ML18079A805
| ML18079A805 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 07/06/1979 |
| From: | Schneider F Public Service Enterprise Group |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 7910706, NUDOCS 7908170471 | |
| Download: ML18079A805 (5) | |
Text
Frederick W. Schneider Vice President Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 201 /430-7373 Production July 6, 1979 Mr. Boyce H. Grier, Director U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region 1
- 631 Park Avenue King of Prussia, Pennsylvania 19406
Dear Mr. Grier:
NRC IE BULLETIN NO. 79-02 NO. 1 AND 2 UNITS SALEM GENERATING STATION In response to your letter of March 8, 1979, transmitting NRC IE Bulletin No. 79-02 which was received on March 13, 1979, the following report is offered.
I.
General
- 1.
The Engineering Department's investigation and evaluation of pipe support base plates in response to the subject bulletin has been undertaken in the*
following three (3} distinct phases.
- 2.
- a.
Development of computer modeling techniques for flexibility analysis and verification testing of anchor bolts.
- b.
Identification of supports and design analysis.
- c.
Field verification of support installation.
To accomplish Item I.l.a above, an Owner's group was formed by thirteen utilities.
Member utilities engaged Teledyne Engineering Services (TES) of Waltham, Massachusetts to perform generic testing and analysis.
TES has provided a computer program based on the ANSYS system for finite element anal-ysis of flexibility.
Results obtained for test cases using this program were verified against other computer models and by physical testing.
The program was also used to produce a series of curves showing plate flexibility influence on bolts, for typical configurations.
These curves in turn are used to expedite analysis for those cases where the plate geometry is applicable.
Mr. Boyce 7/6/79 I.
General (Cont'<l)
Thru TES, we have also acquired the latest manufacturer 1 s data and other test data for load carrying capacities of the Hilti concrete anchor bolts used in our plant.
Where needed information was unavailable from these existing data sources, TES performed additional testing.
These tests included the following:
(a)
Development of data for combined tension/shear loading.
(b)
Cyclic load tests on bolts installed per manufacturer's instructions.
A complete report of the TES program applicable to bolts used at the Salem Station is expected to be available for submittal to the staff in early August, 1979.
- 3.
To accomplish Item I.l.b above, Public Service is identi-fying suppo~ts associated with the subject bulletin by reviewing all currently issued Seismic Class I pipe support detaii drawings.
Forces and moments acting on each identi-fied support are obtained from the latest pipe stress calcu-lations.
ln accordance with NRC Bulletin 79-07 titled, uSeismic Stress Analy~is of Safety Related Piping, reanal-ysis of piping syseems is currently in progress.
This reanaly~is may in some cases cause an increase in calculated loads on base ~late supports.
Wh~re revised loads are obtained, however, they will be*factored into our base plate analysis.
Using the specified geometry, base plate supports are re~~ewed to determi~e if they fall into a flexible category.
Those base plate supports falling into a fle~ibl~ category are reviewed for bolt load by one of three method~ as.follows:
(ftl Use of ANSYS computer program previously discussed.
(~1 Use of curve solutions previously discussed.
~l Use of rigid analysis techniques for those cases whe~e bolt loads are of low magnitude such that safety factors are in the high double digit range.
Mr. Boyce 7/6/79 I.
General
- 4.
To accomplish Item I.l.c above, either of the following techniques are employed using a sampling plan per PSE&G QAI 7-5:
(a)
Ultrasonic testing for embedment of individual bolts.
(b)
Test loading of supports.
Items (a) and (b) above are being done as a supplement to the support installation verification performed during initial plant construction.
The ultrasonic testing for embedment is considered the primary method for this aspect of in~tallation verifica-tion.
With this approach, bolt embedment is checked against manufacturer's data which is verified by TES as discussed in Item I.2.a above.
Where anchor bo1ts are inaccessible, load testing is employed using hydraulic equipment to develop test ioads wh.i.ch. are a func t*ion of' the design.loads.
- 1.
TES has completed development of the pre and post pro~esso~s for use.with ANSYS.
These ate currently in use along w.i.th curve solutions also developed using the programs. *Verification of the program has b~en completed.
Shear-tension interaction testing and cyclic load testing are continuing with an anticipated completion date of July 15,- 1979.
- 2.
Analytical w-0rk to determine base plate flexibility is in progress for Salem Units 1 and 2.
We expect that this work will be a contiriuirig eff6rt thru approximately three -(31 weeks after the completion of our seismic analysts review per Bulletin 79-07.
Based on our revie~ thtis far, we are finding that approximateLy 3% of the supports require revision.
Mr. Boyce 7/6/79 II.
Summary of Program Status (Cont'd)
- 3.
Field verification work in both units is in progress.
In Salem No. 2 Unit, test loading of a sampling of supports in the Reactor Containment and Penetration Areas has thus far indicated no deficiencies.
Support samples irr the Auxiliary Building in No. 2 Unit are being selected and test loads developed to represent the safety related systems in this area.
The current schedule calls for completion af support testing in Unit No. 2. by August 31, 1979.
Testing of supports in Unit No. 1 is slightly behind that of Unit No. 2.
Current schedule calls for completion of testing in the Reactor Containment and Penetration Areas prior to unit startup with Auxiliary Building testing complete by September 30, 197~.
III. Conclusion
- 1.
Analytical review and field verification of pipe support base plates employing concrete expansion anchor bolts in response to NRC Bulletin 79-02 has thus far not identified any significant deficiencies in either unit at Salem Generating Station.
- 2.
Additional field installation verification of concrete anchors used in supports other than those associated with base plates was also undertaken by PSE&G.
The results of this examination did reveal some deficiencies in installation w~th respect t6 embedment.
Corrective acttona to identify and eliminate these deficiencies are in progress on Unit No. 1.
In Unit No. 2, our verification program is complete, and a report was submitt~d to th~ staff with Deficiency Report 6633.
An open item remaining on this ~atter concerns the inaccessi-bility for embedment checking of certain pier mounted base plates.
It is our intention that the load testing discussed in Secti.on I.4 above, when complete, will serve the dual purpose of closing this Unit No. 2 open item with the staff as well as provide compliance with Bu 11 e t :t.n 7 9~ -* 0 2.
L Mr. Boyce 7/6/79 If you require additional information, we will be pl~ased to discuss it with you.
- Sincerely, Attach.
GC~
NRC Office of Inspection and Enforcement Division of Reactor Operations Inspection
- wash~ngton, D. C.
Mr. L. J. Norrholm NRCr Hancocks Bridge,.N.J.