ML011200438

Draft Letter to J Colvin from s Collins with Enclosures. Responds to August 24, 1999 Letter Regarding the Nrrc Draft Study on the Risk of Spent Fuel Pool Accidents at Decommissioning Nuclear Powr Plants

ML011200438
Person / Time
Issue date:	10/15/1999
From:	Collins S Office of Nuclear Reactor Regulation
To:	Colvin J Nuclear Energy Institute
References
FOIA/PA-2000-0368
Download: ML011200438 (7)

Text

UNITED STATES (,- V,

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"Mr. Joseph .Coln President and Chief Executive Officer Nuclear Energy Institute 17761I Street, NW ,f Suite 400 Washington, DC 20006-3708 -A

Dear Mr. Covn:

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I am responding to your letter of August 24, 1999, addressed to Chairman Dicus regarding the NRC draft study on the risk of spent fuel pool accidents at decommissioning nuclear power plants. My reading of your letter suggests that you may not have had the opportunity to appreciate the current status of the NRC's review, previous stakeholder involvement, and our intention for use of the study.

As noted in my phone call to you on October 8, 1999, we have discussed with the industry on several occasions, that the staff's risk assessment was intended as a scoping evaluation to help identify potential risk challenges needing further review by NRC and the industry. At a June 7, 1999, public meeting, the staff acknowledged that many areas contained in the draft report were difficult to analyze using probabilistic risk analysis methods, and therefore proposed to submit the report to external peer review before using it in the regulatory arena. At the meeting, NEI representatives requested that the staff make the draft report public in order to facilitate progress on resolving the regulatory issues involved in decommissioning. Responding to the stakeholder request, the staff used the document as the basis for a very productive public meeting held on July 15 and 16, 1999. Several follow-up telephone discussions were conducted and another public meeting was held on September 21, 1999.

One of the key goals of our agreement related to the early release of the draft report was that the industry and other stakeholders would review it, and where the industry believed that data would support different and perhaps less conservative analyses or conclusions, this information as well as other comments would be provided to the staff for its review and consideration. In contrast to your letter, I believe this mutually agreed upon process has merit and is working effectively to raise issues for consideration and resolution.

At this time, It is premature to judge the content of the study outcome. Clearly, it is our approach and intent that staff conclusions about near-term requests for exemptions from the regulations and longer term actions on rulemaking will be based on the best available probabilistic and deterministic analyses, tempered by good judgment.

J. F. Colvin In the future, the NRC staff intends to continue Its policy of releasing preliminary technical information for public comment and for the benefit of involving stakeholders in NRC initiatives.

We believe this policy leads to more productive public interaction and a more flexible approach to regulatory decision making. As I am sure you would agree, in order for this policy to be successful, it is necessary that the industry and other stakeholders acknowledge the preliminary nature of such information, engage in constructive involvement, and recognize that the NRC will not take regulatory action until it has considered all technical viewpoints. Without this understanding, the benefits of early interaction will be significantly diminished.

Sincerely, _

Director Reactor Regulation A

J1. F. Colvin In the future, the NRC staff intends to continue its policy of releasing preliminary technical Information for public comment and for the benefit of involving stakeholders in NRC initiatives.

We believe this policy leads to more productive public interaction and a more flexible approach to regulatory decision making. As I am sure you would agree, in order for this policy to be successful, it Is necessary that the industry and other stakeholders acknowledge the preliminary nature of such information, engage In constructive involvement, and recognize that the NRC will not take regulatory action until it has considered all technical viewpoints. Without this understanding, the benefits of early interaction will be significantly diminished.

Sincerely, Samuel J. Collins, Director Office of Nuclear Reactor Regulation DISTRIBUTION:

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EDO# G19990438 W. Travers F. Miraglia M. Knapp P. Norry J. Blaha S. Collins/R. Zimmerman B. Sheron PD#1V-D Reading (w/incoming)

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)e F. Colvin FINAL REPLY:

Lclear Energy Institute (NEI)

Chairman Dicus R SIGNATURE OF : ** GRN ** CRC NO: 99-0746 ROUTING:

PROBABILISTIC RISK ANALYSIS (PRA) OF Travers DECOMMISSIONING FACILITIES Knapp Miraglia Norry Blaha TE: 08/27/99 SIGNED TO: CONTACT: Paper *eSS NRR Collins ECIAL INSTRUCTIONS OR REMARKS:

For Appropriate Action.

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OFFICE OF THE SECRETARY CORRESPONDENCE CONTROL TICKET PAPER NUMBER: CRC-99-0746 LOGGING DATE: Aug 27 99 ACTION OFFICE: EDO AUTHOR: JOE COLVIN AFFILIATION: DISTRICT OF COLUMBIA ADDRESSEE: CHAIRMAN DICUS LETTER DATE: Aug 24 99 FILE CODE:

SUBJECT:

DECOMMMISSIONING REGULATIONS....

ACTION: Appropriate DISTRIBUTION: RF, SECY/BILL HIL SPECIAL HANDLING: NONE CONSTITUENT:

NOTES: OCM #4405 DATE DUE:

SIGNATURE: DATE SIGNED:

AFFILIATION:

EDO -- G19990438

ft~J/~3qqO NUCLEAR ENERGY INSTITUTE Joe IF. Celui PRESIDENT AND CH4EF EXECUTIVE OFFICEN August 24, 1999 The Honorable Greta J. Dicus Chairman U.S. Nuclear Regulatory Commission Mail Stop 0-16 C1 Washington, DC 20555-0001

Dear Chairman Dicus:

In performing a probabilistic risk analysis (PRA) of decommissioning facilities, the NRC staff concludes that the public health risk for a decommissioned facility is equivalent to that of an operating power reactor. This illogical conclusion was reached by treating fundamental aspects of the quantitative analysis in a manner that is not consistent with the Commission's PRA policy statement or the approach used for operating plant PRAs. These study results are summarized in SECY 99 168, Improving Decommissioning Regulations for Nuclear Power Plants.

The study concludes that a zirconium fire with offsite health consequences can occur when no action is taken to recover from a loss of pool water inventory. The conclusions of the draft study are in conflict with previous NRC studies of this issue, and result from the use of worst case assumptions and improper coupling of risk analysis with deterministic methods.

A fundamental tenet of PRA (as articulated in the Commission's policy statement) is the use of realistic, best estimate values for treatment of data, sequence analyses, human performance, and success criteria. We performed a detailed review of the assumptions used in the draft NRC study and compared them with similar assumptions used in operating plant PRt.The draft study generally assumes worst case, or bounding assumptions, that are compounded through the quantitative process in such a manner to overstate by two orders of magnitude the likelihood of conditions leading to the zirconium fire.

The study couples this overstated probability value with a conservative thermal hydraulic analysis, including adiabatic heat up conditions, large conservatisms in the zirconium ignition point, and failure to take into account the time to boil off the coolant from the time of initial fuel uncovery until ignition of the zirconium. The end state of the NRC study does not equate to a public health impact, but rather to an intermediate point in the development of the scenario. This approach is again 1776 I STREET. NW SUITE 400 WASHINGTON. DC 20006-3708 PHONE 202 739 8075 fAX 202 F7S 18Q8

. "- The Honorable Greta J. Dicus August 24, 1999 Page 2 inconsistent with operating plant PRAs, which use realistic thermal hydraulic calculations and calculate end states (e.g., large release frequency) that can be related to public health effects and the NRC's safety goal policy statement.

NRC staff is proposing to use the study to justify regulatory requirements (such as emergency planning) for many years after the facility is permanently shut down.

The continuation of these regulations is not justified on the basis of the draft NRC study.

The presentation of staff conclusions to the Commission needs to be given careful and thoughtful consideration. Although the results were acknowledged to be preliminary, the use of flawed analysis as a basis for any decision making is detrimental to the fidelity of the regulatory process. The success of risk-informed regulation is dependent on correct and consistent application of the Commission's policies.

We appreciate your consideration of this important matter, and would be pleased to meet with the Commission, or your technical assistants, to provide more detailed information.

Sincerely, J eol Colvin eHonorable Nils J. Diaz, Commissioner, NRC The Honorable Edward McGaffigan Jr., Commissioner, NRC The Honorable Jeffrey S. Merrifield, Commissioner, NRC Dr. William D. Travers, Executive Director for Operations, NRC