ML18030A021
| ML18030A021 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/21/1980 |
| From: | Curtis N PENNSYLVANIA POWER & LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, PLA-578, NUDOCS 8012020585 | |
| Download: ML18030A021 (6) | |
Text
REGULA T INFORMATION DISTRIBUTION TEA (RIOS)
ACCESSION NBR: 8012020585 DOC ~ DA TE: 80/1 1/21 iiOT4R IZED:
NO DOCKET FACIL:50 387 Susquehanna Steam Electric Stationi Jnit ii Pennsylva 05 8
50 388 Susquehanna Steam Electric Stationi Jnit 2i Pennsylva OSQQ0388 AUTH'A41E 4 J THOR 4FFILI AT ION CUR T IS, N. ~,
Pennsyl vani a Power 8 Light Co ~
RECIP ~ NAME REC IP IE4T AFF ILI AT I 3'J GR TER p 8 ~ H ~
Region ii Philadelphia<
Office of the Director
SUBJECT:
Final deficiency rept re use of Hilti HOI shell anchors first r eoorted on 800523
~ Project soecs wi1 l be revised oy 8011Q1 to ~eflect Teledyne Engineering svcs test results
~
lnsp evaluation 3 reoair to oe done by May 1981 ~
DISTRIBUTION COOK:
8019S COPIKS RECEIVED!LTR I
ENCL SIZE TITLE: Construct i on Oef i ci ency Report (10CFR50.5SE')
NOl'ES:Send IEE 3 cooies FSAR K all amends'end ICE 3 cooies FSAR 8 all amends'5000387 05000388 REC IP IE 9 7 IO CODE/449K ACTION'/0 LICENSNG 04 RUSHBROOi<g'i'6 INTERNAL: AO/RC I/IE 17 ASLBP/J ~ rl4RD EOO 8
STAFF 19 HYD/GKO 8R 22 LIC QUAL BR 12 VRC POR 02 PRO
REV 13 G
F IL 01 T-A S
I)EV 21 COPIES LITTR ENCL 1
1 1
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07 AKOO 18 O/OIR HUB FAC15 EQUIP QUAL. 3R11 IKE 09 MPA 20 OELD 21 QA BR 14 RUTHERFORD'
~ IE COPIES LTTR ENCL
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1 LPDR 03 1
1 TOTAL NUNBER OF COPIES REQJIRKD:
LTTR 39 ENCL 39
PaL t
TWO NORTH NINTH STREETr ALLENTOWNr PA. 18101 PHONE~ t2151 821 515'I NORMAN W. CVRTIS Vice President-Engineering 8 Construction-Nuclear 821 5381 November 21, 1980 Mr. Boyce H. Grier Director, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 SUSQUEHANNA STEAM ELECTRIC STATION FINAL REPORT OF A DEFICIENCY RELATING TO USE OF HZLTl HDI SHELL ANCHORS ERs 100450/100508 FILE 840-4/900-10 PLA-578
References:
PLA-549 dated 09/25/80 PLA-488 dated 05/23/80 s
1I h
V~g J
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~ 3
Dear Mr. Grier:
This letter serves to provide the Commission with a final report of a deficiency relating to the use of HiltiHDI shell anchors.
The condition was originally reported in PLA-488.
The information contained herein is submitted in compliance to the provisions of 10CFR50.55(e).
The attachment to this letter contains a description of the problem, its
- cause, safety impact and significance.
The test programs conducted by Teledyne Engineering and Bechtel are referenced and the test reports are retained at PPSL and are available for your review.
A corrective action plan is also described.
We expect to complete Unit I inspection, evaluation, and rework/
repair by May, 1981.
We trust the Commission will find the information forwarded by this letter to be satisfactory.
Very truly yours,
~ r
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N. W. Curtis Vice President-Engineering 6 Construction-Nuclear Attachment FLW:mcb go/1
.SDlsoaoW5 PENNSYLVANIA POWER 8 LIGHT COMPANY
Mr. Boyce H. Grier 2
November 21, 1980 cc:
Mr. Victor Stello (15)
.. Director-Office of Znspection a Enforcement U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Office of Management Znfozmation
& Program Control U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. Robert M. Gallo U. S. Nuclear Regulatory Commission P.
O. Box 52 Shickshinny, Pennsylvania 18655
0
~
~
ATTACHMENT TO P 578
. FINAL REPORT ON HILTZ~ISHEE ANQKES C"
2 0 PURPOSE The purpose of this report is to provide caaplete inforaation, persuant to 10'0.55(e),
concerning RLLti shell anchors.
HILTI HDI SHEE ANCHORS 30 Concrete expansion anchors can be broadly categorized in three types, i.e.;
- wedge, sleeve and shel1.
HiltiHDI anchors are af the shell type.
Ghe main difference between shell and other types of anchors is that the shell anchor consists af two principal partsthe she11 (including expander plug) which is a female piece, and the bolt which is a male piece.
To achieve proper installation, a s~tly oversi2;ed hole is doled in the concrete and the shell is dropped/inserted 1n the hole.
9he plug is then driven into the shell to a set ~ns5.on using an appropriate setting tool.
Driving the plug expands the shell sga1nst the surrmncUlng concrete; this provides the holding capacity to withstand the design loads.
Thus, unlQ<e wedge ard sleeve anchors, no tozquiag is quired to set the shell anchors.
0 BACKGROUND AND CAUSE On the Susquehanna prospect, a la~e number of Hiltishell anchors have been used to attach supports for mainly electrical items such as conduits, Junction boxes and wireway gutters ard also 1nstrumentat1on tub1ng.
Prospect Specification 8856-C-72 is the governing document for the design, procurement, installation anl 1nspection of all types of'expansion anchors "by Bechtel field personnel.
Table 4.1 of the Specif1cation vied.ch is ccnmnn for all types of anchors, provides the de~ for enbedment, installation torque, allowable loads, etc.
. Haiti's latest published
'Anchor and Fastener Design Manual'tates that for shell anchors, anbedmnt length will be equa1 to anchor, length plus 1/8 inch.
However, ccmputed recesses (defined as the distance between the top of shell and cancrete surface) based upon the values given 1n the table af the aforementioned specification are generally larger than the manufacturer's recQKRIldationse In August 1979, Bechtel prospect mgineering became aware that the actual
. recess provided generally ranged between 1/2 inch and 1 inch and in scm cases greater than 1 inch.
4.0 ANALYSIS OF SAHTX IMPLICATXQNS Under tension loading, the recess would have no beax~ on the proper func-tion~ af anchors.
However, under shear loading, as the bolt is unsupported within the recess, 1t would be,sub)ected to bending @ament in addition to shear load.
With greater recesses, larger axxents willresult.
~
In order to evaluate the above comU.tion, a static shear test prcgram was under
I Ween by Bechtel.
The testing was perfozmed at the jobsite in December 1979 and a report was issued in March, 1980 (see Reference 1).
Test results indicated that the recess has no bearing on the ultimate static shear capacity.
However, the anchor behavior was observed to be non-linear, even for the anchors with 1/8 inch recess.
When the, project specification was developed, the allowable loads were based upon the static shear and tension test results and sara limited data on cyclic and shear-tension test results.
As the majority of the expansion anchors will be subjected to cyclic and 'cxxnbined shear tension under a seismic event, the conclusion of the above mentioned report raised a question zegarding the acceptability and structural adequacy of all Hilti shell anchors used on Susquehanna.
As noted above Hilti. shell anchors have been used to attach safety related items Thezefoze f unless further investigation is done, existing conditiary'nstallation may have adverse safety impact.
Accordingly, Bechtel Engineer-ing determined this problem to be zeportable under 10CFR50.55(e) and an interim report was issued on 5-27-80.
5~0 IMMEZ)IATEACTICN In order to prevent further usage of shaD anchors, a 'HOLD'as placed on construction by Bechtel engineering in Febzuazy 1980.
A new test prcx~n was developed to perform static and cyclic tests under
- shear, tension and canbined shear-tension.
6 0 NEH TEST PE@GRAM The testing was performed by Teledyne Engineering Services-,.Waltham, Mass.
in accordance with the criteria provided in technical specification 8856-C-95.
Report No. 8856-C-100 (See Reference
- 2) includes the details of the testing, test procedures, and test results;= and Report No. 8856-C-101 (See Reference
- 3) contains evaluation of the test results and also the proposed allowable loads.
As the new allowable. shear loads are significant1y smaller than those in the present design criteria, further evaluation is zequized, as described below.
7.0 With the new allowable loads which aze smaller than the present design loads, the following corrective action willbe undertaken.
l.
The project specification will be revised by November 1, 1980, to reflect the findings of the above test reports.
I 2.
As mentioned previously, the majority of HiltiShell anchors have been used to attach electrical and instzutlntation supports.
ATTACHMENT TO PZA-578
For category IE electrical supports per drawing 8856-E-S3," there are many typical supports, for which maximum allowable loads are indicated on the design drawings.
Based upon new revised allowa-ble loads for the anchors, these supports will be evaluated and categorized in two groups.
Those supports for which the maximum allowable loads on the-supports still satisfy the new criteria for the anchors will be included in the first group.
The second group willconsist of all other supports.
The category IE sup-ports in the second group including all other (electrical, instru-
-m ntation and other disciplines) supports willbe inspected by Bechtel field personnel, to obtain actual loading imposed on these supports.
This inspection will be performed in accordance with approved field procedure.
Inspection results wil1 be evaluated, and docutrented including appropriate disposition and details of repair/rework as necessary.
If this evaluation indicates that the existing anchors are structurally inadequate, the. existing support connections will be nadified either by adding mare anchors or by providing additional supports.to reduce actual loading on the supports and thus on the existing anchors.
Above noted activi.ties (inspection, evaluation and repair/rework) willbe caraenced in Noveaher
'1980 and are scheduled for completion by May 1, 1981, for Unit 1 and'caman, to be followed by similar action for Unit 2.
8.0 CCNCLUSICN On axttpletion of the corrective action noted in section $.0, existing Hilti shell'nchors with 1" recess (max) willmeet the new design criteria
- and thus willbe structurally acceptable with adequate safety margin.
1.
20 30 Gore, Aravind S., 'Shear Test Report on Hilti. HDI Shell Anchors for Susquehanna Steam Electric Station." Bechtel Powe'r Corporation, San Francisco, California in March 1980.
Gore f Aravind S g 'Test Report on HiltiHDI Shell Anchors for Susquehanna Steam Electric Station'eport No. 8856-C-100, Bechtel Power ~aration, San Francisco, California.
October 1980.
Gore, Aravind S.,
Technical Criteria for HiltiHDI Shell Anchors for Susquehanna Steam Electric Station'.
Report No. 8856-C-101,
~
Bechtel Power Corporation, San Francisco, California, October 1980..
4 ATTACHMENT TO PIA-578