ML20008E849
| ML20008E849 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/16/1980 |
| From: | Bates A NUCLEAR REGULATORY COMMISSION (TNRC), SUMMERTOWN |
| To: | Ahearne J NRC COMMISSION (OCM) |
| Shared Package | |
| ML20008E848 | List: |
| References | |
| NUDOCS 8103100040 | |
| Download: ML20008E849 (6) | |
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%ss October 16, 1980 Honorable John F. Ahearne Chairman, Nuclear Regulatory Cc= mission 1717 H St. NW Washin'gten, D.C. 20555
Dear Dr. Ahearne,
06 October 8, Harold Denton wrote to inferm me that the pet-ition of The Nucl' ear Regulatory Cc= mission (TNRC) dated May 28th, requesting that your agency revoke the operating license of the Tennessee Valley Authority's Sequoyah Nuclear Plant Unit 1, was the Cc=missio thereby denied. This letter is to request thatDenton's decision before it becomes fin s month.
view Mr.
Our petition asked for revocation of Sequoyah's Operating License. That the license was for 5% power testing at the time of our request should be only of secondary concern. As Mr. Denton's written decision ably su=marizes (DD-80-31), our, concern was primarily whether the ice-condensor containment at Sequoyah --
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would,faiy under conditions of hydrogen generation such as occurred H
,at Three Mile Island on March. 28, 1979.,
TNRC believes that the Action Plan developed to implement the lessens learned at TMI-2 does not place adequate priority en in-stallation of systems to inert Mark III and ice condensor con-tainments. However, your decision of June 16 effectively precludes raising this issue in any licensing process. New that Sequoyah has received its full-power license, the matter of revocation has become even more urgent.
We are aware that the Ccmmissien has placed conditions on the Operating License of Lequoyah to assure that hydrogen control measures are undertaken by TVA which satisfy the USNRC staff. TNRC is ccncerned that these conditions are sufficiently ambiguous and the USNRC staff so easily satisfied that the = cst important issues will not be adequately addressed. We intend to participate in the long-term rulemaking on degraded core phencmena, in regulatory code revisiens such as that centemplated for 10 CFR 50.44, and in regulatory guide formulation en hydrogen control. However, there is an immediate and serious need, recognized in the ACRS letter of September 8, that remedial action on the hydrogen issue not be delayed because the USNRC staff sees little possibility of. future degraded cure situaticns.
Upon a preliminary analysis by our staff of the documents s
ferwarded by Mr. Den:cn, it is apparent that USNRC is unable to c
make a clear determination that Sequoyah would withstand an accident en the scale cf three Mile Island. Sequcyah's present design suggests tC c
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- Dot:ler to Ahearne October 16, 1980 Pace two a number of plausible scenarios where contain=ent would fail under conditions less sericus than actually occurred at Three Mile Island.
There is little indication that the backfits being instituted by TVA will significantly i= prove safety. It is clear that inerting the atmosphere would greatly enhance safety. Mr. Denton's decisien evidences USNRC's failure to articulate a safety goal or backfitting threshold test--as most recently recc== ended by the Senate Sub-cemmittee on Nuclear Regulation and previously proposed in Section 5 of S.
2358, NRC FY 1980 Authorizatiens.
We deplore the actions of the USNRC staff in atta=pting to obtain the licensure of Sequoyah at any cost. At a minimum, a plant should be able to withstand a Three Mile Island-scale accident and maintain containment integrity before receiving a license to operate.
The words of a recent report of the Ecuse Cc==ittee c.7 Interstate and Foreign Cc==erce ccme to mind: "the conflict between prcmoting nuclear power and controlling its safe production and use continues today in the AEC's successor agencies.
s The serious public safety ha: Lad at Sequcyah requires i==ediate remedy and cannot await furt er study. The cc==ents of Cc=missioners k
Gilinsky and Bradford published in the Federal Register at 45 F.R.
65474 indicate that the USSRC is fully aware of the deficiencies in ice condenser centain=ent design. Continued cperation of these plants without design changes of greater substance than the merely cosmetic changes instituted by TVA is in violation of 10 CFR part 50 Appendix A, Criterien 50: "The reacter centainment strv ture, including access openings, penetrations, and the centainment heat removal system shall be designed so that the contain=ent structure and its internal ec=partments can accomodate without exceeding the design leakage rate and with sufficient margin, the calculated pressure and te=perature conditions resulting frc= any loss of coolant accident.'
Knowledge of these violations indicates the USSRC is willfully violating the requirements in the Atomic Energy Act that the public health and.
, safety not he endangered.
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We have therefore requested that th?. Justice Department investigate USSRC conduct for criminal violations of the Atomic Energy Act.
Sincerely, i
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Thc=as Det:ler 1
-Chair =an l
The Nuclear Regulatory Cc==ission Su==ertown, TN 3S423 enciesures
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.e W-THE NUCLEAR REGULATORY CC.vMISSION Summertevn, Tennessee NOTICE OF VIOLATION VIOLATORS : U.S. Nuclear Regulatory *.cmmission (USNRC)
T,ennessee Valley Authoriti (TVA)
CODE SECTIONS:
42 U.S.C.2011, 2012, 203d =*d 10 CFR 5 0.12 (a), 50.40,.50.50, 50. 55 (a) (2), 50.57 (a) (3) (i), and Part 50, Appendix A, Criteria 16, 50, 52, and 53.
Under the Atemic Energy Act of 1954, as amended, and regulations issued thereunder, it is the policy of the United States that the use of atemic energy shall be regulated to assure that public health and safety shall r,ct be endangered by cperation~cf federally licensed facilities. Under Chapter 10, Section 102 (d), no license shculd issue if its issuance would be inimical te the cc= men security or to the health and safety of the public. Under Chapter 16, Section 186, a license may be revoked if conditions are revealed which would warrant the Cc= mission to refuse to grant a license on the criginal application, or for violatiens of any terms or provisions of the Act er rules of the USSRC (See aisc 10 CFR 50.100).
On March 2S, 1979, cperating experience during the Three Mile Island Accident revealed that a less of ecclant accident could result in a 50% metal-water reaction in :ircenium, cladding, releasing hydrogen which could combust before being recc=bined through cen-ventional techniques. At TMI this resulted in containment pressures which exceeded TMI's 28 psi monitoring capability. As a result of this experience USSRC's Director of Nucleaf Reacter Regulation advised' the Advisory Cc=mittee on Reactor Safeguards that no new limited work authorizations or construction permits would be issued to applicants whose proposed design presented a hydrogen-pressure However, USNRC approved issuance of an operating license problem.
2cr TVA's Sequeyah Nuclear Plant. Unit 1, which was constructed with an ice condenser containment only> capable cf withstanding 10.8 psi (designed) to 27 psi ' estimated) of pressure in the event of hydrogen ecmbustion. A metal-water reaction greater than 25% could rupture the containment, with serious radiological consecuences.
13 CFR 50.50 provides thau operating licenses may caly be issued upcn a determination by the Cc= mission that the applicant meets t.~e standards and regulations issued under the Act. Criterion 50 cf part 50 Appendix A, General Design Criteria fer Nuclear Pcwer Plants,provides that the reactor centainment structure, including heat removal system, shall he designed so th'at the structu're can acccmodate, with sufficient
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margin, the calculated presst.re and te=perature conditions resulting from any loss of cociant accident. No license conditions or design changes initiated by the applicant provided assurance that containment integrity would remain intact in the event of a Three-Mile-Island-like accident at Sequoyah Unit 1.
As Ccmmissioners Gilinsky and Bradford have observed (45 F.R.
65474, October 2, 1980), "In proposing not to require additional hydrogen control measures in ice condensor centainments, the staff and Cc= mission have argued that the changes brought about after the Three Mile Island accident have new really made the probability of generating large quantities of hydrogen insignificant. That assumes a rather more ccmplete understanding cf the operational characteristics of large power reacters than (we) believe experience shows. The Cc=missien should have proposed that all power reacters demonstrate an ability to cope effectively with amounts cf hydrogen roughly ccmparable to that generated at Three Mile Island."
At the time of the issuance of the full pcwer cperating license, the Cc= mission was unable to make a determination that all the standards and criteria for safe cperation of the facility had been met. There was no reasonable assurance that the health and safety of the public will,not be endangered by cperation of the facility.
The issuance therefere violated the Atemic Energy Act.
Chapter 18, Section 223 cf the Atemic Energy Act provides:
"Whoever willfully violates, attempts to viciate, er conspires to viciate, any provision of this Act shall, upon conviction thereef, be punished by a fine of not more than $5,000 or by imprisonment for not more than two years, er both.
You are hereby cited for this violation.
Dated this 16th day of October, 1980 Su=mertown, Tennessee 38483 By the Director, Albert Bates Director of Nuclear Reactor Regulation The Nuclear Regulatory Cc=missien e
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October 16. 1CSD NEF-C-80-1 No. 50-327 1
THE NUCLEAR REGULATORY CCIOCSSION Su==ertevn, Tennessee FCR:
The Ccmmission E Ui Albert Eates, Director Office of Nuclear Reacter Regulation FROM:
TNRC Staff u
SU3 JECT:
SEQUOYAH HYDR 00EN PROBLD4 8
FURPOSE:
S===ary of deficiencies in the plant as licensed.
OISCUSSION:
TVA's Sequeyah Nuclear Plant Unit 1 (SQNF-1) received a full-power license frem USNRC en September lith. The centainment has a design strength of 10.6 psi. This pressure rating is certified by Chicago 3 ridge and Steel and by the shift engineers and inspecters that supervised steelverk and concrete pours as construction progressef k'hile material streng.h analyses perferned fer TVA and USNRC subsequeni to TNRC's 2.206 petitien estimated higher yield strengths for S;NP-1 contai==ent (27 h5 psi), the USNRC staff has.. acknowledged (NUREG-0011 l
Supp 3, p. F-51) that 27 psi is the nest tenservative estimate of actual yield strength. Actual tests have been cenducted at enly 4
- 13.5 psi. As stated in the 2.206 petition we de net believe it te be good policy to allov desinn bcsis strencths to be super:eded by subsequent fermulatiens of pessible material strengths. Hevever, if the new estimates of material strengths are used, and with the installatien of dedicated hydresen re cr.biners and distributed igniters, SONF-1 =ay be assumed te be capable of withstanding a 55 (10 CFR 50.hk) metal-vater reactien. Sven greater metal-vater reactions nicht be withstood if they occurred ever long eneush time periods to allev recentination, er other favertble cenditiens prevail.
However, during the accident at Three Mile Island Unit 2 en March 23, 1
1979, a 50% metal-vater reactien caused the release of several hundred
. kilogra=s of hydregen which detonated within the centainment, resultinc in a pres.sure spike which exceeded TMI-P mnnitoring enpnbility of 28 psi. TMI-2 is desicned for 60 p:1 pressures. In erder to miti te 6
the possibility of a similar event at G4NT-1, TVA has placed great reliance upon its distributed inniter (c3pv pluc) cyctem. Independenu tests have indicated, however, that even with the plugs operating at maximum effectiveness and coed air circulation and mixing, pressure icvelo during a burn may exceed E7 pni. in. ncveral plaucible scenaries, internal pressure eeuld exceed even TVA's optimistic esti= ate of h5, psi containment yield strencth. For these reas:..s, cne USNRC censultant suggested that inerting the'atecsphere to avcid cembustien entirely i
veuld be a better use of resources.
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Moreover, te=peratures during any hydrogen burn are capable
- 7. in the ice chest area cf centai=.eni.
0 of exceeding 1000
"'he polyurethane feas insulatien used en the ice chest vill 0
C and vould begin to. degrade at 300, vill ignite at LOO spectaneously etebust at 10000 Lessief the 20 tens of insulation vould destroy the ice chest, create ve y high te=peratres, *.nd liberate large a= cunts of stea= and carten =enexide. Papid burns in specific locations (e.g.: near ice cendenser structural steel, near fans or electrical equipment, er near pipes er valves) could result in multiple systems failure.
i Rapid or very pcverful detonatiens could eccur in the event that steam cendensed out of a fla:.atle =ixtu-e of hydrogen and crygen which would net be ignited by glev plugs with stea: ;-esent. Such a detonation mir,ht exceed h5 psi.
It should also be noted that "VA has received :re: US 30 staff an exe=ptien te g pendix J (NU?E -00~1 Supp 1, p. 6-5) fer leak tests on the centain=ent deer at 12 psi design rating. T/A.infor=ed US GC that the door was not able to be tested at 12 psi and eeuld enly be tested at 6 psi. S;N?-1 also has some 50 tfpass leah pr.ths for which special exemptions were civen which ceuld cause preble=s in the event of everpressurizatien cf centainment. Tnese paths could, for instance, cause the nuxillia y buildine, to beccee a "het" verk area.during a degraded cere accident.
Secause of these design ceficiencies, the hydrogen centrel proble:
vill not be rescived by ecsr. etic, inexpensive neasures like glev plugs, but must be redressed b/ additional steel and cen: rete and/ r by ec=buction inhititien through the use er en inert atmespher.
- lithout these additional meas =es, the Sequeyah plast cannet te regarded as safe. Actual eperating experience at Tnree Mile Island indicates hydregen c:=bustien is possible in a= cunts Greater than S;N?-1 is desi ned to vithstand. Such an event as oce r red at "iC-2 6
could cause ruptre of centainment at SONO-2, resulting in severe radiological consequences.
Centact:
i A. Bates 615C6 h3992 l
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