ML20209C747

Forwards Request for Addl Info Re Allegations NRC Received in Aug 1982 Concerning Design Deficiencies in Class I Piping Sys.Ie Info Notice 83-80, Use of Specialized Stiff Pipe Clamps, Issued to Licensees,Nsss Suppliers & Aes

ML20209C747
Person / Time
Site:	Perry
Issue date:	03/02/1984
From:	Bosnak R Office of Nuclear Reactor Regulation
To:	Youngblood B Office of Nuclear Reactor Regulation
Shared Package
ML20209C752	List: ML20209C747 ML20209E313 ML20211C446
References
FOIA-86-689 IEIN-83-80, NUDOCS 8403120292
Download: ML20209C747 (3)

Text

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!(f*i *% UNITED STATES NUCLEAR REGULATORY COMMISSION 5 g,,:(// g#.j ,E WASHING TON. D. C. 20555 ,

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. liEMORANDUM FOR: B. J. Youngblood, Chief Licensing Branch No. 1, DL

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FROM: Robert J. Bosnak, Chief ~

Mechanical Engineering Bra'nch', DE

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - PERRY NUCLEAR POWER PLANT In August 1982 the NRC received allegations regarding design deficiencies in Class 1 piping system. The alleged deficiencies were specifically related to piping designers ignoring the piping stresses induced by pipe clamps in Class 1 piping analyses. The NRC staff initiated a serics of visits with several piping design organization and pipe clamp vendor s. The results of that investigation were presented in the August 1983 report that was included as an enclosure to Board Notification (BN)82-105A. BN 105, with the enclosure, was sent to the Perry ASLB (among others) on September 29, 1983. -

The conclusion of the staff's report was that spe.cial pipe clamps'have_

been recently developed for large rated load capacity for special applications in nuclear power facilities. These special pipe clamps, referred to as " stiff" pipe clamps in the report, have several new

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design features that represent a significant ct.ange from the __

! _, conventional. pipe clamp design used successfully in previous years.

_ Utilization of these " stiff" pipe clamps without an adequate evaluation ~

may result in inducing large stresses in the piping that have not been explicitly evaluated, and thus can result in a likelihood of underestimation of forces, moments and stresses in the piping system.

The staff found during 'its investigation that industry might not yet have acknowledged or is not aware of the above concerns for the following reasons (1) inappropriate reliance of piping designers on only engineering judgement based on past experience when new design concepts are involved and (2) inadequate lines of communication between

. organizations responsible for controlling the piping to pipe clamp interface design. For these reasons, IE Information Notice No. 83-80,-

"Use of Specialized ' Stiff' Pipe Clamps" was issued to lice'nsees, NSSS suppliers and architect engineers.

EH 105A, issued to the Perry ASLB, indica'ted that the staff intends to address the " stiff" pipe clamp issue during the safety evaluation for new plants. Discussions between the staff and representatives of E-Systems on February 10, 1983 and Gilbert Associates on March 2, 1983 indicated a large use of these " stiff" pipe clamps in the Perry design.

Accordingly, in order for the staff to review the piping to pipe clamp XO WO3/P Q f -

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+- B. J. Youngblood .

interface design in cases where stiff pipe clamps are used for the Perry ,

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design the attached request for additional information sh'ould be "

transmitted to the applicant for the Perry facility. ,

Robe ~rt J.' Bosnak, Chief ,

Mechanical Engineering Branch i' Division of Engineering

Attachment:

As stated cc: R. Vollmer, DE J. Knight, DE A. Schwencer, DL

.J. Stefano, DL M. Haughey, DL R. ilartin, DL H. rammer, DE

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, ATTACHMENT, , , .

' 210.15 Identify the " stiff" pipe clamps installed or expected to be .

installed on Perry Units 1 and 2. Identify also the systems on which they are installed, and the clamp vendor for each clama. Describe in detail how the localized loads from-these " stiff" pipe clamps on the piping, are accounted for. in the analyses performed for all ASME Code Class 1, 2, and 3 piping syster.s. Also discuss how thi special installation and post-installation requirements are controlled for

" stiff" pipe clamps.

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