ML20141E961
| ML20141E961 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 05/14/1997 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20141E145 | List: |
| References | |
| 50-298-96-24, NUDOCS 9705210155 | |
| Download: ML20141E961 (3) | |
See also: IR 05000298/1996024
Text
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ATTACHMENT 5
Errata Sheets for
NRC Inspection Report 50-298/96-24
(pages iv and 5)
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9705210155'970514
ADOCK 05000298
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The team identified a generic issue regarding the licensee's technical basis for the
emergency operating procedures related to an anticipated transient without scram
event. The licensee had not fully considered the mixing effects related to boron
displacement during cooldown. In addition, hot and cold shutdown boron worth
were not calculated conservatively. This item is unresolved pending further
evaluation by the Office of Nuclear Reactor Regulation (Section E3.2).
Maintenance
The team identified one violation of Technical Specification 6.3.1 involving the
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failure of a maintenance worker and a quality control inspector to follow procedural
requirements. This experience is contrary to the information provided in a letter
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dated November 1,1996. The team also identified that procedural guidance for the
installation of the scram valve actuator mounting brackets needed improvement,
and that the licensee's corrective actions addressing repetitive instances of non-
conforming scram valve actuator mounting assemblies have been ineffective
(Section E2.1).
, Enaineerino
The team identified several unverified or questionable assumptions in the sample of
reactor protection system and anticipated transient without scram setpoint
calculations; however, none of the discrepancies affected equipment operability.
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The licensee had programmatically identified similar setpoint calculation problems
during a 1996 quality assurance audit and was in the process of correcting and
updating the calculations. This licensee-identified and corrected violation is being
treated as a noncited violation, consistent with Section Vll B.1 of the NRC
Enforcement Policy (Section E1.1).
The licensee did not clearly describe their intent with respect to implementation of
Safety Guide 11, " Instrument Lines Penetrating Primary Containment," in either the
Final Safety Analysis Report or in the Updated Safety Analysis Report V.2.3.5,
" Primary Containment isolation Valves." Further, the inspection team could not
determine whether the current administrative controls met the intent of the
Supplement to Safety Guide 11 with respect to providing a method to verify during
operation the status of each isolation valve. This item is unresolved pending further
evaluation by the Office of Nuclear Reactor Regulation (Section E1.2).
The licensee had modified their standby liquid control system and made it
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electrically less reliable. Whether this design change was in violation of
10 CFR 50.59 is unresolved, pending an Office of Nuclear Reactor Regulation
review of the licensing basis (Section E1.3).
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Notwithstanding the licensee's position, the team was concerned that the lack of
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separation and qualified isolation devices represented an unevaluated deviation from
the standby liquid control system safety evaluation described in the USAR.
10 CFR 50.59 requires that a proposed change, test, or experiment shall be deemed
to involve an unreviewed safety question if the probability of occurrence or the
consequences of an accident or malfunction of equipment important to safety
previously evaluated in the safety analysis report may be increased. The team was
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concerned that the licensee had not initially identified or evaluated this additional
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vulnerability and its effects, as required to comply with 10 CFR 50.59. Further, the
team questioned the licensee's interpretation that allowed them to delete the single
failure requirement for the electrical portion of the system without a license
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amendment. This item will be referred to the Office of Nuclear Reactor Regulation
to determine whether the licensee's interpretation of their licensing basis is correct.
This item is considered unresolved (50-298/9624-03).
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During the inspection, the team was also concerned that this data acquisition
system interface practice might have been extended to essential circuits other than
standby liquid control system (for example, diesel fuel oil transfer pumps, reactor
building closed cooling water pumps, core spray motor-operated valves, etc.). The
team reviewed an additional sample of essential system interfaces with the plant
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monitoring information system and the plant monitoring information system
procurement specifications. Based on this review and discussions with the
licensee, the team found that the licensee had correctly designed the interface for
essential systems.
c.
Conclusions
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The licensee had modified their standby liquid control system and made it less
reliable. With the modified configuration, a common single failure could be
postulated (i.e., a short and/or ground of the redundant 120V ac control power
circuits) that would de-energize the standby liquid control system pump contactor
circuits and squib valve firirg circuits, rendering them allinoperable until the fault
was located and repaired. On a system level, the standby liquid control system is
not required to be single failure proof. Whether this design change was in violation
of 10 CFR 50.59 is considered unresolved, pending Office of Nuclear Reactor
Regulation review of the licensing basis. The licensee had correctly implemented
the modification to add plant monitoring system inputs to essential systems.
E1.4 USAR Discrecancies (10 CFR 50.71(e))
a.
Insoection Scoce (93801, 37550)
The team evaluated compliance to selected USAR commitments.
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