NRC-92-0090, Responds to Three Outstanding Issues Associated W/Generic Ltr 88-01, NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping. Issues Include Resolution of TS 3/4.4.3.2 Re RCS Operational Leakage Vs Generic Ltr

Responds to Three Outstanding Issues Associated W/Generic Ltr 88-01, NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping. Issues Include Resolution of TS 3/4.4.3.2 Re RCS Operational Leakage Vs Generic Ltr

ML20099C253
Person / Time
Site:	Fermi
Issue date:	07/29/1992
From:	Orser W DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-92-0090, CON-NRC-92-90 GL-88-01, GL-88-1, TAC-M69135, TAC-M77674, NUDOCS 9208040044
Download: ML20099C253 (9)

Text

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cmim w NOCIG8f operations July 29, 1992 URC-92-0090 U. S. Nuclear Regulatory Commission Attu: Docume r Contz1 Desk Washington, 1.

C.

205' F.e f e renc es 2 1)

Fermi 2 NRC Docket No. 50-341 URC License No. NPF-43 4

2) Generic Let ter 88-01, dat ed Janua ry 25, 1988

3) Generic Letter 88-01. Supplement '. dated February 4, 1992

4) Detroit Edicon Letter to NRC. NRC-88-0191, dated August 5, 1988 5)

NRC Letter to Detrc -

Edison. TAC No. 69135, dated ria rch 16, 1989 6)

De t roi t Edison Letter to NRC, NRC-89-0106, dated Way 12, 1989 7)

NRC Letter to Det roit Edison. TAC No. 69135. dated January 4.1990

8) De t roit Edison Letter to NRC, NRC-90-0103, dated

.luly 3, 1990 9)

NRC Letter to Detzt>it Edison, TAC Ho. 77674, dated June 11, 1991

Subject:

Fermi 2 Respcase to Generic Lette_t 88-01. Supplement 1 "NRC Position on Intergranular Strecc Corrosion Cracki ng

_QGECC) in BWR Austenitic Stainless Steel Piping" 1

Detroit Edidon (DECO) hus reviewed Generic Letter 88-01 Supplement 1

(

"NRC Position on Intergranular Stress Corrosion Cracking (IGSCC) in l

BWR Austenitic St ainless Steel Piping" for it s applicability to Fermi i

?.

This review indicates that there are two outstanding issues ansociated with this generic letter.

These issues are: (1) Resolution l

of the dif ference between the currenc Fermi 2 Technical Specifica t ion L

(TS) 3/4.4.3.2. " Reactor Coc.lant Sys tem Ope rational Leakage". leakrate rate of change requirement and the GL 88-01 Staff position; and 9200040044 920729 POR ADOCK 05000341 l,e,d' i

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USNRC July 29, 1992 NRC-92-009C Page 2 (2) Removal of condensate and f eedwater system welds under the secpe of GL 88-01 f rom the Incervice Inspection - Nondest ructive Examination (I SI-NDE) Program (Plan) for Fermi 2 Power Plant (ISI-NDP Program).

The current TS 3/4.4.3.2 leakrate rate of change limit is a 2 gpm increase within any 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> period and the NRC Staf f position expressed in GL 88-01 is a 2 gpm increase in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or less.

This issue has k

been previously discussed in Ref erencec 4 and 6 through 9.

Reference 7, the NRC safety evaluation for the Fermi 2 response to GL 88-01, states that the current Fermi 2 TS limit is not acceptable and that this is the only outstanding GL 88-01 issue.

Reference 9 states that the NRC will review our recponse to this issue as part of the DECO response to GL 88-01 Supplement 1.

DECO propores to resolve the TS lenkrat e issue by submit ting a proposed license amendment that incorporatas the CL 88-01 Staf f position in TS 3/4.4.3.2.

The proposed licenae amendment will be submit t ed under separate cove r.

This license amende;ent is scheduled to be submi+ted to the NRC by h

October 1, 1992.

The scid issue is a new isste identified by DECn.

Through this letter, DECO proposes to resolve thit issue by requesting NRC approval for removing the subject condenst : e and f eedwater system GL 85-01 welda from the ISI-NDE Program. The justi fication f or removing these welds f rom the ISI-NDE Pro am is included in Enc'orure 1 of this letter.

If you have any questions, please contact Mr. David H. Brown at (313)

+

586-4213.

Sincerely,-

/

/l%U

Enclosures:

- Justification for Removing Condensate and Feedwat er System GL 88-01 Welds f rom the Fermi 2 ISI-NDE Program - Table of Welds Proposed for Removal cc: ANIT - M. Furguson Chief Inspector, Michigan Dept. of Labor, Bureau of Constrmetion Codes / Boiler Division - F. Aben T. Colburn A

B. Davis M. Y. Phillips S. Stasek

Enclosure to NRC-92-0090 i

1 ENCLOSURE 1 Justification for T

Removing Condensate and Fem ater System GL 88-01 Wolds from the Fermi 2 ISI-NDE Program l

l H

i i

4

• to NRC'92-0090 Page.1 Ju.stification for Hemoving Condensate and FeEater System GL 88-01 Welds from the Fcrai 2 ISI-NDE Prograu Introduct.lon The NRC issued Generic Letter 88-01, "NPC Position on ICSCC in BWH Austenitic Stainloss Steel Piping" to provice the NRC Staff positions on intergranular stress corrosion cracking problems. The technical bases for the positions outlined in GL 88-01 are detailed in NUREG-0313, Revision 2, " Technical Report on Material Selection and Process Guidelines for BWR Coolant Pressure Boundary Piping"-

In Reference 4, the initial DECO response to GL 8-8-01, DECO focused primarily on piping within ecntainment.

The GL 88-21 welds were identified as Category A, B, and G ASME III, Class 1 welds inside contait. ment,.

In Reference 5, the NRC requested additional information and 3 revised format for the GL 88-01 response. The DECO response (Reference /) provided the information requested and presented the GL 88-01 response in the requested format. This response identified 24 additional Category G welds outside of containment.

These non-safety related, non-seismically qualified ANSI B31.1 welds are part of the condensate and feedwater' systems and are located on the Number 3, 4, S, l

and 6 Feedwater Heaters.

The subiect welds were administratively upgraded from Category G to Category D following inspection during the first refueling outage. They are currently included in the Fermi 2 ISI-NDE Prc cam because they were previously identified as GL 88-01 welds.

As 'a result of the GL 88-01, St.pplement 1, review, EECo concluded that the subje)t condensate and feedwater system welds are not within the scope of GL 88-01. Therefore, the subject welds should be removed f4 on the Fermi 2 ISI-NDE Program.

-Proposed ISI-NDE Program Chango DECO is proposing that the 24 condensat,e and feedwater system M SI B 31.1 welds listed in Enclosure 2 be deleted from the Fermi 2 ISI-NDE Program because they are not within the scope of GL 88-01.

9 '

Enclosure to NRC-92-0090 l

PNCLOSURE 2 Table of Welds Proposs for Removal l

l.

l 1

1.

e

" 4 Enclusure 2 to NRC-92-0090 Page 1 Tpble of Welds Proposed for Hemoval Weld Identification Configuration Diameter System FW-N21-3109-18WO SE-Pipe 24 inches Feeduster SW-N21-01-B002-ASWE Noz-SE 24 inches Feedwater FW-N21-3109-29WO SE-Pipe 24 inches Feedwater SW-N21-01-R001-ASWE Noz-SE 24 inches Feedwater FF-NPO-3107-0W1 SE-Pipe 20 inches Condensate SW-N20-03-8013-BWSE Noz-SE 20 inches Condensate FW-N20-3107-0W17 SE-Pipe 20 inches Condensate SW-N20-03-8014-BWSE Noz-SE 20 inches Condensate FW-N20-3105-24WO SE-Pipe 20 inches Condensate SW-N20-03-8013-AWSE Noz-SE 20 inches Condensate FW-N20-3105-16WO SE-Pipe 20 inches Condensate SW-N20-03-8014-AWSE Non-SE 20 inches Condensate FW-N20-3105-0W23 SE-PIPE 20 inches Condensate SW-N20-03-B011-BWSE Noz-SE 20 inches Condensate FW-N20-3105-0W15 SE-Pipe 20 inches Condensate L

_SW-N20-03-8012-BWSE Noz-SE 20 inches Condensate FW-N20-3105-22WO SE-Pipe 20 inches.

Condensate SW-N20-03-B011-AWSE Noz-SE 20 inches Condensate SE-Pipe : Safe end to pipe t

Noz-SE : Nozzle to safe end l

l l

u

~..

" to-NhC-92-0090 Page 2 Justification -

- GL 88-01 applies to all BWR piping made of austenitic stainless steel that is 4 inches or larger in nominal diameter and contains reactor coolant at a 0

temperature above 200 F during power operation regardless of Code

- classification. It also applies to reactor vessel attachments and appurtenances such as jet pump instrumentation penetration assemblies and head spray and vent components.

The subject welds should be removed from the scope of GL 88-01 because:

1)

.The-welds are not<1ocated on-piping that contains reactor coolant.

The' subject welds are feedwater heater nozzle welds in " nozzle to safe end" or " safe end to pipe" configurations. As noted in Enclosure 2, they are part of the condensate or feedwater systems. These welds are located on piping that contains condensate which is heated by the feedwater heater trains prior to injection into the reactor pressure

vessel, As noted in Regulatory Guide 1.26 and Fermi 2 UFSAR Subsection 3 1.2.2.5, systems and components within the reactor coolant pressure boundary are classified as Quality Group A.

Fermi 2 UFSAR Table 3 2-1 indic;tes that the feedwater piping within the outermost isolation valves is classified as Quality Group A and, as such, is part of the reactor coolant pressure boundary.

However, sloce the subject welds are en piping located outside of the outboard containment isolation valves B21-F076A and B21-F076B and in the l

turbine building, they are not a part of the reactor coolant pressure L

boundary.

2)

The welds are not located an reactor vessel attachments or

. appurtenances. As stated above, the welds are located on piping that is outside of the outboard containment isolation valves and is not part of the reactor pressure boundary. As stated in Fermi 2 UFSAR Subsection 10.4.7 3, the condensate and feedwater systems are not required for the safe shutdown of the reactor or for operation of the nuclear steam supply system safety features.

3)

The welds are not exposed to all the-conditions needed for

-intergranular stress corrosion cracking (IGSCC) to occur. Threo components must.be present for ICSCC to occur: (1) a susceptible u

material; (2) stress conditions; and (3) an aggressive chemical-(oxidizing) environment. The removal of any one of these components will eliminate the possibility of IGSCC attack. Material susceptibility and stress conditions are present but the oxidizing environment is absent, b

i k'

~

' to NRC-92-0090

- Page 3

- For an oxidizing environment-to. propagate a weld crack, high 0

temperatures (greater than 300 F); high dissolved oxygen (greater than 200 ppb); and high total ionic impurities concentration (conductivity greater than 0.2 uS/cas must be present. Experimental results indicate that the individual ionic impurities, specifically chlorides and sulfates, should be maintained less than 50 ppb.

Under normal conditions, dissolved oxygen-levels are approximately 20 ppb; conductivity is less than 0.06 uS/cm; and individual chloride and sulfate concentrations'are less than 50 ppb. Therefore, IGSCC would be insignificant in the feedwater welds because only one parameter (high temperature) is present.

Based on the above; justification, DECO has-determined that the condensate and feedwater system welds listed in Enclosure 2 are not within the scope of GL 88-01 and should be deleted from the Fermi 2 ISI-NDE Program.

s m orn'

' ' to NRC-92-0090 Page 2 Table 21 Welds Proposed for Hemoval (Continued)

Weld Identification Confi,guration Diameter System FW-N20-3105-14WO SE-Pipe 20 inches Condensate

~

5W-N20-03-B012-ASWE Noz-SE 20 inches Condtnsate FW-N20-3105-0W21 SE-Pipe 20 inches Condensate SW-N20-03-B010-BWSE Naz-SE 20 inches Condensate FW-N20-3105-0W13 SE-Pipe 20 inches Condensate SW-N20-03-B009-BWSE Noz-SE 20 inches Condensate SE-Pipe : Safe end to pipe Noz-SE : hozzle to safe end

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