IE Circular No. 80-14, Radioactive Contamination of Plant Demineralized Water System and Resultant Internal Contamination of Personnel
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D. C. 20555
June 24, 1980
IE Circular No. 80-14
RADIOACTIVE CONTAMINATION OF PLANT DEMINERALIZED WATER SYSTEM AND RESULTANT
INTERNAL CONTAMINATION OF PERSONNEL
This circular describes an event which occurred at a nuclear power facility;
however, the generic implications may be applicable to research reactors,
and fuel cycle facilities.
On March 17, 1980, a licensee informed the NRC resident inspector that
portions of the plant demineralized water (DW) system were found to be
radioactively contaminated. A temporary hose used to add demineralized
water to the spent fuel pool was the pathway for the cross-contamination.
After this fuel pool makeup was completed on March 14, the temporary DW line
(still connected to the DW header was inadvertently left submerged in the
fuel pool. Since the DW header pressure at the point of supply was
relatively low (a DW booster pump had been secured), a siphoning action
occurred, resulting in radioactive contamination of portions of the DW
On March 17, 1980,while performing routine secondary system chemical
analyses, the licensee discovered that the demineralized water tap in the
chemistry lab contained high levels of boron and had activity of 1.5 x 10-4
uCi/ml (mainly Cs-134, Cs-137, Co-58, Co-60 and Mn-54). It was subsequently
discovered that demineralized water from the chemistry laboratory supply tap
had been used to make five (5) pots of coffee. The remaining coffee was
confiscated and the twenty-three (23) individuals who had consumed this
coffee were whole-body counted. All involved individuals showed no intake
greater than an equivalent 0.01 MPC-HRS. Analysis performed by the
licensee's radiation consultant, based on the maximum concentration of
radioactivity found in the coffee, indicated that the resultant 50-year dose
commitment of an individual drinking eight ounces of this coffee would be
less than 1 millirem.
Further licensee investigation revealed that the non-radiological chemistry
DW supply tap was the only DW supply point outside the Auxiliary Building
controlled area. This DW supply tap was tagged prohibiting human
consumption to prevent a similar event in the future.
It is recommended that you review your facilities use of demineralized water
(DW) via temporary connections and give attention to the following:
1. Provisions should be made to assure that radioactive materials are not
inadvertently introduced into your facility's DW system via the
improper use of temporary connections. A temporary cross connection
IE Circular No. 80-14 June 24, 1980
Page 2 of 2
contaminated systems and the DW system without adequate physical
controls to prevent cross-contamination should be prohibited.
2. In addition to some physical means of preventing backflow into the DW
system, appropriate administrative controls should be established to
ensure that the DW supply valve is secured and temporary hosing is
disconnected from the DW supply header after use.
3. Use of plant-supplied DW for human consumption should be prohibited.
The potable water system should be the only authorized source of water
for human consumption.
4. Examine potable and demineralized water systems to determine if
pathways exist allowing or having the potential to allow contamination
of these systems including temporary connections whereby siphons could
cause situations described above.
No written response to this Circular is required. Your review of this
matter to determine its applicability to your facility and any corrective
and preventive actions taken or planned, as appropriate, will be reviewed
during a subsequent NRC inspection. If you desire additional information
regarding this matter, contact the Director of the appropriate NRC Regional
Page Last Reviewed/Updated Thursday, March 25, 2021