ML20247J728
| ML20247J728 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 09/13/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20247J724 | List: |
| References | |
| NUDOCS 8909200264 | |
| Download: ML20247J728 (8) | |
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' SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AfEIDENT NO. 42 TO FACILITY OPERATING LICENSE ND. WPF w. w 4
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1.0 INTRODUCTION
By letter dated April 3, 1989 (Ref. 1) and May 31, 1989 (Ref. 2), the Detroit Edison Company (DECO or the licensee) requested amendment to the Technical Specifications (TS) appended to Facility Operating License No. NPF-43 for
~ Fermi-2.
The proposed amendment would revise the TS and license for the operation of Fermi-2 during Cycle 2 (designated hereafter as F2C2) with a reload of General Electric (GE) manufactured fuel. assemblies and GE analyses and methodologies.
TS changes were also proposed to allow operation of Fermi Unit 2 with an Extended Load Line Limit Region (ELLLR).
Enclosed were the requested TS changes and reports discussing the reload and analyses performed to. support and justify Cycle 2 operation including the extended operating region with certain equipment out of service..The use of ELLLR includes limiting conditions of a reduction of feedwater temperature up to 50 deg F and core inlet subcooling less than 45 Btu /lb (existing operating constraints).
By letter dated August 23, 1989 the licensee submitted a revision to the GE report which supported results of transient analyses for operation with an ELLLR (Enclosure 1 to Reference 2).
The revised report provides additional discussion and_a figure which clarify operation with reduced final feedwater
-temperature; however, provisions for such operation are not included in the proposed amendment and the licensee has proposed no changes to the existing final-feedwater temperature constraints. The revised report also changes i gTable 2-1 of the original May 31, 1989 submittal to better describe thes
- I faitial core. conditions used in the analyses.
Finally, the revised report
,makes editoriafchanges to more clearly show that the FSAR transients ar's,
j hounding and corrects minor typographical'and numerical transcriptionierfors.
The. revised report in no way alters the substance or scope of the licpatee's M ioriginal appi cations for amendment or alters the conclusions drawn by.the C ' original R Therefore, the licensee's August 23, 1989 submittal upes N not represent s' modification to the original applications for amendmenti :
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The reload for F2C2 is generally a normal reload with no unusual core features or characteristics.
Proposed TS changes relate to Maximum Average Planar Linear i
Heat Generation Rate (MAPLHGR) and Linear Heat Generation Rate (LHGR) limits for the new fuel, Minimum Critical Power Ratio (MCPR) limits for all of the fuel using Cycle 2 core and transient parameters, extended operating regions and conditions, and editorial changes. The new fuel is the extended burnup type which has been approved for use in several recent GE reloads.
The staff review also acknowledges the licensee's response to NRC Bulletin 88-07, Supplement 1, which identifies GE interim stability recommendations for actions to ensure that the safety limit for MCPR is not violated in the event of regional core thermal-hydraulic oscillations.
No TS changes are presently proposed in connection with this aspect of the reload evaluation.
Further consideration of thermal-hydraulic stability will be given during a separate review in connection with operation in the single loop mode.
l 2.0 EVALUATION 2.1 Reload Description The F2C2 will retain 544 P8x8R GE fuel assemblies from Cycle 1 and add 220 new GE8x8EB fuel assemblies.
The reload is based on a previous end of cycle (E0C) core nominal average exposure of 9,515 MWD /ST and Cycle 2 EOC exposure of 14,769 MWD /ST.
The loading will be a conventional scatter pattern with low reactivity fuel on the core periphery.
2.2 Fuel Desien The new fuel for Cycle 2 is the GE extended burnup fuel GE8x8EB.
The fuel designations are BC318D and BC318E.
This fuel type has been approved in the Safety Evaluation for Amendment 10 to GESTAR-II (Ref. 3).
The specific descriptions of this fuel are presented for F2C2 in Reference 4.
These fuel descriptions are acceptable.
The proposed LHGR limit for the GE8x8EB fuel is 14.4 kW/ft rather than the 13.4 kW/ft for the other GE fuel in F2C2.
This LHGR limit has been reviewed and accepted in the GE extended burnup fuel review (Ref. 3).
This LHGR limit is acceptable for the GE8x8EB fuel in F2C2.
2.3 Nuclear Design The nuclear design for F2C2 has been performed by GE with the approved methodology described in GESTAR-II (Ref. 5).
The results of these analyses are I
given in the GE supplemental reload report (Ref. 4) in standard GESTAR-II l
format. The results are within the range of those usually encountered for BWR t
reloads.
In particular, the shutdown margin is 5.0% and 1.0% delta-k at beginning-of-cycle (BOC) and at the exposure of minimum shutdown margin, respectively, thus fully meeting the raquired 0.38% delta-k.
The Standby Liquid Control System also meets shutdosn requirements with a shutdown margin of 4.6% delta-k.
These and other F2C2 nuclear design parameters have been obtained with previously approved methods and fall within expected ranges.
Thus, the nuclear design is acceptable.
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2.4 Thermal-Hydraulic Design The thermal-hydraulic design for F2C2 has been performed by GE with the approved methodology described in GESTAR-II (Ref. 5) and the results are given in the reload report (Ref. 4). The parameters used for the analysis are those approved in Reference 5 for the Fermi-2 BWR-4 class except for the parameters listed in~ Appendix A of Reference 4.
The GEMINI system of methods (approved in Ref. 6) was used for the relevant transient analyses. Associated with this approval is the use of the GEXL-PLUS critical power correlation for cycle 2.
The Operating Limit MCPR (OLMCPR) values are determined by the limiting transients, which are usually Rod Withdrawal Error (RWE), Feedwater Controller Failure (fMCF), Loss of Feedwater Heating (LFH), and Load Rejection Without Bypass (LRWBP). The analyses of these events for F2C2, using the ODYN Options A and B approaches for pressurization transients, provide new Cycle-2 TS <alues of the OLMCPR as a function of average scram time, for operation in both standard and extended operating regions.
For F2C2 the licensee has elected, following standard practice (Section S.S.I.4 of Ref. 5), to have exposure-dependent OLMCPRs.
Three exposure regions from BOC to EOC were analyzed:
(1) BOC to EOC - 2000 MWD /ST, (2) EOC - 2000 MWD /ST to EOC - 1000 MWD /ST, and (3) EOC - 1000 MWD /ST to EOC.
For standard operating conditions, the load rejection without bypass (LRWBP) event is controlling at both Option A and Option B limits. To accommodate the extended operating region and equipment out-of-service conditions, the OLMCPR has been determined (Ref. 4) for these conditions also.
These OLMCPR results are reflected in TS changes.
Approved methods (Ref. 5) were used to analyze these events (and others which could be limiting) and the analyses and results are acceptable and fall within expected ranges.
Finally, the licensee has proposed MCPR limits for the Control Cell Core (CCC) Operational Mode. A Rod Withdrawal Error analysis was performed for both the CCC and non-CCC modes to determine separate OLMCPRs for standard operating conditions (no equipment out of service). The mort conservative non-CCC OLMCPR limits would only be in use when the plant has not been confirmed to be in the CCC operational mode.
This additional consideration includes a proposed Surveillance Requirement (TS Section 4.2.3) to verify the control rod status and mode.
The Safety Limit MCPR (SLMCPR) is set so that less than 0.1 percent of the fuel pins in the core are subject to boiling transition when some fuel in the core is at the SLMCPR. The SLMCPR is being changed to 1.07 for F2C2.
This change has been approved by the NRC for C-lattice cores operating with the second successive reload core of retrofit 8x8 fuel design (Section 4 of Ref. 5). The increase of 0.01 from the SLMCPR for the initial core loading is to account for additional uncertainties in the Traveling Incore Probe (TIP) readings and R-factors that normally occur in the second and subsequent cycles. The licensee has stated that all fuel types to be loaded for Cycle 2 operation (that is, P8x8R and GE8x8EB) are the retrofit 8x8 fuel types.
Thus the change to the SLMCPR is acceptable.
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The mean and standard deviation of the distribution for average scram insertion time used in the ODYN Option 8 analysis of operating limit MCPR are being changed. These new values are obtained from supplementary information regarding Amendment 11 to GESTAR-II (approved by the staff in Reference 6) which also discusses the use of the improved GEMINI /0DYN methodology in the derivation of Technical Specification MCPR operating limits.
For the expanded operating region, the GE report NEDC-31515 (Enclosure 1 to Reference 2) discusses a range of transient and accident events relevant to the region extension (identified as Extended Load Line Limit Region or ELLLR) and feedwater temperature reduction, and presents results of calculations or previously approved conclusions.
In addition, Enclosure 1 of the F2C2 reload report (Ref. 4) presents additional calculations of limiting MCPR transients specifically for F2C2. The transient analyses demonstrate that the licensing basis results. (e.g.,100 percent flow,102 percent power for pressurization transients) bound the ELLLR results (e.g., 87 percent flow,100 percent power).
These conclusions apply to all relevant MCPR events such as pressurization, rod withdrawal, and slow runout events.
Adoption of the ELLLR option does not in itself require additional changes to MCPR TS. Other relevant areas such as overpressure protection, LOCA and containment analyses have also been examined by the licensee, and the analyses indicate that the results are within allowable design limits. The analyses have been done with approved methodo-logies and the results are similar to previously approved ELLLR extensions for other BWRs. Thus operation within the ELLLR region is acceptable for Fermi-2 during Cycle 2.
Deco has included the recommendations of GE SIL-380 in the Fermi-2 operating procedures. However, due to the LaSalle 2 instability event and the continuing investigation regarding stability concerns, the licensee infomed the staff that Deco will implement the interim recommendations of the General Electric Company on stability (Ref. 7). Deco also responded to NRC Bulletin No. 88-07, Supplement 1, " Power Oscillations in BWRs" (Ref. 8). The licensee's response identified those Bulletin 88-07, Supplement I recommendations which have been implemented on Fermi-2. The present staff position is that additional TS for thermal-hydraulic stability are not required provided that the interim recommendations are followed.
The staff concludes that the licensee has addressed the concerns in a timely manner and is coordinating with the reactor vendor and the BWR Owners' Group. Thermal-hydraulic stability is the subject of a continuing review by the NRC staff, its consultants, the BWR Owners' Group, GE and others.
Any new requirements resulting from the continuing review, including single loop operation, will be applicable to Femi-2.
2.5 Transient and Accident Analyses The transient and accident analysis methodologies for F2C2 are described and NRC approval has been issued in GESTAR-II (Ref. 5). The GEMINI system of methods (Ref. 6) option was used for transient analyses. The limiting MCPR events for F2C2 are indicated in Section 2.4.
The core wide transient analysis methodologies are acceptable and the results fall within expected ranges.
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l The Rod Withdrawal Error (RWE) was analyzed on a plant and cycle specific basis (as opposed to a statistical approach) and a rod block monitor setpoint of 106%
was selected for all fuel types. The mislocated assexuly event is not analyzed for reload cores on the basis of NRC approved studies (see Section 5.2.2.3.6 of Ref. 5) indicating the small probability of such an event exceeding MCPR limits.
The disorientation event is not analyzed for C-lattice cores (Section S.2.2.3.7 of Reference 5). The local transient event analyses are thus acceptable.
Since Banked Position Withdrawal Sequence rod patterns are proposed for F2C2, a cycle-specific control rod drop accident analysis is not moutred. The basis for this position and NRC approval is presented in Section S.2.2.3.7 of Deference 5.
The limiting pressurization event for establishing overpressure protection margin, the main steam isolation valve closure event with flux scras, was analyzed with standard GESTAR-II methods and gave results for peak steam done and vessel pressures well under required limits. These are acceptable methodologies and results.
LOCA analyses, using methodologies approved in Reference 5 (SAFE /REFLOOD/ CHASTE) and parameters applicable to Fermi-2, were performed to provide MAPLHGR values for the new reload fuel assemblies (GE8x8EB).
These analyses and results are acceptable.
2.6 Changes to APRM and RBM Setpoints TheF2C2submittalpropsesanextensiontostandardoperatingregionsinthe GESTAR-II category of ' Operating Flexibility Options" (Section 5.5.2 of Ref.
5). The selected option is the Extended Load Line Limit (ELLL) which is j
described in Reference 2 for F2C2.
The reference and supporting GE report l
(Enclosure 1 to Reference 2) provide the results of transient analyses for setting new instrumentation trip setpoints for F2C2.
The proposed extended operating region changes the APRM flow-biased scram and rod block lines on the power-flow map, and permits operation up to the new APRM flow-biased rod block line (0.58W + 50%) and extending to the intersection with the 100 percent power line at a core flow of 87%.
In the above, W is the recirculation drive flow in percent of rated flow.
Similarly, the new APRM flow-biased scram line is given as (0.58W + 59%). These are standard changes for ELLLR and are acceptable for F2C2.
2.7 Technical Specification Changes The proposed TS changes for F2C2 associated with the reload and operating flexibility options are as follows:
2.7.1 TS 3.2.4 is changed to identify the 14.4 kW/ft LHGR limit for the new GE8x8E8 fuel. The change is acceptable as discussed in Section 2.2 of this Safety Evaluation (SE).
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2.7.2 TS 3/4.2.b, Figures 3.2.3-1, 3.2.3-1A and 3.2.3-1B are changed to identify the new MCPR limits for Cycle 2 operation. These chang s are acceptable as discussed in Section 2.4.
TS 4.2.3.2 is added to identify surveillance to verify the conditions for the CCC operational mode.
2.7.3 TS 3/4.2.1, Figure 3.2.1-3 and Figure 3.2.1-4 are changed to identify MAPLHGR limits for the new fuel and are accaptable as discussed in SE Section 2.5.
2.7.4 Table 2.2.1-1, TS 3.2.2 and Table 3.3.6-2 are changed to identify the new ELLLR APRM flow-biased scram and rod block setpoints. These changes are acceptable as discussed in SE Section 2.6.
2.7.5 Figure 3.2.3-2 is changed to modify the flow correctich factor curve for use with the approved GEXL-PLUS correlation. This is a required change related to CPR and is acceptable.
2.7.6 In Section 1.0 of the TS, (a) the CRITICAL POWER RATIO definition is rewritten to generalize the identification of the critical power correlation from "GEXL" to "an NRC approved critical power" correlation; and (b) the RATED THERMAL POWER definition is changed from 3292 MWt to 3293 MWt. This reflects the analysis assumption in the licensing basis of the plant. Thisalsoeffectsparagraph2.C.(1) of the Facility Operating Licease.
These changes are acceptable.
2.7.7 Section 2.1.2, THERFAL POWER, is changed to identify the safety limit MCPR of 1.07. This is a required change for reload cycles for fermi 2 and is acceptable as discussed in SE Section 2.4.
2.7.8 Section 4.1.4.1, CONTROL R0D PROGRAM CONTROLS, is changed to identify the approved Banked Position Withdrawal Sequence which is acceptable as discussed in SE Section 2.5.
2.7.9 Section 5.3.1, FUEL ASSEMBLIES, is changed to identify the use of generically-approved fuel designs identified in GESTAR-II (Ref. 5).
2.7.10 The BASES Sections for the proposed changes are being modified to correctly reflect the new Safety Limits, Limiting Conditions for Operation, and Surveillance Requirements. These changes are acceptable.
2.7.11 The BASES for the core thermal-hydraulic and physics analyses reference the GE topical report " General Electric Standard Application for Reactor Fuel", NEDE-24011-P-A in a number of sections. This topical report has been subject to periodic revision by GE, Changes to the topical report have been approved by the NRC. Wherever this is referenced in the BASES l
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the words " latest-approved version" are considered to refer to-the most recently approved version (Reference 5 in this-x f
evaluation). There are also changes to the BASES in certain sections to' eliminate information that is redundant to the topical report (GESTAR-II). These changes will eliminate the
- need to change the date on the references if the referenced
. topical-report is revised. This approach has been adopted by most licensees and is endorsed by the staff.
2.8 CONCLUSION
S-DECO has requested TS changes for Femi-2 which would allow operation during Cycle 2 with General Electric fuel assemblies of an approved extended burnup design and with an extended operating region.
The staff has reviewed the report submitted for the Cycle 2 operation of Fermi-2 with an extended operating region. Based on this review the staff concludes that appropriate material has been submitted and that the fuel design, nuclear design, thermal-hydraulic design and transient and accident analyses are acceptable.
2.9 REFERENCES
1.
Letter (NRC-89-0052)~fromB.RalphSylvia(DEC)toDocumentControlDesk (USNRC) dated April 3,1989 transmitting a Proposed Operating License /
Specifications Change (License Amendment) - Cycle 2 Reload Submittal.
2.
-Letter (NRC-89-0115) from B. Ralph Sylvia (DEC) to Document Control Desk (USNRC) dated May 31, 1989 transmitting Proposed Tec'nnical Specification Changes to Allow Operation with an Extended Operating Domain.
i 3.
Letter (and attachment) from C. Thomas (NRC) to J. Charnley (GE) dated May 28, 1985, " Acceptance for Referencing of Licensing Topical Report NEDE-24011-P-A-6, Amendment 10."
.4.
GE Report 23A5949 Revision 0, dated March 1989, " Supplemental Reload Licensing Submittal for Fermi Power Plant Unit 2 Reload 1, Cycle 2."
5.
GESTAR-II, NEDE-24011, Revision 9 " General Electric Standard Application for Reactor Fuel."
6.
Letter (andattachment)fromG.Lainas(NRC)toJ. Charnley (GE), dated March 22,1986, " Acceptance for Referencing of Licensing Topical Report NEDE-24011-P-A 'GE Generic Licensing Reload Report' Supplement to Amendment 11".
7.
NRC Bulletin No.88-007, Supplement No.1 " Power Oscillations in Boiling Water Reactors (BWRs)," dated December 30, 1988.
8.
Letter (NRC-89-0049) from B. Ralph Sylvia (DEC) to Document Control Desk (USNRC)datedMarch 10, 1989,
Subject:
Response to Supplement I to NRC Bulletin 88-007.
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3.0 ENVIRONMENTAL CONSIDERATION
Pursuant to 10 CFR 51.21, 51.32 and 51.35, an environmental assessment and finding of no significant impact have been prepared and published in the
{
Federal Register on September 12, 1989 (54 FR 37736).
Accordingly, based upon the environmental assessment, we have determined that the issuance of this amendment will not have a significant effect on the quality of the human environment.
4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the pubite 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 the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
M. McCoy Date:
September 13, 1989