ML20058N803
| ML20058N803 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 08/14/1990 |
| From: | Lanning W Office of Nuclear Reactor Regulation |
| To: | Gody A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9008150122 | |
| Download: ML20058N803 (4) | |
Text
._
~ AOL 141990 Docket No. 50-458 t
MEMORANDUM FOR: ' Anthony T. Gody, Chief Performance ano Quality Evaluation Branch Division of Licensee Performance and Quality Evaluation Office of Nuclear Reactor Regulation
. ayne D. Lanning, Chief W
FROM:
Special Inspection Branch-
~
i Division of Reactor Inspection-and Safeguards' Office of Nuclear Reactor Regulation l
SUBJECT:
RIVER BEND SALP INPUT l
I have enclosed an RSIB input for the River Bend facility SALP. This SALP.
input is based on our electrical distribution system functional inspection which was conducted on May 21 through June 22, 1990.
If you have any J
questions, please call me'or Anil Gautam (X20988).
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- G Wayne D.- Lanning, Chief Special Inspection Branch-Division of Reactor Inspection and Safeguards Office of Nuclear Reactor Regulation.
Enclosure:
SALP Input for River Bend CONTACT:
Anil.S. Gautam, NRR 492-0988 Distribution:
BKGrimes, NRR
-CMAbbate, NRR BDLiaw, NRR CIGrimes, NRR L
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ENCLOSURE TACILITY NAME: River Bend Station
SUMMARY
OF REVIEW / INSPECTION ACTIVITIES A Nuclear Regulatory Commission (NRC) te6m conducted an electrical distribution system functional inspection (EDSfl) at the River Bend Station. -The inspection the Special Inspection Branch of the Office of Nuclear Reactor was conducted by) f rom May 21 through June 22, 1990.-
Regulation (NRR The NRC inspection team reviewed the oesign and implementation of the plant electrical distribution system (EDS) and the adequacy of associated engineering dnd technical support. Io accomplish this, the team reviewed'the oesign of electrical and nechanical systems and equipment aff tcting the EDS, examined ~
3 installeo EDS equipment, reviewed test programs and procedures affecting the EDS, ano determined the adequacy and interfaces of technical disciplines and functions by interviewing appropriate corporate and' site personnel, The team considered the design and impismentation of the EDS at River Bend to be generally acceptable. The design attributes of the EDS were retrievable and I
verifiable.
In most cases, engineering calculations hed conservative assump-tie: ao conclusions and were technically sound. The scope of-the site test program for EDS equipment was appropriate.
Engineering control of-modifica-tions to the EDS appeared to be effective and there appeared to be proper l
interf acing between engineering disciplines and f unctions.- EDS'equipnent w6s properly installeo in the plant and had adequate traceability toidesign docu-ments. Few ceficiency tags were observed and the equipment appeared to be well
-maintained. ' Engineering ano technical support for the EDS appeared to be adequate. Although the team found a significant backlog of modification i
requests, condition reports, and unincorporated drawing changes, the licensee l
was adoressing the backing through specific task force recommendations and appropriate planned actions.
The team also considered the engineering and technical support for the mechanical systems inspected to be a licensee strength, in that the' associated technical staff was knowledgeable, and a significant' amount of information was l
available, through calculations and system testing, to assess the mechanical systems.
The team had several findings regarding inadequate design reviews for certain conditions of. operations and postulated failures of certain EDS equipnent.
Protection and coordination studies for the 120 volt ac and 125 volt dc control circuits had not been performed. The-licensee prepared an analysis to demonstrate that these circuits were operable based on sufficient independence l
and redundancy of these circuits to. perform their safety functions, assuming a L
single failure.
Capacities of EDGs 1 and 2 to sustain -loads, if loads were sequenced at various tines within the setpoint band, and the capacity of the EDGs to sustain postulated accident transient loads had not been analyzed. Protection of load center 4160/480. volt transformers for power surges had not been analyzed. The possible loss of the Division 3 bus due to incorrect annunciation by the high-1
res 3tance ground schene on the 4160 volt safcty system had not been evaluated.
A.
ess analysis for potential damage to nechanical pip;ng during the possible sin. Itaneous starting of both standby service water pumps had not been per-f orL4d. The sizing of the EDG grounding resistors with regard to current ar.d thermal considerations was not analyzed.
The team found that postulated failures of the high-pressure cooling system (HPCS) pump motors and standby service water (SSW) pump motors that could restit from high transient currents generated during the fast transfer of the Division 3 bus to offsite power had not been analyzed. The licensee had temporarily suspended the f ast transf er scheme before this inspection because of other problems, and was currently feeding the Division 3 bus from the offsite grid rather then from the main generator.
Because of the team's concerns, the licensee decided to continue using the temporary operating procedure while performing studies to evalubte the possible failurcs of the HPCS and SSW pun.p motors.
Examples of other unanalyzed conditions of operation were icentifiec, including the potential for the battery electrolyte temperature falling below assuned values; capability of equipment to sustain the short circuit contribution f rom an emergency ciesel generator (EDG) when tested in parallel with the unit generator or the off site grid; effect of the air start lockout feature on the automatic starting of the diesel at low air receiver pressure setpoint; and the adequacy of the low cifferential pressure setpoint for initiating the SSW pumps under certain normal service water flow conditions.
In aedition, the USAR incorrectly stated the initiating signals for the starting of the SSW pumps; the EDG loading calculations did not take intu occount the magnetizing inrush current for the load center transformers; and the calculations for maximum piping tunnel temperatures and other temperatures applied an incorrect methodology. Examples of unsubstantiated assumptions, missing references, and missing reviews of design calculations were also found.
The team noted that the engineering and technical support staff had not per-formed a critical review of the calculations performed by the architect-engineer, and that many of the missing calculations and other deficiencies would have been identified by such a review. The licensee comitted to perform appropriate analysis and to revise calculations by March 1991.
NARRAllVE DISCUSSION OF LICENSEE PERFORMANCE - ENGINEERING /TECHhlCAL SUPPORT Management involvement and control in assuring quality indicated consistent evidence of prior planning and assignment of priorities. Well stated, con-trolled and explicit procedures for control of activities were noted. Dr. cision making was consistently at a level that ensures adequate management review.
Corporate management was frequently involved in site activities.
Committees were usually properly staffed and functioning. Records were generally complete and available. Reviews and updating of design documents, however, were not tinely. Procedures and policies were rarely violated. However, certain breakdowns of significance regarding design control occurred which indicated a weakness in this area.
2
,iln regard to resolutions of technical issues the licensee den.onstrated an-unoerstanoing of issues from a safety standpoint. Conservatism was routinely exhibited when a potential for safety significance existec. However, in some instances approaches were 'acking in thoroughness or depth.
In regard to enforcement history major violations were rare.
In regard to staffing, positions were identified and au'thcrities and responsi-bilities well oefined. Staffing was acequate.
j in sunmary, the team concluded that _the overall performance of the organiza-tion's engineering and technical support was generally adequate, although -
managenent_ sttention to the area of design control is necessary.
t AUTHOR: Anil S. Gautam 1
L DATE: July 19,1990~
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