05000315/FIN-2013004-05
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Unreliable Level Indications |
| Description | The inspectors identified an Unresolved Item (URI) regarding the requirements pertaining to establishing and maintaining procedures to ensure reliable indication of reactor vessel level during reduced RCS inventory and vacuum fill operations. During the recent refueling outages, the licensee experienced numerous issues monitoring the RCS water level during the vacuum fill activities. Each of the issues described below resulted in additional entries into RCS mid-loop operations with an associated increase in plant risk during each entry. Specific issues include: During Unit 2 refueling outage 20, the licensee made three vacuum fill attempts. The licensee terminated the first attempt due to a failed camera. The licensee terminated the second attempt due to level variations on NLI-122. The third attempt succeeded, During the Unit 1 refueling outage 25, the licensee made five attempts to vacuum fill the RCS before succeeding: Attempt 1: A divergence between RCS level indications caused the licensee to terminate the evolution; Attempt 2: Licensee terminated the vacuum fill attempt due to similar level indication issues observed in Attempt 1; Attempt 3: Licensee checked level instrumentation fittings for tightness and then made a drain down attempt; instrument deltas again resulted in terminating the attempt; The licensee found a leak in a level instrument transducer box; the licensee replaced the transducer and tightened the fittings; the licensee terminated the attempt due to deviations between level indications; The licensee performed a zero adjust on the level indications instruments; the attempt succeeded. The licensee performed a root cause analysis on the vacuum fill attempts described above and determined the root cause to be that the site did not have ownership of the level indicators. Based on review of the root cause analysis and observation of the licensees performance during the vacuum fill evolution, the inspectors concluded that the licensee identified the root cause. The inspectors also noted that the root cause analysis included several examples where procedures were not appropriate to the circumstances. For example, procedures did not: provide direction for a vacuum leak test; provide detailed direction calibration/protection of transducers from shock, or; include requirements to normalize readings between level indications. The inspectors noted that including the above items into procedures would have reduced the time the licensee spent in a mid-loop condition as well as the number of drain downs needed to complete the RCS vacuum fills. At the conclusion of this inspection, the inspectors had not completed their review to determine if a performance deficiency or violations of regulatory requirements occurred. The URI will remain open pending this review. (URI 05000315/316/2013004-05, Unreliable Level Indications) |
| Site: | Cook  |
|---|---|
| Report | IR 05000315/2013004 Section 4OA2 |
| Date counted | Sep 30, 2013 (2013Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | D Szwarc M Mitchell J Lennartz J Benjamin J Ellegood P Laflammeb Cushmand Reeser J Ellegood J Gilliam J Lennartz K Riemer M Bielby M Mitchell T Taylor |
| INPO aspect | |
| ' | |
Finding - Cook - IR 05000315/2013004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Cook) @ 2013Q3
Self-Identified List (Cook)
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||