05000369/FIN-2013008-01
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Finding | |
|---|---|
| Title | Fuel Manipulator Crane Digital Modification |
| Description | The fuel handling system consists of the equipment needed for the refueling operation of the reactor core. This equipment is comprised of manipulator cranes, fuel handling equipment and a fuel transfer system. The manipulator cranes have the potential to initiate a fuel handling accident as described in Updated Final Safety Analysis Report (FSAR) section 15.7.4. The postulated accident assumes a fuel assembly is damaged while being moved inside containment or the Spent Fuel Pool Building. Engineering changes EC 77048, Unit 1 Manipulator Crane Upgrade Project, Rev. 18 and EC 77051, Unit 2 Manipulator Crane Upgrade Project, Rev. 15, were implemented to address reliability and obsolescence problems confronting the fuel manipulator cranes in the reactor containment and spent fuel building. The power and control systems were upgraded, including the position sensors, motor drives, control consoles, and wiring. The existing analog controls were replaced using a digital programmable logic controller (PLC) with a graphic user interface. The PLC can now be programmed in advance with the refueling sequence, and the step-wise destinations of each fuel assembly. The PLC controls allow multi-axial travel (in the x-y dimensions) within established safe operation zones. The maximum crane bridge and trolley speeds were increased, but the existing acceleration limits were retained. The hoist slow-speed zones were reduced, but an adequate distance had been retained for the safe insertion of a fuel assembly into a storage or core location. The licensee performed a 10 CFR 50.59 evaluation in accordance with procedure NSD-209, 10 CFR 50.59 Process, Rev. 14, and determined the change could be implemented without prior NRC review and approval. After reviewing the 10 CFR 50.59 evaluation, the inspectors found that they did not have sufficient information to determine that NRC review and approval was not required prior to the implementation of the modification. The inspectors could not verify the licensees conclusions regarding the reliability and dependability of the software used to operate the manipulator crane. Specifically, the licensee did not address software failure modes and effects, and the software development processes described in section 5.3.3 of NEI 01-01, Digital System Quality, Rev. 1, in enough detail for the team to reach the same conclusion. In order to determine the adequacy of the licensees 10 CFR 50.59 evaluation and whether or not there is a violation of 10 CFR 50.59, Changes, Tests, and Experiments, this issue remains unresolved pending the inspectors review of additional information to be provided by the licensee to address the issues described above. The licensee entered this issue into their corrective action program as problem investigation program (PIP) report M-13-11029 to track the actions taken to address the teams concern. |
| Site: | McGuire  |
|---|---|
| Report | IR 05000369/2013008 Section 1R17 |
| Date counted | Dec 31, 2013 (2013Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.17 |
| Inspectors (proximate) | M Meeks R Cureton R Patterson T Fanelli W Loo A Nielsen A Vargas F Ehrhardt J Rivera J Zeilerj Earglep Cooper R Nease R Patterson T Su W Monk |
| INPO aspect | |
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