ML18059A431

Requests Addl Info Needed Prior to 931012 Proposed Meeting Re Review of Rept on Pressurizer Safe End Crack at Plant

ML18059A431
Person / Time
Site:	Palisades
Issue date:	10/08/1993
From:	Hsia A Office of Nuclear Reactor Regulation
To:	Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
References
TAC-M87760, NUDOCS 9310180053
Download: ML18059A431 (4)

Text

CX::tober 8, 1993 Docket No. 50-255 Mr. Gerald B. Slade Plant General Manager Palisades Plant Consumers Power Company 27780 Blue Star Memorial Highway Covert, Michigan *49043

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION ON PALISADES PLANT REGARDING THE REPORT ON THE PRESSURIZER SAFE END CRACK (TAC NO. M87760)

The NRC staff has performed a preliminary review of your report dated October 7, 1993, documenting your engineering analysis and root cause evaluation of the recent pressurizer safe end crack at the Palisades plant.

Based on a preliminary review, the staff has concluded that additional information is necessary for the staff to perform an adequate review of the subject report. Enclosed is a list of questions which you should respond to in writing prior to our proposed meeting on October 12, 1993.

Please contact me should you have any q~estions regarding this request.

The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, Original signed by

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9310180053-931008' 1

PDR ADOCK

• 05000255 Anthony H. Hsia, Project Manager Project Directorate III-I Division of Reactor Projects - III/IV/V Office of Nuclear Reactor Regulation

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Enclosure:

Request for Additional Information cc:

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Mr. Gerald B. Slade Consumers Power Company cc:

M. I. Miller, Esquire Sidley & Austin 54th Floor One First National Plaza Chicago, Illinois 60603 Mr. Thomas A. McNish, Secretary Consumers Power Company 212 West Michigan Avenue Jackson, Michigan 49201 Judd L. Bacon, Esquire Consumers Power Company 212 West Michigan Avenue Jackson, Michigan 49201 Regional Administrator, Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 Jerry Sarno Township Supervisor Covert Township 36197 M-140 Highway Covert, Michigan 49043 Office of the Governor Room 1 - Capitol Building Lansing, Michigan 48913 Mr. David W. Rogers Safety and Licensing Director Palisades Plant 27780 Blue Star Memorial Highway Covert, Michigan 49043 U.S. Nuclear Regulatory Commission Resident Inspector Office Palisades Plant 27782 Blue Star Memorial Highway Covert, Michigan 49043 Palisades Plant Nuclear Facilities and Environmental Monitoring Section Office Division of Radiological Health Department of Public Health 3423 N. Logan Street P. 0. Box 30195 Lansing, Michigan 48909 Gerald Charnoff, Esquire Shaw, Pittman, Potts and Trowbridge 2300 N Street, N. W.

Washington DC 20037 Alora Davis Commitment Tracking System Coordinator Palisades Plant Consumers Power Company 27780 Blue Star Memorial Hwy.

Covert, Michigan 49043-9530 July 1993

ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION Request for additional information regarding Consumer's Power's engineering analysis and root cause evaluation report dated October 7, 1993 for pressurizer safe-end crack at Palisades plant.

1.

Provide reference (1).

2.

• Provide metallurgical evaluation report including Huey test results.

3.

Docket the crack growth analysis referenced on page 7 in the Engineering Analysis and Root Cause Evaluation Report.

4.

Based on an estimate of the maximum flaw size that could exist after completion of the NOE performed, provide an e*stimate of the time required for the crack to grow through-wall.

Include assumptions on.stress levels and crack growth rates.

5.

Provide a discussion of the safety significance of postulated failures of the PORV, spray relief valve, and surge lines.

6.

Provide 3rd party evaluation of the RT examinations for the PORV line.

What were the conclusions from review of the original Radiography (RT)?

Was the crack present from construction?

7.

Provide dimensioned sketches of the PORV repair weld, spray Safe-End (SE)

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and surge line SE.

8.

What is the source of the reported yield strengths?

9.

We have data to show the heat affected zone (HAZ} is harder than base metal.

How was the value for strength of HAZ in crack growth rate analysis determined?

10.

What was the margin-to-failure for the cracked PORV nozzle safe-end?

11. a.

What are the critical through-wall crack lengths for field welds in the pressurizer PORV line safe-end, the pressurizer spray line safe-end and the surge line safe-end under normal and faulted loading conditions?

b.

What leakage rate could be reliably detected from the pressurizer PORV line safe-end, the pressurizer spray line safe-end and the surge line safe-end under normal operating conditions, and how do these leakage rates compare to the leakage rates that would be associated with the critical through-wall flaws for each of these lines under normal operating conditions.

c.

Guidance on how to perform these calculations is provided in draft NRC Standard Review Plan 3.6.3. Compare the results of your analysis with the factors of safety on load, crack size and leak detection specified in the SRP.

d.

Discuss the symmetry or asymmetry of the stress distributions in the subject lines and the potential for symmetric versus asymmetric crack growth.

12.

Were the three pressurizer safety valve line safe-ends subject to weld repairs during or after fabrication? If they were subjected to repairs or if it cannot be determined that they were not subject to repairs, perform analyses as described in question 11, above, for these lines.

13.

Are there any plans to instrument the pressurizer spray line in order to better quantify the thermal stresses in that line?

-14. Discuss the potential for water hammer in the PORV line and the

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• • . pres Suri zer spray line.

15. Describe the examinations performed on the pressurizer surge line nozzle during the 1987 inspection. If these examinations were not optimized for detection of IGSCC, will IGSCC optimized examinations be performed prior to plant restart?