ML20010F662

Revised Final Deficiency Rept Re Reactor Pressure Vessel Nut & Stud Irregularities,Initially Reported on 810310.Phipps Bend Unit 2 Matl Was Reworked or Replaced & 100% Visual & Gauge Insp Performed

ML20010F662
Person / Time
Site:	Hartsville, Phipps Bend
Issue date:	09/04/1981
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, NUDOCS 8109110116
Download: ML20010F662 (3)

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TENNESSEE VALLEY 'AUTMciRtTV CH ATTANOOGA TENNESSEE 374oh . *, '

400 Chestnut Street Tgher.O II o

U September 4, 1981 0}-} ,y. 1 HTBD-50-518/81-09, -519,

-520, -521/81-08 .9 PBRD-50-553/81-11, -554/81-06 /

8 f,qf N Mr. James P. O'Reilly, Director p, g UI J h b Office of Inspection and Enforcement SEP 101981 m y U.S. Nuclear Regulatory Commission ," d v.s.mnaAa nauwoes ,

Region II - Suite 3100 h """

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101 Marietta Street Atlanta, Georgia 30303 Q% 4

Dear Mr. O'Reilty:

HARTSVILLE AND PHIPPS BEND NUCLEAR PLANTS - REPORTABLE DZFICIENCY -

REACTOR PRESSURE VESSEL NUT AND STUD IRREGULARITIE.* - HTRD-50-518/81-09,

-519, -520, -521/81 -)8 - PBRD-50-553/81-11, -554/51-06 The subject deficiency was initially reported to NRC-0IE, Region II, Inspector P. A. Taylor on March 10, 1981 as NCR S-15. The final report on the deficiency was submitted on April 9, 1981. In response to NRC.'s request documented in OIE Inspection Report Nos. 50-553/81-05 and 50-554/81-05 dated June 30, 1981, we are enclosing the revised final report ori the subject deficiency. If you have any questions, please call Jim Domer at FTS 857-2014 s Very truly yours,

. TENNESSEE VALLEY AUTIJORITY k /

L N. M is, Manager Nuclear gulation av S fety j Enclosure cc: Mr. Victor Stello, Director (Enclosure)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 i

.rssf s/ i 8109110116 810904 '

gDRADOCK 05000518 PDR An Equal Opportunity Employer i ._ __ . _ . _ . . _ _ _ _ , _ _ _ . . . . . . . - . . . . - _ - . . _ _ . _.. . . _ . .

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ENCLOSURE

, HARTSVILLE NUCLEAR PLANTS A AND B AND PHIPPS BEND NUCLEAR PLANT i '

REACTOR PRESSURE VESSEL (RPV) NUT AND STUD IRREGULARITIES

- HTRD-50-518 /81-09, -510, -520, -521/81-08

] PBRD-50-553/81-11, -554/81-6 10 CFR 53.55(e) - REPORT NO. 2 (REVISED FINAL)

Description of Deficiency The subject nonconforming condition identifies three individual deficiencies. They are:

1. Threads on seven nuts, out of 252 inspected, which were improperly

machined and do not conform to standards specified in Industrial Fasteners Institute, Fasteners Standards, Fifth Edition.

2. Failure to stamp studs with material identification as specified in the orocurement document.

3 Overmachining of 11 studs, out of 126 inspected, to an undersized condition.

The nuts and studs are used to hold the reactor pressure vessel to the RPV pedestal. The particular lot of material inspected is for use at Phipps Bend Nuclear Plant (PBN) unit 2. The material was fabricated by Acimet Manufacturing Company (Acimet), Cleveland, Ohio, under subcontract from Lakeside Bridge and Steel Company. Acimet supplied similar naterial for the RPV bolting assemblies at Hartsville Nuclear Plants (HTN) A and B and PBN unit 1.

The nonconforming condition was identified as a result of a 100-percent visual and gauge inspection conducted by TVA at the Acimet Plant. This was an expanded inspection (TVA normally perforns only a random sampling inspection) which was prompted by the identification of deficient nuts at Hartsv111e Nuclear Plant A.

In addition, as a result of the repeated recurrence of discrepant

, material manufactured by Acimet to TVA (NCR HNPA-117; described to NRC-OIE as nonreportable en January 27, 1981, and NBC HNPB-032, described to NRC-OIE as nonrecortable on January 17, 1981), we must conclude that a significant breakdoun of a portion of the Acimet Quality Assurance Program exists.

4 Safety Imolications Three individual deficiencies are identified by the NCR. Material identification will not affect safety of the plant. The improper threading on the nuts is a recurrence of a similar problem identified at HTN (NCR's HNPA-117 and HNPB-032) and deternined not to affect safety of the plant. The undersized thread on the studs, from a safety standpoint, cannot be addeessed due to a lack of adequate information. Therefore, during a seismic event, it is assumed that the integrity of the RPV could be compromised and this could affect the safety of the plant.

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Corrective Action ,

The PBN unit 2 material identified by this NCR wa.s re orked or replaced.

A 100-percent visuaj and gauge inspection was performed, the material was f ,und to be acceptr. die by TVA and was released for shipment to PBN unit In addition, TVA initiated inspection at HTN Plants A and B and PBN unit 1 on all materials shipped from Acimet. The inspection at HNP was a 100-percent visual and gauge inspection of the nuts ~and a 90-percent visual gauge inspe : tion of the studs. Of the 1008 nuts inspected, 179 were rejected. No studs were rejected. The inspection at PBN enit 1 was 100-percent visual inspection of the nuts and studs as soecified in '

subsection HF-2580 of the ASME, Code. Of the 252 nuts inspected, each were, in addition, random 1*r cross assembled on the studs for a determination en whether sny material was overmachined. This resulted in 12 of the 252 nuts being rejected for loose fit. No studs were rejected. A material. verification based on approved heat records was performed on all studs, nuts, and washers that were used in unit 1 to further ensure the material was of acceptable quality. Of.the 12 rejected nuts, several were split and used for an alignment tool to set the 120 studs in place. The remaining nuts were aestroyed.

Documentation on file to substantiate the acceptability of the material actually used consists of:

A. Unique Insoection Record per QCI M-410 for visual inspection of bolts at PBN.

B. Material Verification Record per OCI M-505 at HTN and PBN.

C. Sequence Control Chart for visual inspection of material at HTN and PBN.

D. Quality Control Investigation Report (OCIR) No. 22263 (NCR PBNP-262) at PBN.

TVA has no other contracts with Acimet at this time. TVA has placed a note in the Acimet file for future orders that 100-percent source inspection is required on all contract work provided by them.

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