ML20195K224
| ML20195K224 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 04/30/1988 |
| From: | Neron G NORTHEAST NUCLEAR ENERGY CO. |
| To: | |
| Shared Package | |
| ML20155D855 | List: |
| References | |
| NUDOCS 8806290370 | |
| Download: ML20195K224 (1) | |
Text
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DOCKET NO. 50-336 UNIT SHUTDOWNS AND POWER REDUCTIONS UNIT NAME Milletrne 2 DATE 05-06-88 COMPLETED BY G.
Neron REPORT MONTH APRIL 1988 TELEPHONE (203) 447-1791 Extension 4417 l
Duration Reason 2 Method of Licensee System Component Cause & Corrective No.
Date Type (Hours)
Shutting Event Coded Codes Action to Down Reactora Report #
Prevent Recurrence 88-01 040888 S
138.8*
B 1
88-08 AA CD CL,CCL Initiated reactor power reduction from 100% power for planned maintenance outage; CEA #22 dropped and power was reduced to ~70%; Continued reactor shutdown
- unable to recover the dropped CEA; CEA #4 also dropped before reactor was sub-critical; The dropping of CEA's #4 and #22 was determir.ed to have been caused by major loss of upper gripper coil resistane' :ae to overheating; In additie.3, a high resistance of the CEA #5 upper gripper coil was found, and was determined to have been caused by a loose coil stack connection; Overheating was caused by the reduction of the CEDM Cooler efficiency due to boron clogging of the fan intakes; New CEDM Coil Stacks were installed for CEA's #4, #5, and #22; The CEDM Cooler intakes were cleaned; Determination of the boron source is still under investigation.
See LER.
I 2
3 4
F:
Forced Reason:
Method:
Exhibit G - Instructions S:
Scheduled A-Equipment Failure (Explain) 1-Manual for Preparation of Data B-Maintenance or Test 2-Manual Scram Entry Sheets for Licensee C-Refueling 3-Automatic Scram Event Report (LER) File D-Regulatory Restriction 4-Continued from (NUREG-0161)
E-Operator Training & License Examination previous month F-Administrative 5-Fower Reduction 5
G-Operational E-ror (Explain)
(Duration = 0)
Exhibit 1 - Same Source H-Other (Explain) 6-Other (Explain)