Information Notice 1992-13, Inadequate Control Over Vehicular Traffic at Nuclear Power Plant Sites

Inadequate Control Over Vehicular Traffic at Nuclear Power Plant Sites
	ML031200669
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	02/18/1992
From:	Rossi C; Office of Nuclear Reactor Regulation
To:	;
References
	IN-92-013, NUDOCS 9202110001
	Download: ML031200669 (9)
	v • d • e

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 February 18, 1992 NRC INFORMATION NOTICE 92-13: INADEQUATE CONTROL OVER VEHICULAR TRAFFIC

AT NUCLEAR POWER PLANT SITES

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice

to alert addressees to continuing problems resulting from the failure of some

licensees to maintain adequate control over vehicular traffic at their plants.

These licensees failed to follow established administrative procedures related

to the use of self-propelled cranes. Their failures resulted in unnecessary

challenges to safety systems and threatened the health and safety of plant

personnel. It is expected that recipients will review the information for

applicability to their facilities and consider actions, as appropriate, to

avoid similar problems. However, suggestions contained in this information

notice are not NRC requirements; therefore, no specific action or written

response is required.

Description of Circumstances

Diablo Canyon Unit 1: On March 7, 1991, during a refueling outage, the Diablo

Canyon Nuclear Power Plant, Unit 1, experienced a total loss of offsite power

(LOOP). The event was caused when an electrical flashover occurred between a

500 kV transmission line and the boom of a mobile crane. The boom was positioned

approximately three feet from the transmission line. At the time of the event, power to plant loads was being supplied from offsite by back-feeding through

the main output transformer from the 500 kV switchyard. Two standby startup

transformers, the normal sources of offsite power to the plant, had been

removed from service for scheduled maintenance. The flashover caused protective

relaying to actuate to isolate the faulted line and, as a result, offsite power

to plant loads was interrupted.

All three emergency diesel generators started and loaded successfully. Operation

of the residual heat removal system was restored within about 1 minute. The

temperature of the core did not increase. No radiological release resulted.

The fault did not affect Diablo Canyon, Unit 2, which was operating at full

power.

Palo Verde Unit 3: On November 15, 1991, while the Palo Verde Nuclear Generating

a ion , was shutdown in hot standby, the boom of a 35-ton truck-mounted

CL-

AAClec on 2/1 9 lJ-I

..... IN 92-13 February 18, 1992 crane made contact with one of two 13.8 kV offsite power feeder lines located

in the plant's protected area. The crane was being used to replace the "A" phase

bushing on the main output transformer. The original bushing had been damaged

by lightning a day earlier. Prior to final installation and after high voltage

testing had been completed, the bushing was returned to its shipping cask. The

crane operator shut down the crane motor and engaged one of several braking

devices on the crane boom. The crane operator then exited the crane cab to

discuss replacement procedures with other maintenance personnel.

A wind gust caused the boom of the crane to rotate and contact one of the phases

of the 13.8 kY feeder. The feeder was transmitting power from the startup trans- former to various vital and non-vital loads in the "A" train. The electrical

fault current which was generated was not of sufficient magnitude to cause

protective devices to actuate because the crane had not been grounded as

required by plant procedure. Therefore, the feeder remained energized and the

fault current initiated small asphalt fires in the areas where the crane's

front outrigger pads made ground contact. The rear outrigger pads were not

extended.

The maintenance foreman (the foreman) contacted the shift supervisor and

incorrectly identified the "B" train feeder as being faulted. The shift

supervisor opened the supply circuit breaker for the "B" train feeder before

the foreman could correct his misstatement. Electrical power was interrupted

to non-vital loads, including two of four reactor coolant pumps (RCPs). Power

to vital train "B" loads was momentarily interrupted but was reestablished

following-the successful start and Toa-din-g of the train "B" emergency diesel

generator (EDG).

The correct "A" feeder was subsequently deenergized, resulting in the start

and loading of the "A" EDG and causing the loss of power to the remaining two

operating RCPs. The reactor was cooled by natural circulation for about 28 minutes until a reactor coolant pump was started. A notification of an unusual

event was made by the licensee based on a fire located in the protected area

lasting longer than 10 minutes. The event resulted in no personnel injuries

and no release of radioactive material.

Fermi Unit 2: On December 12, 1991, an event involving a self-propelled crane

occurred at the Enrico Fermi Atomic Power Plant, Unit 2. The Fermi Unit was in

cold shutdown in preparation for replacing a main output transformer. The

crane, with its boom extended, attempted to turn onto a roadway that is outside

the protected area but inside the owner controlled area at the plant. While

the crane spotter was directing traffic, the crane operator proceeded to turn

onto the roadway. A lifting strap, which was dangling from the end of the

crane boom made momentary contact with one phase of a 120 kV transmission line

which was providing offsite power to the plant. The circuit breaker for the

line immediately opened and reclosed, interrupting and reestablishing the power

supply in a matter of cycles. No LOOP resulted.

When the operator stopped the crane, the crane came to rest with the end of

the boom extended above the transmission line and with the transmission line

passing between the boom and lifting strap. The operator then backed up the

crane. A second contact occurred between the transmission line and the lifting

IN 92-13 February 18, 1992 strap. The circuit breaker again opened and reclosed rapidly so that no actual

LOOP occurred. The crane operator then informed his supervisor of the event.

No personnel injuries or equipment damage resulted. No challenge to plant

safety systems occurred.

Discussion

Information Notice 90-25, Supplement 1, "Loss of Vital AC Power with Subsequent

Reactor Coolant System Heat-up," informed licensees of problems that can occur

when vehicular traffic is not properly controlled near safety systems or

systems important to safety. A significant operating event occurred at the

Alvin W. Vogtle Generating Plant (Vogtle) on March 20, 1990. An NRC incident

investigation team described the circumstances of the event in detail in

NUREG-1410 titled, "Loss of Offsite AC Power and the Residual Heat Removal

System During Mid-Loop Operations at Vogtle Unit 1 on March 20, 1990." The

Vogtle Unit 1 event was initiated when a fuel and lubricants truck, conducting

routine operations in the switchyard, backed into a support column for a 230 kV

feeder which was supplying offsite power to the Unit. Ensuing events led to

the total loss of vital ac power at the plant and operation in natural circu- lation while the reactor coolant system was drained down to mid-loop.

One of the lessons learned from the Vogtle incident was the need for licensees

to develop appropriate programs for controlling vehicular traffic at their

sites. Although the events at the Diablo Canyon, Palo Verde, and Fermi plants

were of less safety significance than the Vogtle event, they demonstrate that

problems associated with inadequate control of vehicles continue to occur.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact the

technical contact listed below or the appropriate Office of Nuclear Reactor

Regulation (NRR) project manager.

Charles E. Rossi, Direc

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical contact: N. Fields, NRR

(301) 504-1173 Attachment: List of Recently Issued NRC Information Notices

2 C

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m

Attachment

IN 92-13 February 18. 1992

n~ Page I of I

r Q C)Z LIST OF RECENTLY ISSUED

0z NRC INFORMATION NOTICES

I

la 1-

<C Zoj IInformation Date of

tNotice No. Subject Issuance Issued to

I ,

toW

m 00 92-12 Effects of Cable Leakage 02/10/92 All holders of OLs or CPs

c e 6 Currents on Instrument for nuclear power reactors.

Settings and Indications

92-11 Soil and Water Contamina- 02/05/92 All uranium fuel fabrica- (n tion at Fuel Cycle Facil- tion and conversion facil- ities ities.'

2

92-10 Brachytherapy Incidents 01/31/92 All Nuclear Regulatory Com- Involvihg Iridium-192 Wire mission (NRC) licensees

Used In Endobronchial authorized to use

Treatments iridiwu-192 for brachy- therapy; manufacturers and

distributors of iridium-192 wire for use In brachy- therapy.

92-09 Overloading and Subsequent 01/30/92 All holders of OLs or CPs

Lock Out of Electrical for nuclear power reactors.

Buses During Accident

Conditions

92-08 Revised Protective Action 01/23/92 All fuel cycle and materi- Guidance for Nuclear Inci- als licensees authorized

dents to possess large quanti- ties of radioactive materi-

1al.

92-07 Rapid Flow-Induced Erosion/ 01/09/92 All holders of OLs or CPs

Corrosion of Feedwater Piping for pressurized water

reactors.

92-06 Reliability of ATHS Mitiga- 01/15/92 All holders of OLs or CPs

tion System and Other NRC for nuclear power reactors.

Required Equipment Not

Controlled by Plant Tech- nical Specifications

92-05 Potential Coil Insulation 01/08/92 All holders of OLs or CPs

Breakdown in ABB RXHH2 Relays for nuclear power reactors.

OL - Operating License

0

CP I Construction Permit

a

t 6a;

IN 92-13 February 18, 1992 strap. The circuit breaker again opened and reclosed rapidly so that no actual

LOOP occurred. The crane operator then informed his supervisor of the event.

No personnel injuries or equipment damage resulted. No challenge to plant

safety systems occurred.

Discussion

Information Notice 90-25, Supplement 1, *Loss of Vital AC Power with Subsequent