ML20206F292
| ML20206F292 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/05/1999 |
| From: | Colburn T NRC (Affiliation Not Assigned) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9905060066 | |
| Download: ML20206F292 (2) | |
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May 5,1999 i
1 Note To: Document Control Desk From:
Timothy G. Colburn, Senior Project Manager, Section 2 Project Directorate 1 Division of Licensing Project Management Office of Nuclear Reactor Regulation
Subject:
DOCKETING MATERIAL FAXED TO LICENSEE Please docket the attached draft questions which were faxed to the licensee for the Three Mile Island Nuclear Plant Unit-1 (TMI-1), GPU Nuclear, Inc., on 5/5/99 in preparation for a 5/6/99 conference call on Technical Specification Change Request No. 279.
1
Attachment:
As stated Docket No. 50-289 l
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Reauest for AdditionalInformation Technical Specification Chance Reauest (TSCR) 279 Core Protection Safety Limits
- 1. Define specifically with respect to TSCR 279 what the total EFW (emergency feedwater) flow requirement is, assuming 20 percent average tubes plugged in the once through steam generators, including the flow breakdown, i.e., how much flow is necessary for decay heat removal, pump recirc'ilation, bearing cooling, instrument inaccuracy, etc. and describe how the flow balance will be assured and maintained over time.
- 2. Assuming maximum allowed pump degradation (for all three EFW pumps) as permitted by the ASME Code, compare the established EFW flow requirement above with the EFW flow that will be delivered assuming the worst-case pump combination (assuming single failure).
- 3. In responding to question 1 of the NRC letter dated March 10,1999, regarding TMI-1 TSCR 279, you discussed the loss of feedwater accident and stated in a letter dated March 26,1999, that the EFW system was conservatively assumed to deliver flow (550 gpm) to the steam generators starting 43 seconds after the initiation signal with any (emphasis added) combination of EFW pumps (1TDP or 2 MDPs or 1 TDP and 1 MDP). However, the information you provided during the April 30,1999, meeting with the staff stated that the maximum predicted flow capability of the TDP is 536 gpm. Please either confirm the capability of the TDP to deliver the required 550 gpm flow, or amend your response to question 1 to clarify the correct combination of pumps necessary to achieve the required 550 gpm flow.
This information is necessary for the staff to accurately understand and evaluate the TMI-1 EFW pump capability as it applies to the flow requirement of 550 gpm total flow to the once through steam generators as stated in your March 26,1999 letter.
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