ML20045C975
| ML20045C975 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 06/23/1993 |
| From: | Shiraki C Office of Nuclear Reactor Regulation |
| To: | Farrar D COMMONWEALTH EDISON CO. |
| References | |
| TAC-M84422, TAC-M84423, NUDOCS 9306250175 | |
| Download: ML20045C975 (4) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION:
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June 23, 1993
' Docket Nos. 50-295 and 50-304 i
Mr. D. L. Farrar Manager, Nuclear Regulatory Services Commonwealth Edison. Company Executive Towers West III, Suite 500 1400 OPUS Place Downers Grove, Illinois 60515
Dear Mr. Farrar:
SUBJECT:
ZION NUCLEAR POWER STATION UNITS 1 AND 2, REACTOR VESSEL UPPER SHELF ENERGY (TAC N05. M84422 AND M84423) 1 By letter dated May 11, 1992, Commonwealth Edison submitted a Babcock and Wilcox Owners Group (B&WOG) Materials Committee Report, titled'" Low Upper-Shelf Toughness fracture Analysis of Reactor Vessels of Zion Units 1 and 2 for Load Level A & B Conditions," for-staff review and approval.
The-report describes the analysis of the reactor pressure vessels of Zion Units 1 and 2
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and is intended to demonstrate-through fracture mechanics analysis that there' exist margins of safety against fracture equivalent to?those required by.
Appendix G of-ASME Code Section-lli, for those beltline welds.having Upper-Shelf Energy (USE) values below the screening criterion of 50 ft-lb.
1 The staff, with assistance from Oak Ridge National Laboratory, has completed a; preliminary review of _this report'and has determined that additional information is required to' complete its review.
Ceco is requested to respond.
to the following request for additional information within 30 days of' receipt of this letter:
1.
Report BAW-2148P,-Revision 1 indicates that the Atypical Weld is not the limiting weld for both Zion Units 1 and 2, and does not need to be addressed in this~ report.
To firmly establish this point, provide the following information:
'e The Charpy curve and the analysis used in determining the USE of 79 ft-lb for the Atypical Weld listed in Table 2-2.
The hours of stress relief received by test specimens of the WF70 j
and the Atypical. Weld, and the hours of stress relief received by.
the corresponding vessel beltline welds.
j A. plot showing the comparison of J-R model curves for Weld WF70 and
.i the Atypical Weld, along with the experimentalidata.
If some data i
for WF-209 specimens taken from Capsule CR-3 and tested in 1990 are pertinent to the Atypical Weld, then they:should be' supplied..If
.d the Atypical. Weld has~any correspondence with'the HSST 60. series I
welds, they should be identified.
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Mr. D. L. Farrar 2.
The report indicates that a method other than that in Regulatory Guide 1.99, Revision 2 was used for calculating fluence at a quarter thickness from the fluence at the inside surface.
This method should be provided and its use justified.
3.
A complete list of input parameters and conditions for the thermal ua analysis leading to Kn - 21 ksi.in should be supplied.
This includes specific heat, thermal' conductivity, density, the resulting value of thermal diffusivity, coefficient of thermal expansion, elastic modulus and Poisson's ratio (for both cladding and base metal); also the time history of the heat transfer coefficient and fluid temperature.
Provide the corresponding Kn by using the currently proposed equation in Appendix X.
4.
Table 4-2 of the report shows that 17 weld metals were included in the data base used to develop the J-R correlation model.
A corresponding table, Table 4-2, in BAW-2118P shows 23-weld metals instead.
It should be confirmed that there is only one correlation model applicable to all B&W Owners Group plants.
5.
The legends that appear in Figures 5-1 through 5-10 of the report are not readable, and clear replacement copies should be supplied.
Please contact me at (301) 504-3101 if you have any questions.
Sincerely, Orinina! S cnM By:
Clyde Y. Shiraki, Senior Project Manager Project Directorate III-2 Division of Reactor Projects lil/IV/V Office of Nuclear Reactor Regulation cc:
See next page DISTRIBUTION Docket File NRC & Local PDRs PDIll-2 r/f JRoe JZwolinski JDyer CMoore CShiraki OGC ACRS(10)
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Mr. D. L. Far'ar Zion Nuclear Power Station r
. Commonwealth' Edison. Company Unit Nos. I and 2
-cc:
Michael I.: Miller, Esquire Sidley and Austin One First National Plaza i
Chicago,. Illinois 60603 Dr. Cecil Lue-Hing Director.of Research and Development.
' Metropolitan Sanitary District of Greater; Chicago I
100 East Erie Street Chicago, Illinois 60611 Phillip Steptoe, Esquire Sidley and-Austin One First National Plaza Chicago, Illinois 60603 Mayor of.' Zion Zion, Illinois 60099 Illinois-Department of Nuclear Safety Office of-Nuclear facility Safety 1035 Outer Park Drive Springfield, Illinois' 62704 U.S. Nuclear Regulatory Commission Resident' Inspectors Office 105 Shiloh Blvd.
Zion, Illinois 60099 Regional Administrator, Region Ill U. S. Nuclear Regulatory Commission 799 Roosevelt Road, Bldg. #4 Glen Ellyn, Illinois 60137 Robert Neumann Office of Public Counsel State of Illinois Center i
~100 W. Randolph Suite 11-300 q
-Chicago, Illinois 60601
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4 Mr. D. L. Farrar 2.
The report indicates that a method other than that in Regulatory Guide 1.99, Revision 2 was used for calculating fluence at a quarter thickness from the fluence at the inside surface.
This method should be provided and its use justified.
3.
A complete list of input parameters and conditions for the thermal V2 analysis leading to Kn - 21 ksi.in should be ' supplied.
This includes specific heat, thermal conductivity, density, the resulting value of thermal diffusivity, coefficient of thermal expansion, elastic modulus and' Poisson's ratie (for both cladding and base metal); also the time history of the neat transfer coefficient and fluid temperature.
Provide the corresponding Kn by using the currently proposed equation in Appendix X.
~
4.
Table 4-2 of the report shows that 17 weld metals were included in the data base used to develop the J-R correlation model.
A corresponding table, Table 4-2, in BAW-2118P shows 23 weld metals-instead.
It should be confirmed that there is only one correlation model applicable to all B&W Owners Group plants.
5.
The legends that appear in Figures 5-1 through 5-10 of the report are not readable, and clear replacement copies should be supplied.
Please contact me at (301) 504-3101 if you have any questions.
Sincerely, Origina!9ened By:
Clyde Y. Shiraki, Senior Project Manager Project Directorate III-2 Division of Reactor Projects llI/IV/V Office of Nuclear Reactor Regulation cc:
See next page DISTRIBUTION Docket File NRC & Local PDRs PDill-2 r/f JRoe JZwolinski JDyer CMoore CShiraki OGC ACRS(10)
BClayton, RIII JStrosnider i
1
%s 0
LffDIll-2 PM/PDlII-2 D/PDIIL 01ooreld CShiraki:rc JDyer
(; /U>/93 6 /23/93 4 / Ja/ 3'
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