Information Notice 1999-31, Operational Controls To Guard Against Inadventent Nuclear Criticality
| ML993140347 | |
| Person / Time | |
|---|---|
| Issue date: | 11/17/1999 |
| Revision: | 0 |
| From: | TenEyck E Q NRC/NMSS/FCSS |
| To: | |
| Ten-Eyck E Q | |
| References | |
| IN-99-031 | |
| Download: ML993140347 (4) | |
November 1 7, 1999 NRC INFORMATION NOTICE NO. 99-31 : OPERATIONAL CONTROLS TO GUARD AGAINST INADVERTENT NUCLEAR CRITICALITY
Addressees
All NRC licensed fuel cycle conversion, enrichment and fabrication facilities.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this Inf~rmation Notice (IN) to alert addressees to a recent nuclear criticality accident at a foreign fuel fabrication facility that resulted in a significant radiation exposure to workers and members of the public. Although an evaluation of the impact of this accident is ongoing, the NRC expects that recipients of this IN will review the information for applicability to their facilities and consider actions, as appropriate, to protect against a similar occurrence. However, suggestions contained in this IN are not NRC requirements. Therefore, no specific action nor written response to this notice is required. Descri~tion of Circumstances On September 30, 1999, a nuclear criticality accident occurred at a facility in Japan that preliminary information indicates resulted in the exposure of three operators to extremely high levels of radiation, the extensive contamination of process areas, exposure of emergency responders and members of the public, and contamination of the environment. Preliminary indications are that the accident involved the dissolution of about 5 times the safe mass of uranium oxide (enriched to about 18%) by nitric acid in an "unfavorable" geometry vessel (i.e., the vessel was not designed to preclude a criticality for the enrichments involved). The 18% enriched process was just restarted after a several year shutdown. Discussion The Government of Japan has initiated a formal task force headed by the Prime Minister to thoroughly investigate the causes of the accident and determine any potential criminal liability. As information becomes available from the Government of Japan, NRC plans to conduct an in- depth review of the details surrounding the event to determine whether further improvements in the NRC regulatory program would be prudent. In the interim, a Temporary Instruction has been issued to NRC Resident Inspectors at the two high enriched uranium (HEU) facilities and the two gaseous diffusion plants regulated by NRC to focus inspection resources on criticality safety implementation at these facilities. NRC also plans to review the results of an industry initiative to assess their criticality programs. In view of the above accident, licensees are encouraged to review their policies and procedures and the results of safety assessments to assure that:
IN 99-31 November 17,1999 1. The possibility of commingling HEU and low enriched uranium (LEU) has been considered, where applicable, and appropriately rigorous controls are established to prevent the inadvertent introduction of HEU material into LEU plant areas and processes. 2. Operators who are authorized to handle special nuclear material (SNM) have received proper traininglretraining with regard to the criticality safety rules and postings and that they understand the significance of the operating limits and what their expected response should be if any operating limit is exceeded. 3. Operations are conducted and administrative safety controls are implemented only in accordance with approved operating procedures and postings. 4. New processes and restart of processes that have been shut down for an extended . period of time are covered by current safety assessments and an administrative process confirms that all applicable controls are established and implemented and operator traininglretraining is completed prior to the introduction of SNM into the process. 5. Emergency plans contain appropriate provisions to ensure that both onsite and offsite emergency response personnel are made aware of criticality safety aspects of the facility, and receive proper health physics coverage and protection when responding to plant events. 6. Management provides an appropriate level of oversight of high risk operations to ensure that plant safety programs are effectively implemented and management expectations are being met. Any further information developed as a result of the Japanese investigation will be reviewed by NRC to determine whether further action may be warranted. This IN requires no specific action nor written response. If you have any questions about the information in this notice, please contact the technical contact listed below, or the appropriate NRC regional office. Elizabeth Ten Eyck, Director Division of Fuel Cycle Safety and Safeguards Office of Nuclear Material Safety and Safeguards Technical contact: William Troskoski, NMSS 30 1 -4 1 5-8076 E-mail:wmt@nrc.qov
Attachments:
1. List of Recently Issued NMSS lnformation Notices 2. List of Recently Issued NRC lnformation Notices Attachment 1 IN 99-31 November 17, 1999 LIST OF RECENTLY ISSUED NMSS INFORMATION NOTICES Information Date of Notice No. Subject Issuance Issued to 99-30 Failure of Double Contingency 11/8/99 All fuel cycle licensees and Based on Administrative certificates performing laboratory Controls Involving Laboratory analysis to determine uranium Sampling and Spectroscopic content, in support of Analysis of Wet Uranium administrative criticality safety Waste controls Authorized Contents of Spent I 0/28/99 All power reactor licensees and Fuel Casks spent fuel storage licensees and applicants Recall of Star Brand Fire 9/30/99 All holders of licenses for nuclear Protection Sprinkler Heads power, research and test reactors, and fuel cycle facilities Malfunction of Source Retraction Mechanism in Cobalt-60 Teletherapy Treatment Units Safety and Economic 8/24/99 Consequences of Misleading Marketing lnformation Broad-Scope Licensees' 711 2/99 Responsibilities for Reviewing and Approving Unregistered Sealed Sources and Devices Safety Concerns Related to 7/6/99 Related Control Unit Failures of the Nucletron Classic Model High-Dose-Rate Remote Afterloading Brachytherapy Devices 99-22 10 CFR 34.43(a)(I ); Effective 6/25/99 Date for Radiographer Certification and Plans for Enforcement Discretion Contingency Planning for the 6/25/99 Year 200 Computer Problem All medical licensees authorized to conduct teletherapy treatments All Distributors andlor Manufacturers of Generally Licensed Products All medical licensees' of broad- scope and master materials. licensees All U. S. NRC medical licensees authorized to use brachytherapy sources in Nucletron Classic Model high-dose-rate remote afterloaders Industrial Radiography Licensees All material and fuel cycle licensees and certificate holders Attachment 2 IN 99-31 November 17,1999 LIST OF RECENTLY ISSUED NRC INFORMATION NOTICES lnformation Notice No. Subject 99-30 Failure of Double Contingency Based on Administrative Controls Involving Laboratory Sampling and Spectroscopic Analysis of Wet Uranium Waste Date of Issuance Issued to 1 1 18/99 All fuel cycle licensees and certificates performing laboratory analysis to determine uranium content, in support of administrative criticality safety controls Authorized Contents of Spent 10128199 All power reactor licensees and .Fuel Casks spent fuel storage licensees and applicants Recall of Star Brand Fire 9130199 All holders of licenses for nuclear Protection Sprinkler Heads power, research, and test reactors, and fuel cycle facilities Malfunction of Source Retraction 912199 All medical licensees authorized Mechanism in Cobalt-60 Teletherapy to conduct teletherapy treatments Treatment Units Safety and Economic Consequences of Misleading Marketing lnformation Year 2000 Contingency Planning Activities Broad-Scope Licensees' Responsibilities for Reviewing and Approving Unregistered Sealed Sources and Devices 8124199 All Distributors andlor Manufacturers of Generally Licensed Products 811 0199 All holders of operating licenses for nuclear power plants and fuel cycle facilities 711 2/99 All medical licensees of broad- scope and master materials licensees OL = Operating License CP = Construction Permit