ML19305D468
| ML19305D468 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/27/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19305D463 | List: |
| References | |
| NUDOCS 8004150116 | |
| Download: ML19305D468 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION g/
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SAFETY EVALUATION BY THE OFFICE OF JCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 23 TO FACILITY OPERATING LICENSE N0. NPF-3 THE TOLEDO EDISON COMPANY AND THE CLEVELAND ELECTRIC ILLUMINATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION, UNIT N0. 1 DOCKET NO. 50-346 Introduction By letter dated January 10, 1980, the Toledo Edison Company (TECO or the licensee) requested amendment to Facility Operating License No. NPF-3. The amendment would modify the Technical Specifications (TSs) for Davis-Besse Nuclear Power Station, Unit No.1 (DB-1), to allow ter a delay in the testing of the reactor vessel internals vent valves.
Discussion and Evaluation The reactor vessel internals vent valves are provided to relieve the pressure that could be generated by voiding in the core following a loss of coolant accident. Steam formed in the core that would otherwise block the entry of reactor inlet water is relieved through the valves allowing the core to remain covered. The valves there-fore serve a ufety related function and are subject to an inspection program that ensures their operability to the extent assumed i.. the safety analysis. The inspection also ensures that the valves are not stuck open during normal operation.
To the extent practicable, this inspection program is in compliance with Section XI of the ASME Code.
The DB-1 TSs require that the operability of these valves be demonstrated (which requires that the pressure vessel head be removed) at least once every 18 months, with a provision for extension of this period by twenty five percent.
The valves were last tested on May 12, 1978, during an outage in which burnable poison assemblies and orifice rod assemblies were removed from the core.
In order to meet the TS inspection interval requirement, the valve operability should be demonstrated by March 27, 1980.
In its submittal of January 10, 1980, the licensee stated that the scheduled date for the start of the first refueling outage at DB-1 was March 15, 1980. Subsequent to this submittal, the date of the refueling outage has been revised to commence on April 10, 1980. This projected refueling schedule is not compatible with the TS surveillance interval requirement, and the licensee has requested an extension of the interval to May 30, 1980.
Two bases are cited by the licensee in justifying the proposed extension. The first basis is that several prolonged outages have occurred since the testing of the valves in May 1978. The licensee stated that this saving in core operating i
800115014 $
T time provides sufficient justification for the delay in testing since the intent of Section XI of the ASME Code is to provide a mechanism for scheduling of an inspection based on operating time of the facility. The second basis for the proposed extension is that Babcock & Wilcox has informed the licensee that successful demonstrations of valve operability have taken place at Arkansas Nuclear One, Unit 1, Rancho Seco, Crystal River, Unit 3, and Oconee, Unit 1.
Since the licensee currently expects DB-1 to comence its first refueling outage on April 10, 1980, the proposed extension would allow only about two weeks of power operation beyond the date by which the internals vent valves are currently required to be inspected. The probability of a challenge to the valves during this two week period, which would require a cold leg pipe rupture, is remote.
We consider that operation of the plant during this short period of time will have no significant impact on the public health and safety. Therefore, the pro-posed extension for inspection of the valves to May 30, 1980, is acceptable.
Environmental Consideration We have determined that the amendment does not authorize a change in effluent types'or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of t
environmental impact and, pursuant to 10 CFR 551.5(d)(4), that an environmental. impact statement, or negative declaration and environ-mental impact appraisal need not be prepared in connection with the issuance of this amendment.
Conclusion We.have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered i
and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public l
will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical l
to the common defense and security or to the health and safety of j
the public.
Dated: March 27, 1030