ML20127E524

Insp Rept 50-336/85-18 on 850429-0503.No Violation Noted. Major Areas Inspected:Areas of Inservice Insp Program Activities,Including Ultrasonic Exam of Piping & Eddy Current Test of Steam Generator Tubes & Sleeves

ML20127E524
Person / Time
Site:	Millstone
Issue date:	05/29/1985
From:	Gray E, Wiggins J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20127E492	List: IR 05000336/1985018 ML20127E489
References
50-336-85-18, NUDOCS 8506240575
Download: ML20127E524 (5)

See also: IR 05000429/2005003

Text

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U.S. NUCLEAR REGULATORY COMMISSION

REGION I

Report No. 50-336/85-18

Docket No. 50-336

License No. DPR-65

Licensee: Northeast Nuclear Energy Company

P.O. Box 270

Hartford, Connecticut

Facility Name: Millstone Nuclear Power Station, Unit 2

Inspection At: Waterford, Connecticut

Inspection Conducted: April 29, - May 3, 1985

Inspectors:

E. H. Gray, LeacVReactor Engineer

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Approved by:

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y.pWiggins, pff rf, Materials

Uand ProcesW Section, DRS

Inspection Summary: Inspection during April 29 - May 3, 1985 (Report No.

50-336/85-18).

Areas Inspected: Routine, unannounced inspection by one region based inspec-

tor. The inspection included the areas of Inservice Inspection (ISI) program

activities including ultrasonic examination of piping and eddy current examina-

tion of steam generator tubes and steam generator sleeves. Work in progress

including sleeve installation on steam generator tubes and disassembly of the

service water pump "A" were observed. The control and status of the reactor

vessel material surveillance test coupons were reviewed. The inspection in-

cluded 35 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br /> on site and an additional 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> at the regional office.

Results: No violations were identified.

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1.0 Persons Contacted

Northeast Nuclear Energy Company (NNECo)

J. Bergin, Engineer (Sleeving)

• T. Blanchard, ISI Coordinator - MS #2

S. Brinkman, Engineer (S.W. Pumps)

G. Closius, QC/QA Manager - MS#2

• J. Kelley, Superintendent, Millstone #2

• W. Romberg, Station Superintendent

• J. Smith, Engineering Supervisor

Northeast Utilities Service Company (NUSCO)

L. Baird, ISI Coordinator

H. Cote, Construction QC Supervisor

R. Fuller, UT, Level III

R. Michaud, Construction QC Manager

• Present at exit meeting on 5/3/85.

Combustion Engineering (CE)

C. Ashman, EC, Level III

ZETEC

R. Miranda, EC Data Analyst

2.0 Steam Generator (SG) Tube Eddy Current Examination

By the time of this inspection the eddy current (EC) steam generator tube

examinations were complete although EC data analysis was still in progress.

The inspector observed a portion of the eddy current analysis in progress

and reviewed the applicable procedure number STD-ISI-004, Revision 0.

Comparisons were made to the ASME Code Section XI, IWB 2413 and IWB2420

requirements and the intent of the NRC Regulatory Guide 1.83. The primary

defect identified is pitting on the tube secondary (outside) side at a

location within several inches above the upper surface of the tube sheet.

All of the accessible tubes in both steam generators were examined in this

area, to the first tube support plate, for pitting. Those with pits in ex-

cess of 39% through wall were scheduled for sleeving prior to continued

service.

The secondary side of the tubes in both steam generators were chemical

cleaned as an assist in removal of the secondary side copper bearing

sludge. In the opinion of this inspector, this cleaning operation has

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enhanced the EC response from existing pits or made their detection easier

by removal of superfluous copper indications.

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In the sequence of eddy current data review, data is reviewed separately

by two groups. The results are then compared with differences being

reviewed and reevaluated. The licensee provided an independent third

party review of selected portions of the eddy current evaluation.

No violations were identified.

3.0 Steam Generator Tube Sleeving

The detection of pits greater than 39's throughwall just above the tube

sheet surface resulted in the decision to prepare those tubes for further

service by the insertion of sleeves and hard rolling them to the tube in-

side surface. The inspector reviewed the basic procedure for tube sheet

sleeving and portions of procedures applicable to specific steps in the

sleeving process. The training and mockup area for practice in both

robotic and manual sleeving was observed. Sleeving operations in progress

during the inspection including eddy current examinations to confirm that

sleeving was successfully completed were observed to determine the confor-

mance to applicable procedures, the level personnel training and control

over the sleeving process.

No violations were identified.

4.0 Ultrasonic Examination (UT) For Inservice Inspection (ISI)

The plant outage in progress during this inspection is the Final Examina-

tion period of the first ten year ISI interval. In continuation of in-

spection 50-336/84-17, the progress toward meeting the 10 year interval

ISI plant requirements was reviewed. The inspector noted the status of

completion of examinations, schedule to meet examinations yet required and

the documentation system in place to achieve the 10 year interval ISI

program plan.

In the UT area the inspector observed examination of welds MSA-CG-16 and

MSA-CG-14 as shown on drawing 25203-201-67. This UT was done in accor-

dance with procedures NU UT-1 Revision 4 and NU UT-3 Revision 2 as re-

viewed by the inspector. The UT observed and related activities were

compared to the requirements of the ASME Code Section V, Articles 4 and

5, the ASME Code Section XI and ASNT-TC-1A. The UT test blocks for speci-

fic UT data sheets were examined and data sheets, personnel qualifica-

tions, the procedure of indication evaluation, significance of data sheet

signoffs and the above mentioned UT procedures were reviewed.

No violations were identified.

5.0 Reactor Vessel Irradiation Material Surveillance Specimens

The plant Technical Specification paragraph 4.4.9.1(c) requires that:

"The reactor vessel material irradiation surveillance specimens

shall be removed and examined, to determine changes in material

properties, at the intervals shown in Table 4.4-3."

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Table 4.4.-3 requires capsule W-97 be removed and examined after 3.0 ef-

fective full power years (EFPY), with the next capsule (W104) scheduled

for removal after 10 EFPY.

The inspector determined that surveillance specimen removal and examina-

tion is under control of the plant ISI coordinator. The first surveil-

lance capsule (W-97) was removed from the Millstone Unit 2 reactor vessel

in August -1980 after 3.0 EFPY. Mechanical test specimens of base metal,

weld metal and weld heat affected zone provided for determination of ra-

diation induced changes of both tension and impact properties.

Temperature monitors, alloys with specific melting properties, indicated

the irradiation temperature to be between 536F and 558 F.

The inspector reviewed the report of evaluation of irradiated capsule

W-97 dated April 1982 by Combustion Engineering, Inc., and noted that

provision was made by the ISI coordinator for removal of capsule W-104 in

1988.

No violations were identified.

6.0 Service Water Intake Pump Columns - Independent Measurements

The original material of the service water intake pump columns was cast

iron. The cast iron was replaced with carbon steel on a temporary basis

until stainless steel could be obtained. The last replacement design as

installed in 1983 included type 316L flanges welded to type 316L plate

rolled and welded to form cylinders with welding per the ASME Code

Section IX.

Pumps "A" and "C" operate continuously during normal conditions, which

pump "B" is reserved for backup. During the 1985 outage scheduled

inspection found the internal column welding of pump "C" circumferential

velds had significant weld metal voids partially filled with a powder with

a chemistry of 24.4% Cr, 5.4% Ni, 60.9% Fe. Pump columns "B" and "A" were

removed and examined. Pump "B" had one area of one weld with a condition

similar to pump "C". Pump "A" columns had no visible areas with the

defective condition of pump "C".

The inspector saw a photograph of the defective condition of pump "C"

columns and examined visually the column section welds of pump "A", in-

cluding both the inside and outside surfaces of the longitudinal welds and

the six circumferential flange to pipe welds. The longitudinal welds were

noted to be nonmagnetic while the circumferential welds were slightly

magnetic as typical for austenitic stainless steel weld with at least 10%

ferrite. The Northeast Utilities Engineering / Materials Laboratory report

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dated March 29, 1985, by M. Galler and the purchase order for the columns I

were reviewed. The pump 'B" and "C" columns have been repaired, "C" by the

manufacturer and "B" at the site and examined both visually and ultra-  !

sonically. The pump "A" column flange to pipe welds are scheduled for l

ultrasonic and formal visual examination. The pump manufacturer is con- l

ducting an analysis of the weld problem.

No violations were identified.

7.0 QA/QC Involvement in Areas Inspected

The inspector observed QA/QC personnel to be present and involved in

areas covered by this inspection. Procedures used in ultrasonic

examination, eddy current examination, and sleeving were noted to be

reviewed by QA as part of the plant operating review committee activity

in advance of performance of the actual work activities. During

sleeving and eddy current sleeved tube area examination, QC personnel

were present and actively involved in documentation of work steps and

sequences. Level III nondestructive examination personnel were involved

in both ultrasonic and eddy current examination activity.

No violations were identified.

8. Exit Meeting

The inspector met with licensee representatives, listed in paragraph 1,

at the conclusion of the inspection to summarize the scope and findings

of the inspection. At no time during this inspection was written

material provided to the licm see by the inspector.

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