ML20137H022

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Forwards IE Bulletin 78-08, Radiation Levels from Fuel Element Transfer Tubes
ML20137H022
Person / Time
Site: Dow Chemical Company, 05000000
Issue date: 06/12/1978
From: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To: Langner R
DOW CHEMICAL CO.
Shared Package
ML20136D183 List: ... further results
References
FOIA-85-256, FOIA-85-258, FOIA-85-259, FOIA-85-261 IEB-78-08, IEB-78-8, NUDOCS 8508280056
Download: ML20137H022 (1)
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Text

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JUN 12 1978

. Dockat No. 50-264 Dow Chemical U.S.A.

ATTN: Dr. R. R. Langner Radiation Safety Comittee 1803 Building Midland, MI 48640 Gentlemen:

Enclosed is IE Bulletin No. 78-08 which requires action by you with regard to your power, test or research reactor facility with an operating license.

Should you have questions regarding this Bulletin or the actions required of you, please contact this office.

i Sincerely, l

J. G. Keppler Regional Director

Enclosures:

1. IE Bulletin No. 78-08
2. List of IE Bulletins Issued in 1978 cc w/encia:

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NRC Form 318A (R3E) (5-76) NRCM 02040 .U. S. GOVERNMENT PRINTING OFFICE 1978-253 818

e U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III June 12, 1978 IE Bulletin No. 78-08 RADIATION LEVELS FROM FUEL ELEMENT TRANSFER TUBES Description of Circumstances:

On April 5, 1978, two radiation protection technicians at Portland General Electric Company's Trojan Nuclear Power Plant received whole body radiation doses of 27.3 and 17.1 rem while performing a survey adjacent to an exposed section of the fuel element transfer tube during the plant's first refueling outage. The exposures occurred in a shielded space inside the containment building which housed one of two fuel element transfer tube seismic relief bellows. The second bellows outside of containment had been provided with removable shielding and appropriate access controls. The bellows space inside containment was constructed with labyrinth-type shielding, however, access to the space was not controlled. The technicians were per-forming surveys in an attempt to identify a reported possible source of higher than expected radiation and had scheduled the survey to coincide with the passage of a fuel element through the fuel element transfer tube. The technicians believed that the fuel element transfer tube was buried in the concrete beyond the compartment they occupied and assumed that the structure passing through the compartment was a ventilation duct.

The licensee staff had performed surveys of all areas of the plant during the outage in an attempt to identify intermittent sources of radiation resulting from refueling activities; however, nothing significant was identified because of the transient nature of the resulting radiation fields. Subsequent to the exposures, the licensee performed surveys in numerous areas surrounding the general area of the fuel transfer tube with an irradiated fuel element stopped in the transfer tube. The surveys identified a number of areas previously unidentified where significant radiation streaming was present. The principal paths of radiation streaming were the narrow seismic relief spaces between the containment and internal and external structures.

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IE Bulletin No. 78-08 June 12, 1978 Action To Be Taken By 1.icensees:

While the exposures above occurred at a pressurized water reactor, similar situations could occur at any reactor facility designed to transfer spent fuel between the reactor refueling canal and a spent fuel storage pool outside of containment by means of a fuel element transfer tube. Accordingly, holders of power, test and research reactor operating licenses where plant design incorporates a fuel element transfer tube, are to take the following actions:

1. Perform a thorough review of shielding design of plant areas adjacent to the fuel transfer tube to identify potential high radiation areas, both continuous and transient, as defined in 10 CFR 20.202(b).
2. Assure that positive control of access exists or is included in the facility design for entryways into potential high radiation areas where a portion of a fuel transfer tube is accessible in an unshielded condition.
3. Assure that points of access to potential high radiation areas associated with accessible unshielded portions of a fuel transfer tube are conspicuously posted in accordance with 10 CFR 20.203(c).
4. If the action from Paragraph 1 above identifies the potential for radiation streaming from shielded spaces, plan and conduct special radiation surveys during the next refueling to identify and control such areas. It is not necessary to survey in areas where the transfer tube is exposed, but if it is found desirable, extreme care should be exercised to control and limit personnel exposure. Care should also be taken in planning surveys and fuel movements such that survey requirements do not override any technical limitations on fuel movement.
5. Confirm by written reply to the NRC Regional Office within 60 days that the actions for itema 1-4 above have been or are being taken.

A record, detailing findings, actions taken, and actions to be taken, should be retained for review by NRC during subsequent radiological safety inspection.

Approved by GAO, B180225 (R0072): clearance expires 7-31-80. Approval l was given under a blanket clearance specifically for identified generic L problems.

IE Bulletin No. 78-08 June 12, 1978 LISTING OF BULLETINS ISSUED IN 1978 Bulletin Subject Date Issued Issued To No.

78-01 Flammable Contact - 1/16/78 All Power Reactor Arm Retainers in G.E. Facilities with an CR120A Relays OL or CP 78-02 Terminal Block' 1/30/78 All Power Reactor Qualification Facilities with an OL or CP 78-03 ' Potential Explosive 2/8/78 All BWR Power Gas Mixture Accumula- Reactor Facilities tions Associated with with an OL or CP BWR Offgas System Operations 78-04 Environmental Quali- 2/21/78 All Power Reactor fication of Certain Fa:ilities with an Stem Mounted Limit OL or CP Switches Inside Reactor Containment 78-05 Malfunctioning of 4/14/78 All Power Reactor.

Circuit Breaker Facilities with an Auxiliary Contact OL or CP Mechanism-General Model CR105X ,

78-06 Defective Cutler-Hammer $/31/78 All Power Reactor Hammer. Type M Relays Facilities with an with DC Coils OL or CP 78-07 Protection afforded 6/12/78 All Power Reactor by Air-Line Respirators Facilities with an and Supplied-Air Hoods OL, all class E and F Research Reactors with an OL, all Fuel Cycle Facilities with an OL, and all Priority 1 Material Licensees Enclosure Page 1 of 1

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