ML20236K546

Forwards Writeups on AO Rept to Congress for Second Quarter CY86,per 860701 Memo.Writeup on Facility for Item III.3 (Possible App C Items) Will Be Submitted for Inclusion in Third Rept

ML20236K546
Person / Time
Site:	Catawba, 05000000
Issue date:	07/16/1986
From:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
Shared Package
ML20236K265	List: ML20236K262 ML20236K277 ML20236K280 ML20236K289 ML20236K297 ML20236K324 ML20236K333 ML20236K337 ML20236K357 ML20236K380 ML20236K419 ML20236K427 ML20236K532 ML20236K546 ML20236K557 ML20236K576 ML20236K594 ML20236K601 ML20236K616 ML20236K623 ML20236K629 ML20236K641 ML20236K653 ML20236K661 ML20236K664 ML20236K677 ML20236K682 ML20236K695 ML20236K716 ML20236K723 ML20236K727
References
FOIA-87-377 NUDOCS 8708070157
Download: ML20236K546 (4)

Text

- _ _ _ _ _ _

• - t _

' p #fGg UNITED STATES 1 Do NUCLEAR REGULATORY COMMISSION y"

n REGION la i g ,j 10's MARIETTA STREET, N.W.

• ATLANTA, GEORGI A 30323 t

\,g.."/

. July 16, 1986 l

MEMORANDUM FOR: Clemens J. Heltemes, Jr. , Director, Office for Analysis and Evaluation of Operational Data '

FROM: J. Nelson Grace, Regional Administrator 1

j

SUBJECT:

INPUT FOR THE ABNORMAL OCCURRENCE REPORT TO CONGRESS FOR SECOND l

l QUARTER CY 1986 Enclosed are the writeups on the Abnormal Occurrence Report to Congress for the Second Quarter CY 1986 as requested by your memcrandum dated July 1, 1986.

l The writeup on Catawba Unit 2 for Item III.3 (Possible Appendix C Items) will be l submitted for inclusion in the Third Quarter Report.

l 1

, c .

J. Nelson Grace

{

Enclosure:

Abnormal Occurrence Input

-s. I' ; 29 l l

l CONTACT:

R. Aiello FTS: 242-4196 8708070157 870804 PDR FOIA CORDONB7-377 PDR 3 (v \

fhg

= N- p 1

July 16, 1986 l ENCLOSURE l l

ABNORMAL OCCURRENCE INPUT I Appendix B, Number 85-6 ("Significant Deficiencies in Reactor Operator Training and Material False Statements") l This item involved Grand Gulf. The licensee responded to the Notice in a

! letter dated April 19, 1985. After careful consideration of the licensee's l response, the staff concluded after consultation with the Commission that l four of the five alleged violations should, in whole or in part, be withdrawn j or recategorized to reduce the severity level and that the $25,000 fine q proposed for each should be withdrawn. The staff also concluded that the I fifth alleged violation should stand as originally noticed but that the l

$25,000 fine proposed for it should be withdrawn in view of the inistakes i made in the other citations. This completes the NRC's action in this matter. l Appendix C, Number 1 (" Reactor Vessel Indications at Oconee Unit 1") 1 During March 1986, the Oconee Unit I reactor vessel to flange shell weld (IRPV-WR19) was ultrasonically examined from the flange face. Twenty-two ,

indications were recorded, all from the clad side of the flange. Only one I of the indications extended onto the unciad side of the flange. The indica-  !

tions were located from 24 to 32 inches from the flange and the amplitudes I ranged from 50 to 1600 percent of distance amplitude correction (DAC) curve.  !

Previous examinations conducted from the vessel ID and OD surfaces as well l as the unclad side of the flange face did not detect these same indications. '

The licensee, Duke Power Company (DPC), stated tha- with the exception of one geometric reflector recorded in 1979, there were nu recordable indications on this weld. The 1986 examination, however, was the first examination conducted from the clad side of the flange face.

I Duke Power Company informed the NRC Region II of these flaw indications and 1 Regional personnel conducted a plant-site evaluation of the technical issue.

Considering the reported size, number and ultrasonic amplitude of the flaw indications in a reac+.or vessel, other licensees have performed additional inspections to further confirm and characterize flaw indications. Duke Power Company, however, elected to complete the inservice inspection (ISI) with the available examination data, install the vessel closure head and perform a fracture mechanics evaluation of the flaw indications using the measured dimensions.

Initially, the licensee evaluated the data as though the indications repre-sented real flaws since there was no evidence to prove otherwise. Nine of these indications were acceptable when compared to the ASME Section XI acceptance standard IWB-3510. The remaining 13 indications were accepted by analytical methods permitted by IWB-3600 in accordance with App,endix A (Section XI) procedures.

Because the licensee decided to resolve the issue by this analytical method, e.g., Linear Elaster Fracture Mechanics Analysis, Region II initiated a Task Interface Agreement (TIA 86-3FM dated April 3, 1986) and requested that NRR review '.he licensee's fracture mechanics evaluation.

l Enclosure 2 July 16, 1986 Two meetings were held with the licensee in the NRC Region II office on April 8 and April 21, 1986, during which the licensee presented their inspection results, fracture mechanics evaluation and their proposed action plan. At the April 8,1986, meeting, the licensee informed the staff that some of the reflectors may be geometric in origin. This preliminary conclu-sion was based on a limited qualitative laboratory test on a reactor vessel mock-up at Babcock and Wilcox, Mt. Vernon, Indiana facility. However, the licensee intended to consider the flaw indications as actual flaws and to complete the fracture mechanics evaluation based on the requirements of ASME j Section XI Subarticle IWB-3600. j The staff reviewed the licensee's submittals along with additional informa-tion requested during the April 21, 1986, meeting and concluded that Oconee Unit 1 may restart and operate for eight weeks on the condition that the licensee submit, before June 16, 1986, results on the following work effort: ,

1 Perform a comparison of Units 1 and 3 vessel flange geometry, )

material (s) and cladding and determine why Unit 3 ISI examination of  !

the same weld did nct produce similar results )

Conduct an ultrasonic examination study on the Mt.. Vernon mock-up reactor vessel Review the original weld design and fabrication history including nondestructive examination records of the weld in question ,

1 In addition, the staff stated that the NRC reserves the right to re-evaluate I its position on the above, in the event that a significant transient occurred on the Unit 1 vessel.

In a letter dated April 24, 1986, the licensee submitted their fracture mechanics evaluation and a summary of the ultrasonic testing results which located and sized the flaw indications.

On May 2,1986, NRR issued a Safety Evaluation Report (SER) which concluded that Oconee Unit 1 can be safely returned to full power and operated with actual flaws of the size and circumferential locations described in the SER.

This conclusion was based on the staff's review of the fracture mechanics analysis evaluation performed by the licensee, the pressure temperature limits, and Pressurizer Code Safety Valve Set Point contained in the Oconee Unit 1 Technical Specifications (TSs). This conclusion was supplemented with the following conditions:

The licensee will submit prior to June 16, 1986, a technical report summarizing their on going ultrasonic testing program on the Mt. Vernon mock-up vessel.

The staff will review and determir/a whether the conclusion that the subject flaw indications are enveloped by the dimensions measured by the licensee is still conservative.

~J

\

Enclosure 3 July 16, 1986 I Because the staff considers several of the flaws as conditionally acceptable per IWB-3122.4, three augmented inservice inspections based on 10 CFR 50.55.a(g)(4) will be required.

At least six months before the next scheduled refueling outage, the licensee will provide a report describing detailed plans for the above ISI inspection (s).

On June 13, 1986, the licensee submitted to NRR a report with the requested l

information. This report stated that preliminary results, from the data j obtained at Mt. Vernon, point to a high probability that the data recorded j during the Oconee Unit I examination indicated geometric conditions. The I report provides a detailed description of the examination of the Mt. Vernon i vessel mock-up .using the actual calibration block and similar examination i equipment to that used during the Oconee Unit 1 examination, and results )

from those examinations. Specific recommendations for conducting ultrasonic examination (s) from the flange face of the reactor vessel in future inservice inspections were provided. These will be employed in the upcoming Oconee Unit 2 inservice inspection to be performed in August 1986. This report is currently undergoing review by the staff, The licensee has returned the plant to power operation. This event had no impact on the public health or safety. Therefore, it is not considered reportable as an abnormal occurrence. I I

1 i

.