Information Notice 1999-30, Failure of Double Contingency Based on Administrative Controls Involving Laboratory Sampling and Spectroscopic Analysis of Wet Uranium Waste

Failure of Double Contingency Based on Administrative Controls Involving Laboratory Sampling and Spectroscopic Analysis of Wet Uranium Waste

ML993060157
Person / Time
Issue date:	11/08/1999
From:	TenEyck E Q NRC/NMSS/FCSS
To:
Ten-Eyck E Q
References
IN-99-030
Download: ML993060157 (7)

UNITED STATES

NUCLEAR

REGULATORY

COMMISSION

OFFICE

OF NUCLEAR MATERIAL

SAFETY

AND SAFEGUARDS

WASHINGTON,

D.C. 20555 November

8, 1999 NRC INFORMATION

NOTICE

NO. 99-30:

FAILURE

Of DOUBLE CONTINGENCY BASED

ON ADMlNlSTRATlVE

CONTROLS

INVOLVING

LABORATORY

SAMPLING

AND SPECTROSCOPIC ANALYSIS OF WET URANIUM

WASTE

Addressees

All fuel cycle licensees

and certificants

performing laboratory analysis

to determine uranium

content, in support

of administrative criticality safety

controls.

Purpose

The U.S. Nuclear

Regulatory

Commission (NRC) is issuing this information

notice

to alert addressees

to problems recently noted

with the laboratory and spectroscopic

analysis

of uranium

contaminated

material.

Under certain conditions, incomplete dissolution

of samples

may produce

a nonconsewative laboratory result and

lead to violation

of criticality safety

limits.

When the laboratory

sampling

is backed

up by spectroscopic analysis, care must be taken to ensure

a sufficiently

precise

result through proper

qualification

of the spectroscopic method.

Recipients

are expected

to review this information for applicability

to their facilities and consider

actions, as appropriate, to avoid similar problems. Suggestions contained in this

information

notice

are not NRC requirements. Therefore, no specific

action nor written

response

is required.

Descri~tion

of Circumstances:

On August

12, 1999, a fuel cycle licensee determined

that a laboratory dissolution process

was not completely dissolving the

uranium

in certain

samples, which resulted

in underestimating

the amount

of uranium

in wet process waste. Subsequent

licensee gamma spectroscopic

analysis

of the wet waste also failed to detect the problem, because of inadequate

spectroscopic

analysis

conditions.

Because of these simultaneous failures, excessive uranium was transferred

into the wet process

waste storage

arrays.

These deficiencies

in sampling

and spectroscopic

analysis

of process waste

degraded

the margin

of safety to the

extent that a criticality

safety

limit was violated.

IN 99-30 November

8, 1999 Discussion:

On July 30, 1999, a fuel

cycle licensee

discovered that a

combustible

waste bag containing

laboratory

filter

paper had higher

than expected

radiation

readings.

A subsequent licensee

investigation

revealed

that the acid leach dissolution process used

to prepare

samples

for analysis

of uranium

content

had not completely dissolved

the uranium.

When the samples

were later filtered during the

sample

preparation

process, some uranium was deposited on the

filter

paper with other solids.

The samples in

question came from

a uranium

recovery

process that produced wet solid

waste that was collected into

5-gallon

buckets and stored in

a safe, single-layer

array.

The samples

were used to determine

uranium

content

before

the material

was further

collected

into 55-galon

drums.

Once the waste was

collected into the 55-gallon drums, the drums

were examined

by spectroscopic

analysis

before

being stored

in a safe, triple-layer array.

The licensee

investigation revealed that

the 55-gallon drum spectroscopic

analysis was also assigning a

low value to the uranium

content

of the drums. This was

because

the drum catibration

standard

did not adequately

resemble

the material being

counted and the

spectroscopic

analysis

did not account

for self-shielding

in the drum material.

The licensee

had completed

a criticality

safety

anatysis (CSA) of the tripte-layer

drum storage

array to establish safety parameters.

The analysis made use

of the surface

density

method

to establish

the maximum uranium content limit for

individual drums. Double

contingency

for the storage

array was maintained through sampling of the 5-gallon buckets and

spectroscopic

analysis of the

55-gallon

drums.

As a result of

these independent and simultaneous failures, drums stored

in the array exceeded the

maximum allowed uranium content

for single

drums by up to 32%, thereby

causing

the failure

of the double-contingency arrangement.

This situation was safety significant in

that no controls remained to

limit the mass in the array, although

the total mass

involved

was far less than

what would be required for a criticality.

An important

contributing

factor

in this event was the limited

scope of the wet waste material

process

CSA, which stopped

with the material

being placed into 5-gallon buckets and did

not overlap

the CSA covering the 55-gallon

drum storage. Including the

transfer

from 5-gallon

buckets

to 55-gallon

drums in the

wet waste material

CSA should have

resulted

in more robust

controls

such as a requirement

for dual sampling

before permitting the

transfer.

An additional

important

contributing

factor

in this event was that

the sample

processing

procedures allowed a

choice of dissolution methods under the assumption that either

dissolution

method

would produce

a substantially

similar

result. The procedure writers mistakenly assumed that the

acid leach dissoiution

method

of sample preparation would

put all uranium into

solution

even if the entire sample

was not dissolved.

Finally, the spectroscopic analysis

procedures

did not qualify waste streams

for spectroscopic analysis, ensure optimal packaging for

spectroscopic

analysis, or require

corrective

action, when spectroscopic

analysis results did

not support

laboratory analysis. Spectroscopic

analysis

IN 99-30 November

8, 1999 of the 55-gallon

drums failed to

detect

the drums containing

excess

uranium due to these

failures.

ANSI N15.20-1975 "Guide to

Calibrating Nondestructive Assay Systems" provides

a more complete discussion

of spectroscopic

analysis

sensitivities.

This event highlights

the necessity

for careful review of administrative controls, to ensure that

the failure

of such controls

is actualty

unlikely.

tn addition, CSAs need to be broad enough

that the analyst

will clearly understand the safety significance

of proposed controls. All

procedures

having

an impact

on the control need

to be reviewed carefully

to ensure

that the control is

actually

implemented.

It is expected that addressees

will evaluate the

above information for

applicability

to licensed

activities.

This information

notice

requires

no specific actions nor written

response.

If you have any questions

about the information in

this notice, please contact the technical

contact

listed

below or the appropriate

regionai

office.

ck, Ap Dire ~ivi$on

of ~uel Cycle Safety and Safeguards

Office

of Nuclear

Material

Safety

and Safeguards

Technical Contact:

Dennis

C. Morey, NMSS 301 -41 5-61 07 E-mail:

dcm~nrc.gov

Attachments:

1. List of Recently

Issued

MMSS Information

Notices

2. List of Recently

issued

NRG Information

Notices

Attachment

I IN 99-30 November

1 1, 1999 Page 1 of 1 LIST OF RECENTLY

ISSUED

NMSS INFORMATION

NOTICES

Information

Date of Notice

No. Subject

Issuance Issued to

99-29 Authorized

Contents

of Spent 10128199 All power reactor

licensees

and Fuel Casks spent fuel

storage

licensees

and applicants

99-28 Recall

of Star Brand Fire 913Oig9 Alt holders

of licenses for nuclear Protection Sprinkler

Heads power, research and test

reactors, and fuel cycle facilities

99-27 Malfunction

of Source Retraction

9/2/99 All medical licensees authorized

Mechanism in Cobalt-60

Teletherapy

to conduct

teletherapy

treatments Treatment Units

99-26 Safety and

Economic

8/24/99 All Distributors

andlor

Consequences

of Misleading

Manufacturers

of Generally

Marketing

Information

Licensed

Products

99-24 Broad-Scope

Licensees'

711 2/99 All medical

licensees'

of broad- Responsibilities

for Reviewing

and scope and master materials

Approving Unregistered Sealed

ticensees

Sources

and Devices

Safety

Concerns

Related

To Repeated Control

Unit Failures

of the Nucletron

Ciassic

Model High-Dose-Rate

Remote

Afterloading

Brachytherapy

Devices

?O CFR 34.43(a)(I):

Effective

6/25/99 Date for Radiographer Certification

and Plans for Enforcement

Discretion

Contingency

Planning

for the 612 519 9 Year 2000 Computer Problem

Update

on NRC's Year 2000 611 4199 Activities for Materials Licensees

and Fuel Cycle Licensees

and Certificate Holders Federal Bureau of Investigation's

5/28/99 Nuclear Site Security Program

All U.S. NRC medical licensees

authorized to use brackytherapy

sources

in Nucletron Classic

Model high-dose-rate ((HDR)

remote

afterloaders

Industrial Radiography Licensees All material

and fuel cycle licensees

and certificate holders

All material and fuel cycle

licensees

and certificate

holders

A11 US. Nuclear Regulatory Commission fuel cycle, power

reactor, and non-power

reactor

licensees

Attachment

2 IN 99-30 November

2 I, 1999 Page 1 of l LIST OF RECENTLY

ISSUED

NRC INFORMATION NOTICES

Information

Date of Notice No.

Subject

Issuance Issued to

99-29 Authorized

Contents

of Spent 10/28/99 All power reactor licensees

and Fuel Casks spent fuel storage licensees

and applicants

Recall of Star

Brand Fire Protection

Sprinkler

Heads All holders

of licenses for

nuclear power, research, and test

reactors, and fuel cyde facilities

Malfunction of Source

Retraction

9/2/99 All medical licensees authorized Mechanism in

Cobalt-60

Teletherapy

to conduct teletherapy treatments

Treatment

Units Safety

and Economic

8/24/99 Consequences of

Misleading

Marketing

Information Year 2000 Contingency Planning

8/10/99 Activities

Broad-Scope

Licensees'

7/2 2/99 Responsibilities for Reviewing

and Approving

Unregistered

Sealed

Sources

and Devices

Safety

Concerns Related

To 7/6/99 Repeated Control Unit

Failures

of the Nucletron

Classic

Model High-Dose-Rate

Remote

Aferloading

Brachytherapy

Devices

10 CFR 34.43{a)(l);

Effective

7/6/99 Date for

Radiographer

Certification

and Plans for

Enforcement

Discretion All Distributors

and/or

Manufacturers of Generally

Licensed

Products

All holders

of operating

licenses

for nuclear

power plants and fuel cycle facilities

All medical

licensees

of broad- scope and master

materials

licensees

All U.S. NRC medical

licensees

authorized to use

brachytherapy

sources

in Nudetron

Classic

Model high-dose-rate (HDR) remote

afterloaders Industrial Radiography

Licensees

OL = Operating

License

CP = Construction

Permit

IN 99-30 November

8, 1999 of the 55-gallon drums failed

to detect the

drums containing

excess

uranium

due to these failures.

ANSI N15.20-1975 "Guide

to Calibrating

Nondestructive

Assay Systems"

provides

a more complete

discussion

of spectroscopic analysis sensitivities.

This event highlights the

necessity for careful review of

administrative

controls, to ensure

that the failure

of such controls

is actually

unlikely.

In addition, CSAs need to be broad enough

that the analyst will clearly

understand

the safety

significance of proposed controls.

All procedures

having an impact

on the control need

to be reviewed carefully

to ensure that

the control

is actually

implemented.

It is expected

that addressees will

evaluate the above information for applicability

to licensed

activities.

This information notice requires no specific actions nor written

response.

If you have

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

technical contact listed

below or the

appropriate regional office.

Elizabeth

Q. Ten Eyck, Director

Division

of Fuel Cycle Safety

and Safeguards

Office

of Nuclear Material

Safety

and Safeguards

Technical

Contact:

Dennis

C. Morey, NMSS 301-415-6107 E-mail: dcm@nrc.gov

Attachments:

1. List of Recently Issued

NMSS Information

Notices

2. List of Recently

Issued

NRC lnformation

Notices

FtLE NAME: a:\99-30.in

• See ~revious

concurrences

C = COVER E = COVER & ENCLOSURE

OFFICIAL

RECORD

COPY N = NO COPY

P .: s IN 99-xxx , 1999 It is expected that

addressees will evaluate the

above information

for applicability

to licensed

activities.

This information notice requires no specific actions nor written response. If you have

any questions

about the information

in this notice, please

contact

the tdchnical

contact

listed below or the

appropriate

regional

office.

1 i i i i r' Elizabeth

Q. Ten ~~~k, Director Division of Fuel

Cyqle Safety and Safeguards

/ Office

of Nuclear ,Material

Safety

and safeguards

i Technical

Contact:

Dennis

C. Morey, NMSS 301-475-6107 i it E-mail:

dcm@nrc.gov

/ i' ,/' Attachments:

i 1. List of

Recently Issued NMSS

lnformation

~oticed

2. List of

Recently

lssued

NRC information

Notice,$

./ i /' C = COVER ' E = COVER & ENCLOSURE

1' OFFICIAL

RECORD

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