2CAN129805, Submits Addl Info on TS Change Request Re Main Stream Safety Valves & Pressurizer Safety Valves,In Response to 981222 Conversation with NRC
| ML20198J713 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 12/22/1998 |
| From: | Vandergrift J ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 2CAN129805, TAC-MA2222, NUDOCS 9812300247 | |
| Download: ML20198J713 (3) | |
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g Entergy operations,Inc.
i It48 SR 333 RumelMEe. AR 72801 Tel 501858 5000 T
December 22,1998 2CAN129805 U. S.-Nuclear Regulaton Commission Document Coritrol Desk Mail Station OP1-17 l
= Washington, DC 20555
Subject:
Arkansas Nuclesr One - Unit 2 Docket No. 50 368 License No. NP F-6 Additional Iratirmation On Technical Specification Change Request Concerning The Main Steam Safety Valves And Pressurizer Safety Valves (TAC No. MAM 22)
Gentlemen:
By letter dated June 29,1998 (2CAN069804), Entergy Operations requested changes to the Arkansas Nuclear One, Unit 2'(ANO-2) technical specifications. The' proposed changes increase the allowable as-foin d lin setting tolerance on the main steam safety valves and pressurizer safety valves. In :n br.equent conversations with the NRC Staff on December 22, 1998, additional information ivas requested regarding the relationships of the requested model application to that previoasly reviewed and approved by the NRC StaE In the June 29, 1998 submittal, Entergy Operations provided information regarding application of Supple:nent 2-P-lL of CENPD-137, Calculative Methodsfor the ABB CE Small Beak Evaluation Model (/12M), to ANO-2. In this submittal we reported that the 2
2 revised analysis for ANC-2 usent break size spectrum of 0.02 ft to 0.06 ft. The results of the analysis conclude that the liraling biak size for the small break analysis was determined 2
to be 0.05 ft. However, specifi: tssumptians used in the analysis were not provided in the June 29,1998, submittal.
On~ Page 4 of 9 of the attachmeit to the June 29, 1998 submittal, Entergy Operations
. referenced a November 24,1996 re luest for the approval of a technical specification change for increasing steam generator tub e plugging limits using Supplement 1-P (SIM) of the CENPD-137. As part of the Noven w 24,1996 submittal, Entergy Operations also provided inputs and results of the S2M mokl along with that for the SIM model. As discussed on page 4 of 6 of the November 24,1995 attachment, the input parameters for the S2M analysis 2
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- were effectively the same as those t sed for the SIM analysis for the 0.05 R and 0.06 ft break sizes. As also discussed, th:32M evaluation used more conservt.tive high pressure t
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safety injection pump performance (lower flow rate) and included a +3% main steam safety valve lia setting tolerance (1125 psia). The assumptions used in the SIM analysis are 2
2 discussed on page 2 of 6 of the November 24,1996 letter. The 0.05 A and 0.06 A break sizes discussed therein utilize the more conservative low pressurizer pressure reactor trip and l
low pressurizer pressure SIAS parameters of 1400 psir., as discussed on page 3 of 6. The l
S2M analysis run for the June 29,1998, request is the same run as that which was referenced l
in the November 24,1996, submittal. The S2M peak clad temperature (PCT) results of 1798 2
degrees T represst.2 the same analysis performed in both submittals for the 0.05ft break.
In addition, the comparative results of the PCTs for different break sizes are discussed on l
page 4 of 6 in the attachment to the November 24,1996 submittal. This shows that the most 2
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limiting PCT for the S2M evaluation peaks between the 0.04 ft and the 0.06 A breaks which 2
is at or about 0.05 A. Section 6.3.3.2.3.5 of the ANO-2 Safety Analysis Report (SAR) states that breaks outside this range are either too small or are sufficiently large such that injection from the safety injection tanks will recover the core and terminate cladding heatup. This i
SAR statement is also consistent with the S2M evaluation. Therefore, it is concluded that l
additional break size considerations beyond that currently evaluated for 0.02 ft through 0.06 2
2 ft breaks are not necessary to bound the limiting condition.
Entergy Operations concludes that ANO-2 is in compliance with the five criteria of 10CFR50.46 for application of the S2M model. Criteria 1 through 3 were specifically addressed in the June 29,1998 submittal. Criterion 4 of 10CFR50.46 regarding coolable geometry is enveloped by acceptable results of Criteria 1 through 3. Criterion 5 for long-term cooling is unaffected by this revised evaluation for small break analyses.
l Please contact me if you have further questions.
ery truly you,
Jimmy. Vandergrift Directo, Nuclear Safety JDV b l
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U. S. NRC -
l December 22,1998 2CAN129805 Page 3 cc:
Mr. Ellis W. Merschoff Regional Administrator U. S. Nuclear Regulatory Commission RegionIV.
611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 NRC. Senior Resident Inspector Arkansas Nuclear One j
P.O Box 310 i
London, AR72847 i
l Mr. Chris Nolan NRR Project Manager Region IV/ANO-2
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U. S. Nuclear Regulatory Commission NRR Mail Stop 13-H-3 l-l One White Flint North l
11555 Rockville Pike Rockville, MD 20852 i
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