9. Inventories of fissile materials and nuclear weapons

Summary

While 1994 may have marked a turning point in the development of nuclear
warheads and weapon systems, nuclear disarmament carries its own risks. Weapons
must be dismantled and their components stored, programmes must be established
for disposing of the surplus nuclear weapon material, and steps must be taken
to improve physical security in nuclear weapon states and extend international
safeguards to cover their activities. Reductions under way do not necessarily
reduce the threat of nuclear proliferation, nor do they amount to complete
nuclear disarmament.

Civil nuclear programmes are also giving rise to increasing quantities of
plutonium which could find its way into the wrong hands. In response,
safeguards agencies are taking a number of steps to strengthen safeguards on
civil programmes.

The central estimates of the world inventories of plutonium and highly enriched
uranium (HEU) at the end of 1993, rounded to two significant figures, are: for
plutonium, 1100 tonnes (excluding c. 120 t not yet discharged
from operating commercial power reactors); and for HEU, 1700 tonnes (excluding
100-200 t dedicated to naval reactors).

Much the largest inventories of weapon-grade plutonium are held by Russia and
the USA. About 95% of the world inventory of HEU is located in the FSU and the
USA, with 60% in the FSU alone. While all the nuclear weapon states are
believed to have halted HEU production for weapons, only the UK, the USA and
Russia have officially announced such a halt.

The only countries in which the production of plutonium for military purposes
may still be occurring are India and Israel, estimated to have accumulated
stocks of about 350 kg and 440 kg of weapon-grade plutonium, respectively.
Together, these countries may be producing about 60-80 kg of weapon-grade
plutonium annually.

North Korea has frozen its plutonium production under an October 1994 framework
agreement with the USA. Until that agreement was signed, North Korea
accumulated enough weapon-grade plutonium for at least four to five nuclear
weapons.

At the beginning of 1995, there were at least 20 000 nuclear warheads in
the operational inventories of the declared nuclear weapon states: 7770
strategic and several hundred tactical warheads for the USA; 8527 strategic and
2000-6000 tactical warheads for the CIS; 250-300 warheads for the UK; just over
500 warheads for France; and approximately 300 warheads for China. Israel had
fewer than 100 warheads.

Beyond the implementation of long-established modernization programmes, the UK
and the USA have no plans for developing or deploying newly designed weapons.
Research and development on nuclear weapons has a decidedly end-of-era feeling
as the nuclear weapon states accommodate themselves to the likely agreement on
a comprehensive nuclear test ban (CTB). The nuclear arms race appears to have
been largely halted, at least among the established nuclear weapon states.

Appendix 9A. Plutonium and highly enriched uranium: characteristics, sources of information and uncertainties
DAVID ALBRIGHT, FRANS BERKHOUT AND WILLAM WALKER