Nuclear Energy Agency Advocates
Further Government/Industry Co-operation
In Addressing New Reactor Fuel Performance
And Safety Margins
In a joint statement released today,
the Committee on Nuclear Regulatory Activities (CNRA) and the Committee
on the Safety of Nuclear Installations (CSNI) of the Nuclear Energy
Agency (NEA) - the two major committees of the NEA in nuclear safety
and regulation - support enhanced co-operation with the nuclear industry,
and encourage the nuclear industry to take a more active role in developing
the experimental and analytical basis to support its proposals for new
reactor fuel designs and extended operational characteristics. The full
statement of CSNI and CNRA is given below:
"Over the past several years,
there has been much interest in improving the performance of nuclear
fuel. Work has been performed to develop new cladding materials, new
fuel designs and manufacturing processes intended to improve reliability
and safety, allow higher burnup and longer fuel cycles, and support
the use of MOX fuels.
Some of these new designs are currently
being used in reactors and others are planned for use in the short term.
However, in some cases, these new designs raise safety and regulatory
issues that need to be addressed. These issues involve the fuel safety
margins under accident conditions as well as the possible impact of
fuel behaviour on the performance of safety systems (e.g. hindering
control rod insertion). In particular, one issue relates to the cumulative
effect of many "minor" changes, each of which has been deemed
too small to warrant suitable research and qualification programmes.
These issues were discussed by the CNRA and the CSNI at their 1996 annual
meetings.
As part of their responsibilities
to ensure that criteria are developed and limits are specified to assure
the safety of reactor operations, some regulatory bodies and/or their
technical support organisations in OECD countries are sponsoring or
developing a number of fuel research programmes addressing fuel./.
behaviour under normal, transient
and accident conditions, such that sufficient independent data is available
to support regulation. However, ultimately the responsibility for developing
an adequate safety case for introducing optimised or new fuel designs
rests with the industry. Accordingly, the CNRA and the CSNI support
co-operation with the nuclear industry and encourage the nuclear industry
to take a more active role in developing the experimental and analytical
bases to support its proposals for new fuel designs and extended operational
characteristics. Issues related to cases with a mix of fuel designs
should also be addressed. A more active role implies the sponsoring
of adequate qualification programmes to demonstrate the performance
of the fuel under normal, transient and accident conditions, the sharing
of relevant information with, and the submission of well supported safety
cases to regulatory bodies and their technical support organisations.
Regulatory bodies will review the
adequacy of safety criteria for these new designs based upon available
information, thus it is in the interest of the nuclear industry to ensure
sufficient information is available to support achieving the fuel performance
goals desired."
