NRC-98-0058, Provides Update to Licensee Response to GL 96-06, Assurance of Equipment Operability & Containment Integrity During Design-Basis Accident Conditions,

Provides Update to Licensee Response to GL 96-06, Assurance of Equipment Operability & Containment Integrity During Design-Basis Accident Conditions,

ML20217N772
Person / Time
Site:	Fermi
Issue date:	03/27/1998
From:	Gipson D DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-98-0058, CON-NRC-98-58 GL-96-06, GL-96-6, TAC-M96811, NUDOCS 9804090202
Download: ML20217N772 (4)

Text

a

• Douglas R. Gl;mn Senior W e President. Nu(lear Generation

.g.

fenn12

, 6400 North IMxie lluy, Newyert, Michigan 4466 Tel:3134861d01 fat 3131.86.4172 Detroit Edictus March 27,1998 NRC-98-0058 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) NRC G. neric Letter 90-06: Aswrance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions, dated September 30,1996

3) Detroit Edison Letter to NRC," Detroit Edison 30-Day Response to NRC Generic Letter 96-06," NRC 96-0118, dated October 30, 1996

4) Detroit Edison Letter to NRC," Detroit Edison 120-Day Response to NRC Generic Letter 96-06," NRC 97-0003, dated January 28, 1997

5) NRC Letter to Detroit Edison," Request for Additional Information Related to the Fermi-2 Response to Generic Letter 96-06," dated September 9,1997 (TAC No. M96811)

6) Detroit Edison Letter to NRC," Additional Information Related to Detroit Edison Response to NRC Generic Letter 96-06," NRC 0111, dated October 17,1997 l

7) Electric Power Research Institute (EPRI) Report TR-108812R1,

" Response ofIsolated Piping to Thermally Induced Overpressuization during a Loss of Coolant Accident (GL 96-r,7 n n - () '

06)," dated facuary,1998 -

Q i

Undate of Detroit Edison Response to NRC Generic I etter 96-06

Subject:

[

9804090202 980327 I l PDR ADOCK 05000341' p PDR_ A Irn;!!nergy Compn 3

,- USNRC-e -

NRC-98-0058 Page 2 In Reference 6 Detroit Edison committed to provide an update by March 31,1998, regarding the progress of efforts being made, in participation with the Electric Power Research Institute (EPRI), to resolve the concerns of thermally induced overpressurization in affected piping systems at Fermi 2, as described in Detroit Edison response to NRC Generic Letter 96-06. The purpose of this letter is to provide the committed update to the NRC.. '

As discussed in Detroit Edison's 120-day response to Generic Letter 96-06 (Reference 4), Fermi 2 has.six drywell penetrations that are susceptible to thermally induced overpressurization due to increase in the drywell ambient temperature aAer a Loss of Coolant Accident (LOCA).

These penetrations are:

1. Penetration X-8: Main Steam Drain Line

2. Penetration X-18: Drywell Floor Drain Sump Discharge Line

3. Penetration X-19: Drywell Equipment Drain Sump Discharge Line

4. Penetration X-29Aa: Reactor Recirculation Water Sample Line

5. Penetration X-49a: Reactor Recirculation Pump B Seal Purge Line 6.' Penetration X-Sla: Reactor Recirculation Pump A Seal Purge Line Detroit Edison has participated in the EPRI analysis and testing activities that were -

intended to establish a technical basis to demonstrate the acceptability of these penetrations without modification. Calculations demonstrate that Penetrations X-8, X-49a, and X-S lo will satisfy the strain criteria as proposed in the EPRI Repon TR-108812R1 (Refeience 7). Therefore, no modifications are planned for these piping systems at this tin.e. For the Reactor Recirculation Water Sample Line (Penetration X-29Aa), calculati ms show that pressure acting under the inboard isolation valve seat will open & spring-to-close isolation valve to relieve the penetration pressure to the reactor befort. 3e piping could be subjected to overpressurization. Therefore, the Reactor Recirculation Water Sample Line (Penetration X-29Aa) is also acceptable l without modification. l The EPRI analysis and testing activities have indicated that piping systems with short sections of thinner walled piping are more susceptible t, damage from thermal  !

overpressurization since the piping strain is concentrated in <he thinner wall piping. j

, The Drywell Floor Drain Sump Discharge Line (Penetration X-18) and the Drywell Equipment Drain Sump Discharge Line (Penetration X-19) have long lengths of schedule 160 piping in series with shoner sections of schedule 40 piping. Since these piping systems are not expected to satisfy the EPRI strain criteria if subjected to the thermal overpressure, Detroit Edison intends to implement overpressure  ;

protection modifications for Penetrations X-18 and X-19 during the next refueling j 1

i j

-4 i

,- USNRC.'

.-. - NRC-98-0058 Page 3 l

outage scheduled for Fall 1998. The proposed design for the modification utilizes a single rupture disk with a set pressure much higher than the system operating pressure, that will relieve the overpressure'to an expansion tank. The assembly will be located outside the containment.

If you have any questions, please contact Mr. Norman K. Peterson, Director -

Nuclear Licensing at (734) 586-4258.

Sincerely, ,,

cc: A. B. Beach B. L. Burgess G. A. Harris A. J. Kugler l

j l

l l

1 I

l l

l l

a

Q USNRC NRC-98-0058 Page 4 1, DOUGLAS R. GIPSON, do hereby affirm that the foregoing statements are based on facts rad circumstances which are true and accurate to the best of my knowledge and belief.

~

DOUGLAS R. G1PSON Senior Vice President, Nuclear Generation On this 8 day of 1998 before me personally appeared Douglas R.

Gipson, being first duly sw'cru and says that he executed the foregoing as his free act i and deed.

l Mb Notary Public ROSAUE A. ARMETTA NOTARYPUBLIC MONROECOUNTY,tc MYCOMMISSIONEXPlRF.S10/11/99 I

l l

I