SUBJECT: COMMENTS ON NRC PROPOSED RULE ...

' All reactor control rods are assumed to be inserted when a
scram signal is received. Other sabotage countermeasures are
relied upon to assure that the control rods are inserted.
There is no coincident significant loss of coolant because
loas-of-coolant sabotage events are not amenable to damage
control response.
The plant has been operating at full power for an indefinite
period of time.
Sabotage acts ccmmitted during shutdown periods or refueling
are easier to counter since the time available and access
conditions greatly expand the possible mitigating options.
Under these assumptions, the primary goal of the operator is to
bring'the plant to a safe and stable condition--defined fop this pur-
pone to be hot shutdown. In deriving the mechanisms available to the
operator, the plant and its associated systems were evaluated in light
of the assumed circumstances. (For example, ECCS loads on the vital
electric buses will not be needed.)
For each reactor type (PWR and BWR), the following activities
were undertaken:
1. The principal functions required to maintain the plant in a
hot shutdown condition were determined. In particular, the
basic considerations of coolant inventory control, decay heat
removal, and primary system pressure control were addressed.
2. The systems and canponents that would normally be expected to
perform these functions were identified.
3. Auxiliaries and support systems required for each of the
systems were identified.
4. Alternative ways of performing the principal functions and
providing needed support services, including procedural aspects
of each method, were established.
5. The procedural steps needed to initiate the alternative actions
were defined.
6. Hardware changes required for each action were defined and
examined.
Using the approach delineated above, candidate damage control
actions were identified and described (aee Appendix F). Each of these
options was waluated; the results of this initial evaluation are
.