Event Notification Report for April 28, 2005

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THIS IS NOT A NEW REPORT.

This event report was originally withheld from public release under the NRC's policy for protecting sensitive unclassified information. The NRC has reevaluated this policy and is now making this event report available to the public with suitable redactions.
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INADEQUATELY CONTROLLED OR ANALYZED PATHWAY FOR MATERIAL ACCUMULATION

This event occurred at Building [DELETED] in the Uranium-Aluminum Hydrogen dilution system area. The licensee observed a solution accumulated in a HEPA filter housing on the Building [DELETED] roof. Analysis of the solution determined the liquid to be a caustic byproduct of the process. Further analysis indicated that approximately 3 grams of U-235 were in the HEPA housing and filter. Further reviews of the system design identified potential pathways from the Uranium-Aluminum dissolution system that did not appear to be adequately controlled or analyzed.

The nuclear criticality safety of the system relied on the physical design to prevent uranium [DELETED] materials from entering the hydrogen dilution system and the filter housing. The system also relied on a drain in the dilution system ductwork to prevent material from entering the filter housing.

The licensee considers the Nuclear Criticality Safety significance low given the very low likelihood of accumulating a sufficient mass or concentration of uranium [DELETED] material into the HEPA filter housing

The process was not in operation when the solution in the filter housing was found. The operation will remain shut down until additional reviews and/or design modifications are completed.

The licensee will notify the NRC Resident Inspector, the Region 2 Inspector (Ayres), and HQ contact (Berg).

* * * UPDATE ON 05/11/08 BY J. KOZAL * * *

THIS IS NOT A NEW REPORT.

This event report was originally withheld from public release under the NRC's policy for protecting sensitive unclassified information. The NRC has reevaluated this policy and is now making this event report available to the public with suitable redactions.

UNIT 2 MANUAL REACTOR SCRAM DUE TO LOSS OF MAIN TRANSFORMER COOLING

"At approximately 0700 U2 B Main Transformer cooling was lost. Unit 2 reactor power was reduced from 100% to 75%. Attempts to restore the 2B Main Transformer cooling were unsuccessful, and Unit 2 was manually scrammed from 75% reactor power. RPV water level decreased to -30" due to the SCRAM and was restored by normal Feedwater and RCIC injection. The Main Condenser remained available as a heat sink and there were no SRV lifts. The low water level did result in receiving the Level 2 Division 2 containment isolation signal (-38"), and all expected isolations and initiations did occur.

"This event requires a 4 hour ENS notification in accordance with 10CFR50.72(b)(2)(iv)(B) for an RPS actuation when critical, and an 8 hour ENS notification per 10CFR50.72(b)(3)(iv)(A) for the injection from RCIC and receipt of the level 2 Containment Isolation signal. Additionally, a press release to the public will be issued, and requires a 4 hour ENS notification in accordance with 10CFR50.72(b)(2)(xi)."

All rods fully inserted during the manual scram. The electrical system is in a normal shutdown lineup. Secondary containment ventilation was momentarily disrupted in unit-1 and successfully restored.

The licensee notified the NRC Resident Inspector and will be notifying the state and media concerning this event.

AGREEMENT STATE REPORT - TWO LOST NUCLEAR GAUGES

The State provided the following information via facsimile:

"On 4/28/05 at about 8:46 am, Pacific Soils Engineering, Inc. notified (Radiologic Health Branch) RHB that two nuclear gauges were stolen from a construction site at Oak Valley Parkway, Beaumont, CA. The stolen nuclear gauges were CPN Model M3 with a S/N M330506989 and M38058248 (each gauge contains Am-241/Be, 50 mCi, and Cs-137, 10 mCi).

"According to [licensee] RSO, the nuclear gauges were stored securely, at about 5:00 pm on 4/27/05, in the steel office trailer located at the construction site. The next day, at about 6:15 am, the technicians found that a break-in occurred and the two nuclear gauges were missing. The chain that secured the nuclear gauges was cut off. The local police and Riverside county environmental health were also notified."