ML20246D683
| ML20246D683 | |
| Person / Time | |
|---|---|
| Issue date: | 03/15/1989 |
| From: | Zech L NRC COMMISSION (OCM) |
| To: | Sharp P HOUSE OF REP., ENERGY & COMMERCE |
| Shared Package | |
| ML20246D630 | List: |
| References | |
| CCS, MARKEY-890315, NUDOCS 8907110393 | |
| Download: ML20246D683 (3) | |
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L .e f CUESTION 10. Pr. King, on page 4 of your prepared statement, you l indicate that "the evolutionary LWRs are expected to achieve 1
l an enhanced level of safety over existing LWRs by incorporating evolutionary design improvements (fcr example,
[ implementation of lessens learned from many years of operatino 1
experience), addressino severe accident issues at the design j stage, and standardization. 03n some of the " evolutionary design improvements" you're talking about be backfitted into existing reactors to improve their safety?
A) If your answer is yes, is the NRC asking the nuclear industry to implement these " evolutionary design improvements"? If some of these technologies can be 1 backfitted into existing reactors, why does it take a DOE program to underwrite the cost of developing 90 percent of these cdvanced designs to implement these safety improvements?
B) If your answer is no, does this mean that existing reactors are not safe enough because these new design improvements can't be incorporated into them?
ANSWER Some of the evolutionary design improvements have been backfitted into existing reactors to improve their safety. This has occurred and will continue to occur through several mechanisms, as sumarized below:
8907110393 s90502 PDR COMMS NRCC CORRESPONDENCE PDC
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OUESTION 10. (Continued) l 1
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- 1) As design issues are identified through cperating experience, research and development, or other mechanisms, such as probabi-listic risk analysis, they are evaluated for their safety significance and, if warranted, backfitted onto existing designs using the Commission's rules and regulatory authority provided by the Atomic Energy Act. Additional rulemaking, bulletins, orders, and ger.eric letters are some of the ways by which this upgrading of safety is accomplished.
- 2) Currently, severe accident issues for existing plants are being evaluated, and decisions are being and have been made regarding I
backfitting design and operational or administrative improve-ments. The following specific initiatives are currently underway:
a containment performance improvement program looking at prospective ways to enhance the ability of existing containment designs to withstand the effects of severe accidents an accident management p.ugram looking at ways for plants to enhance the diagnosis, prevention, and control of such unlikely accidents
OllESTION 10. (Continued)
- an individual plant examination program looking at each existing design to determine whether particular vulnera-bilities to severe accidents exist and whether any corrective actions are needed.
It should be noted, however, that the backfitting process in-volves enhancement of existing designs beyond what is required for adequate protection of the public health and safety and that the backfitting process includes an evaluation of additional cost versus potential safety benefit. Backfitting may not be justi-fied in some cases for existing plants because of the high cost of modifying plants compared to the relatively small improvement to safety that could be achieved. However, for new designs, the front end cost of making changes may be very small, thereby making these changes desirable. Thus, the staff expects these new designs to contain many safety enhancements (that might not be justified for backfitting on existing plants) that will make the new designs incrementally safer than existing LWR's.
The Comission is not in a position to coment on DOE funding of evolutionary LWR designs since developmental funding arrangements are not within the Comission's area of responsibility.
Questions in this regard should be directed to DOE.
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