ML20132E173
| ML20132E173 | |
| Person / Time | |
|---|---|
| Issue date: | 07/18/1985 |
| From: | Roberts T NRC COMMISSION (OCM) |
| To: | Udall M HOUSE OF REP., INTERIOR & INSULAR AFFAIRS |
| Shared Package | |
| ML19283F631 | List: |
| References | |
| REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR NUDOCS 8508010731 | |
| Download: ML20132E173 (2) | |
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CHAIRMAN July 18, 1985 i
The Honorable Morris K. Udall, Chairman Subcommittee on Energy and the Environment Committee on Interior and Insular Affairs Un-ited States House of Representatives Washington, D. C.
20515
Dear Mr. Chairman:
In your letter of June 13, 1985, regarding the issue of Pressurized Thermal Shock (PTS), you recommended "that the Commission establish an ad hoc panel of experts to assess the PTS hazard and the adequacy of the Commission's efforts to reduce it to an acceptable level."
As you noted, significant progress has been made toward PTS resolution.
The final PTS rule that the Commission recently approved will provide substantial additional assurance of reactor pressure vessel integrity by placing limits on embrittlement levels and by requiring that steps be taken to slow the current rate of embrittlement on the older pressure vessels.
The development of the rule and the technical bases for it are the result of several years of intensive, multi-disciplinary studies of the PTS issue by technical experts within the NRC staff, by several contractor organizations (0ak Ridge National Laboratory, Idaho National Engineering Laboratory, Los Alamos National Laboratory, Pacific Northwest Laboratory, Brookhaven National Laboratory, and Creare, Inc.),
by consultants at Purdue University, the University of California, and the University of Maryland, and by various PWR owners' group organizations, including individual PWR licensees.
The Commission's Advisory Committee on Reactor Safeguards and their consultants have reviewed the technical studies and the PTS rule in its present form.
The extensive comments received in response to publication of the proposed rule did not include any significant challenge to the technical bases of the proposed rule.
In developing the resolution of a multi-disciplinary issue such i
as PTS, the need arises to consider and resolve a variety of 4
differing views within the staff, from our expert consultants and contractors, and as a result of the public comment process.
The Commission's procedures and practices are designed to assure l
such consideration.
In the case of the PTS issue, one member of our staff, Mr. Demetrios Basdekas, has repeatedly expressed his views regarding many different aspects of the issue, not limited to those technical areas for which he is most qualified by Ts'o V6 'o9s t p
. experience.
Nevertheless, his views have been considered at various stages in the resolution process.
During the final stages of review and approval of the PTS rule, Mr. Basdekas communicated his dissatisfaction with the adequacy of the final rule as a resolution to the PTS issue, and made his recommendation for the establishment of an ad hoc panel of experts to senior NRC staff managers, to the Committee to Review Generic Requirements (CRGR), to the Advisory Committee on Reactor Safeguards (ACRS), and to the Commissioners.
In his letter to you dated March 19, 1985, Mr. Basdekas characterized the establishment of such a panel as his "most urgent recommendation."
After consideration of Mr. Basdekas' views and the recommendations of the ACRS and the staff, the Commission has concluded that the establishment of an ad hoc panel to further review the PTS issue is not needed.
As noted above, the NRC has already had the benefit of wide-ranging in-depth reviews of the PTS issue by technical experts in all areas of the relevant technical disciplines.
Many of these experts also contributed to the technical studies that provided the basis.for development of the PTS rule, and we believe that there is a broad consensus supporting the need for, and adequacy, of the rule.
We appreciate your continued interest in the PTS issue, but respectfully disagree with your conclusion that it is necessary to establish an ad hoc panel for further review of the issue.
The Commission believes that the PTS rule we have recently approved will assure an acceptable level of PTS risk.
Commissioner Asselstine has the following comments:
I share your concerns that every practical step should be taken to avoid a reactor pressure vessel failure.
While I approved the final PTS rule, I would have gone a step further by exploring the practicality of a requirement that would have led to the search for single failure vulnerabilities or common cause events (including human error) that could lead to unacceptable PTS events.
Your recommendation to establish an ad hoc panel of experts to assess the PTS hazard and the adequacy of the Commission's efforts to reduce it to an acceptable level is one approach to examining such a requirement.
Sincerely,
/
omas M. Roberts Acting Chairman cc:
Rep. Manuel Lujan i
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