ML20040C102
| ML20040C102 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/13/1978 |
| From: | Blackwood E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | Sniezek J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| Shared Package | |
| ML13319A635 | List:
|
| References | |
| FOIA-81-313 NUDOCS 8201270270 | |
| Download: ML20040C102 (3) | |
Text
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- . :w 13 N3TE TO:
J. H. Sniezek, A]FC, DROI, IE FT.O.'::
E. E. Bla:b;ood, FC, DROI, IE SUEJECT:
INFUT TC :'J.'ESTIGATICN OF SAN ONOFRE STEAM GENERATOR SUPPORT PLATE CRACKING
Reference:
Me.no E. Case to E. Volgenau, same subject, dated 4/5/78.
As you requested on April 7,1978, the reportability of conditions within the steam cenerators at San Onofre Unit No. I was evaluated via an indepth review of the licensee's reporting requirements and the docketed correspondence between the NRC and the Southern California Edison Company.
It is not apparent that the steam generator lower tube support plate conditions were reportable, or that safety information was withheld from the regulatory staff.
4 The condition of steam generator A and C lower tube support plates appears to be of minor safety significance if significant at all, based on the stable condition of the cracks as observed by the licensee at roughly annual intervals.
In retrospect, based on the actual opera-tion of the facility over the past year,-it does not appear that public health and safety were endangered or degraded due to the existence of lower tube support' plate hourglassing and cracking.
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The enclosure documents the scope of this evalua' tion.
q E. 8. Blackwood FC, DROI, IE
Enclosure:
Details of evaluation
[G. H. Smith, PAT cc:
8201270270 010925 PDR FOIA UDELL81-313 PDR Document 14
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re: n eria; revie=.ec Techrdca'. 5;ecifications License atendments and technical specification changes Ar.nual and Semi Annual Operating Reports Operations file License file Incidents & Inquiries file Inspections file Application file J
Steam Generator Inspection program Inservice Inspection results Steam Generator operating history questionnaire response Reportability Reporting requirements of technical specifications are silent on tube support p' late conditions.
No requirements exist for submission of photographs of tube support plates.
.On 12/28/76 the lice see submitted Proposed Change No. 52 to technical specifications, ~which included inservice. inspection requirements for y
steam generator tubing.
These requirements were consistent with Regulatory Guide 1.83, Revision 1, and the letter request of NRR dated 9/10/76.
The proposed change was not incorporated into technical specifications, but the license was modified on 4/1/77 to require a steam generator tube inspection within 12 months.
The proposed inspection program and reporting of results per R.G.1.83 address the tube condition.
The causes of tube wall thinning or tube denting are not by themselves reportable, whereas the effect, e.g., tube degradation, is reportable.
Licensee Reports Subsequent'to steam generator inspections in 1976, the licensee issued a report dated 1/30/77 and forwarded it to NRR by letter dated 2/1/77.
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"It has reen cor.:iused ;nat San Onofre Unit 1 operation can be resumed folio,.ing the current refueling / maintenance outaoe without compromise to the safety or an increase in the risk associated with the operation of the steam generators.
The basis for this
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conclusion is that (1) there is no evidence in the San Onofre Unit 1 stoma generators of the conditions that resulted in the failure of a steam generator tube at Surry Unit No. 2, (2) there are no safety consequences with regard to steam _oenerator lower
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tube support plate deformation and ligament cracking, and (3) 3 M
further tube and antivibration bar degradation due to excessive vibration damage will be arrested by the addition of new anti-vibration bars. "1/
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Nineteen additional copies of this 'repcrt..ere forwarded to NRR by letter fated 2/4/77.
Additional information was provided to NRR by the licensee in the following documents-..
Initial evaluatien of eddy current inspections performed in September 1977, letter dated 10/3/77.=
i' Evaluation of past eddy current test data, letter dated 11/18/77.
Supplemental information concerning stccm generator inspections, letter dated 12/5/77.
Steam generator inspections, letter dated 2/14/77.
Steam generator inspection program, letter dated 11/2/76.
Steam Generator Operating History Questionnaire forwarded by letter dated 2/17/78.
Steam generator inspections, letter dated 2/23/78.
1/ Southern California Edison Company " Steam Generator Inspections, San Onofre Nuclear Generating Station Unit 1", January 30, 1977, p. 1-3.
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_ y, The fcilowing licer.see event reports '.;ere submitted q IE by the licenses:
50-206/76-8, Steam Generator Tube Inspection Results 50-206/76-10, Steam Generator Anti Vibration Bars IE followed up on tnese LERs as documented in Inspections Reports fios.
50-206/77-02 and 50-206/77-05.
The following documents on this subject were prepared by NRR:
Meeting summary for 1/18/77, memo dated 2/2/77.
Safety Evaluation, memo dated 3/18/77.
Amendment No. 25 to license DPR-13, dated 4/1/77.
Amendment No. 29 to license DPR-13, ' dated 12/20/77.
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