ML20012D819
| ML20012D819 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/19/1990 |
| From: | Shelton D TOLEDO EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-2.F.2, TASK-TM 1784, GL-89-06, GL-89-6, NUDOCS 9003280405 | |
| Download: ML20012D819 (2) | |
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TOLEDO EDISON A Cemern Energy Cmeny DONAU) CL SHELTON Vce F%svlem-Nucheer (419J Pd9 2300 Docket Number 50-346 License Number NPF-3
-Serial Number 1784
-March 19, 1990 United States Nuclear Regulatory Commission
-Document Control Desk Vashington, D. C. 20555 Subj ec t s. Supplemental Response to Generic Letter Number 89-06 Gentlemen:
During a telephone conference call on December 8, 1989, members of the Nuclear Regulatory Commission (NRC) staff (T. V. Vambach-NRC/NRR Senior Project Manager; R. Correia - NRC/NRR Human Factors Branch; C. Goodman - NRC/NRR Human
' Factors Branch; G. Vest NRC/NRR Human Factors Branch) requested that Toledo Edison (TE) provide justification'for not adding Reactor Coolant System (RCS)
Level or Hot Leg Level indication to the Davis-Besse Nuclear Power Station (DBNPS) Safety Parameter Display System (SPDS) pursuant to the item-cited in Section B. of the NRC Staff's July. 16, 1984 (Log Number 1561) Safety Evaluation Report (SER) on SPDS. Toledo Edison verbally responded to the request during the December 8, 1989 telephone conference call and committed to docket the response in order to close the SER item. This letter constitutes Toledo Edison's response.
Davis-Besse Nuclear Power Station,. Unit Number 1 has not installed a Reactor Vessel Level Monitor.
In response to NUREG-0737, Items II.B.1 and II.F.2, TE installed, during the fifth refueling outage in 1988, a Continuous Vent Line from the reactor vessel head to'the steam generator upper head for eventual venting through the RCS hot leg high point vent.
The Continuous Vent Line is passive, contains no valves, and continuously vents gases or steam which may be generated in the reactor vessel during postulated accident conditions to ithe RCS. hot leg high point. Integral system testing conducted on the Continuous. Vent Line design has shown it to be effective in venting gases / steam from the reactor vessel head to preclude potential core uncovery by maintaining the. reactor vessel full of water and, thereby, eliminates the need for the Reactor Vessel Level Monitor.
9003280405 900319 h
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THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652
Dogket Numbar 50-346 i License Number NPF-3
- Serial Number 1784 Page 2 The Hot Leg Level Monitor, installed pursuant to NUREG-0737, Item II.F.2. is not part of the SPDS in that information that may be provided by this monitor is only_available when the reactor coolant pumps are idle and is not addressed in plant emergency procedures for detecting an approach to inadequate core cooling (ICC).
Information is readily available on the SPDS regarding concurrent trending-of RCS temperature and secondary plant pressure-temperature conditions. This information allovs the operators to assess primary to secondary heat transfer and, thereby, provides necessary information on an approach to ICC during a-transient /n tnt when the reactor coolant pumps are running or are idle. Therefore, this type of information is more meaningful and readily available to the operators for assessing RCS/ secondary side performance and any approach to ICC.
The above provides the necessary information to close'the open SER item.
If you have any questions, please contact Mr. R. V. Schrauder, Hanager-Nuclear F
Licensing, at (419) 249-2366.
Very truly yours, IL0d%
RMC/ssg cc P. M. Byron, DB-1 NRC Senior Resident Inspector A. B. Davis, Regional Administrator,.NRC Region III T. V. Vambach, DB-1 NRC Senior Project Manager
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