L-MT-11-003, Request for Formal Interpretation of Regulations

Request for Formal Interpretation of Regulations

ML110120546
Person / Time
Site:	Monticello
Issue date:	01/11/2011
From:	O'Connor T Northern States Power Co, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-MT-11-003
Download: ML110120546 (2)

Text

@ Xcel Energy. Monticello Nuclear Generating Plant 2807 W County Road 75 Monticello, MN 55362 January 11,2011 L-MT-11-003 10 CFR 50.3 10 CFR 50.72 10 CFR 50.73 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555 Monticello Nuclear Generating Plant Docket 50-263 Renewed License No: DPR-22 Request for Formal Interpretation of Reaulations Pursuant to 10 CFR 50.3, Monticello Nuclear Generating Plant (MNGP) requests an interpretation from the Office of General Counsel regarding aspects of 10 CFR 50.72(b)(3)(v). This regulation requires NRC notification of an "event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems" needed to "(A) Shut down the reactor and maintain it in a safe shutdown condition; (B) Remove residual heat; (C) Control the release of radioactive material; or (D) Mitigate the consequences of an accident." Similarly, 10 CFR 50.73(a)(2)(v) requires reporting of "event or condition that could have prevented the fulfillment of the safety function of structures or systems" needed for the same reasons.

Recently, MNGP had an event that resulted in Average Power Range Monitor (APRM) gains being set high outside the Technical Specification (TS) allowable range of 22% when compared to core thermal power. TS Surveillance Requirement (SR) 3.0.1 states that a TS Limiting Condition for Operation (LCO) is not met if an associated SR is not met, even if the surveillance is not being performed. With the APRM gains set more than 2% above core thermal power, SR 3.3. I.I .2 was not met. Therefore, L C 0 3.3.1.Iwas not met for the four channels of the APRM system.

The safety function of the APRM system is to provide a high flux scram in response to a Control Rod Drop Accident. The scram setpoint is established by an Allowed Value of 5 122% rated thermal power. This scram setpoint is not impacted by adjusting the gains of the APRM system.

Since the APRM system now indicated a power higher than actual, the change to the gains would have resulted in a scram at a lower actual power than required and safety function was maintained.

Discussions with NRC staff have resulted in confusion over the reportability of this event. It does not appear to be reportable under 10 CFR 50.72(b)(3)(v) or 10 CFR 50.73(a)(2)(v), in that the answers to conditions (A) through (D) are all NO. However, MNGP has been informed that it is still reportable as such.

Document Control Desk Page 2 MNGP requests a written interpretation per 10 CFR 50.3 for the question:

Is the condition in which a system is declared INOPERABLE due to not meeting Surveillance Requirements reportable under 10 CFR 50.72(b)(3)(v) or 10 CFR 50.73(a)(2)(v) if the system remains capable of performing its safety function?

Summarv of Commitments:

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ommitments and no revisions to existing commitments.

ello Nuclear Generating Plant Northern States Power Company - Minnesota cc: Administrator, Region Ill, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC