ML20140E589

Supplements 970214 Response to GL 96-06, Assurance of Equipment Operability & Containment Integrity During Design- Basis Accident Conditions

ML20140E589
Person / Time
Site:	Crane
Issue date:	06/02/1997
From:	Langenbach J GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
6710-97-2226, GL-96-06, GL-96-6, NUDOCS 9706120151
Download: ML20140E589 (3)

Text

-

l GPU Nuclear, Inc.

(

Route 441 South NUCLEAg Post Office Box 480 Middletown, PA 17057-0480 Tel 717 944 7621 June 02,1997 6710-97-2226 U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555

Subject:

Three Mile Island Nuclear Station, Unit 1 (TMI-1)

Operating License No. DPR-50 Docket No. 50-289 GPU Nuclear Supplemental Response to Generic Letter (GL) 96-06,

" Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions,"-Corrective Actions Generic Letter (GL) 96-06 requested that licensees determine if the piping which penetrates the containment is susceptible to overpressurization from thermal expansion of fluid trapped between the containment isolation valves or if the containment air cooler cooling water systems are susceptible to either water hammer or two-phase flow conditions during postulated accident conditions. Licensees were further requested to assess operability for any systems found to be susceptible to these phenomena and to provide a report on the actions taken, conclusions reached relative to susceptibility, the basis for continued operability of the afTected systems, as applicable, and corrective actions implemented or planned.

GPU Nuclear provided a response to Generic Letter (GL) 96-06 on February 14,1997. In our response we discussed the systems and components that were found to be afTected by the concerns raised by the GL and we provided the basis for our conclusion that operability was g"""'.

unaffected. At the time ofour response, we had not completed design verification of our g

calculations and analysis; nor had we completed the identification of the long-term corrective g

actions. Therefore, the purpose of this letter is to supplement our response and describe our plans ag' for corrective actions. This letter is being provided on the first work day following our g

May 31,1997 commitment schedule with the concurrence of our NRC Project Manager, Ban g

Buckley on May 28,1997.

EB, The design verification of calculations and analyses related to GPU Nuclear review of GL 96-06 has been completed and the conclusions provided in our previous letter regarding operability

.1.,'. 0 0 J pave been confirmed. Our letter reponed that eleven (11) piping segments were afTected although none exceeded the ASME Section Ill, Appendix F criteria. None of these piping segments represent a pressurization concern during normal plant operation and none are required I

to operate post accident. The condition of these piping segments were reviewed and determined 5

9706120151 970602 PDR ADOCK 05000289 P

PDR.

6710-97-2226-Page 2 or2 3

to be operable because they maintain containment integrity and are not required to open following a LOCA. None of the pipes will fail based on ASME Section III, Appendix F criteria for Level D events. Therefore, containment integrity is assured and the containment isolation function of these pipe segments remains operable. Further analysis has demonstrated that the stresses under the postulated accident conditions for one of these piping segments (the Reactor Coolant Pump Seal Return Line) are within the code allowable stress. Therefore, modifications

' for this piping segment will not be required.

To assure compliance with the applicable code requirements, corrective actions are being

. planned for those ten (10) piping segments that were found to be potentially stressed beyond that -

allowed by the code. These ten piping segments are identified as follows: the "A" and "B" Once Through Steam Generator (OTSG) Sampling Lines, the Intermediate Closed Cooling Water

'(ICCW) Return Line, the Reclaimed Water Supply Line, the Makeup and Purification Letdown Outlet Line, the Pressurizer / Reactor Coolant Sampling Line, the Reactor Coolant Drain Tank (RCDT) Transfer Line, the Reactor Coolant Pump Cooling Return Line, and the "A" and "B" Core Flood Tank Sampling Lines. Modifications are being planned to install pressure protection for these piping segments during the Cycle 12 Refueling (12R) Outage which is scheduled for September 1997.-

Our letter also reported that we had evaluated the consequences if a Reactor Building Emergency Cooling (RBEC) System relief valve (RR-Vi1 A/B/C) were to leak, or in the worst case, to lift and fail to rescat during a design basis accident. We stated that there is adequate time to detect and isolate the leaking relief valve before dilution of reactor coolant or flooding of safety related equipment would occur, but we were considering hardware changes or procedural actions to eliminate the need for detection and isolation of a leaking relief valve. To alleviate this concern, a modification to the RBEC System is being planned for the 12R Outage to relocate these valves from the Reactor Building to the Intermediate Building.

j Sincerely, J. W. Langent ac Vice Presidea and Director, TMI MRK Attachment cc:

Administrator, NRC Region I TMI Senior NRC Resident Inspector TMI Senior NRC Project Manager

4 6710-97-2226 Attac,hment METROPOLITAN EDISON COMPANY JERSEY CENTRAL POWER AND LIGHT COMPANY PENNSYLVANIA POWER AND LIGHT COMPANY GPU NUCLEAR INCORPORATED Three Mile Island Nuclear Station, Unit 1 (TMI-1)

Operating License No. DPR-50 Docket No. 50-289 1, James W. Langenbach being duly sworn, state that I am a Vice President of GPU Nuclear, Inc. and that I am duly authorized to execute and file this response on behalf of GPU Nuclear. To the best of my knowledge and belief, the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information by other GPU Nuclear employees and/or consultants. Such information has been reviewed in accordance with company practices and I believe it to be reliable.

P James W. Langenbach Vice President and Director, TMI Signed and sworn before me this day of_dunct.1997.

_h b N Notary Public Notarial Seal J. McElwee, Notary Pubhc ue

• ~e'@3%

r

. a..

. -, ~ ~

i