U.S. Nuclear Regulatory Commission

Proper Operation and Use of Alarm Dosimeters at Nuclear Power Plants

HPPOS-328 PDR-9312130314

Title: Proper Operation and Use of Alarm Dosimeters at

Nuclear Power Plants

See the memorandum with enclosure from L. J. Cunningham to

J. H. Joyner (and others) dated November 15, 1993. This

NRR memo was written by the Radiation Protection Branch in

response to numerous inspection report findings and

regional requests for guidance on the proper use and

operation of alarm dosimeters. NMSS, RES, and Regional

comments were considered in the development of this health

physics position.

IMPROPER USE AND OPERATION OF ALARM DOSIMETERS: The

following examples illustrate the types of problems

occurring with alarm dosimeters (ADs) at nuclear power

plants:

1. ADs not operated in the proper mode for their

intended use [e.g., ADs used in the accumulated dose

(integrating) mode when the licensee procedure or RWP

requires use in the dose-rate mode].

2. Personnel continuing to work in high radiation

areas rather than leaving when their AD alarms in the

integrating mode.

3. HP personnel issuing ADs to individuals without

telling them the proper mode of operation or the alarm

setpoints.

4. Contract HP technicians not receiving training on

the AD in use at the current facility (different facilities

use different ADs).

5. ADs routinely being placed in plastic bags or

inside the pockets of PCs to prevent contamination. These

actions decrease the ability of the wearer to hear the AD

alarms, particularly in high noise areas requiring hearing

protection.

CALIBRATION OF ALARM DOSIMETERS: Regulatory Guide 8.28,

"Audible-Alarm Dosimeters," states that audible-alarm

dosimeters are not generally substituted for conventional

survey meters. While this is technically correct and

consistent with good HP practice, TS 6.12.1 allows an

audible-alarm dosimeter to be used instead of a survey

meter or HPT accompaniment after the dose rates in the area

have been measured with a survey meter and the workers in

the area have been informed of the measured dose rates.

10 CFR 20.1501 (b) states: "the licensee shall ensure that

instruments and equipment used for quantitative radiation

measurements (e.g., dose rate and effluent monitoring) are

calibrated periodically for the radiation measured." Using

an ADs cumulative alarm setpoint to initiate worker actions

in HRAs (i.e., exit an area when the alarm sounds) meets

the intent of the above regulation. Based on the above

requirements, ADs should be part of a routine instrument

calibration program if they are used to satisfy the

requirements under 10 CFR 20.1501 (b) or if used under 10

CFR 20.1601 (c) "alternative methods" as specified in TS

6.12.1 as a condition for entry into high radiation areas.

TRAINING IN PROPER USE OF ALARM DOSIMETERS: In 10 CFR

19.12, "Instructions to Workers", it is stated: "all

individuals working in or frequenting any portion of a

restricted area shall be kept informed of the storage,

transfer, or use of radioactive materials or of radiation

in such portions of the restricted area; . . . shall be

instructed in the purposes and functions of protective

devices employed, . . . and instructed in the appropriate

response to warnings made in the event of any unusual

occurrence or malfunction that may involve exposure to

radiation or radioactive material." To meet these 10 CFR

Part 19 requirements, a licensee needs to train personnel

in the proper operation of ADs. This training should

minimally include: (1) different modes of operation,

integrated dose and dose-rate; (2) the different types of

alarms, including the different sounds of each alarm; (3)

actions to be taken when receiving an alarm, leave the area

and contact health physics or move to a lower dose-rate

area; and (4) guidance for proper use of the ADs. The

guidance for proper use as adapted from RG 8.28 is as

follows:

1. An AD should not routinely be used as a survey

meter (removed from the body and used to check dose rates

in the area).

2. Care should be taken to avoid dropping ADs, but if

dropped, the ADs proper operation should be verified.

3. ADs should normally not be used in high noise

areas, when a user has a pronounced hearing loss, or when

the AD would be muffled by heavy clothing (e.g., PCs).

When ADs are used in high noise areas, workers should be

instructed to frequently check their ADs visually (similar

to reading a pocket ion chamber) or be equipped with a

warning device (e.g., remote ear-piece or visual flashing

light).

4. Source and battery checks should be done daily when

the ADs are in use and before the first use.

Regulatory references: 10 CFR 19.12, 10 CFR 20.1501, 10

CFR 20.1601, ANSI N13.27-1981, Regulatory Guide 8.28,

Technical Specifications

Subject codes: 1.2, 6.1, 6.4, 7.1, 8.1

Applicability: Reactors