Information Notice 1993-77, Human Errors That Result in Inadvertent Transfers of Special Nuclear Material at Fuel Cycle Facilities

Human Errors That Result in Inadvertent Transfers of Special Nuclear Material at Fuel Cycle Facilities
	ML031070075
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:	10/04/1993
From:	Burnett R; NRC/NMSS/FCSS
To:	;
References
	IN-93-077, NUDOCS 9309290006
	Download: ML031070075 (17)
	v • d • e

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, D.C. 20555 October 4, 1993 NRC INFORMATION NOTICE 93-77: HUMAN ERRORS THAT RESULT IN INADVERTENT

TRANSFERS OF SPECIAL NUCLEAR MATERIAL AT FUEL

CYCLE FACILITIES

Addressees

All nuclear fuel cycle licensees.

Purpose

This information notice is to alert addressees to possible sampling program

deficiencies that may arise at nuclear fuel cycle facilities because of the

human factors component of nuclear criticality sampling programs. It is

expected that licensees 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 do not constitute

new U.S. Nuclear Regulatory Commission requirements; therefore, no specific

action or written response is required.

Description of Circumstances

In August 1992, a licensee notified the NRC that an operator had emptied the

contents of a favorable geometry slab hopper, used to store U02 powder on an

interim basis, into an unfavorable geometry blender before receiving the

sample analysis for the contents of the slab hopper. The sampling of the U02 powder in the slab hopper provides one of the controls to ensure that the

moisture content of the powder is below 1 wt(%) H20. This restriction on the

water content in the UO powder is necessary to ensure nuclear criticality

safety in the unfavorable geometry blender.

The licensee conducted an evaluation to determine the cause(s) of the

inadvertent transfer of UO powder from the slab hopper to the blender. This

evaluation revealed that the inadvertent transfer occurred as follows:

(1) An operator erroneously assumed that a completed powder release form

lying on a desk common to all slab hoppers was for a slab hopper whose

sample results had not yet been received.

(2) The operator then retrieved a key from the control room and subsequently

released the contents (750 kg of U02 powder) of the slab hopper into the

unfavorable geometry blender. (This key was supposed to be controlled by

the shift supervisor, as stipulated by procedure.)

9309290006 PDR 3W Notice q3-67 5 9 t1ool- y

IN 93-77 October 4, 1993 (3) The operator informed the supervisor that he

had dumped the contents of

the slab hopper into the blender. The shift supervisor

recorded this information in the shift log. (At subsequently

this time, the shift

supervisor should have realized that this was an

because he had not signed the powder release form unauthorized transfer

required by procedure.) for the slab hopper, as

The inadvertent transfer was later discovered when

found an unsigned powder release form (lying on the the next shift operator

operating room) for the slab hopper whose powder common desk in the

had

operator did note, from the form, that the laboratory been released. The

hopper were within the release limits. The operator results for the slab

who subsequently verified that the results were withininformed the supervisor, limits. The supervisor then completed and signed the prescribed moisture

form. NRC was informed of the event in accordance the powder sampling record

with NRC Bulletin 91-01.

Discussion

The inadvertent transfer of special nuclear material, described event, resulted from deficiencies associated in the previously

component of the licensee's sampling program. In with the human factors

this

program was deficient in two respects. Using a common instance, the sampling

line paper work represented a less than favorable desk for all powder

powder release forms. This led to a situation in method to store completed

easily mistake one powder release form for another. which an operator could

from reoccurring, the licensee uses a separate desk To prevent this problem

each powder line. (This action has made the inadvertent to house the forms for

powder release form unlikely.) reading of the wrong

The licensee's sampling program was also

deficient with respect to securing control of the

keys, which are used to

release the powder from the slab hoppers to the blender.

supervisor control the keys, the licensee created By not having a

a

operator's single mistake could lead to an inadvertent situation where an

licensee's corrective action is to require that the transfer. The

release keys for the slab hoppers. The licensee's supervisor control the

corrective

sufficient to ensure that the following two independent actions are

are necessary before a criticality is possible: and unlikely events

1. The operator mistakenly reads the wrong powder

release form.

2. The supervisor misreads the form and subsequently

key to release the powder from the slab hopper. gives the operator the

K)

IN 93-77 October 4, 1993 It should be noted, however, that another possible path to a nuclear

criticality could involve a contingency in which an operator is given a common

key by the supervisor. In this scenario, the operator could mistakenly use

the common key to release special nuclear material from the wrong slab hopper.

To preclude this event, the licensee utilizes individual keys for each slab

hopper.

In addition to the previously described event, there have been other occasions

in which a deficient nuclear criticality sampling program has led to an

inadvertent transfer of special nuclear material. One such case occurred when

a licensee operator analyzed two samples from one tank, but recorded them as

being from another tank. As a result, an inadvertent transfer occurred.

Another type of event occurred, on two separate occasions, in which a licensee

reported the inadvertent transfer of liquid-bearing uranium to an unfavorable

geometry container. These transfers occurred when an operator mistakenly

entered the analyses for a different tank into the computer.

The previously discussed events illustrate the necessity for licensees to

carefully review their nuclear criticality sampling programs. Licensees

should vigilantly review their respective programs to ensure that the double

contingency principle is fulfilled. This principle requires that at least two

independent and unlikely concurrent process changes occur before a criticality

is possible. For nuclear criticality sampling programs, this requires the

following:

1. Assurance that an operator mistake (contingency) at any juncture

cannot lead to an inadvertent transfer. That is, a second contingency is

necessary before a nuclear criticality event is possible.

2. A contingency must be an unlikely event. This may require one of the

following controls: using color-coded forms, segregating forms, using

different keys, requiring multiple individuals to inspect results, etc.

IN 93-77 October 4, 1993 This information notice requires no specific action or written response. If

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

technical contact listed below or the appropriate regional office.

Robert F. Burnett, Director

Division of Fuel Cycle Safety

and Safeguards

Office of Nuclear Material Safety

and Safeguards

Technical contact: Marc Klasky, NMSS

(301) 504-2504 Attachments:

1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

Attachment 1 IN 93-77 October 4, 1993 LIST OF RECENTLY ISSUED

NMSS INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

93-69 Radiography Events at 09/02/93 All holders of OLs or CPs

Operating Power Reactors for nuclear power reactors

and all radiography

licensees.

93-60 Reporting Fuel Cycle and 08/04/93 All fuel cycle and materials

Materials Events to the licensees.

NRC Operations Center

93-50 Extended Storage of 07/08/93 All licensees authorized

Sealed Sources to possess sealed sources.

93-36 Notifications, Reports, 05/07/93 All U.S. Nuclear Regulatory

and Records of Misadmin- Commission medical

istrations licensees.

93-31 Training of Nurses 04/13/93 All U.S. Nuclear Regulatory

Responsible for the Commission medical

Care of Patients with licensees.

Brachytherapy Implants

93-30 NRC Requirements for 04/12/93 All U.S. Nuclear Regulatory

Evaluation of Wipe Commission medical

Test Results; Cali- licensees.

bration of Count Rate

Survey Instruments

93-19 Slab Hopper Bulging 03/17/93 All nuclear fuel cycle

licensees.

93-18 Portable Moisture-Density 03/10/93 All U.S.'Nuclear Regulatory

Gauge User Responsibilities Commission licensees that

. ,

during Field Operations possess moisture-density

gauges.

93-14 Clarification of 02/18/93 All Licensees who possess

10 CFR 40.22, Small source material.

Quantities of Source

Material

Attachment 2 IN 93-77 October 4, 1993 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

93-76 Inadequate Control of 09/21/93 All holders of OLs or CPs

Paint and Cleaners for for nuclear power reactors.

Safety-Related Equipment

93-75 Spurious Tripping of 09/17/93 All holders of OLs or CPs

Low-Voltage Power Circuit for nuclear power reactors.

Breakers with GE RMS-9 Digital Trip Units

93-74 High Temperatures Reduce 09/16/93 All holders of OLs or CPs

Limitorque AC Motor for nuclear power reactors.

Operator Torque

93-73 Criminal Prosecution of 09/15/93 All NRC licensees.

Nuclear Suppliers for

Wrongdoing

93-72 Observations from Recent 09/14/93 All holders of OLs or CPs

Shutdown Risk and Outage for nuclear power reactors.

Management Pilot Team

Inspections

93-71 Fire at Chernobyl Unit 2 09/13/93 All holders of OLs or CPs

for nuclear power reactors.

93-70 Degradation of Boraflex 09/10/93 All holders of OLs or CPs

Neutron Absorber Coupons for nuclear power reactors.

93-69 Radiography Events at 09/02/93 All holders of OLs or CPs

Operating Power Reactors for nuclear power reactors

and all radiography

licensees.

93-68 Failure of Pump Shaft 09/01/93 All holders of OLs or CPs

Coupling Caused by for nuclear power reactors.

Temper Embrittlement

during Manufacture

OL = Operating License

CP = Construction Permit

IN 93-77 October 4, 1993 This information notice requires no specific action or written response. If

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

technical contact listed below or the appropriate regional office.

Robert F. Burnett, Director

Division of Fuel Cycle Safety

and Safeguards

Office of Nuclear Material Safety

and Safeguards

Technical contact: Marc Klasky, NMSS

(301) 504-2504 Attachments:

1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

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IN 3-XX

ptember , 1993 age 4 of 4 This information notice requires no specifi ct r written response. If

you have questions about the information this tice, please contact the

technical contact listed below or the a ri egional office.

Robert F. Bur tt, Director

Division of F el Cycle Safety

and Safegu rds

Office of N lear Material Safety

and Safe ards

Technical contact: Marc Klasky, NMSS

(301) 504-2504 Attachments:

1. List of Recently Issued NMSS Info tion Notices

2. List of Recently Issued NRC Info tion Notices

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IN 93-XX

August , 1993 In addition to the previously described event, there have been oth occasions

in which a deficient nuclear criticality sampling program has le to an

inadvertent transfer of special nuclear material. One such cas occurred when

a licensee operator analyzed two samples from one tank, but rcorded them as

being from another tank. As a result, an inadvertent trans r occurred.

Another type of event occurred, on two separate occasions in which a licensee

reported the inadvertent transfer of liquid-bearing ura um to an unfavorable

geometry container. These transfers occurred when an erator mistakenly

entered the analyses for a different tank into the c puter.

The previously discussed events illustrate the n essity for licensees to

carefully review their nuclear criticality samp. ng programs. Licensees

should vigilantly review their respective pro ams to ensure that the double

contingency principle is fulfilled. T nciple requires that at least two

independent and unlikely concurrent oce changes occur before a criticality

is possible. For nuclear criticali y s ing programs, this requires the

following:

1. Assurance that an operator ke Cc ntingency) at any juncture

cannot lead to an inadvertent transfe. That is,a second contingency is

necessary before a nuclear criticali y event is possible.

2. A contingency must be an unlikely vent. This may require one of the

following controls: using color- oded forms, segregating forms, using

different keys, requiring multip e individuals to inspect results, etc.

This information notice requires n specific action or written response. If

you have questions about the infor ation in this notice, please contact the

technical contact listed below o the appropriate regional office.

Robert F. Burnett, Director

Division of Fuel Cycle Safety

and Safeguards

Office of Nuclear Material Safety

and Safeguards

Technical contact: Marc lasky, NMSS

(30 504-2504 Attachments:

1. List of Recently ssued NMSS Information Notices

2. List of Recentl Issued NRC Information Notices

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KYJ IN 93-XX

August , 1993 In addition to the previously described event, there have been other occasions

in which a deficient nuclear criticality sampling program has led to an

inadvertent transfer of special nuclear material. One such case occurred when

a licensee operator analyzed two samples from one tank, but recorded them as

being from another tank. As a result, an inadvertent transfer occurred.

Another event occurred, on two separate occasions, in which a licensee

reported the Inadvertent transfer of liquid-bearing uranium to an unfavorable