ML19211A158
| ML19211A158 | |
| Person / Time | |
|---|---|
| Issue date: | 11/14/1979 |
| From: | Carbon M Advisory Committee on Reactor Safeguards |
| To: | Hendrie J NRC COMMISSION (OCM) |
| References | |
| ACRS-R-0849, ACRS-R-849, NUDOCS 7912170107 | |
| Download: ML19211A158 (2) | |
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8 NUCLEAR REGULATORY COMMISSION L
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ADVISORY COMMITTEE ON REACTOR SAFEGUARDS o,
WASHINGTON, D. C. 20555 November 14, 1979 V
i Honorable Jose #1 M. Hendrie Chairman b
U. S. Nuclear Regulatory Commission i
Washington, D.C. 20555 l
SUBJECT:
NUREG-0600 " INVESTIGATION IN'1V ' HIE MARCH 28, 1979 THREE rCTE ISIAND ACCIDENT BY OFFICE OF INSPECTICF AND ENFORCD4ENr"
Dear Dr. Hendrie:
During its 235th meeting, November 8-10, 1979, in accordance with the Com-mission's request, the Advisory Committee on Reactor Safeguards completed its review of NUREG-0600. We report was also discussed at a Subcommittee meeting in Washington, D. C. on October 30, 1979. During its review the Comittee had the benefit of discussions with the Nuclear Regulatory Com-mission (NRC) Inspection and Enforcement (I&E) Staff, and of comments from the licensee.
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The stated scope of NUREG-0600 is limited to investigation of the licensee's
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operational actions prior to and during the course of the accident, and his actions to control release of radioactive materials and to implement his emergency plan during the course of the accident. Consistent with this limi-tation, emphasis is placed on departure from Technical Specifications prior to the accident and departure from the licensee's procedures during the course of the accident, with little consideration of other factors.
Other investigations and other NRC task force sttx3ies have considered not only the actions taken by the licensee, but also other facets of the acci-dent, including peculiarities of the nuclear steam supply system that terried to inhibit recovery or to confuse the operators by leading to pressure and level conditions not anticipated by the written procedures, and deficiencies of the control room and system design that degraded the quality of informa-tion available to the operator. Additional details not in NUREG-0600 can be found, for example, in a report entitled " Analysis of Three Mile Island Unit 2 Accident" (NSAC-1, July 1979) prepared by the Electric Power Research In-stitute, Nuclear Safety Analysis Center.
,4 NUREG-0600 includes a factual chronology with event descriptions, and a find-ing of operational and administrative shortccmings and errors.
It concludes (Appendices IB and IIF) that a total of 36 items of potential operational or administrative noncompliance existed. W e Office of Inspection and En-forcement subsequently, by letter of October 25, 1979 to Metropolitan Edison Company, imposed fines for seventeen violations, infractions and deficiencies, many of them multiple occurrences.
1595 053
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Honorable Joseph M. Hendrie November 14, 1979 Beca' usa the limited scope of the report tends to lead to a catalog of viola-tions with only limited reccgnition of other factors that contributed to er-rors by the operators, the Committee has some concern that i.t may be con-cluded from the charges of failure to follow accident procedures that such failure is automatically a violation.
Accident procedures are prepared by the licensee arri are not approved by NRC, but the licensee is required to follow them. W e Commi_ttee believes that an accident procedure cannot be sufficiently detailed to encompass every possible sequence of events, and that it must be based on the asstrap-tion that a particular set of conditions cxists; a deviation from this set of conditions may make it necessary to depart from the procedure. As an example, MI-2 Emergency Procedure 2202-1.3 (Loss of Reactor Coolant / Reactor Coolant System Pressure) which is referred to in NUREG-0600, is believed by
'the Committee to include confusing symptoms and. instructions.for.the. case of a loss of reactor coolant at the top of the pressurizer. Likewise MI-2 Emergency Procedure 2202-1.5 (Pressurizer System Failure) -which calls for pressurizer level controi is believed to be unacceptable for the MI-2 ac-cident or for any other loss of reactor coolant at the top of th3 pressuri-We question, therefore, arises whether an operator, using his best zer.
jtrigment, is guilty of a violation if he consciously takes an action that is at variance with procedures which in themselves may contain confusing or in-correct guidarce. The Committee believes that, if so, this is the wrong approach to protecting the health and safety of the public during an emer-gency and that the operator, guided by the written procedures, his trainini, and available technical advice, should be allowed to use his best judgment to deal with the problem. His judgment will obviously be subject to pest-facttrn appraisal.
We Committee has found this report less than sat.isfactory, and its title For misleading, chiefly because of limitations M its predefined scope.
this rt.ason, the committee recommends the preparation and issuance of a summary report that consolidates and integrates the findings of the eaveral NRC Task Forces that have investigated and reparted on this accident.
Sincerely, Max W. Carbon Chairman 1595 054 9