ML20211L176

Corrected Registry of Radioactive Sealed Sources & Devices Safety Evaluation of Device for Model 35-0402,35-0403 & 35-0404.Certificate NR-192-D-108-U

ML20211L176
Person / Time
Issue date:	07/05/1989
From:	NRC
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Shared Package
ML20211L147	List: ML20211L144 ML20211L176
References
SSD, NUDOCS 9710100127
Download: ML20211L176 (3)

Text

f/A - @O? b 00 P.EGISTr." 0F RADlQACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE (Corrected Page) '

JUL 0 5 1989 NO.: NR192D108U DATE: Februa ry 09, 1968 PAGE 1 0F 3 DEVICE TYPE: Fill-level Gauge Source Holder MODEL: 35-0402, 35-0403, 35-0404 f1ANUFACTURER/ DISTRIBUTOR: Brun Corporation Columbus, OH f1ANUFACTURER/ DISTRIBUTOR:

SEALED SOURCE MODEL DESIGNATION: AECL C-168 ISOTOPE: Cobalt-60 MAXIMUM ACTIVITY: 150 millicuries LEAK TEST FRE00ENCY: 6 months PRINCIPAL USE: (D) Gamma Gauge CUSTOM DEVICE: YES X N0 4

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e REGISTRY OF RADI0 ACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE NO.: NR1920108U DATE: February 9, 1968 r AGE 2 0F 3 DEVICE TYPE: Fill-Level Gauge Source Holder DESCRIPTION:

These devices essentially consist of the internals used in the 35-0102 and 0103 devices surrounded by additional shielding.

4 for the 35-0402 and 35-0404, this additional shielding consists of the use of an upper Mallory 1000 shield 3 inches in thickness giving an additional 1-23/32 inches of shielding over the 35-0102 and 35-0103; 2-1/4 inches of additional lead shielding on the periphery (wall) of the shield; and an additional 1-7/16 inches of lead shielding at the bottom of the device.

For the 35-0403, the additional shielding is the same with-the exception of the bottom of the shield assembly where the additional lead shie, ding is 11/16 inch.

All units have fan-shaped collimators. The 35-0402 collimator is 1/4 inch wide and has a 15' spread, the angle being measured downward from a horizontal at the top of the source. The 35-0403 collimator is 1/4 inch wide at its origin and 1 inch wide at the outer surface of- the device and has a 27' spread.

EXTERNAL RADIATION LEVELS:

In accessible areas at one foot from the surface of. a Model 35-0402 containing 100 millicuries of cobalt-60 are 4 mr/hr or .less. A radiation level of-20 mr/hr exists over a small area in the region of the beam port which is inaccessible with the unit installed. The radiation level at the " bottom" of the 35-0402 is less than 2 mr/hr. The 35-0403 has less shielding in this area than the 35-0402.

Radiation levels for higher activities may be derived by extrapolation.

LIMITATIONS AND/0R OTHER CONSIDERATIONS OF USE:

The devices were evaluated on the basis that they will be mountec' flush to the

- side of a steel mode' thereby preventing access to the beam of radiation and reducing radiation levels in the forward direction to about 0.1 mr/hr. If other applications are proposed, an evaluation of radiation levels in the forward direction will be necessary.

The user is instructed by the Brun Corporation to avoid tampering with the device z containing the cobalt-60 source. The Brun Corporation states that 3 service contract will normally be sold with each device to include visits at six-month intervals by a Brun Corporation representative for the purpose of inspecting the devices and performing source leak tests.

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REGISTRY OF RADI0 ACTIVE SEALED SOURCES AND DEVICES SAFETY-EVALUATION OF DEVICE NO.: NR19201080 DATE: February 9,1968 PAGE 3 0F 3 DEVICE TYPE:. Fill-Level Gauge Source Holder LIMITATIONS AND/0R OTH.1 CONSIDERATIONS OF USE (CONT'D):

The.Brun Corporation has also stated that they will install and relocate the source holders and perform radiation surveys at the time of installation.

Since an "on-off" indicator is not located at the source shield and since the control console may be remote from the shield, consideration must be given to exposure of persons not aware of the exposed position of the source.

ISSUING AGENCY:

U.S Nuclear Regulatory Commission 1

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