Information Notice 2000-15, Recent Events Resulting in Whole Body Exposures Exceeding Regulatory Limits

Recent Events Resulting in Whole Body Exposures Exceeding Regulatory Limits

ML003753235
Person / Time
Issue date:	09/29/2000
From:	Cool D NRC/NMSS/IMNS
To:
Psyk L
References
IN-00-015
Download: ML003753235 (6)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, D.C. 20555 September 29, 2000

NRC INFORMATION NOTICE 2000-15: RECENT EVENTS RESULTING IN WHOLE BODY

EXPOSURES EXCEEDING REGULATORY LIMITS

Addressees

All radiography licensees.

Purpose

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

addressees to recent events that resulted in radiographers receiving occupational whole body

doses in excess of the 0.05 sievert (5 rem) total effective dose equivalent limit specified in 10 CFR 20.1201(a)(1). It is expected that recipients will review this information for applicability to

their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not new NRC requirements; therefore, no

specific action nor written response is required.

Description of Circumstances

In March of this year, the NRC was notified that several radiographers had exceeded the

annual whole body dose limit of 0.05 sievert (5 rem) for calender year 1999. The following

describes the two cases:

Case 1:

A licensee reported that four radiographers received total effective dose equivalents of 7.224,

6.534, 6.104, and 5.112 cSv (rem) for 1999. The licensee stated that the exposures arose from

an unprecedented workload during 1999. Radiographers were using daily pocket dosimeters, although readings did not reflect the exposures expected for a larger workload. The reason for

this discrepancy was not determined, although improper use of the daily pocket dosimeters may

have been the cause. Dosimetry records for the fourth quarter of 1999 were not received until

late February 2000. Thus, the licensee did not realize that its employees had exceeded

exposure limits until the dosimetry reports arrived. The dosimetry processor stated that the

delay in dosimetry record returns was caused by computer difficulties, which it encountered

when upgrading its system for year 2000 compliance.

The licensee took several corrective actions. It now has a database program, allowing it to

determine the total personal pocket dosimeter readings at any given time. On a monthly basis, the licensee will review the pocket dosimeter readings to ensure that radiographers are not

approaching a dose limit. If an individual receives a personal dosimetry reading of greater than

0.4 cSv (rem) in any month, the individual will be notified and a plan will be developed for

keeping the dose within limits.

Case 2:

A licensee reported that two radiographers received annual doses that exceeded the yearly

limits for 1999. One individual received 2.14 cSv (rem) during the last quarter of 1999, which

put his total dose at 5.23 cSv (rem) for the year. Another individual received 0.93 cSv (rem) for

the last quarter of 1999, which made his total year dose 5.16 cSv (rem).

The licensee was slow to return the badges to be processed, sometimes delaying returning

badges up to 6 weeks after receiving them from the field. The control badges were not being

returned with the employee badges, further delaying the process time. Also, the dosimetry

processor had computer problems that delayed the generation of dose reports. The licensee

did not receive one radiographers 1999 fourth-quarter badge results until late February 2000,

and the second radiographers quarterly badge results until March 2000. The provisions in 10 CFR 34.47 (a)(4) require that, after replacement, each film badge or TLD must be processed as

soon as possible.

The dosimetry processor notified the licensee that an employee had exceeded his/her ALARA

level for the second quarter of 1999. The licensee did not document or follow up this

notification.

The licensee also stated that there were discrepancies between the weekly dosimeter records

and the quarterly film badge results from the processor. Pocket dosimeters were being used

and recorded weekly, although the licensee did not review the records. The licensees weekly

records indicated that one radiographer had exceeded the yearly limit of 0.05 sievert (5 rem) in

August 1999, but no action was taken to remove the individual from duties involving exposure

to radiation. At year end, the weekly pocket dosimeter records indicated 6.905 cSv (rem) for

one individual and 1.678 cSv (rem) for the other individual, which differs significantly from the

film badge results of 5.156 cSv (rem) and 5.233 cSv (rem). Although dosimeter sharing was a

possibility, this could not be determined. The provisions in 10 CFR 34.47(a)(2) require that each

film badge and TLD must be assigned to, and worn by, only one individual.

Three major causes contributed to these overexposures: 1) the licensee did not return

employee badges and control badges together to the processor; 2) the licensee did not return

the badges to the processor in a timely manner; and 3) the licensee did not review pocket

dosimeter results.

The licensees corrective actions included: 1) shipping the badges to the processor using an

express mail carrier; 2) documenting telephone notifications from the dosimetry processor that

quarterly ALARA dose levels are exceeded; 3) reviewing the weekly pocket dosimetry reports;

and 4) retraining personnel and emphasizing that the sharing of dosimeters is an unacceptable

practice.

IN 2000-15 Page 3 of

Discussion:

Some of the contributing causes of these exposure events can be summarized as follows:

ÿ Licensee failed to monitor pocket dosimetry results;

ÿ Dosimetry badges not mailed to the processor in a timely manner by the licensee;

ÿ Dosimetry badges and controls were not mailed together to the processor;

ÿ Dose determined solely on the results of quarterly dosimeter records;

ÿ Radiographers were assigned jobs before knowing their current cumulative doses;

ÿ Impact of the workload was not assessed regarding its impact on exposures.

All licensees using radiography devices are reminded of the importance of:

ÿ Tracking doses on a timely basis, to ensure that an individual is not approaching a

dose limit;

ÿ Timely return of badges and controls, together, to the dosimetry processor;

ÿ Obtaining reports from dosimetry processors in a timely manner;

ÿ Training employees on the importance of not sharing pocket dosimeters and badges;

ÿ Assessing increased workload and its impact on employee exposures;

ÿ Not allowing work pressures and workloads to interfere with appropriate radiation safety

practices and the radiation safety program; and

ÿ ALARA programs reflecting appropriate and timely actions.

Licensees are ultimately responsible for ensuring that their workers do not exceed the annual

dose limits in 10 CFR Part 20. Licensees may wish to consider actions to improve the tracking

and control of worker doses.

This information notice requires no specific action 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.

/RA/

Donald A. Cool, Director

Division of Industrial

and Medical Nuclear Safety

Office of Nuclear Material Safety

and Safeguards

Linda M. Psyk, NMSS

(301) 415-0215 E-mail: lmp1@nrc.gov

Attachments:

1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

ML003753235 C:\Ticket7886 IN Radiographer ~.wpd

OFC MSIB E MSIB TECH ED IMNS

NAME LPsyk JHickey EKraus DCool

DATE 8/2/00 9/20/00 8/3/00 9/25/00

Attachment 1 LIST OF RECENTLY ISSUED

NMSS INFORMATION NOTICES

_____________________________________________________________________________________

Information Date of

Notice No. Subject Issuance Issued to

_____________________________________________________________________________________

2000-12 Potential Degradation of 9/21/2000 All holders of licenses for nuclear

Firefighter Primary Protective power, research, and test

Garments reactors and fuel cycle facilities

2000-11 Licensee Responsibility for 8/7/2000 All U.S. NRC 10 CFR Part 50 and

Quality Assurance Oversight of Part 72 licensees, and Part 72 Contractor Activities Regarding Certificate of Compliance holders

Fabrication and Use of Spent

Fuel Storage Cask Systems

2000-10 Recent Events Resulting in 7/18/2000 All material licensees who

Extremity Exposures prepare or use unsealed

Exceeding Regulatory Limits radioactive materials, radio- pharmaceuticals, or sealed

sources for medical use or for

research and development

2000-07 National Institute for 4/10/2000 All holders of operating licenses

Occupational Safety and for nuclear power reactors, non- Health Respirator User Notice: power reactors, and all fuel cycle

Special Precautions for Using and material licensees required to

Certain Self-Contained have an NRC approved

Breathing Apparatus Air emergency plan

Cylinders

2000-05 Recent Medical 3/06/2000 All medical licensees

Misadministrations Resulting

from Inattention to Detail

2000-04 1999 Enforcement Sanctions 2/25/2000 All U.S. Nuclear Regulatory

for Deliberate Violations of Commission licensees

NRC Employee Protection

Requirements

2000-03 High-Efficiency Particulate Air 2/22/2000 All NRC licensed fuel-cycled

Filter Exceeds Mass Limit conversion, enrichment, and

Before Reaching Expected fabrication facilities

Differential Pressure

2000-02 Failure of Criticality Safety 2/22/2000 All NRC licensed fuel-cycled

Control to Prevent Uranium conversion, enrichment, and

Dioxide (UO2) Powder fabrication facilities

Accumulation

Attachment LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

_____________________________________________________________________________________

Information Date of

Notice No. Subject Issuance Issued to

________________________________________________________________________________

2000-14 Non-Vital Bus Fault Leads to 9/27/2000 All holders of licenses for nuclear

Fire and Loss of Offsite Power power reactors

2000-13 Review of Refueling Outage 9/27/2000 All holders of OL for nuclear

Risk power reactors

2000-12 Potential Degradation of 9/21/2000 All holders of licenses for nuclear

Firefighter Primary Protective power, research, and test

Garments reactors and fuel cycle facilities

2000-11 Licensee Responsibility for 8/7/2000 All U.S. NRC 10 CFR Part 50 and

Quality Assurance Oversight of Part 72 licensees, and Part 72 Contractor Activities Regarding Certificate of Compliance holders

Fabrication and Use of Spent

Fuel Storage Cask Systems

2000-10 Recent Events Resulting in 7/18/2000 All material licensees who

Extremity Exposures prepare or use unsealed

Exceeding Regulatory Limits radioactive materials, radio- pharmaceuticals, or sealed

sources for medical use or for

research and development

95-03, Supp 2 Loss of Reactor Coolant 7/03/2000 All holders of OL for nuclear

Inventory and Potential Loss of power reactors except those who

Emergency Mitigation have ceased operations and have

Functions While in a Shutdown certified that fuel has been

Condition permanently removed from the

reactor vessel

2000-09 Steam Generator Tube Failure 6/28/2000 All holders of OL for nuclear

at Indian Point Unit 2 power reactors, except those who

have permanently ceased

operations and have certified that

fuel has been permanently

removed from the reactor vessel

2000-08 Inadequate Assessment of the 5/15/2000 All holders of operating licensees

Effect of Differential for nuclear power reactors

Temperatures on Safety- Related Pumps

____________________________________________________________________________________

OL = Operating License

CP = Construction Permit

____________________________________________________________________________________

OL = Operating License

CP = Construction Permit