ML20207F886
| ML20207F886 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/19/1986 |
| From: | Miraglia F Office of Nuclear Reactor Regulation |
| To: | Tiernan J BALTIMORE GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8701060249 | |
| Download: ML20207F886 (4) | |
Text
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December 19, 1986
= Docket No. 50-317 Mr. J. A. Tiernan Vice President-Nuclear Energy Baltimore Gas & Electric Company P. O. Box 1475 Baltimore, MD 21203
Dear Mr. Tiernan:
SUBJECT:
INTERIM APPROVAL OF ASME CODE UPDATE AND RELIEF FOR MAIN STEAM PIPING FLAW AT CALVERT CLIFFS UNIT 1 The Commission staff has completed their preliminary review of your requests for ASME Code relief and update as provided in your submittals dated December 16, 1986 and December 19, 1986.
These requests for ASME Code update and relief were necessitated by your determination of an existing flaw in the base metal of the #12 steam generator main steam line adjacent to and downstream of weld # EB-01-1005-05.
This weld is located at the second elbow downstream from the flow restrictor.
The existing flaw consisted of reduced wall thickness readings as low as 0.86" (minimum required wall thickness is 0.95") in a 1/2" wide band extending 24" along the circumference of the pipe.
This length is approximately 22.5% of the pipe's circumference.
The pipe is 34" in diameter.
You are currently required by 10 CFR 50.55a(g)(4)(i) to meet the requirements of Section XI of the 1974 Edition and Addenda through the Summer of 1975 of the ASME Boiler and Pressure Vessel Code.
Section XI, Article IWA-3000,
"$tandards for Examination Evaluations" requires this type of material and weld flaw (type C-F) be evaluated by comparison to the original construction requirements as provided in ANSI 831.1 - 1967.
This flaw does not meet the original construction requirement of a minimum wall thickness of 0.95".
The Commission agrees with your December 19, 1986 request to update in accordance with 10 CFR 50.55a(g)(4)(iv) the ASME Code Section XI requirements for this flaw from the currently required edition to the 1983 Edition with Addenda through Summer 1983. This is primarily due to the fact that Article IWB-3600 of the 1983 Edition provides analytical evaluation techniques superior to those prescribed by the 1984 Edition but also because during this cycle (in April 1987) you are required by 10 CFR 50.55a(g)(4)(ii) to update to the 1983 Edition of the ASME Code,Section XI.
In your submittal dated December 16, 1986, you provided a flaw evaluation analysis to satisfy the requirements of Article IWB-3610(a) of the 1983 Edition of the ASME Code.
In addition, you requested relief until the next Unit I refueling outage from the requirements of Article IWB-3610(b) that you meet the primary stress limits of NB-3000. Currently, you do not meet the loop stress requirement for this piping due to the wall thickness being below the minimum specification.
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Mr. J. A. Tiernan The Commission understands that you have committed in your December 16, 1986 submittal to ensuring that the affected piping will meet all applicable requirements of ASME Code Section XI of the 1983 Edition through Summer 1983 Addenda prior to entering mode 2 following the next Unit 1 refueling outage.
The staff has made an initial determination that your requests are acceptable on an interim basis until our completion of a more detailed review of your flaw evaluation analysis.
This letter shall serve as interim approval of your request to update the abova identified #12 steam generator main steam line flaw to the requirements of the 1983 Edition with Addenda through Summer 1983 of Section XI of the ASME Boiler and Pressure Vessel Code.
In addition interim relief is granted for this flaw only, for the 1983 Edition Section XI Article IWB-3610(b) requirements for primary stress limits.
This interim approval of the ASME Code update as required by 10 CFR 50.55a(g)(4)(iv) and of the relief from the Section XI Article IWB 3610(b) requirements shall expire either upon the issuance of a final approval for ASME Code update and relief along with the issuance of the appropriate Safety Evaluation or upon a determination that ASME Code relief or update is not acceptable for this flaw.
Sincerely, giginals@ W Frank J. Miraglia, Director Division of PWR Licensing-B cc:
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Mr. J. A. Tiernan The Commission understands that you have committed in your December 16, 1986 submittal to ensuring that the affected piping will meet all applicable requirements of ASME Code Section XI of the 1983 Edition through Summer 1983 Addenda prior to entering mode 2 following the next Unit 1 refueling outage.
The staff has made an initial determination that your requests are acceptable on an interim basis until our completion of a more detailed review of your flaw evaluation analysis.
This letter shall serve as interim approval of your request to update the above identified #12 steam generator main steam line flaw to the requirements of the 1993 Edition with Addenda through Summer 1983 of Section XI of the ASME Boiler and Pressure Vessel Code.
In addition interim relief is granted for this flaw only, for the 1983 Edition Section XI Article IWB-3600(b) requirements for primary stress limits.
This interim approval of the ASME Code update as required by 10 CFR 50.55a(g)(4)(iv) and of the relief from the Section XI Article IWB 3600(b) requirements shall expire either upon the issuance of a final approval for ASME Code update and relief along with the issuance of the appropriate Safety Evaluation or upon a determination that ASME Code relief or update is not acceptable for this flaw.
i Sincerely, Frank J. Miraglia, Director TWR Project Directcrate "8 Division of PWR Licensing-B cc:
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Mr. J. A. Tiernan Baltimore Gas & Electric Company Calvert Cliffs Nuclear Power Plant CC:
Mr. William T. Bowen, President Regional Administrator, Region I Calvert County Board of U.S. Nuclear Regulatory Commission Commissioners Office of Executive Director Prince FreJerick, Maryland 20768 for Operations 631 Park Avenue D. A. Brune, Esq.
King of Prussia, Pennys1vania 19406 General Counsel Baltimore Gas and Electric Company P. O. Box 1475 Baltimore, Maryland 21203 Jay E. Silberg Shaw, Pittman, Potts and Trowbridge 2300 N Street, N.W.
Washington, DC 20037 Mr. M. E. Bowman, General Supervisor Technical Services Engineering Calvert Cliffs Nuclear Power Plant MD Rts 2 & 4, P. O. Box 1535 Lusby, Maryland 20657-0073 Resident Inspector 3
c/o U.S. Nuclear Regulatory Commission i
P. O. Box 437 Lusby, Maryland 20657-0073 l
l Bechtel Power Corporation l
ATTN:
Mr. D. E. Stewart l
Calvert Cliffs Project Engineer
(
15740 Shady Grove Road j
Gaithersburg, Maryland 20760 Combustion Engineering, Inc.
ATTN:
Mr. W. R. Horlacher, III Project Manager P. O. Box 500 1000 Prospect Hill Road Windsor, Connecticut 06095-0500 Department of Natural Resources Energy Administration, Power Plant Siting Program ATTN:
Mr. T. Magette Tawes State Office Building Annapolis, Maryland 21204
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