ML20127M089
| ML20127M089 | |
| Person / Time | |
|---|---|
| Issue date: | 06/16/1992 |
| From: | Dunning T Office of Nuclear Reactor Regulation |
| To: | Barrett R, Jocelyn Craig, Jerome Murphy Office of Nuclear Reactor Regulation, NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20127M067 | List: |
| References | |
| NUDOCS 9301280106 | |
| Download: ML20127M089 (2) | |
Text
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June 16, 1991 Q+LQe S. .
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(6. h Ao NOTE FOR: Joseph A. Murphy, RES John W. Craig, NRR M Richard J. Barrett, NRR l Lawrence J. Chandler, OGC p ,;
FROM: Thomas G. Dunning, NRR '
SUBJECT:
DIFFERING PROFESSIONAL OPINION - REGULATORY AND TECHNICAL :
SPECIFICATIONS REQUIREMENTS FOR ELECTRICAL POWER SOURCES As you have been requested by Mr Sniezek's memorandum of June 12, 1992, to make a recommendation to the EDO or provide legal counsel regarding the disposition of the differing professional opinion (DPO) that I have expressed, I wish to take this opportunity to indicate that I would be more than willing to provide you copies of any of the docunients referenced in the DPO.
Enclosed is a correction to page 2 of the DP0 which highlights the reference to GDC 17 which was inadvertently mislabeled as GDC 19.
It is hoped that your deliberations on this matter will consider not only the legal aspects of the GDC but also those of other regulations, nuclear power plant operating licenses, and the associated plant technical. specifications cited in the DPO.
If there is any other way that I could provide any-assistance that would facilitate your completion of this matter, please do not hesitate to ask.
For example, all the information provided in the DP0 and its enclosures is available as Wordperfect documents.
(
Thomas G. Dunning
Enclosure:
As stated CC:
J. Sniezek Enclosure 4 9301280106 921220 PDR 1
MISC 9301280098 -PDR - -
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,. accomplish system safety functions assuming a single failure and I with only the availability of either the onsite or the offsite electrical power systems, assuming the other is not available. l The NRC is not enforcing these requirements for the residual l heat removal safety function of nuclear power plants when the i reactor is shutdown, j
- 2. The current standard technical specifications (STS) include !
explicit requirements for the operability of redundant residual heat removal systems and the associated onsite and offsite elec-trical power systems. However, previous versions of the STS and guidance provided to licensees in NRC letters have been incon-sistent with the requirements of the GDC that require both en-site and offsite electrical power systems to be available and operable to support the capability for residual heat removal.
Consequently, plant technical specifications (TS), that are based on this guidance, are inconsistent with the rcquirements of the GDC. However, the NRC is not enforcing the plant TS' requirements for operable onsite electrical power systems, that are necessary to support the operability of residual heat removal systems, where such requirements do exist.
, 3. The draft report, NUREG-1449, " Shutdown and Low-Power Operation at Comme rcial Nuclear Power Plants in the United States,"
addresses regulatory requirements for chutdown and low-power operation. However, the report ignores the requirements of GDC 17 and 34 for the availability of onsite and offsite electrical powersystems,thatarenecessarytosupportresidualheatre-moval, and for the capability of these power systems to accom-plish the system safety functions assuming a single failure.
The report does not address the inconsistencies of past guidance and existing plant TS with the requirements of the GDC. Thus, the report fails to acknowledge existing regulatory require-ments, the fact that the current STS are consistent with those requirements but many plant TS are not, or that some of its recommendations for TS improvement would simply implement exist-ing regulatory and STS requirements.
- 4. The staff's current draft of the new STS has defined the term operable / operability in a manner to imply that only the cffsite or the onsite power systems need be available to satisfy TS requirements specifying that a system, subsystem, train, compon-ent, or device shall be operable. This is another example where the NRC is failing to make clear the proper application of TS requirements that are consistent with the regulatory require-ments of the GDC.
S. The 1&ck of consistency in plant technical specifications and -
the NRC's failure to ensure that they are consistent with the
. requiremer.ts of the GDC should be addressed as the first step to the broader issue of shutdown and low power risks. Without this step, a common base will not exist from which to judge the
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