United States Nuclear Regulatory Commission - Protecting People and the Environment

Bulletin 80-10: Contamination of Nonradioactive System and Resulting Potential for Unmonitored, Uncontrolled Release of Radioactivity to Environment

                                                            SSINS No.: 6820 
                                                            Accessions No.: 
                                                            8002280677 

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                           WASHINGTON, D.C. 20555 
                                     
                                 May 6, 1980

                                                      IE Bulletin No. 80-10 

CONTAMINATION OF NONRADIOACTIVE SYSTEM AND RESULTING POTENTIAL FOR 
UNMONITORED, UNCONTROLLED RELEASE OF RADIOACTIVITY TO ENVIRONMENT 

Description of Circumstance 

At the Brunswick Nuclear Facility, the auxiliary boiler was operated for an 
extended period of time with radioactively contaminated water in the boiler 
at levels up to 2 x 10 -2 micro curies per milliliter.  A tube leak in the 
firebox of the oil fired auxiliary boiler resulted in an unmonitored, 
uncontrolled release of radioactivity to the environment. 

The initial contaminating event was caused by the use of a temporary heating
hose from the auxiliary boiler to a radioactive waste evaporator concentrate
tank. Upon cooling and condensation of the steam in the temporary hose, 
contaminated water siphoned from the concentrate tank back to the auxiliary 
boiler. Due to additional, continuing leaks in the heat exchanger of the 
waste evaporator (to which the auxiliary boiler also provides process 
steam), the licensee's efforts to decontaminate the auxiliary boiler 
feedwater had been ineffective. 

Maintenance of proper boiler chemistry was difficult because blowdown 
options were severely restricted due to the contamination. As a result, a 
boiler tube failure caused on the order of 100 millicuries of radioactive 
material to be released off-site via the auxiliary boiler fire box and 
smokestack in the form of steam. This resulted in increased environmental 
levels of cesium and activation products being detected as far as eight 
miles downwind from the site boundary. 

Action to be Taken by Licensee with an Operating License 

1.   Review your facility design and operation to identify systems that are 
     considered as nonradioactive (or described as nonradioactive in the 
     FSAR), but could possibly become radioactive through interfaces with 
     radioactive systems, i.e., a nonradioactive system that could become 
     contaminated due to leakage, valving errors or other operating 
     conditions in radioactive systems. In particular, special consideration
     should be given to the following systems: auxiliary boiler system, 
     demineralized water system, isolation condenser system, PWR secondary 
     water clean-up system, instrument air system, and the sanitary waste 
     system. 

2.   Establish a routine sampling/analysis or monitoring program for these 
     systems in order to promptly identify any contaminating events which 
     could lead to unmonitored, uncontrolled liquid or gaseous releases to 
     the environment, including releases to on-site leaching fields or 
     retention ponds. 
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IE Bulletin No. 80-10                                       May  6,  1980 
                                                            Page 2 of 2 

3.   If these nonradioactive systems are or become contaminated, further use
     of the system shall be restricted until the cause of the contamination 
     is identified and corrected and the system has been decontaminated. 
     Decontamination should be performed as soon as possible. However, if it
     is considered necessary to continue operation of the system as 
     contaminated, an immediate safety evaluation of the operation of the 
     system as a radioactive system must be performed in accordance with the
     requirements of 10 CFR 50.59. The 10 CFR 50.59 safety evaluation must 
     consider the level of contamination (i.e., concentration and total 
     curie inventory) and any potential releases (either routine or 
     accident) of radioactivity to the environment. The relationship of such 
     releases to the radioactive effluent limits of 10 CFR 20 and the 
     facility's Technical Specification and to the environmental radiation 
     dose limits of 40 CFR 190 must also be evaluated. The record of the 
     safety evaluation must set forth the basis and criteria on which the 
     determination was made. 

4.   If it is determined in the 10 CFR 50.59 safety evaluation that 
     operation of the system as a radioactive system is acceptable (i.e., 
     does not involve an unreviewed safety question or a change to the 
     Technical Specifications), provisions must be made to comply with the 
     requirements of 10 CFR 20.201, General Design Criterion 64 to 10 CFR 
     50, Appendix I to 10 CFR 50 and the facility's Technical 
     Specifications. In specific, any potential release points must be 
     monitored and all releases must be controlled and maintained to "As Low 
     As is Reasonably Achievable" levels as addressed in Appendix I to 10 
     CFR 50 and within the corresponding environmental dose limits of 40 CFR 
     190. However, if in the 10 CFR 50.59 determination it is determined 
     that operation of the system as a radioactive system does constitute an 
     unreviewed safety question or does require a change to the Technical 
     Specifications, the system shall not be operated as contaminated 
     without prior Commission approval. 

Actions taken in response to Items 1 and 2 above shall be completed within 
45 days from the date of this Bulletin. A verification letter shall be 
submitted within an additional 15 days to the Director of the appropriate 
NRC Regional Office. This letter shall document the completion of the 
required actions but need not delineate the specific actions taken. The 
specifics shall be documented and made available to the NRC for review 
during future onsite inspection efforts. 

For facilities with a construction permit, no action is required. The 
Bulletin is provided for information. The subject of the Bulletin and the 
action required of operating plants should prove useful in the planning of 
systems designs and future operations. 

Approved by GAO, B180225 (ROO72); clearance expires 7-31-80. Approval was 
given under a blanket clearance specifically for identified generic 
problems. 
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