ML20126F422

Forwards Response to Generic Ltr 85-02 Re Recommended Actions Stemming from NRC Integrated Program for Resolution of Unresolved Safety Issue Concerning Steam Generator Tube Integrity

ML20126F422
Person / Time
Site:	Seabrook
Issue date:	06/13/1985
From:	Johnson W PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	Thompson H Office of Nuclear Reactor Regulation
References
GL-85-02, GL-85-2, SBN-815, NUDOCS 8506170466
Download: ML20126F422 (9)

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Wendell P. Johnson Vice President Putse Sendce of New Hampshire New Hampshire Yankee Division June 13, 1985 SBN - 815 T.F. B5.3.7 United States Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Mr. Hugh L. Thompson, Jr., Director Division of Licensing Office of Nuclear Reactor Regulation

References:

a) Construction Permits CPPR-135 and CPPR-136, Docket Nos.

50-443 and 50-444 b) Generic Letter 85 Staff Recommended Actions Stemming From NRC Integrated Program for the Resolution of USI Regarding Steam Generator Tube Integrity, Dated April 17, 1985. ,

. 1 Subj ect: Response to Generic Letter 85-02

Dear Sir:

In answer to your request in Reference b, enclosed please find our response to each item as it relates to the Seabrook Station Steam Generator Tube Integrity.

Very truly yours, Vilhi/Q Wendell P. Johnson Enclosures cc: ASLB Service List 8506170466 850603 3 PDR ADOCK 050 i

f e g P.O. Box 300 Seabrook,NHO3874 Telephone (603)474-9521

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' William S. Jordan, III Donald E. Chick Town Manager

• Diane Curran Harmon, Weiss & Jordan Town of Exeter 20001 S. Street, N.W. 10 Front Street Exeter, NH 03833 Suite 430 Washington, D.C. 20009 Brentwood Board of Selectmen RED Dalton Road Robert G. Perlis Brentwood, NH 03833 Office of the Executive Legal Director U.S. Nuclear Regulatory Commission Richard E. Sullivan, Mayor Washington, DC 20555 City Hall Robert A. Backus, Esquire .

Newburyport, MA 01950 116 Lowell Street Calvin A. Canney P.O. Box 516 City Manager Manchester, NH 03105 City Hall Philip Ahrens, Esquire 126 Daniel Street Assistant Attorney General Portsmouth, NH 03801 Augusta, ME 04333 ,

Dana Bisbee, Esquire Assistant Attorney General Mr. John B. Tanzer Office of the Attorney General Designated Representative of the Town of Hampton 208 State House Annex Concord, NH 03301 5 Morningside Drive Hampton, NH 03842 ~

Anne Verge, Chairperson Board of Selectmen Roberta C. Pevear Town Hall Designated Representative of South Hampton, NH 03842 the Town of Hampton Falls Drinkwater Road Patrick J. McKeon Hampton Falls, NH 03844 Selectmen's Office 10 Central Road Mrs. Sandra Gavutis Rye, NH 03870 Designated Representative of the Town of Kensington Carole F. Kagan, Esquire RFD 1 Atomic Safety and Licensing Board Panel East Kingston, NH 03827 U.S. Nuclear Regulatory Commission Jo Ann Shotwell, Esquire Washington, DC 20555 Assistant Attorney General Mr. Angi Machiros Environmental Protection Bureau Chairman of the Board of Selectmen Department of the Attorney General Town of Newbury One Ashburton Place, 19th Floor Newbury, MA 01950 Boston, MA 02108 Town Manager's Office Senator Gordon J. Humphrey Town Hall - Friend Street-U.S. Senate Amesbury, MA 01913 Washington, DC 20510 (ATTN: Tom Burack) Senator Gordon J. Humphrey 1 Pillsbury Street Diana P. Randall Concord, NH 03301 70 Collins Street (ATTN: Herb Boynton)

Seabrook, NH 03874 1

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. Paga 1 of 6 ENCLOSURE 1 TO SBN - 815 1.a PREVENTION AND DETECTION OF LOOSE PARTS (INSPECTIONS)

Staff Recommended Action Visual inspections should be performed on the steam generator secondary side in the vicinity of the tube sheet, both along the entire periphery of the tube bundle and along the tube lane, for purposes of identifying loose parts or foreign objects on the tubesheet, and external damage to peripheral tubes just above the tubesheet. An appropriate optical device should be used (e.g., mini-TV camera, fiber optics). Loose parts or foreign objects which are found should be removed from the steam generators. Tubes observed to have visual damage should be eddy current inspected and plugged if found to be defective.

These visual inspections should be performed: (1) for all steam generators at each plant at the next planned outage for eddy current testing, (2) after any secondary side modifications, or repairs, to steam generator internals, and (3) where eddy current indications are found in the free span portion of peripheral tubes, unless it has been established that the indication did not result from damage by a loose part or foreign object.

For PWR OL applicants, such inspections should be part of the preservice inspection.

For steam generator models where certain-segments of the peripheral region can be shown not to be accessible to an appropriate optical device, licensees and applicants should implement alternative actions to address these inaccessible areas, as appropriate.

Licensees should take appropriate precautions to minimize the potential for' corrosion while the tube bundle is exposed to air. The ,,resence of chemical species such as sulfur may aggravate this potentini, and may make exposure to the atmosphere inadvisable until appropriate remedial measures are taken.

Response

Steam generator secondary side visual inspections will be performed:

1. Following completion of Hot Functional Testing of each unit,

2. .after secondary side repairs or modifications to steam generator internals,

3. when eddy current examinations indicate potential fretting or wear indicative of potential loose parts.

Page 2 of 6 1.b PREVENTION AND DETECTION OF LOOSE PARTS (QUALITY ASSURANCE)

Staff Recommended Action

_ Quality assurance / quality control procedures for steam generators should im reviewed and revised as necessary to ensure that an effective system exists to preclude introduction of foreign objects into either the primary or secondary _ side of'the steam generator whenever.it is opened (e.'g. , for maintenance, sludge lancing, repairs, inspection operations, modifications). As a minimum,'such procedures ~should include: -(1) detailed accountability procedures for all tools and-equipment used

. during an operation, (2) appropriate controls on foreign objects such as eye glasses and film badges,.(3) cleanliness requirements, and (4) accountability' procedures for components and parts removed from the internals of major components (e.g., reassembly of cut and removed components).

Response

Seabrook Station housekeeping and cleanliness procedures, as well as

' detailed work _ procedures involving. secondary side entry, will contain the four recommendations listed above.

2.a. INSERVICE INSPECTION PROGRAM (FULL LENGTH TUBE INSPECTION)

' Staff Recommended Action The Standard Technical Specifications (STS)' and Regulatory Guide 1.83, Part .C.2.f, currently ~ define a U-tube inspection as meaning ;an inspection of:the steam generator tube from the point of entry on the hot-leg side icompletely around the U-bend.to the top support of the cold-leg side.

The staff recommends that tube ~1nspections 'should ' include an inspection

of the entire length of the tube (tube end to tube end) including the hot leg side, U-bend, and cold leg side.

This' recommended action does not mean-that the hot leg inspection sample and the cold leg inspection sample should necessarily involve the'same tubes. .That is, it does not preclude making separate entries from the hot and cold leg sides and selecting different tubes on the. hot and cold

. leg sides to meet the minimum sampling-requirements for inspection.

Consistent with the current STS requirement, supplemental sample inspections (after the initial 3% sample) under this staff recommended

-action'may be limited to a partial length inspection provide (. the inspection includes those portions of the tube length where degradation was found during initial sampling.

Response

Although Standard Technical Specifications only require inspection to the top support of the_ cold leg side (hot leg-entry), Seabrook Station intends to perform tube end to tube end inspections whenever feasible.

Seabrook Station Unit No.1 Steam Generator' Preservice Inspections were performed tube end to tube end.

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Pzga 3 of 6 2.b -INSERVICE INSPECTION PROGRAM (INSPECTION INTERVAL)

Staff Recommended Action The maximum allowable time between eddy current inspections of an; individual steam generator should be limited in a manner consistent with Section 4.4.5.3 of the Standard Technical Specifications, and in addition should not extend beyond 72 months.

-Response The ISeabrook Station Steam Generator eddy current Inservice Inspection

. Program,' will be in accordance with the Seabrook Station Technical Specifications.

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Paga 4 of 6 3.a SECONDARY WATER CHEMISTRY PROGRAM Staff Recommended Action Licensees and applicants should have a secondary water chemistry program (SWCP) to minimize steam generator tube degradation.

The specific plant program should incorporate the secondary water chemistry guidelines in SGOG Special Report EPRI-NP-2704, "PWR Secondary Water. Chemistry Guidelines," October 1982, and should address measures taken to minimize steam generator corrosion, including materials selection, chemistry limits, and control methods. In addition, the specific plant procedures should include progressively more stringent corrective actions for out-of-specification water chemistry conditions.

These corrective actions should include power reductions and shutdowns, as appropriate, 54uen excessively corrosive conditions exist. Specific functional individuals should be identified as having the responsibility / authority to interpret plant water chemistry information and initiate appropriate plant actions to adjust chemistry, as necessary.

The referenced SGOG guidelines above were prepared by the Steam Generator Owners ~ Group Water Chemistry Guidelines Committee and represent a consensus opinion of a significant portion of the industry for state-of-the-art secondary water chemistry control.

Response

The Seabrook Station Secondary Water Chemistry Program conforms to the SGOG "PWR Secondary Water Chemistry Guidelines." The program was developed from the Westinghouse and EPRI recommendations and sets the limits and minimum sampling schedule for steam generator blowdown and feedwater. The' program will delineate the control points for critical parameters and the process ' sampling points. The methods for control of secondary-side water chemistry data and record management and the

-corrective actions for off-control-point chemistry are explained in the program.

Action levels are imposed progressively for plant deviations from control limits which can result in power reductions and shutdowns, as appropriate.

The program delineates levels of technical review for chemistry data.

Initial review is by the Chemistry Technician. A computer data handling system' aids the technician by flagging out-of-specification parameters and displaying previous data for trend review. Critical parameters will be trend graphed and reviewed by Chemistry Supervision.

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'Page 5 of 6 3.b' CONDENSER INSERVICE INSPECTION PROGRAM Staff-Recommen'ded Action Licensees 1should implement a condenser _ inservice inspection program. The program should be defined in plant specific safety-related-procedures and include:

1. Procedu'res to implement a condenser inservice inspection program that will~be-initiated if condenser leakage is of such a magnitude that a power reduction. corrective action:is required more than once per three month. period;.and.

2. Identification and location of leakage source (s), either water or air;-

3. . Methods of; repair of leakage;

4. Methodology for determining the cause(s) of leakage; L5. A preventive maintenance program.

Response

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Seabrook Station has formed a Condenser Task Group to address condenser integrity. . The Group's main objective is to ensure equipment and

-procedures ~are in place to. control. air and seawater intrusion into the condenser. 'The following tasks in this program are complete or are in the process of being completed.

1. Procure a helium mass spectrometer.

2. LDevelop a condenser leak detection procedure for air and seawater intrusion.

3. Establish prioritized surveillance list of condenser air inleakage points to check.-

4. Establish visual inspection criteria for water boxes and tube sheets.

5. Stake condenser tubes in high vibration-areas.

s6. Develop map and record keeping system for plugging condenser tubes.

7. ' Perform base line eddy current examination of the condenser tubes prior to commercial operation.

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4. -PRIMARY TO SECONDARY LEAKAGE LIMIT STAFF: RECOMMENDED' ACTION All PWRs that have Technical Specification limits for primary to secondary leakage' rates which are less restrictive than the Standard Technical Specification (STS) limits should implement the STS limits.

Response

Seabrook Station will implement Revision 4, Standard Technical

~ Specification limits for primary to secondary leakage.

5. COOLANT IODINE ACTIVITY LIMIT Staff Recommended Action

PWRs that have Technical. Specifications limits and surveillance for coolant iodine activity that are less restrictive than the Standard Technical Specification.(STS) should implement the STS limits. Those

_ plants identified above_that also have low head high pressure safety injection pumps should either: (1) implement iodine limits which are 20%

of the.STS values, or (2) implement reactor coolant pump trip criteria

~which:will ensure that if offsite power is retained, no loss of forced reactor coolant' system flow will occur for steam generator tube rupture events up to and including the design basis double-ended break of a single steam generator ~ tube, and implement iodine limits consistent with

-the STS.

Response

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Seabrook Station will-implement Revision 4, Standard Technical Specification' limits and surveillance ~for coolant iodine activity.

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In addition, Seabrook Station Emergency Procedures, developed from the WOG Emergency Procedures , provide guidance.for response to steam generator tube rupture and reactor coolant pump trip ~ criteria.

'6. SAFETY INJECTION SIGNAL RESET Staff Recommended' Action The control'1ogic associated with the safety injection pump suction flow c path should be reviewed and modified as necessary,'the-licensees, to minimize the loss' of safety. function associated with safety injection reset.during an SGTR event.' Automatic switchover of safety injection pump' suction from the boric acid storage tanks (BAST) to the refueling.

water storage tanks. should be evaluated with respect to whether the switchover should be made on the basis of low BAST level alone without consideration"of the condition of the SI signal.

Response

Not applicable to Seabrook Station.

p Page 1 of 1 ENCLOSURE 2 TO SBN - 815 Information Requested The enclosed draf t NUREG-0844 Section 2.2.1.2 describes certain limitations which the staff believes to be inherent in the present Technical Specification steam generator ISI requirements pertaining'to Category C-2 inspection results. Licensees and applicants are requested to provide a description of their current policy and actions relative to this issue and any recommendations they have concerning how existing Technical Specification steam generator ISI requirements pertaining to Category C-2 inspection results could be improved to better ensure that adequate inspections will be performed. This descriptio'n should include a response to.the following questions:

1. What factors do, or would, the licensee or applicant consider in determining (a) whether additional tubes should be inspected beyond what is required by the Technical Specifications, (b) whether all steam generators should be included in the inspection program, and (c) when the' steam generators should be reinspected.

2. To what extent do these factors include consideration of the degradation mechanism itself and its potential for causing a tube to

.im vulnerable to rupture during severe transients or postulated

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. accident before rupture or leakage of that tube occurs during normal operation.

Response

1. Seabrook Station would consider the following factors in determining whether additional tubes should be inspected, all steam generators should be included, or inspection frequencies should be shortened:

a) margin to the Technical Specification acceptance criteria,.

b) abnormal trends; e.g., localized indications or indications of a specific degradation mechanism that requires additional data,-

c) accelerated mechanisms, d) ambiguous or unusual data that may require refined techniques or special equipment.

2. Degradation mechanisms will be closely monitored 'and analyzed. Since-

,L Seabrook Station is a seawater cooled plant; .particular attention

, will be paid to chloride induced mechanisms. ._ Degradation mechanisms will be considered when' making preventive tube plugging decisions, especially in those cases where stress may contribute -to the

. corrosion mechanism.

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