ML20217A545
| ML20217A545 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 03/18/1998 |
| From: | Muench R WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| ET-98-0021, ET-98-21, NUDOCS 9803250104 | |
| Download: ML20217A545 (6) | |
Text
...
, c W$LF CREEK NUCLEAR OPERATING CORPORATION Richard A. Muench Vice Preplant Engineering 1
March 18, 1998 ET 98-0021 U. S. Nuclear Regulatory Commission ATTN:
Document Control Denk Mail Station Pl-137 Washington, D. C.
20555 f
Subject:
Docket No.
-482:
10 CFR 50.46 Annual Report of I
ECCS Model Changes I
Gentlemen:
This letter describes changes to the Emergency Core Cooling System (ECCS)
Evaluation Models and the estimated effect on the limiting ECCS analysis for Wolf Creek Generating Station (WCGS) for 1997.
This letter is provided in accordance with the criteria and reporting requirements of 10 CFR i
- 50. 4 6 (a) ( 3) (1) and (11),
as clarified in Section S.1 of WCAP-11451,
" Westinghouse Methodology for Implementation of 10 CFR 50.46 Reporting."
The chanijon in calculated Peak Cladding Temperatures (PCT) caused by the changes to Westinghouse ECCC Evaluation Models are reportable per 10 CFR 50.46.
Wolf Creek Nuclear Operating Corporation (WCNOC) has reviewed the annual 10 CFR 50.46 summary report of ECCS Evaluation Model changes that were implemented by Westinghouse during 1997.
The report concludes that there are no reportable Peak Clad Temperature (PCT) impacts for the NOTRUMP and BASH evaluation model analyses associated with the WCGS for 1997.
The attachment contains the calculated Large Break LOCA and Small Break LOCA PCT margin allocations resulting from the permanent changes to the evaluation models.
Since the PCT values determined in the Small Break and Large Break LOCA analyses of record, which, combined with all the PCT margin allocations, j
remain-well below the 2200 degrees Fahrenheit regulatory limit, nr. rearalysis will be performed.
I i
60 9003250104 900"I153 PDR ADOCK 05000482 I
P PDR PO. Dox 411/ Durhngton, KS 06839 / Phone: (316) 364-8831 An Equal Opporturuty imployer WF/HC/ VET
ET 98-0021 en Pags 2 of 2 If you have any questions concerning-this matter,' please call me.at (316) 364-8831, ext'ension-4034, or Mr. Michael J. Angus at extension 4077 Very truly yours,
- w, Richa d A. Muench RAM /jad-
' Attachment-
=cc:
E. W. Merschoff (NRC), w/a W.
D.
Johnson (NRC), w/a J. F. Ringwald (NRC), w/a K,, M. Thomas (NRC), w/a 1
o J
1 1
.l Attachment'to ET 98-0021.
. 7 ?.'; '
Page 1 of 3
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i ATTACHMENT ECCS EVALU/ TION :ODEL PEAK CLAD TEMPERATURE (FCT)
MARGIN ASSESSMENTS
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'e Attachment to ET 98-0021 Page 2 of 3 l
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- SMALL BREAK PEAK CLAD TEMPERATURE (PCV') MARGIN UTILIZATION ***
Evaluation Model:
1995 EM with NOTRUMP ruel:
17X17 V5H w/IFM, non-IFBA 275 psig Peaking Factor:
FO-2.50, FdH=1.65 SG Tube Plugging:
10%
Pcwer Level:
3565 MWth Limiting transient:
3-inch Break A. ANALYSIS OF RECORD (Rerating 8/92)
Peak Cladding Temperature (PCT):
1510 F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS APCT = 31 F
.C.
10 CFR 50.59 SAFETY EVALUATIONS
- 1. Loose Parts APCT =
45'F
- 2. C):le 10 Fuel Assembly Design Changes APCT =
1*F (1)
- 2. Reduced Feedwater Inlet Temperatuto APCT =
10*F
- 4. Fuel Rod Crud APCT =
4*F TOTAL 10 CFR 50.59 SMALL BREAK ASSESSMENTS APCT =
60*F D.
1997 10 CFR 50.4 6 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)
- 1. None APCT =
0,F L
E. TEMPORARY ECCS MODEL ISSUES
- 1. None APCT = 0F i-F. OTHER MARGIN ALLOCATIONS
- 1. Cold Leg Streaming Temperature Gradient APCT = 7F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1608 F Notes:
_(1)
A detailed evaluation of the impacts of fuel design changes on the small break LOCA analysis was provided in WCNOC's license amendment application to revisc WCGS Technical Specification Gection 5.3.1, Fuel Assemblies.
The NRC issued Ateendment N o.' 110 to the Wolf Creek Generating Station Technical Fpecifications on September 22, 1997, to allow fuel rods to be constructed with ZIRLO and to allow fuel assembly reconstitution with Zirconium alloy, i.e.,
Zirealoy or ZIRLO.
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..* Attachment to ET 98-0021
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'Page-3 of 3 l
I Evaluation Model:
1981 EM with BASH j
Fuel:
17X17 V5H w/IFM, non-IFBA 275 psig Peaking Factor:
FQ-2.50, FdH-1.65
-]
SG Tube Plugging:
10%
l Power Level:
3565 MWth 1
Liniting transient:
Co=0.4, Min. SI, Reduced Tavg A. ANALYSIS OF RECORD (Rerating 8/97)
Peak Cladding Temperature (PCT) 1916 F B. PRIOR PE!WANENT ECCS MODEL ASSESSMENTS APCT =
0F C.
10 CPR 50.59 SAFETY ENALUATIONS
- 1. Loose Parts APCT =
20*F
- 2. Containment Purge Evaluation APCT =
0*F
- 3. Cycle 10 Fuel Assembly Design Changes APCT =
95*F (3)
TOTAL 10 CFR 50.59 LARGE BRElsK ASSESSMENTS APCT = 115 F D.
1997 10 C."R 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)
- 1. None APCT =
0,F E. TEMPORARY ECCS MODEL ISSUES APCT =
0F F. OTHER MARGIN ALLOCATIONS
- 1. Transition Core (STD to V5H)
APCT = 50 F(2)
- 2. Cold Leg Streaming Temperature Gradient APCT =
0 F(1)
LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 2081 F Nottps :
(1) A PCT benefit of < 2.5 F was assessed; however, a benefit of O'F will be tracked for reporting purposes.
(2) Transition care penalty applies on a cycle-t.pecific basis for reloads utilizing both V5H (with IFMs) and STD fuel until a full core of V5H is achlaved.
.(3)
A 95'F PCT margin was allocated to Fuel Assembly Design Cnanges which were implemented in Cycle 10.
A detailed evaluation of the impacts of fuel design changes on the large break LOCA analysis was provided in WCHOC' s license amendment application to revise Wolf Creek Generating. Station Technical
~ Specification Section 5.3.1, Fuel Asse:r.blies.
The NRC issued Amendment No. 110 to the. Wolf Creek Generating Station Technical Specifications on September 22, 1997, to. allow fuel rods to be constructed with ZIRLO and to allow fuel assembly reconstitution with Zirconium alloy, i.e.,
I