ML18079A926
| ML18079A926 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/22/1979 |
| From: | Stephens R Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7909180522 | |
| Download: ML18079A926 (4) | |
Text
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Distribution Docket Fil~
NRC PDR NRR Reading H. Denton E.,Case R.~Mattson F.;Schroeder D. Muller D. Crutchfield D. Vassallo D. Skovholt W. Ga11111 i ll F. Williams J. Stolz R. Baer O. Parr S. Varga ACRS (16)
H. Berkow A. Dromerick Attorney, ELD IE (3)
L. Rubenstein J. Knight R. Bosnak H. Brammer J. Faire NRC
Participants:
R. Stephens, MEB,NRR H. Ashar, OSD L. Tripp, IE Region I H. Walker, ACRS K. Brown, MEB,NRR H. Wong, IE Hq
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SUBJECT:
50-311 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 Public Service Electric & Gas Salem Unit 2
SUMMARY
OF MEETING TO DISCUSS THE SALEM UNIT 2 RESPONSE-TO IE BULLETIN 79-02 On August 17, 1979, the NRC staff met in Bethesda, Maryland, with representa-tives of Public Service Electric & Gas to discuss the Salem Unit 2 response to IE Bulletin 79-02, "Pipe Support Base Plate Designs Using Concrete Expansion Anchor Bolts
- 11 A list of meeting attendees is attached.
For purposes of responding to this bulletin, PSE&G has joined an owner's group which has contracted with Teledyne to perform certain generic testing of various anchor bolts. During this meeting PSE&G described how tt was using the results of the generic Teledyne testf ng for the s*pectfic anchor bolts in use at Salem Unit 2. Additionally, PSE&G described the status of the analyses and tests being performed by its*elf on the anchor bolts installed at Salem Unit 2.
Approximately 10,000 anchor bolts are used in Salem Unit 2 of which approximately 3,000 are on safety related systems. Of these safety related anchor bolts, 1,295 are associated with 362 baseplates, nearly all of which are floor mounted.
The remaining safety related anchor bolts are us*ed to connect structural steel directly to walls and ceilings. All anchor bolts used in Salem Unit 2 are of the wedge type, specifically, Hilti Quik-Bolts.
PSE&G stated that the original anchor bolt design cr1terfa spec1f1ed a minimum factor of safety of four against pullout and assumed baseplate rtgfdity.
During its reevaluation of anchor bolt adequacy, PSE&G is using analytic.al tools developed by Teledyne to account for baseplate flexibility. To date, 136 baseplates have been analyzed with 9 requiring modification. Also, the applicant is using an elliptical shear-tension interaction curve with a minimum factor of safety of four against manufacturer's specified ultimate bolt capacities.
Prior to the issuance of IE Bulletin 79-02, PSE&G verified the correct embedment depth of most of the 10.000 anchor bolts in S-alem Untt 2 and corrected the few which were deficient.
Due to some fnstallation practices used by PSE&G, the verification of embedment depth for floor mounted anchor bolts is impractical. Therefore, for a sample of these floor mounted supports, PSE&G fs performing hydraulic pull tests to demonstrate a factor of safety of four against pullout.
PSE&G anticipates approximately 60-90 of these pull tests AA 1 I wn l be necessary to demonstTiate a 95/95 confidence* level for each safety
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related piping system.
To date,* 27 supports have been pulled with 26 passin9.
One support was considered a fatlure due to excessive deflection l0.008 inch}
although it did not pull from tfle floor:: *eompTetion of the remai.n1f1$ pull tests is scheduled for September 30, 19.79.
The N~C staff stated the following positions to PSE&G:
(1)
The intent of IE Bulletin* 79~02 is to cover anchor bolts other than only those associated with baseplates, such as the anchor bolts used to attach structural steel to walls and ceilings.
(2)
PSE&G should determine the extent and configuration of these safety related wall and ceiling mounted anchor bolts and provide this information to the NRC.
[3)
PSE&G should propose and frnpl ement for the wall and cefl ing mounted anchor bolts a testing program to satisfy the bulletin provisions and to tnclude verification on a sampling basis that the wedges have been properly set.
(4) At this time, it is not necessary for PSE&G to demonstrate any specific value of preload on its anchor bolts other than what is necessary to correctly set the wedge.
This 1s a continuing generic issue whose resolution depends upon additional experimental work.
Enclosure:
Ltst of Attendees U'A~z<-
Randal M. Stephens Mechanical Engineering Branch Dtvfsion of Systems Safety
NRC Mtg. with PSE&G:
Salem 2 Response to IE 79-02 8/17 /79 Attendees * >
..; ;Name Affiliation Randal M. Stephens MEB/DSS/NRC Hans Ashar OSD/NRC Lowe 11 E. Tri pp NRC/IE Region I Kenneth Bass PSE&G Alfred Dambra PSE&G Harold Walker ACRS Kelvin T. Brown MEB/DSS/NRC Howard J. Wong NRC:IE-HQ Robert W. Skwarek PSE&G/Salem Unit 2/Licensing J