ML031120507
| ML031120507 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 04/21/2003 |
| From: | Donohew J NRC/NRR/DLPM/LPD4 |
| To: | Randolph G Union Electric Co |
| Donohew J N, NRR/DLPM,415-1307 | |
| References | |
| TAC MB6505 | |
| Download: ML031120507 (14) | |
Text
April 21, 2003 Mr. Garry L. Randolph Vice President and Chief Nuclear Officer Union Electric Company P.O. Box 620 Fulton, MO 65251
SUBJECT:
CALLAWAY PLANT, UNIT 1 - ISSUANCE OF AMENDMENT RE: PHYSICS TESTS EXCEPTIONS - MODE 2 (TAC NO. MB6505)
Dear Mr. Randolph:
The Commission has issued the enclosed Amendment No. 154 to Facility Operating License No. NPF-30 for the Callaway Plant, Unit 1. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated October 3, 2002 (ULNRC-04742).
The amendment revises Limiting Condition for Operation 3.1.8, "Physics Tests Exceptions -
Mode 2," to reduce the required number of channels from four to three channels for certain functions in Table 3.3.1-1, "Reactor Trip System Instrumentation."
A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions next biweekly Federal Register notice.
Sincerely,
/RA/
Jack Donohew, Senior Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-483
Enclosures:
- 1. Amendment No. 154 to NPF-30
- 2. Safety Evaluation cc w/encls: See next page
Callaway Plant, Unit 1 cc:
Professional Nuclear Consulting, Inc.
19041 Raines Drive Derwood, MD 20855 John ONeill, Esq.
Shaw, Pittman, Potts & Trowbridge 2300 N. Street, N.W.
Washington, D.C. 20037 Mr. Mark A. Reidmeyer, Regional Regulatory Affairs Supervisor Regulatory Affairs AmerenUE P.O. Box 620 Fulton, MO 65251 U.S. Nuclear Regulatory Commission Resident Inspector Office 8201 NRC Road Steedman, MO 65077-1302 Mr. J. V. Laux, Manager Quality Assurance AmerenUE P.O. Box 620 Fulton, MO 65251 Manager - Electric Department Missouri Public Service Commission 301 W. High P.O. Box 360 Jefferson City, MO 65102 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 Mr. Ronald A. Kucera, Deputy Director for Public Policy Department of Natural Resources 205 Jefferson Street Jefferson City, MO 65101 Mr. Rick A. Muench President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KA 66839 Mr. Dan I. Bolef, President Kay Drey, Representative Board of Directors Coalition for the Environment 6267 Delmar Boulevard University City, MO 63130 Mr. Lee Fritz Presiding Commissioner Callaway County Court House 10 East Fifth Street Fulton, MO 65151 Mr. David E. Shafer Superintendent Licensing Regulatory Affairs AmerenUE P.O. Box 66149, MC 470 St. Louis, MO 63166-6149 Mr. John D. Blosser, Manager Regulatory Affairs AmerenUE P.O. Box 620 Fulton, MO 65251 Mr. Scott Clardy, Director Section for Environmental Public Health P.O. Box 570 Jefferson City, Missouri 65102-0570
ML031120507 NRR-041 OFFICE PDIV-2/PM PDIV-2/LA RORP/TS/SC OGC - NLO PDIV-2/SC NAME JDonohew EPeyton RDennig AFernandez RAGramm for SDembek DATE 3/14/2003 3/13/03 3/27/03 4/7/03 4/16/03 DOCUMENT NAME: G:\\PDIV-2\\Callaway\\AMD\\MB6505-PhysicsTestsExceptions.cw.wpd
UNION ELECTRIC COMPANY CALLAWAY PLANT, UNIT 1 DOCKET NO. 50-483 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 154 License No. NPF-30 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Union Electric Company (UE, the licensee) dated October 3, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commissions 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 Commissions 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 Commissions 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 2.C.(2) of Facility Operating License No. NPF-30 is hereby amended to read as follows:
(2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 154 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
3.
This amendment is effective as of its date of issuance and shall be implemented within 60 days of the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
/by Robert A. Gramm for/
Stephen Dembek, Chief, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance: April 21, 2003
ATTACHMENT TO LICENSE AMENDMENT NO. 154 FACILITY OPERATING LICENSE NO. NPF-30 DOCKET NO. 50-483 Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains vertical lines indicating the areas of change.
REMOVE INSERT 3.1-19 3.1-19
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 154 TO FACILITY OPERATING LICENSE NO. NPF-30 UNION ELECTRIC COMPANY CALLAWAY PLANT, UNIT 1 DOCKET NO. 50-483
1.0 INTRODUCTION
By application dated October 3, 2002, Union Electric Company (the licensee) requested changes to the Technical Specifications (TSs, Appendix A to Facility Operating License No. NPF-30) for the Callaway Plant, Unit 1 (Callaway). The proposed amendment would revise Limiting Condition for Operation (LCO) 3.1.8, "Physics Tests Exceptions - Mode 2," to reduce the required number of channels from four to three channels for certain functions in Table 3.3.1-1, "Reactor Trip System Instrumentation."
The proposed amendment applies only to Mode 2 during physics testing and certain reactor trip system (RTS) instrumentation listed in Table 3.3.1-1. The licensee also provided in its application the corresponding changes to the TS Bases for LCO 3.1.8.
The proposed amendment adopts NRC-approved generic changes in Technical Specification Task Force 315, Revision 0 (TSTF-315). The licensee adopted the Improved Technical Specifications (ITS) in License Amendment No. 133 (issued May 28, 1999) based on NUREG-1431, "Standard Technical Specifications [STS] for Westinghouse Plants," Revision 1, dated April 1995. Since then, the industry and the staff have been working to improve the ITS, in NUREG-1430 through NUREG-1434 for the different plant vendors, and as a result, generic changes have been developed for the standard ITS in NUREG-1431 in NRC-approved TSTFs, such as TSTF-315. Changes to NUREG-1431 would be applicable to Callaway because the TSs for Callaway are based on NUREG-1431. In its proposed amendment, the licensee did not submit any plant-specific differences to the TSs given in TSTF-315.
2.0 REGULATORY REQUIREMENTS In accordance with Standard Review Plan (SRP) (NUREG-0800) Sections 7.1, "Instrumentation and Controls - Introduction," and 7.2, "Reactor Trip System," the acceptance criteria for the review of reactor trip system (RTS) instrumentation are the relevant requirements of the following regulations:
10 CFR 50.55a(h) which requires IEEE Standard 279-1971, "Criteria for Protection Systems for Nuclear Power+ Generating Stations."
General Design Criterion (GDC) 2, "Design Basis for Protection Against Natural Phenomena," of Appendix A to 10 CFR Part 50.
GDC 4, "Environmental and Missile Design Basis."
GDC 13, "Instrumentation and Control."
GDC 20, "Protection Systems Functions."
GDC 21, "Protection System Reliability and Testability."
GDC 22, "Protection System Independence."
GDC 23, "Protection System Failure Modes."
GDC 24, "Separation of Protection and Control Systems."
GDC 25, "Protection System Requirements for Reactivity Control Malfunctions."
GDC 29, "Protection Against Anticipated Occurrences."
SRP 7.2 also gives the following major design considerations: (1) system redundancy requirements to assure that at least two redundant logic trains (i.e., a minimum degree of redundancy of one) are provided to initiate reactor trip, and (2) electrical and physical independence, and single failure criterion requirements.
3.0 TECHNICAL EVALUATION
Currently, LCO 3.1.8 states that in Mode 2 during the performance of physics tests, the following LCOs may be suspended:
LCO 3.1.3, "Moderator Temperature Coefficient (MTC),"
LCO 3.1.4, "Rod Group Alignment Limits,"
LCO 3.1.5, "Shutdown Bank Insertion Limits,"
LCO 3.1.6, "Control Bank Insertion Limits," and
LCO 3.4.2, "RCS [Reactor Coolant System] Minimum Temperature for Criticality."
The above LCOs may be suspended if the following three conditions are met: (1) RCS lowest operating loop average temperature is greater than or equal to 541F, (2) the shutdown margin is within the limits specified in the core operating limits report (COLR), and (3) the thermal power is less than or equal to 5 percent rated thermal power (RTP).
Physics tests defined in the TSs are those tests performed to measure the fundamental nuclear characteristics of the reactor core and related instrumentation. These tests are described in Chapter 14 of the Final Safety Analysis Report and authorized under 10 CFR 50.59. They are performed in Mode 2 at less than or equal to 5 percent RTP.
None of the above is changed by the proposed amendment.
In its application, the licensee proposed to add the phrase "and the number of required channels for LCO 3.3.1, "RTS Instrumentation," Functions 2, 3, 6, and 18.e may be reduced to 3 required channels" to the following phrase currently in LCO 3.1.8: "may be suspended, provided." Therefore, the proposed amendment reduces the number of required operable channels for the following RTS instrumentation that is listed in TS Table 3.3.1-1:
Power range neutron flux-high (Function 2.a)
Power range neutron flux-low (Function 2.b)
Power range neutron flux rate-high positive rate (Function 3)
Overtemperature deltaT (Function 6)
Power range neutron flux P-10 interlock (Function 18.e) where Functions 2.a and 2.b comprise Function 2 of TS Table 3.3.1-1.
Currently, TS Table 3.3.1-1 requires for Mode 2 that the above five functions have four operable channels. The proposed amendment would reduce the number of operable channels for the above five functions from four to three channels, but only for Mode 2 during physics tests. No other changes are being made to the RTS instrumentation for the five functions and none of the instrumentation for other functions in the table is being changed.
The above five functions involve the four power range neutron flux channels. Their purpose is to initiate (1) a reactor trip on high or low flux, high positive rate of flux change, or overtemperature delta T, or (2) the P-10 interlock, at the allowable values specified in TS Table 3.3.1-1. The P-10 interlock automatically deactivates, during power ascension in plant startup, the low power range and intermediate power range trips when 3 of the 4 power range neutron flux channels go above the lower P-10 allowable value in TS Table 3.3.1-1, and activates these trips, during power reduction, when the channels go below the higher P-10 allowable value in the table. In addition, the power range neutron flux channels provide input to plant control functions. The effect of the proposed amendment on reactor trip, reactor trip interlock P-10, and plant control functions are discussed below.
3.1 Reactor Trip Function To support its application, the licensee provided the following example as to how the amendment would be applied during physics testing. For the example of performance of bank reactivity worth measurements using the dynamic rod worth measurement (DRWM) process, the licensee stated that one power range neutron flux channel is used to provide input to the advanced digital reactivity computer (ARDC). The DRWM process is used to measure the integral reactivity worth of the control and shutdown banks by a method of dynamic insertion of the banks, in which the selected bank is fully inserted into and withdrawn from the core while reactivity changes in the core are measured by the ARDC. The insertion/withdrawal sequence would be repeated for each bank that is selected to determine its reactivity worth.
The licensee stated that when the DRWM process is currently used, the instrument power fuses associated with the power range neutron flux channel to be connected to the ARDC are removed, which results in that channel being bypassed for the RTS Functions 2, 3, and 6. In other words, when the instrument power fuses are removed for that power range neutron channel, the RTS functions of power range neutron flux-high (Function 2.a), power range neutron flux-low (Function 2.b), power range neutron flux rate-high positive rate (Function 3),
and overtemperature delta T (Function 6) are being bypassed. Because that channel cannot perform these RTS functions, the channel is inoperable, and in accordance with Conditions D and E of LCO 3.3.1, which are specified in TS Table 3.3.1-1, the channel would have to be placed in trip (i.e., the control power fuses are removed) within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and power would have to be reduced to no more than 75 percent RTP within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The removal of the control power fuses would have to be done, but since the plant is not above 5 percent rated thermal power in Mode 2 during physics testing, there would be no action to reduce power.
The licensee states further that once Conditions D and E for LCO 3.3.1 are entered they can not be exited until that power range neutron flux channel is disconnected from the ARDC and reconnected to the RTS functions (i.e., the normal system configuration is restored). This would not occur until the DRWM process for all the selected control rod banks is over. During this process, with one channel tripped, the trip logic for the power range nuclear instrumentation system (NIS) would be placed in a one-out-of-three coincidence status such that a spurious high signal on any of the other three power range neutron flux channels would result in a reactor trip. With the proposed amendment, the power range neutron flux channel connected to the ARDC during physics testing in Mode 2 would be bypassed, but not tripped, and the power range NIS trip logic would be in a two-out-of-three coincidence status, not one-out-of-three, which would preclude spurious signals from causing a reactor trip because signals in two channels would be needed for the reactor trip.
Therefore, to preclude spurious reactor trips during physics testing, the proposed amendment would reduce the number of required channels for the above five functions in TS Table 3.3.1-1 from four to three channels. This reduction in the number of channels would allow only three power range neutron flux channels to be required for reactor trips during physics testing and the coincidence trip logic for the three channels to be a two-out-of-three configuration.
Thus, two channels would have to have signals for a reactor trip to occur and spurious signals should not cause a reactor trip unless they occur in two channels at the same time. Without the amendment, four channels would be required and, with one channel being used for other than reactor trip, the fourth channel would have to be put in a tripped condition. The coincidence trip logic for the other three channels would be a one-out-of-three configuration and, therefore, a spurious signal in any of the three channels would cause a reactor trip.
Therefore, the proposed amendment would allow the three power range neutron flux channels, which would be used for sensing reactor flux conditions needing a reactor trip during physics testing, to have a two-out-of-three coincidence trip logic configuration to initiate the reactor trip instead of the currently required (by Conditions D and E of LCO 3.3.1) one-out-of-three coincidence trip logic configuration.
In its analysis of the proposed amendment, the licensee stated the following for reducing the required number of power range neutron flux channels for Functions 2, 3, and 6, which perform a reactor trip function:
Only one power range neutron flux channel for RTS Functions 2, 3, 6, and 18.e of TS Table 3.3.1-1 is affected by the proposed amendment.
The Westinghouse Owners Group has identified four instances of reactor trips at plants during physics testing caused by spurious signals, and the two-out-of-three coincidence logic will reduce the plant susceptibility to such spurious reactor trips.
The amendment will allow one power range neutron flux channel to be bypassed, instead of tripped, so that the NIS trip logic, for the remaining three non-bypassed power range neutron flux channels for the RTS Functions 2, 3, and 6, is a two-of-three coincidence logic configuration for reactor trip to reduce the chance for a spurious reactor trip.
The RTS Functions 2, 3, and 6 are still required to be operable for reactor trip in Mode 2 for physics testing, although in a two-out-of-three coincidence logic configuration.
This will apply only to physics testing in Mode 2 where the RCS lowest operating loop average temperature is greater than or equal to 541F, the shutdown margin is within the limits specified in the COLR, and the thermal power is less than or equal to 5 percent RTP.
The accidents mitigated by the power range neutron flux channels during physics testing (5 percent RTP) remain normally bounded by the accidents at full power (100 percent RTP).
There will be no changes to the RTS instrumentation design such that the power range neutron flux channels will remain in compliance with GDC 13, 20 through 25, and 29, and 10 CFR 50.55a(h).
The functional performance of the power range neutron flux channels is retained in the two-out-of-three coincidence logic configuration and that the functionality will continue to be demonstrated by the surveillance requirements (SRs) of TS Table 3.3.1-1.
Based on this, the staff concludes that the proposed amendment will reduce spurious reactor trips during physics testing without adversely affecting the safety functions of the power range neutron flux channels, and that there has been a sufficient number of spurious reactor trips during physics testing to conclude that the proposed amendment will increase plant safety.
3.2 Backup Protection for Change to Functions 2, 3, and 6 The licensee also addressed the backup protection that exists for the proposed amendment.
The licensee described the following defense-in-depth that exists during physics testing:
LCO 3.1.8 requires that the following three conditions are met: (1) RCS lowest operating loop average temperature is greater than or equal to 541F, (2) the shutdown margin is within the limits specified in the COLR, and (3) the thermal power is less than or equal to 5 percent RTP.
The intermediate range neutron flux trip is active and also provides reactor trip protection at these low power levels.
During physics testing, the plant is held in a stable state with minimal changes in steam or feed flow.
Physics testing is normally performed at the beginning of the operating fuel cycle with the minimum fuel burnup and decay heat.
The shutdown margin is maintained above the required limits in the COLR and procedural controls are in place for monitoring plant parameters.
Based on this, the staff concludes that there is backup protection for the reduction in the number of required channels of power range neutron flux for Functions 2, 3, and 6.
3.3 Reactor Trip Interlock P-10 The P-10 interlock automatically deactivates, during power ascension in plant startup, the low power range and intermediate power range trips when 3 of the 4 power range neutron flux channels go above the lower P-10 allowable value in TS Table 3.3.1-1, and activates these trips, during power reduction, when the channels go below the higher P-10 allowable value in the table.
The P-10 interlock is also affected by the proposed amendment in that if only three power range neutron flux channels are required for Functions 2, 3, and 6, then only three channels can be required for the P-10 interlock. The justification for Functions 2, 3, and 6 to reduce the chance of a spurious signal causing a reactor trip during physics testing does not apply to the P-10 interlock; however, the same power range neutron flux channels used for Functions 2, 3, and 6 are the ones used for the P10 interlock. Therefore, if the proposed amendment is approved for Functions 2, 3, and 6, the change also needs to be approved for the P-10 interlock. Reducing the number of required power range neutron flux channels to three in LCO 3.1.8 for Function 18.e will, however, prevent the licensee from having to enter Condition S for LCO 3.3.1 during physics testing when one power range neutron flux channel is used for other than Functions 2, 3, 6, and 18.e. However, LCO 3.1.8 during reactor startup requires that the P-10 interlock is operable and has enabled the low power range and intermediate power range trips before entry into Mode 2 for the low power physics testing with power below the lower P-10 allowable values. Therefore, the low power range and intermediate power range trips are already enabled before the low power testing begins, and bypassing the NIS channel will not affect these low power reactor trips.
Based on the above, the staff concludes that the reduction in required power range neutron flux channels for the reactor trip interlock P-10 will not affect the P-10 safety function of having the low power trips enabled below the lower P-10 allowable value in TS Table 3.3.1-1.
3.4 Plant Control Functions The licensee stated that the control functions which use input from the power range neutron flux channels are the following: (1) rod control from power mismatch, and (2) steam generator water level control.
For rod control, the licensee stated that rod control at the physics testing power levels (i.e., less than or equal to 5 percent RTP) is in manual mode and is not affected by the testing configuration of the channels. Manual rod control uses an auctioneered power range neutron flux input and the bypass of one channel does not eliminate the auctioneered input from the other three channels for this portion of the control signal.
For steam generator water level control, the licensee stated that at power levels below 25 percent RTP, the water level control system modulates the position of the feedwater control bypass valves using an auctioneered power range neutron flux input. As for manual rod control, the bypass of one channel does not eliminate the auctioneered input from the other three channels for this portion of the control signal.
Based on this, the staff concludes that the proposed amendment will not adversely affect the control systems using input from the power range neutron flux channels.
3.5 Conclusions Based on the above and its review of the proposed amendment, the staff concludes the following:
The proposed amendment does not change the design of any NIS channels or its conformance with the regulatory requirements stated in Section 2.0 of this safety evaluation.
The functionality of the power range neutron flux channels, the only NIS channels affected by the proposed amendment, is retained in the new coincidence logic configuration.
The functionality of the channels will continue to be demonstrated by the SRs of TS Table 3.3.1-1.
The minimum degree of redundancy for reactor trip during physics tests is met in that there are at least two redundant channels of power range neutron flux (i.e., three channels will be used for reactor trip).
The change in coincidence logic configuration for Functions 2, 3, and 6 would reduce spurious reactor trips, and the P-10 interlock function and plant control functions are not affected.
The change in the coincidence logic configuration of the power range neutron flux channels for Functions 2, 3, and 6 in this proposed amendment does not affect the staffs previous conclusion that the power range neutron flux channels meet the requirements of GDC 2, electrical independence, and physical independence when the plant was licensed.
Based on the above conclusions and on the proposed amendment being consistent with TSTF-315, the staff concludes that the proposed amendment is acceptable. Also, after its review of the TS Bases changes for LCO 3.1.8, the staff has no disagreement with the licensees identified changes to the TS Bases for the LCO.
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the Missouri State official was notified of the proposed issuance of the amendment. The State official did not offer any comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes 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 amendment involves 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 amendment involves no significant hazards consideration and there has been no public comment on such finding (67 FR 70771). Accordingly, the amendment meets 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 amendment.
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 Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Jack Donohew Date: April 21, 2003