawla, Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos.: 50-254 and 50-265

Enclosures:

1. Amendment No. 203 to DPR-29

2. Amendment No. 199 to DPR-30

3. Safety Evaluation cc w/encls: See next page

O. Kingsley Quad Cities Nuclear Power Station Exelon Generation Company, LLC Units 1 and 2 cc:

Exelon Generation Company, LLC Illinois Department of Nuclear Safety Site Vice President - Quad Cities Office of Nuclear Facility Safety 22710 206th Avenue N. 1035 Outer Park Drive Cordova, Illinois 61242-9740 Springfield, Illinois 62704 Exelon Generation Company, LLC Document Control Desk-Licensing Station Manager - Quad Cities Exelon Generation Company, LLC 22710 206th Avenue N. 4300 Winfield Road Cordova, Illinois 61242-9740 Warrenville, Illinois 60555 Exelon Generation Company, LLC Mr. John Skolds Regulatory Assurance Manager - Quad Cities Chief Operating Officer 22710 206th Avenue N. Exelon Generation Company, LLC Cordova, Illinois 61242-9740 4300 Winfield Road Warrenville, Illinois 60555 U.S. Nuclear Regulatory Commission Quad Cities Resident Inspectors Office Mr. John Cotton 22712 206th Avenue N. Senior Vice President, Operation Support Cordova, Illinois 61242 Exelon Generation Company, LLC 4300 Winfield Road William D. Leech Warrenville, Illinois 60555 Manager - Nuclear MidAmerican Energy Company Mr. William Bohlke P.O. Box 657 Senior Vice President, Nuclear Services Des Moines, Iowa 50303 Exelon Generation Company, LLC 4300 Winfield Road Vice President - Law and Warrenville, Illinois 60555 Regulatory Affairs MidAmerican Energy Company Mr. Robert J. Hovey One River Center Place Vice President 106 E. Second Street Mid-West Regional Operating Group P.O. Box 4350 Exelon Generation Company, LLC Davenport, Iowa 52808 4300 Winfield Road Warrenville, Illinois 60555 Chairman Rock Island County Board Mr. Christopher Crane of Supervisors Senior Vice President 1504 3rd Avenue Mid-West Regional Operating Group Rock Island County Office Bldg. Exelon Generation Company, LLC Rock Island, Illinois 61201 4300 Winfield Road Warrenville, Illinois 60555 Regional Administrator U.S. NRC, Region III 801 Warrenville Road Lisle, Illinois 60532-4351

O. Kingsley Quad Cities Nuclear Power Station Exelon Generation Company, LLC Units 1 and 2 Mr. Jeffrey Benjamin Vice President - Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, Illinois 60555 Mr. K. A. Ainger Director - Licensing Mid-West Regional Operating Group Exelon Generation Company, LLC 4300 Winfield Road Warrenville, Illinois 60555 Mr. Robert Helfrich Senior Counsel, Nuclear Mid-West Regional Operating Group Exelon Generation Company, LLC 4300 Winfield Road Warrenville, Illinois 60555

ML020100131 TS Accession No.: ML020460296 OFFICE PM:LPD3-2 PM:LPD3-2 LA:LPD3-2 SC:EEIB OGC SC:LPD3-2 NAME MChawla FLyon CRosenberg EMarinos RHoefling AMendiola DATE 01/16/02 01/17/02 01/10/02 01/17/02 01/24/02 02/11/02 EXELON GENERATION COMPANY, LLC AND MIDAMERICAN ENERGY COMPANY DOCKET NO. 50-254 QUAD CITIES NUCLEAR POWER STATION, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 203 License No. DPR-29

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Exelon Generation Company, LLC (the licensee) dated July 6, 2001, as supplemented by your letters dated October 25, 2001, and December 17, 2001, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 3.B. of Facility Operating License No. DPR-29 is hereby amended to read as follows:

B. Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 203, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of the date of its issuance and shall be implemented within 30 days of the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Anthony J. Mendiola, Chief, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: February 11, 2002

EXELON GENERATION COMPANY, LLC AND MIDAMERICAN ENERGY COMPANY DOCKET NO. 50-265 QUAD CITIES NUCLEAR POWER STATION, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 199 License No. DPR-30

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Exelon Generation Company, LLC (the licensee) dated July 6, 2001, as supplemented by your letters dated October 25, 2001, and December 17, 2001, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 3.B. of Facility Operating License No. DPR-30 is hereby amended to read as follows:

B. Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 199, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of the date of its issuance and shall be implemented within 30 days of the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Anthony J. Mendiola, Chief, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: February 11, 2002

ATTACHMENT TO LICENSE AMENDMENT NOS. 203 AND 199 FACILITY OPERATING LICENSE NOS. DPR-29 AND DPR-30 DOCKET NOS. 50-254 AND 50-265 Replace the following pages of the Appendix A Technical Specifications with the attached pages. The revised pages are identified by number and contain marginal lines indicating the area of change.

Remove Pages Insert Pages 3.3.1.1-9 3.3.1.1-9

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 203 TO FACILITY OPERATING LICENSE NO. DPR-29 AND AMENDMENT NO. 199 TO FACILITY OPERATING LICENSE NO. DPR-30 EXELON GENERATION COMPANY, LLC AND MIDAMERICAN ENERGY COMPANY QUAD CITIES NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-254 AND 50-265

1.0 INTRODUCTION

By letter dated July 6, 2001, the Exelon Generation Company, LLC, (Exelon, the licensee) submitted a request to the Nuclear Regulatory Commission (NRC) to amend the Technical Specifications (TS) for the Quad Cities Nuclear Power Station, Units 1 and 2. The proposed TS change will permit replacement of thermal switches made by Fluid Components International (FCI), to float switches made by Magnetrol, in the scram discharge volume (SDV) instrumentation of the reactor protection system (RPS) to interface with the existing RPS logic.

Further, in response to NRCs request, the licensee provided additional information by letters dated October 25, 2001, and December 17, 2001.

The proposed amendment will modify the description of Function 7.a of TS Table 3.3.1.1-1, Reactor Protection System Instrumentation from Thermal Switch to Thermal Switch (for Unit 1 only through cycle 17) Float Switch.

The proposed plant design changes are scheduled for implementation during the next refueling outage on Unit 2 in February 2002. A similar design change will be implemented on Unit 1 during the 17th refueling outage scheduled to begin in October 2002.

The October 25, 2001, and December 17, 2001, supplements provided clarifying information that was within the scope of the original Federal Register notice and did not change the staffs initial proposed no significant hazards considerations determination.

2.0 BACKGROUND

INFORMATION The RPS has protection and monitoring functions which have been designed to ensure safe operation of the reactor. The RPS initiates a reactor scram when one or more monitored

parameters exceed their specified limits, to preserve the integrity of the fuel cladding and the reactor coolant system (RCS), and minimize the energy that must be absorbed following a loss-of-coolant accident (LOCA).

The current instrumentation for the SDV - high level trip, Function 7.a of TS Table 3.3.1.1-1, Reactor Protection System Instrumentation, utilizes FCI thermal type level switches mounted directly in the scram discharge instrument volume (SDIV) to initiate a reactor scram when the monitored parameter exceeds its specified limit. If the SDV were to fill to a point where there is insufficient volume to accept the water from the control drives that are displaced during scram, control rod insertion would be hindered. This scram is required to be functional in Modes 1, Power Operation, 2, Startup, and 5, Refueling with any control rod withdrawn from a reactor core cell containing one or more fuel assemblies.

3.0 EVALUATION 3.1 Evaluation of Proposed Instrument Change The current SDV instrumentation consists of four internally mounted, non-indicating thermal switches, which monitor the SDV level. The switches are arranged in pairs on each of two SDVs, so each switch pair provides an input to RPS trip systems A and B. The sensor of each FCI thermal type level switch is mounted directly in the SDIV and comprises a pair of resistance temperature detectors (RTDs), one heated and the other one unheated. When covered with water, the temperatures and RTD outputs will approach the same value. The signals from the RTDs are compared via a bridge circuit and when the setpoint is reached, a trip signal is generated, which corresponds to a four-second time delay from the time of immersion. This delay desensitizes the instrument loop to transient type conditions in the SDIV, such as splashing, moisture/steam intrusion, etc.

The current setpoint incorporates the maximum delay, which ensures that the SDV is not full at the end of the time delay, and there is sufficient free volume in the SDV to provide rod insertion capability. The licensee stated that it has experienced spurious half and full scrams because the delay is inadequate to fully desensitize the instrument to low quality steam flow (steam/moisture environment).

The proposed replacement Magnetrol float switch consists of a float attached to a vertical shaft which magnetically actuates a switch on high water level. Since the replacement float switches will be installed external to the SDV, it eliminates sensitivity to transient conditions in the SDIV and thus eliminates spurious half or full scrams. The new assemblies will be mounted to actuate at the same level as the existing FCI sensors, and since there is no time delay involved in the new assemblies, the scram signal will be received 4 seconds earlier. Therefore, application of these float switches will eliminate the current four second time delays in the SDV instrumentation. There are no setpoint changes required due to the SDV instrumentation change.

The licensee has used these switches for multiple applications at Quad Cities, namely Table 3.3.5.1-1, ECCS Instrumentation, Sub-Function 3.d, CCST Level - Low, and Sub-Function 3.e, Suppression Pool Water Level - High. Also, the licensee states that the modification has been successfully evaluated under Exelons design change process and does

not introduce any new failure modes. Moreover, there is no credit taken for a scram initiated by this function for any of the design basis accidents or transients analyzed in the updated final safety analysis report.

During a telephone conference held on October 3, 2001, between NRC staff and Exelon representatives, the licensee was asked to provide additional information regarding the improved reliability of the upgrade instrumentation. In its letter dated October 25, 2001, the licensee stated that these switches have historically, throughout the nuclear industry, proven to be highly reliable since they require low maintenance and experienced little to no functional failure. These float switches provide increased accuracy of detecting actual water level within the SDV.

During the follow-up telephone conference held on November 29, 2001, between NRC staff and Exelon representatives, the licensee was asked to describe the process to determine the allowable value for the scram discharge volume instrumentation loop. In its letter dated December 17, 2001, the licensee stated that Exelon methodology as defined in procedure NES-EIC-20.04, Analysis of Instrument Channel Setpoint Error and Instrument Loop Accuracy, was used to determine the allowable value (AV). This methodology has been reviewed and accepted by the NRC as part of the Quad Cities implementation of improved technical specifications (NRC letter from Anthony J. Mendiola to Exelon, dated March 30, 2001).

No changes were made to the analytical limit (AL) during the change to the new Magnetrol level switches. A Quad Cities evaluation and the placement of the new switches allowed the AV to remain unchanged. The evaluation demonstrated a significant margin between the AV and AL, due to the differences in the time response characteristics of the Magnetrol switches as compared to the FCI switches.

3.2 Conclusion The licensee proposes to replace the current FCI thermal type switches used in SDV instrumentation with Magnetrol float switches. These switches are free from sensitivity to steam/moisture changes in the SDIV, have increased accuracy in detecting actual water level, and have demonstrated more reliable operation in multiple applications at Quad Cities and in the nuclear industry. The overall effect of this modification is to provide an identical function as the previous SDV Water Level - High trip signal and to provide increased reliability and better overall performance of the SDV level trip function.

Based on the proven industry performance record of the float switches, including those installed at Quad Cities in similar applications, and the licensees use of NRC-approved calculation methodology to determine AVs for the SDV instrumentation loop, the NRC staff concludes that the proposed TS change is acceptable.

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Illinois State official was notified of the proposed issuance of the amendments. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (67 FR 1520). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

6.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: Subinoy Mazumdar Mahesh Chawla Date: February 11, 2002