United States Nuclear Regulatory Commission - Protecting People and the Environment

Bulletin 79-14: Seismic Analysis for As-Built Safety-Related Piping Systems

                                 UNITED STATES
                         NUCLEAR REGULATORY COMMISSION
                            WASHINGTON, D.C. 20555

                                 July 2, 1979

IE Bulletin No. 79-14

SEISMIC ANALYSES FOR AS-BUILT SAFETY-RELATED PIPING SYSTEMS  

Description of Circumstances:

Recently two issues were identified which can cause seismic analysis of 
safetyrelated piping systems to yield nonconservative results. One issue 
involved algebraic summation of loads in some seismic analyses. This was 
addressed in show cause orders for Beaver Valley, Fitzpatrick, Maine
Yankee  and Surry. It was also addressed in IE Bulletin 79-07 which was
sent to all  power reactor licensees.

The other issue involves the accuracy of the information input for seismic 
analyses. In this regard, several potentially unconservative factors were 
discovered and subsequently addressed in IE Bulletin 79-02 (pipe supports)
and  79-04 (valve weights). During resolution of these concerns,
inspection by IE  and by licensees of the as-built configuration of
several piping systems  revealed a number of nonconformances to design
documents which could  potentially affect the validity of seismic
analyses. Nonconformances are identified in Appendix A to this bulletin.
Because apparently significant  nonconformances to design documents have
occurred in a number of plants, this  issue is generic.

The staff has determined, where design specifications and drawings are
used to  obtain input information for seismic analysis of safety-related
piping  systems, that it is essential for these documents to reflect as-
built  configurations. Where subsequent use, damage or modifications
affect the  condition or configuration of safety-related piping systems
as described in  documents from which seismic analysis input information
was obtained, the  licensee must consider the need to re-evaluate the
seismic analyses to  consider the as-built configuration.



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                                                    IE Bulletin No. 79-14 
                                                    July 2, 1979        
                                                    Page 2 of 3

Action to be taken by Licensees and Permit Holders:

All power reactor facility licensees and construction permit holders are 
requested to verify, unless verified to an equivalent degree within the
last  12 months, that the seismic analysis applies to the actual
configuration of  safety-related piping systems. The safety related piping
includes Seismic  Category I systems as defined by Regulatory Guide 1.29,
"Seismic Design  Classification" Revision 1, dated August 1, 1973 or as
defined in the  applicable FSAR. For older plants, where Seismic Category
I requirements did  not exist at the time of licensing, it must be shown
that the actual  configuration of these safety-related systems meets
design requirements.

Specifically, each licensee is requested to:

1. Identify inspection elements to be used in verifying that the seismic 
analysis input information conforms to the actual configuration of safety-
related systems. For each safety-related system, submit a list of design 
documents, including title, identification number, revision, and date,
which  were sources of input information for the seismic analyses. Also
submit a  description of the seismic analysis input information which is
contained in  each document. Identify systems or portions of systems which
are planned to be  inspected during each sequential inspection identified
in Items 2 and 3.  Submit all of this information within 30 days of the
date of this bulletin.

2. For portions of systems which are normally accessible*, inspect one
system  in each set of redundant systems and all nonredundant systems for
conformance  to the seismic analysis input information set forth in design
documents.  Include in the inspection: pipe run geometry; support and
restraint design,  locations, function and clearance (including floor and
wall penetration);  embedments (excluding those covered in IE Bulletin
79-02), pipe attachments;  and valve and valve operator locations and
weights (excluding those covered in  IE Bulletin 79-04). Within 60 days
of the date of this bulletin, submit a  description of the results of this
inspection. Where nonconformances are found  which affect operability of
any system, the licensee will expedite completion  of the inspection
described in Item 3.

__________

*Normally accessible refers to those areas of the plant which can be
entered  during reactor operation.




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                                                    IE Bulletin No. 79-14 
                                                    July 2, 1979        
                                                    Page 3 of 3

3. In accordance with Item 2, inspect all other normally accessible safety 
related systems and all normally inaccessible safety-related systems.
Within  120 days of the date of this bulletin, submit a description of the
results of  this inspection. 

4. If nonconformances are identified:

A. Evaluate the effect of the nonconformance upon system operability under 
specified earthquake loadings and comply with applicable action statements
in  your technical specifications including prompt reporting.

B. Submit an evaluation of identified nonconformances on the validity of 
piping and support analyses as described in the Final Safety Analysis
Report  (FSAR) or other NRC approved documents. Where you determine that
reanalysis is  necessary, submit your schedule for: (i) completing the
reanalysis, (ii)  comparisons of the results to FSAR or other NRC approved
acceptance criteria  and (iii) submitting descriptions of the results of
reanalysis.

C. In lieu of B, submit a schedule for correcting nonconforming systems
so  that they conform to the design documents. Also submit a description
of the  work required to establish conformance. 

D. Revise documents to reflect the as-built conditions in plant, and
describe  measures which are in effect which provide assurance that future
modifications  of piping systems, including their supports, will be
reflected in a timely  manner in design documents and the seismic
analysis.

Facilities holding a construction permit shall inspect safety-related  
systems in accordance with Items 2 and 3 and report the results within 120 
days.

Reports shall be submitted to the Regional Director with copies to the 
Director of the Office of Inspection and Enforcement and the Director of
the  Division of Operating Reactors, Office of Nuclear Reactor Regulation, 
Washington, D.C. 20555.

Approved by GAO (R0072)j clearance expires 7/31/80. Approval was given
under a  blanket clearance specifically for generic problems.




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                                  APPENDIX A

PLANTS WITH SIGNIFICANT DIFFERENCES BETWEEN ORIGINAL DESIGN AND AS-BULT 
CONDITION OF PIPING SYSTEMS

PLANT              DIFFERENCE                    REMARKS

Surry 1            Mislocated supports.          As built condition     
                   Wrong Support Type.           caused by majority of
                   Different Pipe Run            pipe overstress problems,
                   Geometry.                     not algebraic summation

Beaver Valley      Not specifically identified   As built condition
                   Licensee reported "as-built   resulted in both pipe and
                   conditions differ signifi-    support overstress.    
                   cantly from original design."

Fitzpatrick        IE inspection identified      Licensee is using as   
                   differences similar to        built configuration    
                   Surry.                        for reanalysis

Pilgrim            Snubber sizing wrong.         Plant shutdown to restore
                   Snubber pipe attachment       original design condition
                   welds and snubber support
                   assembly nonconformances.

Brunswick 1 & 2    Pipe supports undersize       Both units shutdown to
                                                 restore original design
                                                 condition.

Ginna              Pipe supports not built       Supports were repaired
                   to original design.           during refueling outage.

St. Lucie          Missing seismic supports.     Install corrected      
                   Supports on wrong piping.     supports before start  
                                                 up from refueling.





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Page 2
                                  APPENDIX A

PLANT              DIFFERENCE                    REMARKS

Nine Mile Point    Missing seismic supports.     Installed supports before
                                                 startup from refueling.

Indian Point 3     Support location and          Licensee performing as
                   support construction          built verification to be
                   deviations.                   completed by July 1.

Davis-Besse        Gussets missing from main     Supports would be over-
                     Steam Line Supports.          stressed. Repairs will
                                                   be completed prior to
                                                             start-up.



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