IR 05000271/1985029

Insp Rept 50-271/85-29 on 851007-11.No Violation Noted. Major Areas Inspected:Proposed Tech Specs Changes,Operating Procedures & Supporting Hardware for Plant Operation Under Degraded Grid Voltage Conditions

ML20137M903
Person / Time
Site:	Vermont Yankee
Issue date:	11/25/1985
From:	Anderson C, Woodard C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20137M902	List: IR 05000271/1985029 ML20137M896
References
50-271-85-29, NUDOCS 8512040028
Download: ML20137M903 (5)

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i U.S. NUCLEAR REGULATORY COMMISSION

REGION I

3 Report No. 85-29

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Docket No. 50-271 License No. CPR-28 Licensee: Vermont Yankee Nuclear Power Corporation RD 5, Box 169 Ferry Road Brattleboro, Vermont 05301 Facility Name: Vermont Yankee

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Inspection At: Vernon, Vermont Inspection Conducted: October 7 - 11, 1985 Inspector: 02 YhYd Carl H. Woodard, R ctor Engineer

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Date C.J.Anb4rsojSection Plant Systems Inspection Summary Areas Inspected: Announced inspection to review proposed technical specifi-cation changes, operating procedures, and supporting hardware for plant oper-ation under degraded grid voltage cond'. .f ons. Followup on licensee corrective actions on previously identified outsta. ding open items. This inspection involved 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> on site by one region-based inspecto Results: No violations were identified in the areas inspecte $ NPM 71

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~ t DETAILS 1.0 . Persons Contacted 1.1 Vermont Yankee

• Jim Pelletier, Plant Manager

• David Phillips, Senior Electrical Engineer David LaBarge, Senior Engineer

• Rick Lopriore, Maintenance Supervisor

• Dan Reid, Operations Supervisor

• Bob Wanczyk, Technical Services Superintendent

• Pat Donnelly, Maintenance Superintendent

• Dennis Girrota, Senior Quality Assurance Engineer

• Mike Mete 11, Engineering Support Supervisor

• Larry Mullens, ISI Coordinator Jeff Cox, Licensing Administrator Joe Galonka, Maintenance Supervisor 1.2 General Electric Corporation

• Bill Neal, Technical Services Representative 1.3 'NRC

• 8ill Raymond, Senior Resident Inspector

• Tom Silko, Resident Inspector

• Denote: tho:e present at the exit interview on October 11, 198 .0 Status of Previous Inspection Findings 2.1 (Closed) Unresolved Item 84-18-05: Relating to the unreliability of the reactor protection system (RPS) alternate power supply. This is a Class IE power source that is used as an alternate supply instead of the RPS motor generator sets. The power feed for the alternate supply is through a single phase unregulated 480/120 volt transformer

. fed from Motor Control Center 88. This power feed can replace either of the two regulated sources provided by the MG sets. The unregu-lated characteristics of the alternate feed in conjunction with the undervoltage, overvoltage, and frequency protection provided by the RPS power supply protection panels have caused loss of the alternate supply on several occasions. This type of transient occurs.when starting large motor loads or transferring loads between startup and auxiliary transformers. However failure of the power supply are fail-safe in nature in that they can cause or contribute to plant shutdown (scram). A review and safety evaluation of this system was

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conducted by NRC and reported June 27, 1984. Based upon the o licensees current corrective action plan to install a regulated feed for the alternate power supply during this outage and the fact that failures of the power supply feed are fail safe in nature; this item is close .0 Review of Technical Specifications and Operating Procedures Changes Regarding Operations Under Conditions of Degraded Grid Voltage 3.1 Degraded Grid Voltage Technical Specifications By letter dated November 2,1984 the licensee proposed changes to the technical specifications to provide for degraded grid voltage pro-tection as a part of the Reactor Protection System (RPS). These changes will be addressed in an upcoming NRC Supplemental Safety Evaluation report. Briefly the changes are the following: Add to Section 3.2 of the technical specifications the limiting conditions of operation, the required instrumentation, trip settings, and required action for two levels of degraded grid voltage 3700 volts and 3600 volt . Add to Section 4.2 of the technical specifications the func-tional tests and calibration requirements for the degraded grid voltage syste This inspection was made to assess the adequacy and clarity of the proposed technical specification changes. The changes were reviewed in detail with the licensee and the physical locations of protective equipment, alarms, indications, and circuitry were inspected. The limiting conditions of operation, required operator actions, trip settings, calibration, surveillance and testing requirements were evaluated for clarity. No deficiencies were discovere .2 Degraded Grid Operating Procedures By letter dated November 2,1984 the Itcensee submitted for staff review operating procedure, "0P-3140 Low Grid Voltage Without an Accident Signal, Alarm Annunciator Response Procedure." Prior to this inspection, this procedure was reviewed and recommendations were made by the staff to the licensee for establishing time limitations during which operator action is required for each level of degraded voltage. The licensee concurred with changes recommended and had

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incorporated them in the procedur This inspection was made to determine the adequacy and clarity of licensee Operating Procedure OP-3140. The inspector walked through

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each step of the procedure in order to evaluate equipment, operator and plant response actions. No deficiencies were discovered during

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this inspection. This issue will.be addressed by the NRC in an upcoming safety evaluation report.

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4.0 Independent Inspection

.. 4.1 Uninterruptable Power Supplies (UPS) IE Exide Batteries The inspector conducted an inspection of the UPS batteries in follow-up of a 10 CFR Part 21 battery failure report. Vermont Yankee has two redundant UPS systems each powered by 192 "E" size Exide Type EC11 battery cells. These batteries were initially installed during 1979 and were replaced in 1984 because of "noduler corrosion" of the lead battery posts which caused stress and cracking in the plastic components adjacent to the posts, copper contamination of the neg-ative plates, and degraded battery performance. Exide inspected the batteries in March 1984 and reported these battery failures under 10 CFR 50 Part 21. The batteries were replaced with Exide Type EC11 batteries with a new seal design to overcome the problem. Visual inspection by the inspector did not reveal similar corrosion problem No deficiencies in the new batteries were discovered during this

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inspectio .2 Station Batteries The inspector made an inspection of the two Class IE 125 volt station batteries to observe reported erosion (mossing) around the battery

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terminals and on top of the battery plates and to assess the licensee's battery maintenance program for compliance with NRC requirements and licensee commitmen These are C&D batteries which have been in service for approximately 13 years. Inspection, main-tenance records were reviewed covering the period since 197 Battery capacity is periodically determined by Station Battery Discharge Test OP-4211 to assure compliance with Technical Specifi-cations and FSAR requirements. Defective or deficient cells or bat-teries are replaced. There was no evidence of excessive failure or replacements during this time.- Most of the cells showed little evi-dence of the mossing or corrosion reported except for cell 16 which has heavy massing on top of the plates and appeared to have a cracked seal around one of the posts. The licensee =has planned to replace all of these batteries with the same type and size batteries during this outage. No deficiencies in the licensee's battery maintainance program were discovere .0 Unresolved Item .

Unresolved items are matters about which more information is required to ascertain whether they are acceptable items, or violations. Unresolved items are discussed in paragraph . _ - - _ _ _ _ - _ - - _ - - _ _ _ _ _ _ _ _ - _

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6.0 Exit Interview-The inspector met with licensee and construction representatives (denoted in Paragraph 1.0) at the conclusion of the inspection on October 11, 1985, ,

at the construction site. The inspector summarized the findings of the-inspection and the licensee acknowledged the inspector's comment The inspector also confirmed with the licensee that the documents reviewed by the team did not contain any proprietary information. The licensee agreed that the inspection report may be placed in the Public Document Room without prior licensee review for proprietary information (10 CFR 2/790).

At no time during this inspection was written material provided to the licensee by the inspecto i

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