ML20246A019

Submits Comments on Containment Performance Improvement Program (Cpi).Believes Program Will Be Generic Approach to Improving Containment Performance During Severe Accident

ML20246A019
Person / Time
Site:	Susquehanna
Issue date:	06/30/1989
From:	Keiser K PENNSYLVANIA POWER & LIGHT CO.
To:	Carr K NRC COMMISSION (OCM)
Shared Package
ML20246A011	List: ML20246A019
References
REF-GTECI-A-45, REF-GTECI-DC, RTR-NUREG-1150, TASK-A-45, TASK-OR NUDOCS 8908220338
Download: ML20246A019 (2)

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(:id] Pennsylvania Power & Light Company Two North Ninth Street e Allentown, PA 18101-1179 e 215/770-5151 June 30, 1989 Harold W. Keiser Senior Vice President-Nuclear 215/770-4194 The Honorable Kenneth M. Carr Commissioner U. S. Nuclear Regulatory Commission Washington, DC 20556

Dear Mr. Commissioner:

Pennsylvania Power & Light Company has been evaluating Susquehanna SES's ability to respond to transients including severe accidents for several years and based on the insights gained by our analysis, I would like to share my perspective on the Containment Performance Improvement Program (CPI).

The CPI program is a generic approach to improving containment performance during a severe accident. The containment vulnerabilities we have identified in our risk assessment work at PP&L, however, are the result of specific characteristics of our plant support systems and the ability to more i fully exploit the capability of our existing equipment. Since these vulnerabilities result from plant specific characteristics, no assurance exists that the proposed CPI modifications will address the real causes of containment vulnerabilities. Consequently, prior to mandating additional equipment through the CPI program it seems only reasonable to first explore how installed plant equipment can be used to improve containment performance.

Such investigations, however, are necessarily plant specific and properly belong in the Individual Plant Evaluation (IPE) program.

Our Susquehanna IPE and the most recent NUREG-1150 study demonstrate that the BWR plant is significantly less likely to either suffer core damage, or result in fatalities than the other reactor designs. Therefore, there is no impetus to try to generically fix perceived BWR problems prior to completion of the IPEs.

PP&L is dedicated to resolving severe accident issues at our Susquehanna plant. Our analysis tells us, however, that these issues rewit from the particular design and operation of our plant. Therefore, we have focused our efforts or, identifying and resolving these plant specific problems. This is precisely the intent of the IPE process. We have derived real safety improvements by following this apprcach and believe similar improvements will be achieved when the industry implements the IPE on a plant specific basis. The following two examples illustrate my point.

Our risk assessment identified battery failure during station '

blackout to be a dominant contributor to core melt and containment failure.

Battery failure results in loss of control power to high pressure pumps and safety relief valves. Thus, battery failure results in loss of injection which causes a core melt, vessel failure and containment failure. We resolved this problem by obtaining a 100 kw mobile diesel generator which maintains DC 8908220338 890g]

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power and therefore core cooling. This specific solution is very effective at

. reducing plant damage and it does it at an insignificant cost.

.The second example concerns containment failure due to failure of decay heat removal systems. . A reactor isolation with failure of'the decay heat removal system will result-in containment failure. This problem is identified as USI. A-45' We will resolve' this prnblem by operating the Reactor Water Cleanup. system in the blowdown mode. This procedural modification effectively eliminates the "TW" (transient initiator with less of decay heat removal) sequence at minimal cost. We plan-to implement the appropriate procedural changes in our next revision to our Emergency Operating Procedures.

Neither of these fixes are identified in the CPI program.

As discussed above, the perceived weakness in BWR containment performance can most effectively be eliminated on a plant specific basis.

Since the CPI program attempts to improve containment performance generically, its focus is inappropriate. I therefore recommend you vote to cancel the CPI program.

Sincerely yours, G ' -Y

/Ldug H. W. Keiser Senior VP-Nuclear l

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