ML17262A428
| ML17262A428 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 03/22/1991 |
| From: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
| To: | Andrea Johnson NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9104030150 | |
| Download: ML17262A428 (7) | |
Text
ACCELERATED DISTRIBUTION DEMONSTPA.TION SYSTEM r,
h REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
CCESSION NBR:9104030150 DOC.DATE: 91/03/22 NOTARIZED: NO FACIL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G
AUTH.NAME AUTHOR AFFILIATION MECREDY,R.C.
Rochester Gas 6 Electric Corp.
RECIP.NAME RECIPIENT AFFILIATION JOHNSON,A.R.
Project Directorate I-3
SUBJECT:
Forwards annual rept of ECCS model revs as applicable to facility,per 10CFRS0.,46.Info provides effects of ECCS evaluation model mods on large' small bxcak LOCA analysis.
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TITLE: OR Submittal:
General Distribution NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72)'.
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S'ECIPIENT ID CODE/NAME PD1-3 LA JOHNSON,A INTERNAL: NRR/DET/ECMB 9H NRR/DOEA/OTSB11 NRR/DST/SELB 8D NRR/DST/SRXB 8E 0
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~zzzziis ROCHESTER GAS AND ELECTRIC CORPORATION 0
e9 EAST AVENUE, ROCHESTER N.Y. 14649-0007 ROBERT C MECREOY Vice President Cinna Nuclear Production March 22, 1991 TELEPHONE AstEAcooE 7 te 546-2700 TJ.S. Nuclear Regulatory Commission Document Control Desk Attn:
Allen R. Johnson Project Directorate I-3 Washington, D.C.
20555
Subject:
10CFR50.46 Annual Report ECCS Evaluation Model Revisions R.E.
Ginna Nuclear Power Plant Docket No. 50-244
Reference:
RG&E letter from R. C. Mecredy to A. R. Johnson (NRC),
"10CFR50.46 Annual Report," dated March 28, 1990.
Dear Mr. Johnson:
This letter provides the annual report of. Emergency Core Cooling System (ECCS) model revisions as they apply to R. E. Ginna.
The attachment to this letter provides information regarding the effects of the ECCS evaluation model modifications on the Ginna large and small break LOCA analysis.
For completeness, the effects of 10CFR50.59 evaluations has also been included.
Since the submittal of Reference 1, large break LOCA peak clad. temperature (PCT) has increased by 1
to 1890'nd small break LOCA PCT has increased by 55'o 1147'.
Very truly yours, RWE/147 Attachment Robert C. Mecredy
~ xc: Mr. Allen R. Johnson (Mail Stop 14D1)
Project Directorate I-3 Washington, D.C.
20555 U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA, 19406 Ginna Senior Resident Inspector
)o go~
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~0 9104030150 910322 PDR ADQCK 05000244 R
ATTACHMENT TO 10CFR50.46 ANNUAL REPORT Reference 1 presented the changes in PCT for both large and small break LOCA analysis through 1989.
The following summarized the changes in PCT for 1990.
PCT changes are presented for evaluation model modifications, 10CFR50.59 evaluations, and. margin temporarily allocated by Westinghouse for potential issues related to the ECCS Evaluation Model.
When the potential issues are resolved.
the temporarily allocated margin will either become permanent or dismissed depending upon the. resolution.
LARGE BREAK LOCA - EVALUATIONMODEL MODIFICATIONS None.
LARGE BREAK LOCA - 10CFR50.59 SAFETY EVALUATION
~ Reference 2 approved.
an amendment to the Ginna Operating License that allowed uses of reconstituted fuel assemblies.
The effect of reconstituted fuel assemblies on the LOCA analysis was estimated in Reference 3 to be approximately 0.5'.. Therefore, a
conservative PCT penalty of + 1.0'as been assigned for use of reconstituted. fuel.
LARGE BREAK LOCA POTENTIAL ISSUES Several potential issues are being evaluated. by Westinghouse.
The issues that apply to Ginna are:
fuel rod. initial condition inconsistency, LOCA power distribution assumption, and steam generator seismic/LOCA assumption.
The total temporary PCT margin assigned to these issues for Ginna is 160'.
Table 1 summarizes the large break LOCA PCT margin assessment.
SMALL BREAK LOCA - EVALUATIONMODEL MODIFICATIONS'one.
~ 59 SAFE.Z EVALUATION' A safety evaluation of the effect of purging the steam generator auxiliary feedwater piping of the residual main feedwater during a small break LOCA was performed internal to Westinghouse.
As reported in Reference 4, this evaluation determined that the small break LOCA analysis PCT results for Ginna could increase up to 11~.
~
A safety evaluation was performed,.
based on Reference 5
to increase the feedwater isolation time from 5 sec. to 10 sec.
The effect of the increase in isolation time on small break LOCA was evaluated.
The evaluation accounted for the PCT penalty associated with the additional secondary side energy as a result of the delayed valve closure and. the benefit of the additional subcooled feedwater liquid. due to the delayed closure.
The net result using an energy balance calculation was a PCT penalty of 43'.
~ Reference 2 approved an amendment to the Ginna Operating License that allowed. uses of reconstituted fue1 assemblies.
The effect, of reconstituted.
fuel assemblies on the LOCA analysis was estimated in Reference 3 to be approximately 0.5'.
Therefore, a
conservative PCT penalty of + 1.0'as been assigned for use of reconstituted fuel.
SMALL BREAK LOCA POTENTIAL'SSUES Several potential issues are being evaluated by Westinghouse.
The issues that apply to Ginna are:
fuel rod initial. condition inconsistency and rod internal pressure assumption.
The total temporary PCT. margin assigned to these issues for Ginna is 65'.
Table 2 summarizes the small break LOCA PCT margin assignment.
CONCLUSIONS The large break and small break LOCA total PCTs exhibit continued margin to the 10CFR50.46 PCT limit of 2200'.
REFERENCES 1.
RG&E letter from R.
C.
Mecredy to A.
R.
Johnson (NRC),
"10CFR50.46 Annual Report," dated March 28, 1990.
2.
NRC letter from A.
R.
Johnson to R.
C.
Mecredy (RG&E),
"Issuance of Amendment No. 39 to Facility Operating License No.
DPR-18-R.
E. Ginna Nuclear Power Plant," dated. April 12, 1990.
3.
Safety Analysis, "Cycle 20 Core Loading Pattern,"'WR
- 5021, Rev.
1, dated April 27, 1990.
4.
Westinghouse letter RG&E-89-693 from S.
P.
Swigart to G. J.
Wrobel (RG&E)
"Report of ECCS Evaluation Model Revisions,"
dated December 20, 1989.
5.
Westinghouse letter RGE-90-520 from. S.
P.
Swigart to R.
W.
Eliasz (RG&E),
"Evaluation to Support Increased Feedwater Isolation Delay Time," dated, February 5, 1990.
TABLE 1 10CFR50.46 PCT MARGIN ASSESSMENT LARGE BREAK LOCA ANALYSIS OF RECORD
(Ref.
1) b.
10CFR50.59 SAFETY EVALUATIONS (Permanent Assessment. of PCT Margin)
PCT = 1887~
PCT = +
2'PCT=+
1'ICENSING BASIS PCT = 1890 POTENTIAL ISSUES (Temporary Use of PCT Margin)
~ Fuel rod initial condition inconsistency
~
LOCA power distribution assumption
~
SG tube seismic/LOCA assumption Total i PCT = +
160'ICENSING BASIS PCT + TEMPORARY ALLOCATED PCT = 2050
TABLE 2 10CFR50.46 PCT MARGIN ASSESSMENT SMALL BREAK LOCA ANALYSIS OF RECORD
(Ref. 1) b.
10CFR50.59 SAFETY EVALUATIONS (Permanent Assessment of PCT Margin)
PCT =
1092'CT= 0 PCT = +
55'ICENSING BASIS PCT = 1147 POTENTIAL ISSUES (Temporary Use of PCT Margin)
~ Fuel rod initial condition inconsistency Rod internal pressure assumption Total
~ PCT = +
65'ICENSING BASIS PCT + TEMPORARY'LLOCATED PCT' 1212
V