NRC-97-0037, Application for Amend to License NPF-43,relocating Surveillance Requirements for Reactor Recirculation Sys MG Set Scoop Tube Stop Setpoints to UFSAR
| ML20141B881 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/20/1997 |
| From: | Gipson D DETROIT EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20141B885 | List: |
| References | |
| CON-NRC-97-0037, CON-NRC-97-37, RTR-NUREG-1433 NUDOCS 9706240197 | |
| Download: ML20141B881 (11) | |
Text
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4 Douglas H. Gipson 4
Senior Vice President, Nuclear Generation fermi 2 7
6400 North Dixie Hwy, Newport, Michigan 48166 Tel: 3133MI>2ul Fax: 311T>E.41U Detroit Edison June 20,1997 NRC-97-0037 J
i U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555
References:
1)
Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43 4
2)
NUREG-1433, " Standard Technical Specifications, General Electric Plants, BWR/4", Revision 1, April 1995.
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Subject:
Proposed Technical Specification Change (License Amendment) for Relocation of Reactor Recirculation System Motor-Generator (MG) 4 Set Scoco Tube Stoo Setting Surveillance Pursuant to 10CFR50.90, Detroit Edison Company hereby proposes to amend l
Operating License NPF-43 for the Fermi 2 plant by incorporating the enclosed changes into the Plant Technical Specifications. The proposed change relocates the surveillance requirements for the Reactor Recirculation System MG Set Scoop Tube Stop setpoints to the Updated Final Safety Analysis Report. Changes in testing methodology are also proposed and are described in Enclosure 1. These changes will be implemented within 60 days of approval via LCR 97-088-OPL.
. provides a description and evaluation of the proposed changes. provides an analysis of the significant hazards consideration assessment using the standards in 10CFR50.92. provides marked up pages of the existing Technical Specifications to show the proposed changes and a typed version of the affected Technical Specification pages with the proposed changes incorporated.
4 Detroit Edison has evaluated the proposed Technical Specification change against the l
criteria of 10CFR50.92 and determined that no significant hazards consideration is involved. The Fermi 2 Onsite Review Organization has approved and the Nuclear i
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USNRC NRC-97-0037 Page 2 is involved. The Fermi 2 Onsite Review Organization has approved and the Nuclear Safety Review Group has reviewed the proposed Techmu' Specification change and concurs with the enclosed determinations. In accordance with "CFR50.91, Detroit Edison has provided a copy of this letter to the State of Michigan.
If you have any questions, please contact Mr. Steven M. Avila at (313) 586-4269.
Sincerely, Enclosures cc: A. B. Beach G. A. IIarris M. J. Jordan A. J.
Kugler Supervisor, Electric Operators, Michigan Public Service Commission J. R. Padgett
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'I, DOUGLAS R. GIPSON, do hereby affirm that the foregoing statements are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.
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.i DOUGLAS R/GIPSON Senior Vice President On this day of
/LO,1997 before me personally appeared Douglas R. Gipson, being fidt duly sworn and says that he executed the foregoing as his free act and deed.
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N'otary Public.
ROSALIE A. ARMElTA NOTARYPUBUC MONROECOUNTY,MI MYCOMMISSION EXP;RES10/11/99 Y
r j-NRC-97-0037 PageI l
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l ENCLOSUREI FERMI 2 NRC DOCKET NO 50-341 OPERATING I,1 CENSE NPF-43 REQUEST TO REVISE TECIINICAL SPECIFICATIONS:
RELOCATION OF RECIRCULATION MG SCOOP TUBE SETTING SURVEILLANCE DESCRIPTION AND EVALUATION OF Tile PROPOSED CIIANGES l
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. Enclosure !
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Page 2 BACKGROUND:
The proposed change involves relocating the requirements of Technical Specification (TS) Surveillance Requirement (SR) 4.4.1.1.2 to the Updated Final Safety Analysis Report (UFSAR) to correct an apparent conflict with TS surveillance requirements with no associated Limiting Condition for Operation (LCO). The conflict arises when the Recirculation Pump Motor-Generator (MG) set speed stops are considered inoperable without a related LCO requirement for operability since the TS only requires two recirculation loops to be "in operation." With no requirement to be
" OPERABLE" and thus no action requirement provided, this situation could be erroneously construed to require plant shutdown.
SR 4.4.1.1.2 requires that each recirculation pump MG set scoop tube mechanical and electrical stop be demonstrated OPERABLE with overspeed setpoints less than or equal to 110% and 107%, respectively, of rated core flow every 18 months. The adjustable scoop tube mechanism converts an electrical input signal from the speed controller into a mechanical scoop tube position. The positioner has both mechanical (stop block) and electrical (cam-operated switch) stops that limit recirculation flow by limiting the speed of the MG set. The electrical stop actuates first. The mechanical stop is set to prevent scoop tube motion if the electrical stop fails or to mitigate overshoot of the electrical stop. Additional description of the scoop tubes is in UFSAR Subsection 7.7.1.2.3.
In addition to relocating the surveillance requirement to the UFSAR, this amendment includes changes to the surveillance testing methodology. These changes include:
(1) eliminating any licensing basis requirement for the electrical stops, and (2) revising the periodicity from a calendar basis to a situational basis (i.e., plant conditions which would dictate a change in stop positions). Any future additional changes will be reviewed and implemented under the provisions of 10 CFR 50.59.
BASIS:
The purpose of the mechanical stop is to terminate a postulated reactor recirculation pump slow flow runout transient which is not terminated by a reactor scram (the design basis event for the Maximum Extended Operating Domain (MEOD) analysis documented in NEDC-31843P). This event stabilizes at a new core power level, corresponding to the maximum possible core flow along the Maximum Extended Load Line Limit (MELLL) rod line, which is dictated by the actual MG set scoop tube mechanical stop. The MG set scoop tube electrical stop is functionally similar but not redundant to the mechanical stop, and it is not credited for mitigating any accident or transient event. The mechanical stop ' protects the fuel cladding by limiting the reactor power increase which would result from a postulated increase in
NRC-97-0037 Page 3 recirculation flow, such that neither the one-percent plastic strain limit nor the Minimum Critical Power Ratio (MCPR) Safety Limit are violated. This analysis assumes that the core is being operated within the flow dependent limits for
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Maximum Average Planar Linear Heat Generation Rate (MAPLHGRr) and Minimum Critical Power Ratio (MCPRr), which are also dependent on the MG set -
i scoop tube' mechanical stop settings. Thus, although the verification of scoop tube stop setting is located in the Reactor Coolant System section of the TS, it is more correctly associated with the requirements for the MCPR Operating Limits and the APLHGR Limits.
l The MCPR Operating Limits and APLHGR Limits, which are specified on a cycle l
specific basis in the Core Operating Limits Report, are established such that f
postulated transients and accidents will not, as analyzed, result in the violation of a MCPR Safety Limit or other fuel thennal/ mechanical limits. Implicit in the establishment of the MCPR and APLHGR Limits is that the plant is operated and configured in accordance with the plant design and licensing basis contained in the UFSAR. Details of this configuration or routine activities needed to give reasonable j
assurance that the limits are satisfied is, in general, not maintained within the TS but i
rather within the UFSAR, which is controlled via the 10 CFR 50.59 process.
l This provides the flexibility for licensee control of these details under an appropriate framework of regulatory control. The TS requirement to operate consistent with the MCPR Operating Limits and APLHOR Limits provides adequate assurance that the plant will be operated consistent with adequate protection of the public health and safety. Additionally, the proposed relocation is consistent with the BWR Improved l
Standard Technical Specifier. tion, NUREG-1433, Rev i [ Reference 2], which has
- been approved by the NRC.
As previously discussed, this amendment also includes two changes with respect to the testing methodology in which the surveillance is performed. The bases for these changes are:
(1) Eliminating any licensing basis requirement for the electrical stops The proposed change to eliminate any licensing basis requirement for the electrical stops is based upon the electrical stops not being credited for mitigating any accident or transient event. The ftmetion of the electrical stop is l
similar but not redundant to the mechanical stop; however, it does not provide as L
effective 'a means of stopping an uncontrolled increase in reactor recirculation
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pump speed because it is still possible for the scoop tube positioner to drive through the brake that the electrical stop applies. Furthermore, the ability for the positioner to drive through this brake is a design requirement in order to reset i
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NRC-97-0037 Page 4 i
the brake's limit switch. The MEOD analysis only gives credit to the mechanical stops for terminating a postulated reactor recirculation pump slow i
flow rtmout transient, if not terminated by a reactor scram, i
(2) Revising the periodicity from a calendar basis to a situational basis i
The proposed change in periodicity from a calendar (i.e., once per 18 months) basis to a situational basis is based upon the fundamental assumption that the performance interval should coincide with the beginning of each new cycle because any change to the Recirculation System MG set speed versus core flow L
correlation would be expected to occur during a reload of new fuel or following i
maintenance.
i SIGNIFICANT HAZARDS CONSIDERATION In accordance with 10CFR50.92, Detroit Edison has made a determination that the L
proposed amendment involves no significant hazards considerations. To make this j
determination, Detroit Edison must establish that operation in accordance with the proposed amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. The significant hazards consideration assessment is presented in Enclosure 2.
ENVIRONMENTAL IMPACT Detroit Edison has reviewed the proposed Technical Specification change against the criteria of 10CFR51.22 for environmental considerations. The proposed change does not involve a significant hazards consideration, nor significantly change the types or significantly increase the amounts of effluents that may be released offsite, nor significantly increase individual or cumulative occupational radiation exposures.
Based on the foregoing, Detroit Edison concludes that the proposed Technical Specifications do meet the criteria given in 10CFR51.22(c)(9) for a categorical -
exclusion from the requirements for an Environmental Impact Statement.
CONCLUSION Based on the evaluation above: 1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and
- 2) such activities will be conducted in compliance with the Commission's regulations and proposed amendments will not be inimical to the common defense and security or to the health and safety of the public.
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NRC-97-0037 Page1 ENCLOSURE 2 FERMI 2 NRC DOCKET 50-341 OPERATING LICENSE NPF-43 REQUEST TO REVISE TECIINICAL SPECIFICATIONS:
10CFR50 6 ALUATION BASIS FOM SIGNIFICAN'l U.AZARDS DETERMINATION:
The proposed Technical Specification changes described in Enclosure 1 do not involve a significant hazards consideration for the following reasons:
- 1. The changes do not involve a s;gnincant increase in the probability or coasequences of an accident previously evaluated.
The proposed change removes from the Fermi 2 Technical Specifications (TS) a Surveillance Requirement (SR 4.4.1.1.2) that is an implementation detail and celocates it to the Updated Final Safety Analysis Report (UFSAR), where it is raore adequately and more appropriately controlled in accordance with 10 CFR 50.59. In addition, this proposed change revises the test me'thodology by: (1) eliminating the requirement for the electrical stops because they are not credited for mitigating any transients or accidents, and (2) revising the periodicity from a j
calendar basis to a situational basis to coincide with the beginning of each l
oprating cycle or post-maintenance. These changes do not eliminate the net essary testing of the MG set mechanical stops. The MG set mechanical stops wil' continue to remain operable because the recirculation pump MG set mechanical speed stop settings will continue to be maintaineci at or below the required limits. The MCPRrand MAPLHGRrlimits, along with the recirculation pump MG set mechanical speed stop settings on which they are based, are specified in the Core Oper-Gay Limits Report and operation within these limits is required by Technical Specifications 3.2.1 and 3.2.3. The changes described will therefore have no impact on the probability or consequences of an accident previously evahiated.
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- 2. The changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.
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The proposed Technical Specification change does result in any changes to the design (equipment / configuration) or operation of the plant and will thus not create a new failure mode or common mode failure. T : MG set mechanical sps will continue to operate as intended and as designed. These changes will i
therefore not create the possibility of a new or different kind of accident, from y
any accident previously evaluated.
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- 3. The changes do not involve a significant reduction in the margin of safety.
Changes in the methodology and frequency of testing will not involve a significant reduction in the margin of safety because the testing necessary to ensure the stops are set correctly will continue to be performed. Additionally, the MCPRrand MAPLHGRrlimits, along with the recirculation pump MG set mechanical speed stop setting that they are based on, are specified in the Core Operating Limits Report, anJ meration within these limits is still required by Technical Specifications 321 c.nd 3.2.3. Therefore, the margin of safety as defined in the bases of any Technical Specification is not reduced by relocating the surveillance requirement from the TS to the UFSAR. In addition to the above, relocation of the TS is consistent with the BWR Improved Standard Technical Specification, NUREG-1433, Rev.1.
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