ML20088A549
| ML20088A549 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 04/04/1984 |
| From: | William Jones OMAHA PUBLIC POWER DISTRICT |
| To: | John Miller Office of Nuclear Reactor Regulation |
| References | |
| LIC-84-098, LIC-84-98, NUDOCS 8404120197 | |
| Download: ML20088A549 (5) | |
Text
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1 Omaha Public Power District l
1623 Harney Omaha. Nebraska 68102 l
402/536 4000 l
April 4, 1984 LIC-84-098 Mr. James R.
Miller, Chief U.
S.
Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Licensing Operating Reactors Branch No. 3 Washington, D.C.
20555
Reference:
Docke t No. 50-285
Dear Mr. Miller:
Fort Calhoun Station Cycle 9 Core Reload Submittal Attached is Omaha Public Power District's response to your request for additional information dated March 22, 1984 concerning the Fort Calhoun Station's Cycle 9 core reload submittal.
This infor-mation was requested by your staff to enable them to continue their review of the Cycle 9 reload facility license change appli-cation.
Sincerely, N NM W.
C. Jones Divisi'on Manager Production Operations WCJ/JJF:jmm Attachment cc:
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, D.C.
20036 Mr.
E.
G.
Tourigny, Project Manager Mr.
L.
A.
Yandell, Senior Resident l
Inspector M
8404120197 840404 l
DR ADOCK 05000 85 f
ff 45 5124 Employment with Equal Opportunity Maleffemale
ATTACHMENT NRC Question 1:
What was the EFPY when the unit shut down at the end of Cycle 8?
Response
6.77 EFPY NRC Question 2:
Results of the evaluation of Surveillance Capsule W-265 were referenced. However, the report was not submitted.
When does the licensee plan to submit the report per 10 CFR 50, Appendix H?
Response
The Surveillance Capsule W-265 final report is currently in the process of being printed and bound. The District expects to submit this report to the Commission in April.
NRC Question 3:
A)
What material is in weld metal block 5 and block 3 heat af fected zone?
B)
Were they fabricated from materials used in making of the Fort Calhoun beltline?
C)
Are there base line tests data for these naterials?
Responses:
A)
The material in weld block 5 and block 3 heat affect-ed zone is material fabricated as part of the Fort Calhoun reactor vessel materia.s irradiation surveil-lance program which was archived by the District.
Further information concerning this material is con-tained in Reference 1.
B)
These materials were fabricated from materials used in making the beltline of the Fort Calhoun reactor vessel.
C)
There are baseline test data for these materials.
This information is contained in Reference 2.
In addition, material from the manufacturer of these capsules was retained for further benchmarking.
NRC Question 4:
What is the AT bebdeen (the reactor vessel) metal 1/4T and Tw and 3/4T and Tw at (a heatup rate of) 100'F/ hour?
Response
The AT between 1/4T and Tw for the heatup curve was zero.
For the case of heatup, the thermal stresses are opposite in sign from the pressure stresses. Therefore, it is con-servative, when calculating KIR, to assume an isothermal heatup (KIT equal to zerf. A correction from the 1/4T location to the reactor sel fluid is not made for the heatup case because there is no thermal gradient through the reactor vessel wall for the isothermal condition.
If thermal stresses were taken into consideration for heatup (non-isothermal), the reactor vessel fluid temperature would be higher than the reactor vessel 1/4T wall temper-ature because the vessel wall lags the fluid temperature
i during a change in fluid system temperature. The curves are based on an isothermal heatup and are found to be con-servative as compared to similar heatup curves that account for thermal stresses and a fluid temperature cor-rection due to the temperature gradient in the reactor vessel wall.
The tit between 3/4T and Tw was not calculated because the 3/4T location was not considered in the generation of the heatup curves. The basis for the Fort Calhoun Station Technical Specifications is a crack sized in accordance with Section III, Appendix G, of the ASME Code which ex-tends from the inner surface to the 1/4T location. There-fore, calculations were not perfomed at the 3/4T loca-tion.
NRC Question 5:
What is the RTNDT at the 3/4T Location?
Response
Fluence
- RTNDT**
Basis (n/cm2)
( F) m.
3 B0C to E0C7 1.5 x 1018 174 BOL to 8.5 EFPY assuming 30% fluence reduction following Cycle 7 2.0 x 1018 185 Peak fluence axial and azimuthal locations Adjust RTNDT( F) = -56 + 283 (1/1019)0.194 + 34 The 1/4T fluence and RTNDT are discussed in the basis section of the proposed Technical Specification.
i NRC Question 6:
The 2/14/84 application refergnces an end of life vessel ID fluence of 3.6 x 1019 n/cm on pages 2-4, 2-5, and 2-6.
However,19 n/cm.the jugtification contained in Attachment B uses 4.8 x 10 c
In addition, the licensee answers dated 1/27/84 to questions posed in another license ammeng9ment request (R. V. Surveillance Capsules) used 4.8 x 10 n/cm2 Which fluence is correct?
Response
Both values are correct as they are described. The 4.8 x 1019 n/cm2 value represents the end of life (E0L) fluence based on a linear extrapolation of the BOL to EOC7 fluence calculated for the W-265 surveillance capsule removed at the end of Cycle 7 (E0C 7). Data from this capsule indicated a reactor vessel wall fluence of 0.88 x 1019 n/cm2 Beginning with Cycle 8, the District implemented a low leakage fuel management program which guarantees a vessel flux reduction of at least 30%. Therefore, based on an EOC7 fluence distribution resulting from standard fuel. management, and a 30% flux reduction resulting from low leakage fuel management for Cycle 8 through E0L, the
EOL fluence is projected to be 3.6 x 1019 n/cm2
- Thus, the E0L fluence used in the Technical Specifications is correct. The 4.8 x 1019 n/cm2 EOL fluence is also cor-rect, as described, but does not reflect the E0L fluence based on the current fuel management strategy.
i rh/J
REFERENCES 1.
TR-0-MCM-001, Revision 1, Evaluation of Irradiated Capsule W-225, Augus t, 1980.
2.
TR-0-MCD-001, Evaluation of Baseline Specimens, March,1977.
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