ML17180A681
| ML17180A681 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 04/15/1994 |
| From: | Greenman E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Lyster M COMMONWEALTH EDISON CO. |
| References | |
| NOED-94-3-008, NOED-94-3-8, NUDOCS 9404200125 | |
| Download: ML17180A681 (2) | |
Text
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Docket No. 50-237 License No.
DPR~l9 NOED No.
94-3~008
.Commonwealth Edison Company ATTN: Mr. M. Lyster Site Vice President Dresden Station 6500 North Dresden Road Morris, IL 60450
SUBJECT:
NOTICE *aF ENFORCEMENT DISCRETION FOR COMMONWEALTH EDISON COMPANY REGARDING DRESDEN STATION UNIT 2
Dear Mr. Lyster:
By letter dated April 14, 1994, you requested the U. S. Nuclear Reguiatory Commtssion (NRC) to exercise its discretion not to enforce compliance with the*
action requirement frir Technical S~ecification Table 3.2.l. Technical Specification Table 3.2.2 requires that the trip level settings of the degraded voltage relays on the 4 kV emergency buses shall be greater than or equal to 3708 volts (equals 3784 volts less 2 percent tolerance) after less than or equal to 5 minutes (plus 5 percent tolerance) with a 7 second (plus or
- minus 20 percent) inherent time delay.
You declared the degraded voltage relays for the 4 kV emergency buses 24-1 and 23-1 inoperable at 3:00 p.m. on April 13, 1994, after determining that these relays will *not trip prior to the actual bus voltage reaching the critical bus voltage.
You info~med the NRC on April 13, 1994, at about 3:30 p~m. that Dresden Station was required to commence a power reduction to cold shutdown because two ~egraded voltage relays for each 4 kV emergency bus on Unit 2 were not operable in accordance with Technical Specification Table 3.2.2.* You requested exercise of enforcement discretion for a period of 7 days in li-eu of the required reactor shutdown.
The specified period was to allow time to evaluate and implement either the calibration or replacement option for these relays.
Details of the situation were discussed among staff of this office, the Office of Nuclear Reactor Regulation, arid members of your staff in a telephone conference call following your notification.
You provided justification for co~tinued operation based on:
- 1.
Unit 2 degraded voltage relays will be available and functional until they are removed for replacement.
Each relay outage was estimated to be.
about 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
- 2.
Replacement of the relays will be cqnducted such that at least one degraded voltage relay will be*in~service and monitoring voltage. This will change the logic of the degraded voltage trip from two~out-of-two 41'\\,
taken once to one-out-of-one.
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9404200125 940415
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PDR ADOCK 05000237
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- Commonwealth Edison Company 2
- 3.
The.CECo electrical grid status is currently greeri with a daily potential to change to red at peak peribds of electrical consumption.
- 4.
The first level undervoltage relays are operable and will not be affected by the relay replacement.
- 5.
All emergency core cooling systems are operable.
On the basis of our evaluation* of your justificatibn, including compensatory measures discussed with your staff and subsequently documented in your letter, the NRC staff has concluded that this exercise of enforcement discretion is warranted fr6m the perspective of public health and safety.
Based on the above, this-documents our verqal notification _on April 13, 1994 at 4:30 p.m. (CDT), of our intention to exercise discretion not to enforce compliance to the action requirement of Technical Specification Table 3.2.2 for the period from April 13, 1994, at 3:00 p.m. (CDT}, when the action requirement became effective, until April 20, 1994, at 6:00 p.m. (CDT).
However, we will_ consider enforcement action, as appropriate, for the conditions that led to the need for this exercise of enforcement dis~retion.
Distribution:
L.O. DelGeorge,. Vice President, Sincerely,
- Edward G. Greenman, Director Division of Reactor Projects
- Nuclear Oversight and Regulatory Services Gary F. Spedl, Station Manager J. Shi~lds, Regulatory Assurance Supervisor D. Farrar, Nuclear Regulatory Services Manager OC/LFDCB Resident Inspectors LaSalle, Dresden, Quad Cities Richard Hubbard
- Nathan Schloss, Economist Public Utilities Division Licensing Project Manager, NRR.
. State Liaison Officer
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