ML19325F035

Forwards Plan Addressing Implementation of Insp for Piping Susceptible to IGSCC for Winter 1989 Refueling Outage. Augmented Leakage Monitoring Program Will Continue,Per NUREG-0313,Rev 2

ML19325F035
Person / Time
Site:	Quad Cities
Issue date:	11/07/1989
From:	Stols R COMMONWEALTH EDISON CO.
To:	Murley T Office of Nuclear Reactor Regulation
References
RTR-NUREG-0313, RTR-NUREG-313 0346T:1, 346T:1, GL-88-01, GL-88-1, NUDOCS 8911130256
Download: ML19325F035 (5)

Text

- - . . . _

b

[h . j,7

/ s Commonwealth Edison  ;

• ,'f _ 72 West Ad:.ms Street, Chicago, Illinois

\ "' . Kdoress Reply to:PoTorsiiBoBF  ;

- N Chicago, Illinois 00600 0767 November 7, 1989 l

i Dr. Thomas E. Murley, Director' 1

Office of Nuclear Reactor Regulation l U.S. Nuclear Regulatory Commission Nashington, DC 20555 a I

l.

l' I ~

Subject:

Quad Cities Station Unit 2 Inspection Plan for Piping Susceptible to Intergranular Stress Corrosion Cracking (IGSCC)

NRC Docket No. 50-265 i

Referer.ces (a): Generic letter 88-01: NRC Position on IGSCC:in BHR Austenttic Stainless Steel Piping dated January'25, 1988 (b): . T.M. Ross letter to T.J. Kovach dated October 3, 1989. ,

i Dr. Hurley:

Reference (a) provides the requirements for inspection of piping that is susceptible to Intergranular' Stress Corrosion Cracking (IGSCC) at BHR facilities. The attached plan' addresses the implementation of the inspection requirements contained in Generic Letter 88-01 for the upcoming Unit 2 Refuelint Outage currently scheduled for February, 1990.

The inspection plan addresses the recommendations contained in the lanit 2 IGSCC Inspection Plan and Repairs Safety Evaluation for the previous outage (Reference (b)). Specifically, Helds 02AS-S6 and 02BS-F14 and all IGSCC j

-welds treated with Induction Heating Stress Improvement will be examined during

% the upcoming refueling outage. Finally, Quad Cities Station will continue to ,

s' l- implement the augmented leakage monitoring program which is consistent with l the guidance of NUREG-0313, Revision 2.  !

l l

1, 1 0346T:1 hod '

e t l l

+

f 1 8911130256 891107 fDR1 ADOCK05000g65 l

= -

l- .  !

I Dr. T.E. Murley November 7, 1989  :

i f

. i I )

r Comm>nwealth Edison requests preliminary approval of the inspection  !

plan by December 8, 1989 to facilitate outage planning. i

!- Please direct any qtestions you may have regarding this matter to '

! this office, j

Very truly yours, i /

R. Stols Nuclear Licensing Administrator t

im -

i Attachments ,

4 cc: T.M. Ross - Project Manager, NRR  ;

NRC Resident Inspector - Quad Cities i

P  !

QUAD CITIES UNIT TH0 PLAN FDA IGSCC )

RELATED ACTIVITIES r HINTER 1990 REFUELING DUTAGE i

1. The accompanying table for Quad Cities Unit Two provides the inspection i plan for the Hinter 1990 refueling outage to address the Intergranular  :

Stress Corro ;on Cracking (IGSCC) concerns. The plan meets or exceeds the requiremeats of Generic letter 88-01 (or NUREG-0313. Revision 2). It also addresses the requirements of the Safety Evaluation Report dated October 3, 1989, for Quad Cities Nuclear Power Station, Unit Two.

2, The proposed inspection plan includes the examination of 183 austenitic stainless steel weldments categorized in accordance with Generic Letter 88-01 (or NUREG-0313, Revision 2).

Six (6) category "A" weldments will be ultrasonically examined during the upcoming refueling outage (minimum is 2). Two (2) 12-inch safe-end to nozzle (SE-N0Z) welds were selected to assure integrity in light of the recent industry experience with flaws in the SE-N0Z and the thermal tieeve weld areas.

All 100 category "C" weldments which were stress improved by IHSI or MSIP will be ultrasonically examined during the upcoming refueling outage, including welds 02AS-S6 AND 02BS-F14.

All 16 remaining category "D" weldments, after the planned removal of the Head Spray and Control Rod Drive piping, will be ultrasonically examined during the upcoming refueling outage.

All 31 category "E" weldments will be ultrasonically examined during the upcoming refueling outage.

l All 6 category "F" weldments will be examined during the upcoming l refueling outage. Ultrasonic examination will be performed on these six welds after they receive additional repair to be in compliance with the Generic Letter 88-01 requirements for overlay repaired welds.

l All 24 remaining and accessible category "G" weldments, after the planned L piping modification, will be ultrasonically examined during the upcoming refueling outage. Due to the planned piping repair on t'le Reactor Water Cleanup (RHCU) line, one (1) category "G" weldment will be replaced by i two (2) category "A" welds. IGSCC resistant material will be used for the replacement.

Because the scope of the proposed inspection plan satisfies the Generic

, Letter 88-01 inspection requirements of categories A, C, D, and E welds for two (2) refueling cycles, no ultrasonic examination of categories A, C, D, and E welds will be performed during the following refueling outage, currently scheduled in the Fall of 1991.

However, if new flawed welds are found and repaired during the Hinter 1990 refueling outage with standard overlay design, half of these newly repaired welds will be ultrasonically examined during the following refueling outage in 1991.

3. Examination of 100'f. of categorier C. O, and E is proposed because:

a. This plan will provide a baseline of IGSCC susceptible weldments prior to the operation of the Hydrogen Water Chemistry System,

b. This plan will facilitate outage p1haning by eliminating the possibility of inspection sample expansion.

c. This plan will save CECO money it, the long run by eliminating the need to mobilize large NDE and weld repair crews during the 1991 refueling outage.

4. Ultrasonic examination cf austenitic stainless steel welds will be performed by Level II or III examiners qualified by EPRI after September 10, 1985. Examination of overlay repaired welds will be performed by Level II or III examiners qualified by EPRI to examine overlay repaired welds using the EPRI developed technioue. Automated ultrasonic examination may be utilized on both piping and overlay repaired weldments.

5. If IGSCC flaw indications are identified, they will be resolved consistent with the intent of Generic Letter 88-01 If repairs are required, weld overlays may be utilized which will take into account flaw characterization, depth, length, and material toughness.

6. Up to 36 weldments will be stress ~ improved using the Mechanical Stress Improvement Process (MSIP) during the upcoming outage. These welds are in either category D or G. It is the intent of the station to ultrasonically examine all welds following MSIP.

7. The following are three (3) planned stainless steel piping modifications to be implemented during the upcoming refueling outage,

a. The replacement of a section of RHCU piping with conforming material. This section begins at the last elbow inside the containment and ends at the outboard containment isolation valve.

b. The removal of the CRD Return piping inside the containment and capping of the CRD Return nozzle,

c. The remeval of the Head Spray piping and installation of a blind flange on the Head Spray nozzle.

8. This inspection plan supercedes previously submitted plans.

6646B/2-3

_m

x AUGMENTED STAINLESS STEEL +

HELD INSPECTION PLAN WINTER 1990 L CATEGORY QUAD-CITIES

_ UNIT - 2 SIZE TOTAL A 8 C D E F . G REMARKS RECIRCULATION Outlets 28" 32 2 0 18 0 6 6 0 Noz - SE 28" 2 2 0 0 0 0 0 0 Header 22" 22 8 0 10 2 2 0 0 Risers 12" 44 0 0 23 0 21 0 0 Noz - SE 12" 10 10 0 0 0 0 0 0

_ Bypass 4" 12 4 0 0 4 0 0 4 RHR - SDC 20" 18 0 0 2 5 2 0 9 1 inaccessible weld LPCI 16" 23 0 0 26 -- 0 0 0 0 CORE SPRAY 10" 25 4 0 21 0 0 0 0 Jat Pump Inst. 12",8",4" 10 0 0 0 4 0 0 6 RHCU,Hd.Sp, Spare Noz 6" 45 33 0 0 3 0 2 7 3 inaccessible welds on RNCU Hd_.Sp. Hd.Vt CR_D 4" 28 2 0 0 11 0 0 15 1 inaccessible weld on Hd._.Sym CURRENT HELD POPULATION 274 65 0 100 29 31 8 41 Estimated Held Population After 248 68 0 100 16 31 6 27 2 inacc. welds on RMCU (Cat. A) '

the Planned Piping Removal 1 inacc. weld on RNCU (Cat. G)

Proiect (CRD. RNCU. Hd. Sp.) 1 inacc weld on SDC E at. G)

Generic Letter 88-01, Inspection 127 3 50 14 16 8 36 R_e_quirements e (Note 1) (4.21) (501) (501) (50%) (1001) (1001)

Planned IGSCC Inspection During Hinter 1990 Refueling Outage 183 6 0 100 16 31 6 24 Note 2)

Revision Date: 11-06-89 Note 1: The Generic Letter 88-01 inspection requirements are based on current weld population.

Note R: The Planned IGSCC inspection is based on the g_stimated weld population after the implementation of the planned piping removal / replacement project. If the estimated weld population is changed for any reasons, the Planned IGSCC inspection requirements will be adjusted accordingly.

66478/2

- - _ _ . . _ _ _ _ _ . - - _ _ _ _ _ _ _ . _ . _ . - -