In discussing the improvements I'll focus on safety, an area in which the ABWR and SBWR plants have built upon and improved the fundamental safety features of all boiling water reactors.

With respect to controlling the reactivity or power level of the reactor, these advanced plants incorporate electro-hydraulic fine motion control rod drives, which provide electrical fine rod motion during normal operation and hydraulic pressure for immediate shutdown (scram). The electric motor also gives increased reliability over current hydraulic-only drives for the scram function by providing a diverse back-up electrical motor run-in following scram. Also, the drives do not require a scram discharge volume thus eliminating a potential source of common mode failure. The Standby Liquid Control System is a manually initiated, boron injection system which has a safety related function for backup reactivity control as in previous BWR designs. The ABWR safety systems design has been significantly improved over past designs and incorporates three redundant and totally independent divisions of ECCS and containment heat removal. The ECCS prevents any core uncovery for all design basis Loss Of Coolant Accidents (LOCA). Each division has its own emergency diesel generator and one high pressure and one low pressure inventory makeup system. Additionally, a non-safety grade combustion turbine-generator is provided as a diverse source of backup AC power.

The SBWR accomplishes the same results (no core uncovery for all design basis events and post-accident containment cooling) as the ABWR, however, we adopted a more passive approach. The SBWR utilizes a Gravity Driven Core Cooling System (GDCS) and a Passive Containment Cooling System (PCCS).

As a result of these improvements there is a substantial increase in safety performance margin in these designs over the already outstanding capability of earlier BWRs. The risk of core damage is calculated to be 10 times less than earlier designs.

Several passive features have been added to both the ABWR and SBWR designs to mitigate the consequences of a severe accident in the extremely unlikely event one should occur. The containment atmosphere is inerted with nitrogen gas to prevent the evolution of hydrogen from causing combustion or detonation and threatening the containment integrity. A system has been included which passively floods the area under the Reactor Pressure Vessel with water to cool the core debris and thus reduce the threat of containment overpressurization. This system is initiated by high temperatures in the area (caused by the debris) which passively open fusible plug valves. Water then flows from the suppression pool by gravity. The suppression pool, as in all BWR pressure suppression containments, serves as a fission product scrubber removing most of the fission products released due to the accident from the steam and entrained gases as they pass through the suppression pool water during the quenching process.

On the ABWR, the containment also has a passive overpressure protection device to prevent containment failure even under extreme conditions where containment cooling is assumed to be unavailable. A rupture disk opens to allow release of the containment pressure and decay heat while most of the radioactive fission products

are retained in the suppression pool.

Once again the SBWR accomplishes the same public protection goal in a different manner. Due to the passive nature of the containment cooling system, it is much less likely that the function would be unavailable; therefore, no overpressure protection is provided. However, the potential for installing a vent is still under consideration.

With their safety features, both the ABWR and the SBWR greatly surpass the ALWR goal for protection of the public.

Another major advancement in safety is the Safety System Logic and Control (SSLC) system which integrates the logic for the reactor trip, containment isolation and emergency core cooling functions. The SSLC together with the Essential Multiplexing System, a fiber-optic network, consolidates all the data acquisition and logic processing equipment for the plant protection functions. These systems are microprocessor-based, fault tolerant, and include extensive self-test and selfdiag ostic functions. Four essential divisions, totally separated from each other and the non-essential functions, are provided for absolute assurance of function.

Both the ABWR and SBWR designs exceed established safety requirements outlined for advanced reactor designs. They incorporate, in my view, the best approach to plant safety namely an optimal combination of active and passive features which provides the maximum assurance of safety in an economical, environmentally sound power plant.

In summary, over the past thirty years, light water reactor technology has matured and been proven. We have encountered difficulties as we gained experience along the way; however, we have responded positively to the challenges and now have a demonstrated capability to design, build and operate even better plants in a safe, economical, and environmentally sound manner. While other advanced technologies are in development, the advanced light water reactor is ready now for large scale deployment.

Question: You state in your testimony that our licensing system is at the forefront of institutional impediments to increased use of nuclear power. What factor or factors do you believe pose the greatest hindrance to increased nuclear development?

Answer: As I indicated earlier in my responses, the key problems inhibiting the increased use of nuclear power in this country are institutional, not technical. I went on to note that at the forefront of these institutional impediments is our licensing system but that there are some initiatives aimed at correcting the situation. The licensing provisions of title XII and title XIII are vitally important in that they clarify Congressional intent and will remove grounds for extended litigation.

In addition to these items, there are a number of other items which must also be addressed. The most concise statement of all the conditions which must exist if the use of nuclear power is to increase is contained in the NPOC Strategic Plan. Of the fourteen elements, there are a number in the plan, in addition to licensing reform and commercialization issues, which require congressional support to achieve. These include high-level radioactive waste management, adequate fuel supply, enhanced public and political acceptance, clarification of plant ownership & financing, and possibly state regulatory issues. Leaders of the nuclear community look forward to working with the Congress so that solutions to these difficult issues may be found and nuclear energy will make an even greater contribution toward meeting the nation's energy requirements.