United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 97-57: Leak Testing of Packaging Used in the Transport of Radioactive Material

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
              OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
                         WASHINGTON, D.C. 20555-0001

                                July 30, 1997


NRC INFORMATION NOTICE 97-57:  LEAK TESTING OF PACKAGING USED IN THE           
                               TRANSPORT OF RADIOACTIVE MATERIAL


Addressees

Suppliers and users of packaging for the transportation of radioactive
material required to perform packaging leak tests.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to observed shortcomings in leak testing of
packaging used in the transport of radioactive material.  It is expected that
recipients will review the information for  applicability to their operations
and consider actions, as appropriate, to avoid similar problems.  However,
suggestions contained in this information notice are not NRC requirements;
therefore, no specific action or written response is required.

Description of Circumstances

As part of the fabrication, operation, and maintenance of transportation
packaging, leak testing may be used to verify the integrity of a packaging�s
containment.  NRC, through its transportation inspection program, has noted
shortcomings in the performance of packaging leak tests.  Specifically, NRC
has found that purging, used to remove packaging cavity air and establish a
known representative tracer mixture at the containment boundary being tested,
has been performed inadequately and that gas used in tests has not been
controlled to ensure its quality (e.g., tracer gas concentration).  These
findings introduce uncertainties that could lead to the acceptance of
erroneous test results.

Discussion

To obtain accurate leak test data, measures must be taken to ensure that a
known representative tracer mixture reaches the containment boundary being
tested.  However, NRC has found that leak tests have been performed without
using the appropriate level of control.  American National Standard Institute
(ANSI) N14.5-1987, "Leakage Tests on Packages for Shipment of Radioactive
Materials," Appendix A, Section A2.2, states:  "Tracer materials are to be
clean and free of contaminants that might affect test results.  Care must be
taken to ensure that a known representative tracer mixture reaches the
boundary being tested."  It should be noted that NRC finds ANSI N14.5
generally acceptable, as described in NRC Regulatory Guide 7.4, "Leakage Tests
on Packages for Shipment of Radioactive Materials."  


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NRC inspections have identified two factors that may not allow a known
representative tracer mixture to exist at the boundary being tested; (1)
incomplete purging of the packaging cavity, and (2) lack of objective evidence
documenting critical characteristics of gas used in testing (e.g., tracer gas
concentration).  Each factor is described in further detail below.  

(1)   Packaging design and configuration during testing have been identified
      as contributing factors to incomplete packaging purging.  NRC has
      observed purging operations and identified the following inappropriate
      coincident conditions:  (a) adjacent vent and drain ports located at
      same end of the packaging, (b) small packaging diameter-to-length ratio,
      (c) absence of an internal purge path, and (d) port orientation incom-
      patible with tracer gas characteristics (i.e., specific gravity).  It
      was not evident  to NRC that the purge operations observed during leak
      tests would produce a known concentration of tracer gas or a uniform gas
      mixture throughout the packaging cavity.  Evaluation of the effects of
      packaging design and configuration on purge operations can be used to
      improve purge results.  Other methods of establishing a known repre-
      sentative tracer mixture, such as evacuation and fill, have been found
      to be effective.  

(2)   In order to ensure that a known representative tracer mixture exists at
      the boundary being tested, objective evidence about critical
      characteristics of the tracer gas must be known before the gas is
      introduced into the packaging cavity for testing.  The required level of
      objective evidence depends on a material�s safety-related application. 
      In the case of leak testing, tracer gas is used to verify the integrity
      of a packaging's containment, which is typically classified as "critical
      to safe operations." NUREG/ CR-6407, "Classification of Transportation
      Packaging and Dry Spent Fuel Storage System Components According to
      Importance to Safety," provides guidance on component classification and
      required quality assurance records.  NUREG/CR-6407 also addresses
      quality assurance records for the dedication of safety-related
      commercial-grade items, such as a tracer gas. 

      Further guidance on procurement of commercial-grade items for safety-
      related applications can be found in NRC Generic Letter 89-02, "Actions
      to Improve the Detection of Counterfeit and Fraudulently Marked
      Products."  This generic letter conditionally endorses the guidelines
      contained in Electric Power Research Institute Group NP-5652, "Guidance
      for the Utilization of Commercial-Grade Items in Nuclear Safety-Related
      Applications (NCIG-07)."  The guidance provides examples of commercial-
      grade items (e.g., fuel oil, lubricating grease/oil, materials, etc.) 
      and potential critical characteristics in terms of product
      identification (e.g.,  color coding, industry standard markings, part
      number/unique identifier, etc.) and physical characteristics (e.g.,
      concentration, purity, etc.).  The guidance further provides four
      acceptance methods:  (a) special tests and inspections, (b) commercial
      grade survey of supplier, (c) source verification, and (d) acceptable
      supplier/item performance record.    

      It should be noted that industry practice such as in American Society
      for Testing and Materials, Designation E 1212-92, "Standard Practice for
      Quality Control Systems for Nondestructive Testing Agencies," requires
      that the quality control system include .                                                            IN 97-57
                                                            July 30, 1997
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      procedures to assure effective supplier quality for all purchased
      materials and that requirements for quality shall be established in the
      purchase agreement.  It further requires that quality records include
      product identification to allow traceability of  what was tested and
      what materials and equipment were used.

This information notice requires no specific action or written response.  If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below.




                                          William F. Kane, Director
                                          Spent Fuel Project Office
                                          Office of Nuclear Material 
                                            Safety and Safeguards

Technical contacts: James E. Spets, NMSS
                    301-415-8553
                    E-mail:  jes2@nrc.gov

                    Alternate:
                    Nancy L. Osgood, NMSS
                    301-415-8513
                    E-mail:  nlo@nrc.gov 

Attachments:
1.   Referenced Codes and Standards
2.   List of Recently Issued NMSS Information Notices
3.   List of Recently Issued NRC Information Notices.                                                            Attachment 1
                                                            IN 97-57
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                                                            Page 1 of 1


REFERENCES


1.    American National Standard Institute N14.5-1987, "Leakage Tests on
      Packages for Shipment of Radioactive Materials."

2.    American Society for Testing and Materials, Designation E 1212-92,
      "Standard Practice for Quality Control Systems for Nondestructive
      Testing Agencies."

3.    Electric Power Research Institute Group NP-5652, "Guidance for the
      Utilization of Commercial-Grade Items in Nuclear Safety-Related
      Applications (NCIG-07)."

4.    NUREG/CR-6407, "Classification of Transportation Packaging and Dry Spent
      Fuel Storage System Components According to Importance to Safety."

5.    Regulatory Guide 7.4, "Leakage Tests on Packages for Shipment of
      Radioactive Material." 

6.    U.S. Code of Federal Regulations, 10 CFR Part 71, "Packaging and
      Transportation of Radioactive Material."

7.    U.S. Nuclear Regulatory Commission, Generic Letter 89-02, "Actions to
      Improve the Detection of Counterfeit and Fraudulently Marked Products." 


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