ML20248L407
| ML20248L407 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 06/05/1998 |
| From: | Backus R BACKUS, MEYER & SOLOMON |
| To: | Hoyle NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| FRN-62FR25101 62FR25101-00002, 62FR25101-2, NUDOCS 9806110138 | |
| Download: ML20248L407 (7) | |
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BACKUs, MEYER, SOLOMON, N MW/J Rooo & BRANCH d
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ATTORNEYS AT law 116 LowcLL STsccT i
JON MEYER*
ALSO ADMITTED l
STEVEN A. SOLOMON 0" 8 '8
- TO MASSACHUSETTS BAR l
JENNIFER ROOD **
MANCHESTER, NH Oaios Osts
- TO MA'NE e^a l
S.J, BRANCH OF COUNSCL ROBERT A. BACKUS DARIN HOOD TUCKER F Ax (EiO38 668-0730 NANCY E. HART l
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O g[c=C Chief Rules and Directives Branch 7
Division of Administrative Services om
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(( qUQ Office Administration U. S. Nuclear Regulatory Commission
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ATTN: Secretary Hoyle Re:
May 6,1998 NAESCO License Exemption Request
Dear Mr. Hoyle:
The purpose of this letter is to submit commen.4 on a license exemption requested by North Atlantic Energy Service Corporation. The exemption request was published in Volume 62 of the Federal Register at page 25113 under date of May 6,1998.
NAESCO, the requestor, is the operator of the Seabrook Nuclear Power Plant. The request
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seeks changes to the Technical Specifications to permit a 24 month refueling cycle at Seabrook.
The staff, based upon the review of the licensee's application, has made a determination that the requested exemption involves no "significant hazards considerations."
This is to advise the Commission that the Seacoast Anti-Pollution League (SAPL), a concerned citizens organization, disagrees with the staff and believes that the Commission should either deny the exemption or institute a proceeding and grant a hearing on the exemptic. request. At the
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least, the Commission should afford the citizens in the Seabrook area an opportunity for a public i
hearing prior to granting the request.
SAPL's concerns about the exemption are based on four grounds: 1) the request will substantially lengthen the intervals between necessary surveillance of the steam generators; 2) the request will n
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provide additional stress on and increase the likelihood of the fuel assembly degradation; 3) the exemption request will inevitably lead to the performance of more online maintenar.ce, and 4) the exemption request may delay the discovery of either inadvertent or deliberate mispositioning of values or other components. Each of these factors can o'aly result in an increase in the nuclear hazard and should therefore be held to involve a "significant hazards consideration."
For these reasons, discussed further below, SAPL believes the staff can not justify the granting of an exemption on the grounds that this action does not involve a significant hazards consideration.
1.
Steam Generator Tube Degradation:
The staff, in recommending the exemption, discusses only the issue ofless frequent steam generator surveillance, referencing Technical Specification 4.4.5.3. The staff states:
"While the proposed changes will lengthen the intervals between surveillance, the increased interval has been evaluated; and based on the reviews of the steam generator tube Eddy Current Tests (ECT) inspections, it is concluded that the real growth rate of the only active degradation mechanism (Anti-Vibration Bar)(AVB) wear) identified to date that Seabrook Station is such that suflicient margin exists between the plugging criteria and structural limit such that no tubes are predicted to exceed the structural limit even with the longer surveillance interval."
Steam generator tube degradation is discussed, intsr alia, in Inspection Report 97-03 which indicates, that, as of the date of the inspection,36 tubes had been plugged. The report notes:
"Although the number of tube's requiring plugs is low, the inspector recognized that the operating life is less than scen years. Most steam generated degradation problems have been found only afler longer periods of operation. The E/C results to date indicate wall thinning attributable to flow induced vibratory relative motion between the tube and its inf. ended support."
Based on the foregoing, it appears unreasonable for the staff to rely on the past growth rate of degradation due to AVB wear and then to boot strap from this alleged growth rate into a conclusion that extending the surveillance intervals by six months does not present e safety concern, since, as the staff has stated, major t.2be degradation may only develop afler approximately seven years of operation. Seabrook began commercial operation in August,1990.
SAPL, whose membership includes citizens of the State of Maine, is well aware of the rapid growth of steam generator tube degradation at the Maine Yankee plant and believes it is l
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l, extremely unwise for the staff to conclude, with no supporting independent analysis, that increasing the interval for steam generator inspection at Seabrook by 25% is without safety significance.
SAPL is aware that extending the refueling intervals to 24 months is not in any way intended to enhance the safe operation of the plant, but only the economic viability of the plant on behalf ofits utility owners, all of whom are facing competitive pressures. Given this circumstance, it is unacceptable for the staff to conclude that a major increase in the steam generator surveillance intervals, beyond that allowed by the current technical specifications, is acceptable.
2.
Stress on Nuclear Feel Cladding:
As the staff will be aware, at the time oforiginal full power licensing, Seabrook was anticipated to have annual refuelings. Subsequently, the staff approved extending the refuelings to 18 months. If the present exemption is allowed, the refuelings will be double that anticipated when the plant went into operation.
It is SAPL's understanding that this increased operational period is achieved both by the use of more highly enriched fuel and an increase in the burn up of that fuel.
Both of these factors may cause additional stresses on fuel cladding, through the build up of gaseous by products near the end of the run. This potential has not been sufficiently evaluated by the Commission. The problem is addressed in a paper submitted by G. Rothwell and J. Russ "On tl e Optimal Life of Nuclear Power Plants." (1995). Rothwell and Russ acknowledge that
" refueling durations are the most important factors limiting achievable availability factors." They add:
"One of the difficult problems confronting nuclear plant operators is to determine the optimal length of operating (or refueling) cycles.
There is a primary trade off between (1) the potential improvement and capacity factor with longer operating cycles and (2) the potential increased risk of unplanned mid-cycle outages due to fuel and other failures.... The high energy released by fission has deleterious effects on the stmeture of fuel rods. Some fission products appear as gasses that eventually create pressure within the fuel rods. As a result, a fuel rod can swell, crack, and become physically distorted to such an extent that it is no longer usable.
The loss in fuel reactivity due to gradual depletion of radioactive uranium and build up of fission products, combined with the effect
. of radiation-induced fuel swelling and distortion, are limiting factors determining how long an NPP (Nuclear Power Plant) can run between refuelings. Maximum safe duration between refuelings is a function of the initial level of enrichment of the uranium, the design 3
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of the fuel rods, and the fuel management strategy adopted by the operator."
With the 18 month fuel cycle currently in effect, Seabrook has already had fuel failure problems.
As the result of detecting increases in noble gasses and iodine on December 10,1996, it was deterrained that there were five failed fuel rods, in the first burned batch of Westinghouse Vantage ZH Zurlo clad fuel assemblies.
Inspection Report 97-03 states, at p. 20:
"The licensee root cause evaluation determined that a probable cause of the fuel failures was the combined effects of power history, core design and an operational strategy that resulted in interaction between the fuel pellets and the fuel cladding. The effective fuel assemblies apparently carried a very large load (produced high power) for all of the last cycle."
Since the staff has already concluded that the " power history" played a role in a fuel rod failure, on an 18 month cycle, it is inconceivable to SAPL how the staff can fail to assess, or give consideration to an increased risk, from extending that power history by 25% to two years.
SAPL calls on the Comission to demonstrate that these additional stresses, resulting from the longer operational run, will not result in a loss of the safety capability of the first barrier of defense against radioactive releases, the fuel assemblies themselves.
3.
Online. Maintenance:
SAPL is aware, but regrets, that pursuant to a letter of August 22,1996, from Richard W.
Cooper, II, Director of Division of Reactors Projects, the NRC staff authorized the use of online maintenance at Seabrook Station as of July 19,1996. Online maintenance, by definition, involves the intentional disabling of safety related structures and components (SSC's) "that could initiate or effect a transient accident..." Reg. Guide 1.160, Introduction, June,1993. SAPL would point out that Mr. Cooper's Letter of Authorization fails to mention, much less explain, the fact that this constitutes a complete reversal of the position the staff took on this very issue in 1987. In an Inspection Report (87-16,10/21/87), the staff stated as follows:
"Also, during this inspection period, the inspector confirmed with the station operations manager [New Hampshire Yankee (the fhrmer Seabrook Station operator)] position that TS Limiting Condition for Operation (LCO) 3.0.0 is not intended for you as an operational convenience to permit redundant safety systems to be removed from service for a limited period of time. Based upon problems ofinterpretation of LCO 3.0.3 at other plants, the NRC 4
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nosition is that voluntarv entry into LCO 3.0.3 is unacceptable."
(Emphasis added.)
SAPL has never been afforded an explanation ofwhy the NRC changed its position from one that would not tolerate online maintenance, to one that permits online maintenance Any claim that online maintenance isjustified as a safety measure must be viewed with extreme scepticism given the obvious economic advantages of performing online maintenance, thereby shortening refueling outages, or now, under the proposed exemption, extending operational runs.
SAPL, in fact, believes that online maintenance is not properly authorized by 10 CFR 50.36(c)(2)(II). Nothing in the regulation authorizes voluntary, i.e., deliberate, disabling of the safety systems. This is documented by the fact that this requirement was part of the Commission's regulations prior to 1987, the time when the Commission's inspector advised Seabrook's former licensee that voluntary entry into the LCO's was not authorized. Furthermore, not or.svord on the regulatory analysis supporting the adoption of the Commission's maintenance rule,10 CFR 50.65(A)(3), supports the use of online maintenance, and the
' environmental assessment fails to mention it.
NRC Inspection Manual 62706 illustrates methods for licensee compliance with the maintenance rule. This manual, which the staff cited when SAPL protested the use of online maintenance, states, at page 17C, " Assessment of Equipment Out of Service":
"In order to minimize outage time and reduce costs, many licensees are increasing the amount ofpreventive maintenance being performed during power operation. This can result in the simultaneous removal of multiple systems from service. which can result in significant increases in risk during these periods. The NRC is concerned that some licensees may not be adequately analyzing the risk or safety impact associated with these unavailabilities. The failure to adequately evaluate safety when planning and scheduling maintenance has lead to simultaneous unavailabilities of multiple redundant or diverse systems at some sites, possibly leading to unacceptable increases in risk despite the fact that such configurations may not be prohibited by technical specifications. Technical specifications for most sites were crafted for random failure; voluntary removal of multiple systems from service may not be bounded by worst case single failure assumptions and technical specifications. The NRC is,concemed that risk is significantiv increased during periods when multiole redundance or diverse safety systems are unavailable due to preventive maintenance." (Emphasis added.)
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1 This Manual clearly sets forth a concern about the improper use of online maintenance, which will be exacerbated if the proposed exemption is granted.
Mr. Cooper's letter of August 22,1996, although authorizing online maintenance, acknowledged a "small risk associated with the unavailability" of certain safety systems due to online maintenance. No basis for assessing the risk to be small was provided, either in Mr. Cooper's letter, or by any of the regulatoiy analysis underlying the maintenance rule, nor is any basis provided for believing that "online maintenance can show a high degree of reliability that the equipment will perform its function if required," as the Cooper letter assens.
Since, by definition, the systems taken deliberately out of service are important to safety, online maintenance represents an increase of the nuclear hazard which may not be offset by the claimed i
benefits.
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. The extension of the operational run to two years, before a refueling outage, obviously increases the need for online maintenance, increasing the very hazards that the NRC staffin the position taken in 1987 thought sufficiently serious to prohibit the practice. The exemption request provides no discussion of the increased risk that would be caused by the additional online maintenance required by the proposed exemption. Therefore, the exemption should not be deemed without safety significance.
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Inadeounte Surveillance of Other Safety Items:
In addition to the steam generators, the technical specifications indicate that the hydrogen recombiner system is to be subject to verification "at least once per 18 months during shutdown."
- A similar requirement exists for portions of the Containment Enclosure Emergency Air Clean-up System and the emergency diesel generators.8 These items illustrate that a previously deemed necessary interval of surveillance, during shutdown, of 18 months for important systems is now no longer considered important to safety. SAPL protests this change of position, for which no rationale is offered.
- In addition, S APL,is advised, and believes, that a refueling outage is the best opportunity for a licensee to find misaligned valves, either inadvertently or otherwise, or other evidence of tampering as well as numerous other conditions which may be important to safe operation.
Nothing in the staff's proposed approval of the exemption addresses this aspect of increased risk.
'SAPL is aware that under a previous exemption request, which, SAPL also protested (see letter to the Commission's Secretary from Mr. Steve Haberman of May 22,1998), that NAESCO has requested a waiver of the current required surveillance frequency for the emergency diesel generators.
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CONCLUSION SAPL strongly protests the staff's preliminary conclusion that the licensee's request to extend Seabrook's run to two years between refuelings does not involve a significant hazards l
consideration. The staff has failed to evaluate many of the risks involved, and failed to properly justify its conclusion for the one risk it discusses, less frequent steam generators tube inspections.
i In addition, the steff fails to acknowledge that, according to the last SALP report, performance at Seabrook is declining. As noted in Inspection Report 97-08, April 1,1998, " Failure to correct these [3] conditions sooner indicates the decline in your performance with respect to analysis of root cause of problems as well as implementation of appropriate corrective action. This concern was presiously highlighted in my January 23,1998 letter transmitting the latest SALP report to l
you." (p.2.) A plant recently cited for four violations and considered to be in a state of declining performance chould not be given the benefit of a 25% increase in its operational run without clear I
justification..
SAPL notes, finally, that NAESCO is a wholly owned subsidiary ofNortheast Utilities, which
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through another whouy owned subsidiary, permitted the disastrous decline in the three Millstone Units, which has proved to be both costly for Northeast Utilities and embarrassing for the NRC.
To suggest that the fourth, and currently only operating NU plant, should be given a " bonus" of permitting extended operation, with unresolved safety issues as a result, is unjustifiable.
We call on the Commission to reject the exemption request or, in the alternative, direct the institution of a proceeding under the Atomic Energy Act.- We also request an opportunity to meet with the Commission concerning this issue.
Respectfully submitted,
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/ Robert A. Backus RABlacw cc: Governor Jeanne Shaheen Congressman John Sununu Senator Judd Gegg i
Senator Bob Smith 7
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