Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
SSINS No.: 6835
IN 84-15
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
March 2, 1984
Information Notice No. 84-15: REPORTING OF RADIOLOGICAL RELEASES
Addressees:
All nuclear power reactor facilities holding and operating license (OL) or
construction permit (CP).
Purpose:
This information notice is issued to alert licensees of two recent events
involving radioactive gaseous releases. In both events, the offsite
radiological dose consequences were negligible. However, the incomplete or
anomalous initial reporting and the lack of aggressive licensee followup for
these events clearly demonstrate that (1) more attention could be given to
better screening of initial reports to the NRC, and (2) more effort could be
made to actively follow up and provide timely closure for radiological
events.
On a somewhat related matter, recent random checks with licensees reveal
that some facilities do not have the correct backup phone numbers for
contacting the NRC Operations Center in the event of a failure to the
Emergency Notification System (ENS). On June 1, 1982, the commercial
telephone number of the Operations Center was changed to 202-951-0550. The
new number was disseminated via Information Notice No. 82-16 dated May
28, 1982. In addition, Attachment 1 to this notice provides three additional
telephone numbers for use in the event of an ENS failure. As IE Information
Notice No. 82-15 pointed out, changes to licensee procedures may be
necessary to accommodate the new numbers.
No specific licensee action or response is required.
Description of Circumstances:
Event 1
Recently, during a weekend, a pressurized water reactor (PWR) experienced a
short-duration, unplanned, radioactive gaseous release followed by a 3-hour
release 1.25 hours later. The second event caused the plant vent stack to
alarm. These releases were not reported to the NRC Operations Center until
5.5 hours after the start of the 3-hour release. At that time the licensee
did not know whether the plant's technical specifications (TS) limit for
radioactive gaseous release rate had been exceeded.
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IN 84-15
March 2, 1984
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The NRC Headquarters Operations Officer (HOO) asked the licensee to call
back when the releases could be quantified. Given the release duration and
the receipt of the vent stack alarm, the licensee should have initiated
timely followup action to quantify the releases and to determine if a TS
violation had occurred. Not until two days later were the releases
quantified and shown to be approximately 33% of TS instantaneous release
rate limit. The 3-hour sustained release occurred while condensation was
being drained from the vent line of the volume control tank (VCT) to the
waste gas decay tank. The plant's reactor coolant activity was equal to
about 50% of the TS limit for specific activity.
Event 2
Another PWR experienced an unplanned gaseous release lasting 15-20 minutes.
The licensee notified the NRC HOO about 1 hour later and reported
radioactive effluent release rates of approximately 6 x 10-4 Ci/s (noble
gas) and 1.5 x 10-1 Ci/s (iodine). The source of the release was reported to
originate from the VCT vapor space. In accordance with emergency
implementing procedures, the licensee had declared a notification of unusual
event (NOUE) upon receipt of effluent monitor alarm. The NOUE was terminated
about 40 minutes after the release had stopped. An iodine release of this
magnitude (180 curies) would have presented a significant offsite dose
potential, dictating prompt initiation of licensee, state, and local
actions, as well as NRC emergency response actions. At the time of the
initial report, neither the licensee nor the NRC HOO recognized the offsite
dose potential for the reported iodine release. The HOO asked the licensee
for a callback/update when dose calculations were completed.
Early the following morning the relieving NRC HOO questioned the improbable
noble gas-to-iodine release rate ratio, given the source of the release was
the VCT vapor space. The HOO called the licensee for possible clarification
and validation of release data. The licensee could not provide further
clarification, but did suspect (but could not confirm) that the iodine
release number may have been erroneous. Not until later in the morning did
the licensee provide closure by reporting that the iodine release rate
originally reported was incorrect and the actual release consequences were
negligible.
Discussion:
Both events demonstrate the need for licensees to focus more attention on
the reporting requirements of 10 CFR 50.72. A more thorough technical review
of initial reporting data, followed by aggressive followup to resolve
potential anomalous/incomplete data can help provide timely resolution of
reported events. For example, licensees should normally have sufficient
information to rapidly bound the magnitude of a gaseous release--noble gas
effluent monitor reading can be directly related to the TS instantaneous
release rate.
The NRC has initiated a program to upgrade and broaden the HOO's level of
knowledge in the radiological area. The initial training for HOO's covered
radioactive gaseous and liquid releases, focusing on recognition of release
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IN 84-15
March 2, 1984
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magnitude, rates, and potential offsite dose consequences. If you have any
questions regarding this matter, please contact the Regional Administrator
of the appropriate NRC Regional Office, or this office.
Edward L. Jordan, Director
Division of Emergency Preparedness
and Engineering Response
Office of Inspection and Enforcement
Technical Contact: J. E. Wigginton, IE
(301) 492-4967
Attachments:
1. Backup Phone Numbers to NRC
2. List of Recently Issued IE Information Notices
.
Attachment 1
IN 84-15
March 2, 1984
Page 1 of 1
BACKUP PHONE NUMBERS FOR NRC
OPERATIONS CENTER
In the event of Emergency Notification System failure, the NRC Operations
Center can be contacted at any of the following numbers:
(202) 951-0550
(301) 427-4056
(301) 427-4259
(301) 492-8893
