ML20098B124
| ML20098B124 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 09/27/1995 |
| From: | James Knubel GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20098B125 | List: |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR C311-95-2361, GL-87-02, GL-87-2, NUDOCS 9510020226 | |
| Download: ML20098B124 (4) | |
Text
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.s GPU Nuclear Corporation Route 441 South M
P.O. Box 480 1
Middletown, Pennsylvania 17057-0480 (717)944-7621 i
Writer's Direct Dial Nurnber:
(717) 948-8005 September 27, 1995 C311-95-2361 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Subject:
Three Mile Island Nuclear Generating Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Response to NRC Request For Additional Information Regarding Generic Letter 87-02, " Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors, Unresolved Safety Issue (USI) A-46" GPU Nuclear Corporation hereby submits its response to the NRC request for additional information concerning the TMI-l submittal for Generic Letter 87-02 (Letter No.
C311-95-2190, dated May 17, 1995). The request was made by the NRC letter dated August 29,1995. The enclosure presents botb the NRC questions and the GPU Nuclear j
responses.
1 If you have any additional questions or concerns regarding the enclosed responses, please contact Yosh Nagai, Licensing Engineer at (201) 316-7974.
l Sincerely,
?
J. Knubel Vice President / Director, TMI JK\\YN\\ch 020.138 9510020226 950927 PDR ADOCK 05000289
/
i P
PDR yi GPU Nuclear Corporation is a subsidiary of General Public Utilities Corporation 1
ENCLOSURE Three Mile Island Nuclear Plant, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Response to Questions on USI A-46 Submittal NRC Ouestion 1:
Page 30 of the USI A-46 Seismic Evaluation Report (the report) discusses an option of overflowing the makeup tank to the auxiliary building sump when the makeup tank becomes full from recirculation flow. Is this overflow volume recoverable for later use? If not, why would this option be exercised?
GPU Nuclear Resconse:
The overflow would not be recoverable for future injection. We do not intend to exercise the option of overflowing the makeup tank to the auxiliary building sump. The revised pages 3 (Table of Revisions) and 30 (Section 2.2.3 Part 1) are enclosed to reflect this.
NRC Ouestion 2:
Injection with the high head safety injection pumps (makeup pumps) and venting with the pressurizer pressure-operated relief valve (PORV) was mentioned in several places in the report for pressure, inventory and reactivity control. Does TMI-l plan to use this feed and bleed method as addressed in the emergency operating procedures for decay heat removal as well during an accident?
GPU Nuclear Response:
1 TMI does not intend to use the " feed and bleed" method for decay heat removal as both Once-Through Steam Generators (OTSGs) are available for cooling. Both the primary and alternate paths for decay heat removal rely upon secondary side cooling, and procedures drive operators eventually to the use of river water, as a last resort. However, the " Feed and Bleed" method can be implemented, as an option, by plant Abnormal Transient Procedures if secondary side heat transfer is lost. All of the components required for high pressure injection cooling are on the Safe Shutdown Equipment List (SSEL) i i
f 1
Three Mile Island Nuclear Plant, Unit 1 (TMI-1) j Operatir.g License No. DPR-50 Docket No. 50-289 Response to Questions on USI A-46 Submittal NRC Ouestion 3:
Does TMI-1 have established and tested procedures for all the methods and paths stated in the report?
1 GPU Nuclear Resoonse:
Following development of the SSEL list, simulator scenarios were run using existing Emergency Operating Procedures to carry out secondary side cooling, with Loss of Offsite Power. From " desktop reviews" of existing procedures handling of seismic events were verified to be within the scope of the procedures currently in effect, with two minor changes to the procedures for loss of instrument air and the station blackout procedure, both of which were modified accordingly.
NRC Ouestion 4:
The report does not mention times that certain water sources (condensate storage tank (CST),
borated water storage tank (BWST), etc) are capable of lasting before depletion. Are such calculations available? Check for the total amount of time that seismically qualified sources would be available.
GPU Nuclear Resoonse:
Based on the CSTs solely, with a total volume of 300,000 gallons, and without any source of makeup to these tanks, our calculations show that this seismically qualified source would last for approximately 42 hours4.861111e-4 days <br />0.0117 hours <br />6.944444e-5 weeks <br />1.5981e-5 months <br />.
l NRC Ouestion Sa:
I Which of the following sources of water and how paths are seismically qualified?
SmLrgn CST A:
CST B:
Condensate hotwell:
Demin. Water Storage Tank (DWST):
Makeup Tank:
BWST:
' Rx. Bldg. Rvr. Wtr. Sys: (is entire flow path seismic 7) 1.
Three Mile Island Nuclear Plant, UIlt 1 (TMI-1) j, Operating License No. DPR-50 Docket No. 50-289 Response to Questions on USI A-46 Submittal GPU Nuclear Resoonse:
The provided sources of water are qualified as follows:
Source:
Oualification:
CST A:
seismic CST B:
seismic Condensate hotwell:
non-seismic DWST:
non-seismic Makeup Tank:
seismic BWST:
seismic Rx. Bldg. Rvr. Wtr. Sys:
The entire flow path is seismic.
NRC Ouestion 5b:
What are their capacities?
Source Caoacitv(gal.)
CST A:
7 CST B:
7 Cond. Hotwell 7
DWST:
?
Makeup Tank:
7 BWST:
?
Rx. Bldg. Rvr. Wtr. Sys:
?
GPU Response:
The capacities for provided sources of water are as follows (with Tech. Spec. capacities, where applicable):
Source Capacity CST A:
150,000 gal (T.S. 3.4.1.1.c)
CST B:
150,000 gal (T.S. 3.4.1.1.c)
Cond. Hotwell 764,000 gal DWST:
1,000,000 gal Makeup Tank:
2,250 gal (approx. useable vol.)
BWST:
350,000 gal (T.S. 3.3.1.1.a)
Rx. Bldg. Rvr. Wtr. Sys:
infinite: two (2) pumps each rated at 5,400 gpm -
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