ML20037B280
| ML20037B280 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 09/15/1976 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Brian Lee COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8009100901 | |
| Download: ML20037B280 (1) | |
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dNITED STATES b.
NUCLEAR REGULATORY COMMISSION REclON lll 799 ROOSEVELT RO AD CLLN CLLYN. ILLINOIS 60137 SEP 151976 Con:inonwealth Edison Company Dochet No. 50-10 AITN: Mr. Byron Lee, Jr.
Docket No. 50-237 Vice President Docket No. 50-249 P. O. Box 767 Docket No. 50-254 Chicago, Illinoin 60690 Docket No. 50-265 Gentleman:
The enclosed Circular No. 76-03 is forwarded to you for cction.
The same docucent is being trcnsnitted to each cpplicant for, or holder of a Construction Permit for information. Therefore, if you have a nuclear power plant in the construction stanc.
you will also receive a copy of Circular No. 76-03 vhich vill not require a separate response.
Sincerely, James G. Keppler Regional Director
Enclosure:
IE Circular No. 76-03 cc w/ encl Fr. B. B. Stephenson Station Superintendent 1:r. N. J. Kalivianakis Station Superintendent bec w/ enc 1:
local PDR Anthony Roisman, Esq.,
Attorney
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LJ Septemhcr 13, 1976 IE Circular No. 76-03 RADIATION EXPOSURES IN REACTOR CAVITIES DESCRIPTION OF CIRCUMSTANCES:
On March 18, 1976, an employee at the Zion station received a "whole
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body" radiation dose of 8 rems or more upon entering the cavity beneath the reactor vessel during a refueling outage.
On April 5, 1976, a similar reactor cavity entry at Indian Point resulted in a 10-rem whole body dose to a licensee employce.
A similar entry on October 5, 1972, caused a 5-rem dose to a Point Beach employce.
These three overexposures appear to have been caused by failure to appropriately control entry'into high radiation areas, failure to conduct adequate surveys and failure to compensate for exposure rate variations that can occur in various areas in power reactors, c.g.,
the cavity beneath the reactor vessel.
With the incore thimbles and detectors inserted into the core, radiation levels in the cavity appear to be low.
With the thimbles or detectors with-drawn into the cavity, however, exposure rates of' hundreds or possibly thousands of roentgens per hour can exist.
Overexposures can occur in seconds.
1 All three overexposure events involved entry into potentially high radiation areas without surveys and/or special controls over equip-
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ment which could cause transients in the exposure rate.
ACTION TO BE TAKEN BY LICENSEES:
While the three exposures above occurred at pressurized water reactors, similar situations could develop at other types of reactors, e.g.,
pneumatic irradiation equipment areas (research reactors) and traveling incore probe equipment areas (boiling water reactors).
Accordingly, holders of power, test and research reactor operating licenses are to complete the following:
1.
Perform a thorough review of plant areas and operations to identify high radiation areas, both continuous and transient, as defined in 10 CFR 20.202(b).
2.
Verify that entryways into high radiation areas are conspicuously posted and locked or otherwise controlled in such a manner as to explicitly identify the nature of the hazard, appropriately control entry, and require adequate pre-entry surveys, 3.
Ensure that radiation protection procedures and radiation pro-tection training and retraining pronratn rpecifically addrens the 4Qp(
catter of control of and access t o such arcar and inmnte f
- qpropriatt: retraining of all pinn:. perwn:21, v
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j IE Circular No. 76-03 September 13, 1976 1
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Ensure that the procedures governing personnel entry into all actual or potential high radiation areas permit such entry only after appropriate management review and approval so that conditions within the area are known and not subject to change while the area is occupied, 5.
Periodically audit whatever controls result from items 1-4, above, to ensure their continued effectiveness, and 6.
Confirm by written reply within 60-days that the actions for items 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 the next radiclogical safety inspection.
This request for information was approved by GAO under a blanket clearance number B-180225 (R0072); this clearance expires July 31, 1977.
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