THE Faslane submarine base on the Gare Loch was a hive of activity

yesterday after the Royal Navy's discovery of a nuclear reactor fault in

a Valiant class vessel.

There were believed to be eight submarines at the base, two Polaris,

four nuclear-powered vessels, and two diesel craft, an unusually large

number. On the Gare Loch itself, protesters from the peace camp in an

inflatable dinghy flew the symbol for radioactivity.

The peace campers, using a boat that had only just been returned to

them after being confiscated by Ministry of Defence police, were watched

by two police launches and Royal Marines in four larger inflatable

craft.

All five of the Navy's Valiant class submarines are now in port for

checks after the discovery of the fault. According to sources, HMS

Valiant, Conqueror, and Courageous are at Faslane; HMS Churchill is in

Rosyth; and HMS Warspite, in which the fault was found, is in Devonport.

Another Polaris is also at Rosyth.

The Ministry maintained no vessels were being recalled from patrol to

undergo inspections. But analysts said it was a remarkable coincidence

for all five to be in port at the same time.

A Ministry spokesman said there was no danger to personnel working on

a refit, and added: ''The submarines are not unsafe. Safety is

paramount.''

The fault, believed to be a hairline crack in the primary cooling

system of the reactor, was found in Warspite, the second oldest of the

Valiant class boats, during a refit at Devonport.

The Navy said it knew of no faults in any submarines except Warspite,

though independent sources said it was understood cracks had been

discovered in the cooling system of all five of the Valiant boats.

Scottish CND said yesterday that two anonymous phone calls to its

office had warned of problems with submarines based at Faslane. One

caller had referred to a ''potential Chernobyl''. The campaign yesterday

called for a public inquiry.