L-2024-097, Technical Specification Special Report
| ML24172A186 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 06/20/2024 |
| From: | Rasmus P Florida Power & Light Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-2024-097 | |
| Download: ML24172A186 (1) | |
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U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Re:
Florida Power & Light Company St. Lucie Unit 2, Docket No. 50-389 Event Date: May 6, 2024 Technical Specification Special Report June 20, 2024 Containment High Range Radiation Monitor Inoperable L-2024-097 10 CFR 50.36 to this letter is a 14-Day Special Report submitted pursuant to the requirements of St.
Lucie Unit 2 Technical Specification (TS) 3.3.9, Condition B, Table 3.3.9-1, Function 9, and TS 5.6.4.
This report provides notification that a containment high range radiation monitor (CHRRM) is inoperable. Attachment 2 to this letter provides alternate means of radiation monitoring implemented in accordance with TS 5.6.4.
This letter contains no new regulatory commitments.
Should you have any questions regarding this report, please contact Mr. Kenneth Mack, Senior Manager, Licensing and Regulatory Compliance, at (561) 904-3635.
General Manager, Regulatory Affairs Florida Power & Light Company : Containment High Range Radiation Monitor Inoperable Technical Specification 5.6.4 Special Report : EPG-08, Attachment 2, Alternate Monitoring Method with the CHRRM Channels Inoperable cc:
USN RC Regional Administrator, Region II USNRC Project Manager, St. Lucie Nuclear Plant USNRC Senior Resident Inspector, St. Lucie Nuclear Plant Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957
ATTACHMENT 1 L-2024-097 CONTAINMENT HIGH RANGE RADIATION MONITOR INOPERABLE TECHNICAL SPECIFICATION 5.6.4 SPECIAL REPORT (2 pages follow)
Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957
EVENT DESCRIPTION L-2024-097 Page 1 of 2 On May 6, 2024, containment high range radiation monitor (CHRRM), RIM-26-40, was out of service, declared inoperable. Technical Specification 3.3.9 Condition A was entered which states:
One or more Functions with one required channel inoperable Restore required channel to operable status in 30 days.
On June 5, 2024, RIM-26-40 was not restored to operable status therefore Condition B was entered which states:
Required Action and associated completion time of Condition A not met Initiate action in accordance with Specification 5.6.4 immediately Technical Specification 5.6.4 states:
When a report is required by Condition B or F of limiting condition for operation (LCO) 3.3.9, "Post Accident Monitoring (PAM) Instrumentation," a report shall be submitted within the following 14 days. The report shall outline the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to operable status."
The preplanned alternate methods for monitoring containment radiation levels were implemented in accordance with plant procedure EPG-08, "Monitoring Plant Equipment Important to the Radiological Emergency Plan," Attachment 2, "Alternate Monitoring Method with the CHRRM Channels Inoperable."
The CHRRMs are used in emergency action level (EAL) determinations. Specifically, a CHRRM reading is one of the inputs that can be used to determine loss of the fuel clad barrier and also to determine the potential loss of the primary containment barrier in the Emergency Plan (EP).
In addition to directing EP EAL entry conditions as described above, the CHRRMs also support Emergency Preparedness dose and core damage assessment capabilities. However, dose and core damage assessment continue to be functional without reliance on CHRRMs as the pre-existing procedures and training for members of the Emergency Response Organization (ERO) and Operations provide diverse means for obtaining the required information.
With the loss of both channels, other plant parameters, such as core exit thermocouple temperatures, Emergency Coordinator judgement, and containment pressure can be utilized to determine EALs. Due to the ability to use other plant parameters, loss of CHRRMs would not be considered a major loss of emergency assessment capability. There are no automatic functions provided by CHRRMs other than annunciation.
CAUSE OF THE EVENT L-2024-097 Page 2 of 2 During the St. Lucie Unit 2 refueling outage, SL2-27, the digital high range radiation monitor functional test was performed satisfactorily for RIM-26-40. The radiation monitor was declared operable. The monitor however began spiking and was subsequently taken out of service. The cause for spiking has not been determined.
ACTIONS TAKEN The licensee planned action list was entered into the site corrective action program. Preplanned alternate monitoring was implemented in accordance with EPG-08, "Monitoring Plant Equipment Important to the Radiological Emergency Plan," Attachment 2, "Alternate Monitoring Method with the CHRRM Channels Inoperable." This 14-Day Special Report is submitted in accordance with TS 5.6.4.
SCHEDULE FOR RESTORING SYSTEM Trouble shooting is planned for the next St. Lucie Unit 2 refueling outage, SL2-28, in the fall of 2024. After making repairs, as necessary, the digital high range radiation monitor functional test will be performed to determine operability.
ATTACHMENT 2 L-2024-097 EPG-08, ATTACHMENT 2, ALTERNATE MONITORING METHOD WITH THE CHRRM CHANNELS INOPERABLE (1 page follows)
Unit 2 Alternate Monitoring Methodology L-2024-097 Page 1 of 1 Unit 2 CIS radiation monitors (Channels 3-6) are not EQ for post-LOCA conditions. Therefore the operator should use other diverse indications as defined in the EAL table to evaluate for the Loss of the Fuel Clad Barrier (e.g. CETs, Dose Equivalent 1-131, Loss of Core Heat Removal Safety Function and entry into EOP-15).
- Unit 2 Post-LOCA radiation monitor (Channels 38 and 39) will be used to correlate to the CHRRM reading of 2,700 R/hr (potential loss of the Primary Containment Barrier). The equivalent dose rate at the Post-LOCA radiation monitors corresponding to 2,700 R/hr threshold is 29.1 mr/hr.
- IF the Unit 2 CHRRMs alternate monitoring method is used, THEN Operations should verify the Post-LOCA monitors are in service once per 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> shift (as defined for the CHRRM channel Check in Technical Specifications) in Modes 1-4.
CHRRM Post-LOCA RIM-26-40 and RIM-26-41 RIM-26-38 and RIM-26-39 1.4E+2 R/hr N/A 2.7E+3 R/hr 29.1 mr/hr Ref: EC-OCR 286673 Cale No. PSL-2LHN-16-001 LOSS OF CHRRMs and EMERGENCY ASSESSMENT CAPABILITY The loss of ability to monitor and quantify radiological conditions for emergency assessment capability was assessed as per 10CFR50.72(b)(3)(xiii). This regulation requires that a licensee to notify the NRC as soon as practical and in all cases within eight hours of the occurrence for any event that results in a major loss of emergency assessment capability, offsite response capability, or offsite communications capability(e.g., significant portion of control room indication, Emergency Notification System, or offsite notification system).
As stated above, the CHRRMs are used in Emergency Action Level (EAL) determinations.
Specifically, a CHRRM reading is one of the inputs that can be used to determine loss of the fuel clad barrier, and also used to determine the potential loss of the primary containment barrier (per the EPIP-01 hot conditions table). With the loss of both channels, other plant parameters, such as core exit thermocouple temperatures, Emergency Coordinator judgment, and containment pressure can be utilized to determine EALs. Due to the ability to use other plant parameters, loss of the CHRRMs would not be considered a major loss of emergency assessment capability.