ML19323G720
| ML19323G720 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/30/1980 |
| From: | Smith I Atomic Safety and Licensing Board Panel |
| To: | ANTI-NUCLEAR GROUP REPRESENTING YORK, METROPOLITAN EDISON CO., UNION OF CONCERNED SCIENTISTS |
| References | |
| CLI-80-16, NUDOCS 8006060536 | |
| Download: ML19323G720 (8) | |
Text
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Bd 5/30/80 9 i l e t / yp UNITED STATES OF AMERICA N
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M 3 0 E * $j NUCLEAR REGULATORY COMMISSION Ustinc eM ATOMIC SAFETY AND LICENSING BOARD wn of ne Secabr/
s 0 4 c.'s & Ser.ic:
3 Ivan W. Smith, Chairman Dr. Walter H. Jordan C'Of 1
Dr. Linda W. Little P
In the Matter of
)
)
Docket No. 50-289 SP METROPOLITAN EDISON COMPANY
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(Restart)
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(Three Mile Island Nuclear
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Station, Unit No. 1)
)
MEMORANDUM AND ORDER ON HYDROGEN CONTROL CONTENTIONS (May 30,198'))
1 On January 4, 1980 the board certified to the Commission two questions:
1.
Whether the provisions of 10 CFR 550.44 should be waived or exceptions made thereto in this proceeding where a prima facie showing has been made under 10 CFR 52.758 that hydrogen gas generation during the TMI-2 accident was well in excess of the amount required under 10 CFR 550.44 as a design basis for the post-accident j
combustion gas control system for TMI-1.
2.
Whether post-accident hydrogen gas control should be an issue in this proceeding where post-accident hydrogen gas control was perceived to be a serious problem and was in fact a problem during the TMI-2 accident.
LBP-80-1, 11 NRC 37.
In the Commission's Memorandum and Order of May 16, 1980, CLI-80-16, the Commission answered certified question No. 1, in the negative.
In declining to waive the pro-visions of 10 CFR 550.44, the Commission observed that it is 8 0 0 6 0 6 0 f3 (,
C
.- planning a general rulemaking on the question of possible safety features to deal with degraded core conditions and that $50.44 should remain in place pending the more deliberate and considered rulemaking.
As to certified question No. 2 the Commission commented that it did not intend to exclude the issue of hydrogen gas control from its Notice and Order for Hearing of August 9, 1979; that the hydrogen control issue can be litigated under 10 CFR Part 100.
Emphasizing that the assumptions of hydrogen generation under 10 CFR 550.44 are dependent upon ECCS design as opposed to actual ECCS operation, the Commission's Order authorizes litigation of the likelihood of an accident generating hydrogen in quantities exceeding 10 CFR 550.44 design bases, the likelihood of such hydrogen combusting, and the ability of the containment to withstand pressures beyond containment design pressure.
The Commission also noted that a critical issue in the chain of circumstances under consideration would be the likelihood of an operator interfering with the ECCS operation.
Three intervenors have submitted contentions relating to post-accident hydrogen:
Mr. Sholly, Union of Concerned Scientists (UCS), and Anti-Nuclear Group Representing York (ANGRY).
The board authorized discovery on the hydrogen control contentions, but their acceptance or rejection as
. issue's for litigation is still pending.
The contentions are:
Sholly Contention 11 It is contended that the production of hydrogen in the reactor core from clad metal-water re-actions following a LOCA poses an unacceptably high risk of catastrophic failure of the reactor pressure vessel and the reactor containment with the subsequent release of a substantial portion of the core inventory into the environ-ment.
It is further contended that until a safe and reliable means for eliminating hydrogen gas from the containment is installed at Unit 1, and is provided with suitable redundancy as required by GDC 41, restart of Unit 1 poses a risk to public health and safety and must be denied.
UCS Contention 11 The design of the hydrogen control system at TMI was based upon the assumption that the amount of fuel cladding that could react chemically to pro-duce hydrogen would, under all circumstances, be limited to less than 5%.
The accident descastrated both that this assumption is not justified and that it is not conservative to assume anything less than the worst case.
Therefore, the hydrogen control systems should be designed on the assumption that 100% of the cladding reacts to produce hydrogen.
ANGRY Contention V (A)
V.
The NRC Order fails to require as conditions for restart the following modifications in the design of the TMI-1 reactor without which there can be no reasonable assurance that TMI-l can be operated without endangering the public health and safety:
(A)
Installation of a Hydrogen Re-combiner as recommended by a minority position in NUREG 0578;
, Major elements of Mr. Sho11y's Contention 11 may be litigated as a Part 100 issue and in accordance with the standards of the Commission's May 16 order.
However we have redrafted Sholly's Contention 11 to bring it into alignment with the Commission's Order and to accommodate the views of the board members.
Whether any part of UCS's Contention 11 falls within the permissible scope of the contention is debatable and ANGRY's Contention V (A) is only marginally within the scope, if at all.
However, we need not analyze the deficiencies of the UCS and ANGRY contentions, because, having raised the general subject matter and having demonstrated an interest in this aspect of the litigation, we will permit UCS and ANGRY to consolidate with Mr. Sholly 1
on the revised Sholly contention.
This, we believe, will protect their interests in the subject to the extent that their interests fall within the scope of the issue.
In-asmuch as it is Mr. Sholly's contention that survives, it would seem to be his prerogative to be lead intervenor, but we leave that to the affected intervenors to arrange.
Accordingly the board accepts Sholly Contention 11, as we have redrafted it:
. Revised Sholly Contention 11 The licensee has not demonstrated that, in the event of a loss-of-coolant accident at TMI-1:
1.
substantial quantities of hydrogen (in excess of the design basis of 10 CFR 550.44) will l
not be generated; and 2.
that, in the event of such generation, the hydrogen will not combust; and 3.
that, in the event of such generation and combustion, the containment has the ability to withstand pressure below or above the contain-ment design pressure, thereby preventing releases of off-site radiation in excess of Part 100 guideline values.
Item 3 of the contention is intended to include intentional venting of the containment as postulated in the basis of Mr. Sholly's contention, and would permit the licensee to place into issue a defense that, even assuming the generation and the combustion in excess of 550.44 design bases and the threat of breach of containment, that post-accident hydrogen control measures would limit releases to guideline values under Part 100.
As stated in the Commission's May 16 Order, "A critical issue here would be the likelihood of an operator interfering with the ECCS operation."
The board expects the parties to develop fully a record on the operator interference issue.
. The contention will of course be construed according to the terms of the Commission's May 16 Order.
This, how-ever, raises the possibility of a problem which we invite the parties to address.
The board quorum has been unable to agree on certain 1/
aspects of the Commission's May 16 Order.-
Dr. Jordan believes that the Order precludes litigation of engineered post-accident hydrogen control measures beyond those re-quired by 550.44 because the commission has reserved that issue to rulemaking.
He relies upon, inter alia, the Commission's statement'that "This rulemaking proceeding will include measures to deal with hydrogen generation following a loss-of-coolant accident."
Order, p.3.
- Moreover, Dr. Jordan believes that, as a practical matter, the litiga-tion will center around hydrogen generation, combustion, and containment integrity, with other hydrogen control issues becoming factually immaterial as an issue in this particular proceeding.
Mr. Smith, defers to Dr. Jordan's assessment of the practical aspects of the possible litigation on post-accident mydrogen control measures, but he believes that such issues should not and, under the Commission's Order, must not be foreclosed.
1/
Dr. Little has not participated in this action, but she will be available to consider the parties' comments and any reconsideration.
.- In support of his position, Mr. Smith points to the language of the Commission's Order on page 2:
The Commission believes that, quite apart from 10 CFR 550.44 hydrogen gas control could properly be litigated in this pro-ceeding under 10 CFR Part 100.
Under Part 100, hydrogen control measures beyond those required by 10 CFR 550.44 would be required if it is determined that there is a credible loss-of-coolant accident scenario entailing hydrogen generation, hydrogen combustion, containment breach or leaking, and offsite radiation doses in excess of Part 100 guideline values.
Under Mr. Smith's view of the Order, in a credible scenario where ECCS operation, particularly operator interference, as opposed to ECCS design, leads through a chain of events to offsite radiation in excess of Part 100 guidelines, the adequacy of engineered post-accident hydrogen control measures would become an issue under the Order.
Dr. Jordan and Mr. Smith agree that, under the contention as it is redrafted, the issue is unlikely to become critical but it is not foreclosed from consideration.
The licensee may elect to defend against the contention on the. questions of the likelihood of generation, the likelihood of combustion, or the capacity of the containment to withstand the effects of combustion.
Perhaps licensee may never reach the point of depending upon engineered post-accident hydrogen control measures.
But, we agree that the impending rulemaking does
4 e
8-not prohibit the licensee from asserting, in addition to one or more of the first three defense elements, that additional hydrogen control measures may be relied upon to meet Part 100 guidelines.
In that event, of course, the intervenors would i
be permitted to follow wherever licensee's defense takes them.
i The parties may submit comments, motions for reconsidera-tion or corrections, and requests for discovery relief within 10 days following the service of this order.
THE ATOMIC SAFETY AND LICENSING BOARD
? ll:. !ll t it tl Ivan W.
Smith, Chairman Bethesda, Maryland May 30, 1980