ML20215M063
| ML20215M063 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 05/04/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20215M050 | List: |
| References | |
| NUDOCS 8705130077 | |
| Download: ML20215M063 (4) | |
Text
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3 UNITED STATES -
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~ SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION
.RELATED TO AMENDMENT NO. 22 TO FACILITY OPERATING LICENSE N0. NPF-30 UNION ELECTRIC COMPANY CALLAWAY PLANT, UNIT 1 DOCKET NO. STN 50-483 t
INTRODUCTION By letter dated April 16, 1987, Union Electric Co'mpany (the licensee) informed-F the staff that Westinghouse Electric Corporation recently discovered that it had assumed simultaneous, rather than sequential, operation of valves in the j
calculation of-time it takes to get a safety injection (SI) of 2000 ppm borated water into the Reactor Coolant System (RCS). Since the valves that transfer the charging pump suction from the Volume Control Tank (VCT) to the Refueling Water Storage Tank (RWST), which contains 2000 ppm boron, are operated sequentially, it was found that safety injection-(ECCS) response times listed in Table 3.3-5 of the Technical Specifications (TS) were not achievable.- There were too short by the 15-second delay encountered by the sequential operation of the two valves, t
t EVALUATION The primary function of the ECCS is to supply water to the RCS in the event of alossofcoolantaccident(LOCA). Since a LOCA is not a reactivity induced accident, the 2000 ppm boron is not immediately needed.
It is only needed to i
i maintain subscriticality in the long term. Therefore, for those SI actuation signals that are only intended to provide protection against a LOCA, this 15-second delay in the delivery of 2000 ppm borated water has no effect on the g
safety analysis.-
l The only non-LOCA transient impacted by this increased response time is the steam line break event. No other FSAR Chapter 15 transient takes credit for L'
short-term boration from the RWST.
The licensee compared calculations of the steam line break accident with and without the additional SI delay. The calculations showed no significant change l
in the consequences. One of the reasons for this is that the additional delay L
cccurs early in the steam line break event when the RCS pressure is high and the SI flow rate is relatively small.
In addition, the licensee stated that studies'of the steam line break accident have generally shown that the consequences are not sensitive to large changes in SI flow or boron concentration.
The licensee, therefore, concluded that the departure from nucleate boiling i
design basis for the steam line break analysis is still met and that the conclusions presented in the FSAR remain valid.
8705130077 870504 DR ADOCK 0500 3
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. The staff has reviewed the licensee's analysis and finds the licensee's conclusions. acceptable. Thus, the staff concludes that the requested technical specification changes satisfy the applicable regulatory requirements and are acceptable.
EMERGENCY CIRCUMSTANCES These TS changes are being issued before the expiration of the notice period to prelcude an unnecessary delay in plant startup from the current outage. On April 13, 1987, the licensee received a letter from Westinghouse informing them of a poter.tial issue concerning the time required to change charging pump suction from the VCT to the RWST following a postulated steam line break event (see introduction section). The licensee completed their own evaluation and determined on April 15, 1987 that the issue was indeed applicable to Callaway Plant and that changes to the TS were needed for plant startup from the current outage. The licensee then promptly notified the staff (on April 15, 1987) of the situation at Callaway and followed-up with a license amendment application dated April 16, 1987.
The Commission has determined that emergency circumstances exist in that swift action is necessary to avoid a delay in startup not related to safety.and finds that for the reason stated above, and an accelerated outage schedule.
- emergency circumstances exist.
In connection with a request indicating an emergency, the Connission expects its licensees to apply for license amendments in a timely fashion. However,-
with this consideration in mind, it has been detennined that a circumstance has arisen where the licensee and the Connission must act quickly, and'the licensee has made a good effort to make a timely application.
FINAL NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION In accordance with 10 CFR 50.92, the Commission may make a final detennination that a license amendment involves no significant hazards consideration if operation of the facility in accordance with the amendment would not:
(1) involve a significant increase in the accident previously evaluated; or (2) probability or consequences of an create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. The infonnation in this section provides the staff's evaluation of this license amendment against the three criteria.
The staff has confirmed the basis of the no significant hazards findings described in the notice published in the Federal Register on April 22, 1987 (52 FR 13367). The amendment does not involve a significant increase in the probability or consequences of accidents previously evaluated. An increase in the acceptance criterion for the ESF response time is acceptable since the i
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.3 evaluation of the impact of the increasec delay on the steam line break event demonstrated-that the departure from nucleate boiling design basis is still met. The conclusions-in the FSAR remain valid.
The amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated. There are no new failure modes associated with this proposed change, as no design changes have been made. No new accident is created because the same equipment is assumed to perform in the same manner as before. Therefore, an increase in the ESF response times for high containment pressure, low pressurizer pressure, and low steam line pressure does not create the possibility of an accident or malfunction-of a different type than any evaluated previously in the safety analysis report.
'The ' amendment does.not involve a significant reduction in a margin of safety.
There is no impact on the consequences on protective boundaries, and all acceptance criteria in the analysis of record are still met. Therefore, the safety limits will still be met.
Therefore, the staff conclu'ed that:
d (1) Operation of the facility.in accordance with the amendment would not significantly increase the probability or consequences of an accident previously evaluated.
l (2). Operation of the facility in accordance with the amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated.
(3) Operation of the facility in accordance with the amendment would not involve a significant reduction in a margin of safety.
Therefore, we conclude that the amendment to Facility Operating License No.
NPF-30 to support operation of the Callaway Plant, Unit 1, which revises Table 3.3-5 of the TS to increase the response tima by 15 seconds for certain SI functions involves no significant hazards considerations.
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-STATE CONSULTATION l'
In accordance with the Commission's regulations, consultation was held with the State of Missouri by telephone. The State expressed no concern, either from the standpoint of safety or of our no significant hazards consideration de termination.
ENVIRONMENTAL CONSIDERATION
'This amendment involves a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The staff has determined that the amendment involves no significant increase in the amounts, and no significant chance in the types, of any effluents that may be released offsite and that there is no significant increase in individual L
' or cumulative occupational radiation exposure. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set fcrth in 10 CFR 51.22(c)(9). Pursuant to 10 CFP. 51.22(b) no environmental impact statement er environmental assessment need be prepared in connection with the issuance of this amendment.
C0hCLUSION We have concluded, based on the considerations discussed above, that: (1) there'is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
T. Alexion, PD33, DRSP, E. Lantz, SRXB, DEST Dated: May 4, 1987
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