Text

Backup Questions & Answers to Use in Preparation for Hearing on TMI Before Senate Subcommittee on Nuclear Regulation
	ML19220C884
Person / Time
Site:	Crane
Issue date:	04/09/1979
From:	Kammerer C; NRC OFFICE OF CONGRESSIONAL AFFAIRS (OCA)
To:	Gilinsky V, Hendrie J, Kennedy R; NRC COMMISSION (OCM)
Shared Package
ML19220C882	List: ML19220C881; ML19220C884;
References
	NUDOCS 7905160027
	Download: ML19220C884 (38)
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To the Com.r.issioners:

Enclosed for your information and use are a series of questions and answers prepared by OPE on the basis of information at hand.

Unfor-tunately, because the supplementary material prepared by the staff was not available in time, the consistency of the answers with the staff's material could not be confirmed.

The pages are numbered ccnsecutively.

The general subje:: of each Q & A is as follows:

1. Resident inspector presence

2. Inspectica & enforcement program

3. vependence on operator judgment

4. Other B & W facilities

5. Resteration of TMI

6. NRC, State roles in emergency

7. E? sis of Gov. Thornburgh's recom.mendation on evacuation

8. Commission consideration of evacuation

9. Responsibility for ordering evacuation

10. Future a: tion on evacuation reccamendations

11. Reason for no evacuation order

12. Agencies monitoring TMI

13. Source of radiation at TMI

14. Likelihood of meltdown at TMI

15. Anticipation of hydrogen bubble problem

16. International (export) implications (4 Q's & A's) 7905160 049-7 i17'220

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. Her might the events and the outcome h' ave been changed if an NRC resident inspecter had been present?

The auxiliary feedwater pump discharge va'ives were closed f or two weeks prior to and into the accident while the reactor was operating.

It is very likely that an NRC resident inspector would have noted this situation and insisted on immediate correction.

If the situation had been corrected the accident might have been avoided or, at least, had greatly reduced c nsecuences.

Ir. additi:n, a resident inspector expects to be contacted and to respond immediately to licensee events.

If such contact had been made, NRC would have had a highly qualified reactor operations inspector on site much earlier in the unfolding events rather than at about 10 a.m. on March 28 (when NRC's Region I response car arrived at the site).

Nevert.seless, the presence of a residen'. inspe: tor in the control room at the time of the accident might not have affected the initial phase of the accident.

The NRC inspector would not n! responsible for ope ator actions --

Metropolitan Edison is responsible for tperating the Three Mile Island plant.

i17 2Zi r

. at crevision does NRC have to see thct liter.se re:uirerents--such as

.avin; auxiliarv fee water available--are obeyed?

.ThefiRhhasaninspectio5andenforcementprogramtoseethatlicensees comply with regulatory repuirements.

Regional inspectors conduct periodic routine inspections at licensees' facilities.

Where assigned, resident inspectors are on site daily to perform these inspections and observe licensee operations.

When non-compliance with regulations is identified any imminent hazard to public health and safety mu'st be rectified immediately.

N,0 uses immediate action letters and orders to obtain such quick action.

. cen an imminent hazard does not exist or when it is rectified, t;RC applies

tner enforcement actions including civil penal 3ies and modification er revocation of license to assure that such situations do not arise again.

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':rC 's cr41:n v concernin: decer. der:e er ::e-at - 'udaren in

1f t:v-critical e ations,such as coeration of ECC50 It must be emphasized that although operator judgment is relied on for safe

eration cf a nu: lear porter plant, this does n:: mean that safety devices c; not operatzentil the coerator acts.

Many critical actions, su;h as i.itiating emergen:y core cooling, are taken autcmatically when certain sensors detect potentially hazardous conditions.

The operator can manually c /erride certain of these automatic actions if, for-example, the information a-hand indicates to the operator that the initiating sicnal is spurious.

As a ceneral rule, any safety-related action that would ordinarily require

: :t initiation is made by an automatic device ra:ner than by the operator.

,0C re uires reac r operators to cass a series of written examinations and cn-:ite operatin; test: before they receive an operater licenee.

Each license is valid for one specific nuclear facility and for two years at v hi:h time a rene<!al must be applied. for.

Renewal is based on evidence c' satisf actory performance, operating experience, end ccmpletion 'of a

'a:i', i ty-a:-inis tered recualifica tion progra.

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' hat crecautiola y actic. is N?.: 1 in: at the etner Babcc.k & Wilcox nuclear facilities?

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By Acril 1, NRC's 0?fice of Inspection and Enforcement transmitted a bulletin (IE. Bulletin 79_05) to all utilities with an operating Babcock

& U,.cox pressurized water reacter.

The eight operating B&W reactors are

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Arkansas Unit l, Crystal River Unit 3, Davis Besse Unit 1, Oconee Units 1, 2, 3, Rancno Secc, and Three Mile Island Unit 1.),The bulletin requested that each utility inmediately review its facilities and procedures in light of the Three Mile Isiand event te ;reclude a similar event.

Utilities have 10 days to submit to N?.C detailed esults of their reviews of the Bulletin's seven items.

Also, on April 1 NRC disp 2tched an inspector to three sites with operating B&W reactors:

Crystal River'(Fla.), Davis Besse (Ohio), and Rancho Seco (Cali-(Resident inspectors had previously been assigned to the othen two sites.)

In addicion to the usual resident inspector duties, these inspectors are required to assure that licensees are conscientiously fulfilling the Bulletin's provisions.

They will also keep licensees informed of the details of the Three Mile Island accident.

Currently NRC is inspecting these reactors during every operating shif t.

The NRC has initiated a generic review of all B&W reactors to determine whether there are any inherent design flaws. This investigation includes NRC licensing offices and various licensing boards and panels.

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0: youanticipatetha((eactorwilltecperationalagain?

If 50, when?

'r: bat stcps must be done to restore it to~ operating capacity?

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It is too early to even consider whether the reactor will or will not be restored to operation.

The Commission's investigation should be completed and the extent of damage known befare the question ccn be addressed.

If it is decided to restora the reactor t. d put it b5ck into service, it is clear that it will be --

c.,eiva p ocess.

The most expensive phase is likely to be the clean-e 7.r1 e s ;;r :.t v; -

'f the reactor cad contaihment --

including such opera;.on. as ereval of the fuel, decontamination of the primary _ system, verifi

, a vf the structural integrity df the pressure vessel and other major 07 ;;nencs, replacement of damaged instrumentation and equipment.

Even after all the neri and repaired hardware is in place, extensive testing will be required before operation can be permitted.

The time required to restore the plant may range from one to several years --even though the turbines, generators, cooling towers, as well as most of the secondary cooling system, were not affected by the event.

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.m i a e resre::ive

es Of i?.C ant State and 10:21 govern. Tents relating acicic;ical emergent;. situationst i;RC has no statutory authority tc re:uire State and local governments to deeire or to test radiological emerger.cy response plans.

The Cornission's regulations recognize the States' authority and responsibility to respond to emercency situations within their jurisdictions.

fiRC policy provides for guidance for the States in developing radiological emerger y response plans.

RC conducts training courses for State and local personnel engaged in emerge'ncy response activities and evaluates State emergency plans against a neck list cf 70 esser.: ial elements.

Tnrough a Federal assistance program fiRC r deral a;er.:ies r.ake re::

endations for improv em,e n; -

!?RC also an: c:her e

exercises a lead agency role in a is:eral interagency program which provides cuidance and assistance to State and local governments in developing and testing their radiolo:ical emergency res::cnse capabilities.

f?RC has been able to v;ork cooperatively with the States in reviewing their plans and capabilities.

Thus f ar, f?RC has concurred in theemergency response plans of 11 S'ta'tes.*

' Pennsylvania is not a Or.g them.)

s Facility cperators view emergency actions to protect public health and safety outsice a f acility's boundaries as the responsibility of State and local governments.

Under f;RC regulations (10 CFR Part 50, Appendix E) licensees are recuired, as part of the f:RC-approved licensee emergency plan, to have pro-Cedures in place for notifying local, State and Federal officials and agencies in the event of an emergency.

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-Cailfornia, Connecticut, Delaware, Florida, fiew Jersey, I;ew York, Washington, 50:nh Carolina, Kansas, Alabama, lovea.

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.a basis di: the Governor of Pennsylvania re: mmend eva: ation of

e;.ar.: m:mer and cniidren out to 5 miles?

0- Triday, March 30, following a release of radioactivity fro the Three Mile Island plant, Governor Thornburgh of Pennsylvania recommended the evacuation Of pre-schooT children and pregnant women within 5 miles of the plant.

The G vernor's press office reported a reading of 1200 millirems per hour at the r

lant vent from which the gases escaped.

This is 20 percent higher than the

~:evel at v;hich the EPA protective action guides call for prote::ive action.

Tne rer vinole body, dose if received in one hour would trigger a protective es::nse under EPA guidance.

At 5 rem projected dese, resp:nse would be i.:itory under EPA guidance.)

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Di: the Ccmmission consider reccamending evacuation of the nearby population during the Three Mile Island accident?

Tr.e Commission was continually aware of the possibility that evacuation would be recessa y.

'In particular, during the period March 30 to April 1, when the potential dangers of " bubble" expansion and hydrogen explosion were evident, the question cf re, commending ev?.cuation was discussed.

At about 11 a.m. on Friday, March 30, the senior staff at the Operations ' Center recommended that Cnairman Hendrie (who was about to call Gove.nor Thornburgh) recommend that

he Governor of Pennsylvania ca'l for a general evacuation out to 5 miles and

e crepared for a general evacuatier out o 10 miles frcm the plant if con-ci-icns worsened.

crcm the data at hand -- the Cormissioners were fully infermed -- the Commission considered that the healtn and safety risk of not evacuating the nearby population was substantially less than the health and safety risk associated with a mass evacuation. The decisidn not to recommend evacuation reflected the Commssion's belief that both the bubble and ' hydrogen prcblems could be resolved without releasin; sig ificant cuantities of radicactivity.

117 228

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' n:se responsibility is it to order }m ev.acuation?

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This is the responsibility of the Governor of the State in which the reactor is located, in.this case, Pennsylvania.

fiormally,the way emergency plans are currently set up, the licensee has the undelegable responsibility to a%6 assess the magnitude of the accident,to make recommendations to State and local author _ities concerning protection measures, inc.luding evacuation.

The governor'.s a: tion advising pregnant women and pre-school children to leave the area was based on a Commission recommendation.

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\\\\1 2)~('I acticns should I;RC take in the 2eture to avoid confusing dissemination

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of informition to the general public concerning the possibility of evacuation?

Unter current arrangements, any recommendation for evacuation w:ould come f rcm the licensee to State and local authorities.

In the case of Three "iie Island, f RC cade recommendations to the Ouvernor, thus by-passing the licensee-Tr.e role cf the licensee in making such recommendations must obviously be clarified on the basis of this experience.

If in the future IG.C intends exercise that responsibility, that f act must be made clear to all participar.ts, and licensee and State emergency plans must be mcdified accordingly.

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Gi'.en the risks of a ccre eltdcan or a hydrogen explosion, why were no evacuation plans put in:c. 'fect?

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The State infc-c5 us that evacuation plans were in readiness.

Had the experts involved judged a core r:eltdown would occc-dering the course of the accide7t or that a hydrogen explosion could occur if certain ch iges itUl.6 AT an evacuation would have in the plant's operatio.s were purposely maJe,b been ordered by the 5:a e.

The decision would have been Governor Thornburgh's.

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.. '.it agencies and organizations monitored radiatien levels a: TMI?

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I P., HD.' (Eureau of Radiological Health), DDE, EPA, the licensee and the State of Pennsy)vania (Bureau of Radiological Health, Department of Encironmental Resources).

The States surrounding Pennsylvania have also car.e mar.itoring on their own.

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,.n i :,.as the source of the radiation?,,

'..ater conta.inated by exposure to radioactive fuel in ruptured fuel rods was trar.sferred through pipes to storage tanks outside the reactor containment

_ i '. d i n g.

Subsequent venting of evolved radioactive gases and spillage from tne overfice of tanks released radicactive gases to the atmusphere.

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.-:-i'.e a number of employees at the site received more than routine occupational e.;:sure, it does not now appear to have been a cangerous amount.

Radiation licels cu: side the site exceeded. levels permitted ir, normal operation but did.

esul. ir, ex;osures of individuals to more than a fraction Of the annual

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';as there at any time during the course of~the accident a reasonable chance for a meltdown?

This question can only be responded to in a somewhat speculative mann.

s we do not have all the relevant information at hand.

We know that during the course of_ the TMI accident there were periods when the core cooling was

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marginal.

If there had been no effective cooling of the co're for an appre-ciable length of time, a melcdown could have resulted.' Since there is evidence that the core was damaged it is possible that some fuel meltir.g occurred during one of the short periods when core cooling appeared to be insufficient, although it is more likely that, if melting did occur, it was limi'e.d to the fuel cladding.

Our grea est concern about the potential for maltdown was during the period when a large gaseous bubble was formed in

".2 reactor vessel.

If this bubble had expanded to the point where the water covering the core was displaced -- the core became uncovered -- and if this condition existed for any appreciable time, it is likely that a meltdown would,have resulted.

However, the bubble did not approach this condition and, since-tnere were means available to control it and reduce its size, the po;sibility of celtdown was not considered to be sufficient for emergency evacuation of the nearby population.

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Was the bubbie's forming in :ne reactor vessel an anticipated event?

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Answer:

No, it was not..

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9 puestion:

have any nuclear reactors excorted by the United States been supplied by Sabcock and Wilcox?- If so, where are they located?

If none have been previously exported, are any planned?

Enswer:

A Babcock and Wilccx design reactor is now being constructed in Gemany and is aporoximately 60% cc pleted.

Question: Will foreign nucisar exparts be pemitted to participate in the after-accident review?

Ansv:e":

Of course.

Information on nuclear safety should be shared freely throughout the world.

Technical excerts from other countries were received and briefed in Dennsylvania as well as Washington.

On April 3 representatives of IS ccuntries and international agencies were briefed at tiRC headcuarters.

This process of sharing in the post-accident review will of course continue.

Ques tion: Will the United States continue to export nuclear reactors, particularly to lesser-ceveloped countries which have minimal experience in assuring the safety of reactors?

It is not expected that this accident will affect U.S. willingness A.swer:

to export nuclear reactors.

The safety cf U.S. olant design is under continuing evaluation by our own regulatory authorities.

Question: Will the United States be in a position to offer required technical tssistance to f.; reign utilities which have purchased U.S. reactors?

Answer:

As part r f its on-going cooperative program in nuclear safety, the Nuclear Regulatory Comission orovides such technical assistance as is recuired, not only for any reactor exported by the United States, but for any country wishing to avail itself of U.S. nuclear safety

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,b,g experience.

Three. Mile-Island Incident

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Summary cf Initial Resp nse and Radiological Surveys At about 0700 hours0.0081 days 0.194 hours 0.00116 weeks 2.6635e-4 months , the license identified high levels of radioactivity in the reactor coolant sample lines - there were radiation readings of about

' 5 00 rr/nr a contact with tl [ sample lines - and a " site emergency" was

e:lared.

~730.: rs ne li:ense declared a " general emergency" based on hi h a:ia.icn le els in r.e reacter building, and began notification of certain r e:eral, Sta e and local agencies according to energency procedures.

At 0530 hou s the radiation levels at the site boundary were reported to be less than I cr/hr.

NF.C Regicn I received notification of the general emergen:y condition at t,e olant at agprcxiestely 0745 hours0.00862 days 0.207 hours 0.00123 weeks 2.834725e-4 months , March 28.

After evaluation of the eported conditions, an NRC incident response team was assembled an_d cispatched to the site and the situation was reported to NRC Headquarters.

The NRC res,ponse teac, consisting of reactor operations specialists and nealth physicists, left the Region I Office at 0545 hours0.00631 days 0.151 hours 9.011243e-4 weeks 2.073725e-4 months and arrived onsite at 1005 hours0.0116 days 0.279 hours 0.00166 weeks 3.824025e-4 months , March 28.

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-2 Concurrent with the assembly and dispatch of the team, cperations centers

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were activated both at the Region I office and at NRC Heedquarters.

Notifi-c?. ton procedures were initiated at both NRC Region I and NRC Headquarters to inform the Commissioners, NRC staff and other State and Federal agencies.

At 0859 hours0.00994 days 0.239 hours 0.00142 weeks 3.268495e-4 months the NRC notified the Department of Energy's Emergency C erations Center at Germantown, Maryland and requested that an aerial s urvey (AMS, Aerial Measurement System) team be dispatcned promptly to the s '.e.

The A."5 helicopter arrived at the site and had located, tracked and ace miasuren.en s in the plure by 1515 hours0.0175 days 0.421 hours 0.0025 weeks 5.764575e-4 months , March 28.

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Returning to earlier events, the NRC incident teara, arriving onsite at 1005 hours0.0116 days 0.279 hours 0.00166 weeks 3.824025e-4 months ,.measurec radiation levels of less than 1 mr/hr at tne north gate, 3 cr/hr in the north parking lot and 7 cr/hr at the east side of the island.

The NRC team, after being briefed by the licensee regarding radiol'ogical and plant conditions, immediately set out to gainer additional radiological c ata.

Radiation monitors in the plant showed abnormally high radiation levels in the containment and auxiliary building which prevented personnel access into certain areas.

Radiation surveys also identified elevated levels of radiation outside plant buildings; however, the condition outside were not cf such a level to prevent the gathering of survey data.

Radiation surveys determined that a releast of airborne radioactivity was cccurring.

117 230 At1110 hours,radiationlevelso'f3mr/hrweremeasuredattheplants' ebservation center on Route 441 immediately east of the plant, a'nd at 1130 nours, ievels of 0.3 mr/hr were measured on Route 283 near Harrisburg.

By the afternoon of March ?d, survey measurements showed radiation levels

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up to ]5 mr/hr (beta ga=a) in the plume at ground level and levels generally less.han 1 mr/hr (beta ga=a) ot'tside the plume.

The highest easurement of about 70 cr/nr (beta ga=a) was at 1620 hours0.0188 days 0.45 hours 0.00268 weeks 6.1641e-4 months at the north

a: E of the plant. -

-e-ia' surveys the af ternoon of March 28 locatec the plume t'ravellinc in a N to NE direction in approximately a 30 sector, and radiation levels of 0.1 mr/hr were measured at aboct 16 miles from the site at an altitude of several hundred feet.

The aircraft survey ':c,ntified, by gamma spectral analysis, the radioactivity as principally xenon-133.

3y the evening of March 28, the acencies conducting radiation surveys and sampling operations included the licensee, NRC, DOE and the State of Pennsylvania.

In addition to the DDE AMS helicopter and ae-ial survey team and the NRC team and portable equipment, a mobile laboratory of the NRC Region I office had arrived at the site to process and analyze samples.

Sampling and analysis of milk and air sampling for radiciodine had begun and has continued to date.

Thus far, only low levels of radiciodine in 117 239

_4 mil ~ and air have been reported.

The -levels are f ar below the level of action for control of dairy herds or milk.

The sampling will co.;tinue until some time in~the future and the results are continuing to be evaluated.

By March 29, the NRC team at the site had established a routine operation and procecures for obtaining both onsite and offsi'te radiological data.

Tnis information was -being relayed to the NRC Region I (Philadelphia) office and to tne NRC operations center in Bethesda, Maryland.

Aerial surveys were :ef ng c:ncu:te: at 3-5 nour intervais.

During Mar n 25, radiation levels at the s 'e boundary on the island ranged up to about 50 cr/hr (beta gamma).

The plume during the morning of March 29 extended in a N to hi' direction, and aerial surveys measured 0.5 mr/nr at i mile and 0.2 mr/nr at 10 miles from the site.

Offsite grc>nd surveys measured levels generally less than 1 mr/hr during the cay; maximum offsite adia:icn levels of 20 rr/hr (gamma) and 30 =r/hr (beta / gamma) were measured one mile wast of the plant in Gol.dsboro at 0500 hours0.00579 days 0.139 hours 8.267196e-4 weeks 1.9025e-4 months .

These levels persisted for a short period of time, less than one hour.

By the end of March 30, the number of HRC staff at the. site had 9 own to E3, including Regional Office and Headquarters personnel.

Radiation surveys were core scheduled and routine.

Ground level surveys in offsite areas downwind fro: the site measured radiation level ranging from less i17 240

5 Aer~ial, surveys measured radiation levels of

nan 0.1 up to 1.8. r/hr.

f S-10 cr'/hr over the site, and leYels of 6-8 nr/hr in the plume ne'ar the site.

In the evenin; of March 30, the plume was tracked in a northwesternly westernly direction from the site and was not detectable beyond 5-6 miles away.

Ey the end of Mar:h 31, cround and aerial surveys were being coordinated

n a f recuent schecuisd basis and the results being reported regularly to N O. : Hea: quarters. Information on results of milk, water and air sampling

..as cei.; re:e,ved and evaluated.

Resuits of licensee's TLD stations (18 s ta:'c s wi-hin a 15 -iie radius of the reactor) were received.

7ne TLDs had een in place for three months and had been exposed for about 32 hours3.703704e-4 days 0.00889 hours 5.291005e-5 weeks 1.2176e-5 months after tne incident.

Three dosimeters showed exposures above normal levels; the nighest was from a station on Three Mile Island, 0.2 miles NNW of the eactor - 921 mr, ap;roximately 905 mr above previous normal quar,terly eadings, the other high readings were 0.4 miles north of the reactor -81 r, approximately 55 mr acove previous normal quarterly readings and a station at north bridae, 0.7 miles NNE of the reactor - 17 mr, about 22 mr above normal quarterly readings.

On March 31, the NRC established 37 TLD stations within a radius of 12 tiles of the site.

Two or more dosimeters were placed at each station, one to be left indefinitely for integrated dose and the others to be changed daily.

The first day of this monitoring (March 31-April 1) showed the

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-ighest reading of 1.1 cr/hr at 4-mile.ENE cf the plant.

SUMMARY

OF RADI0 ACTIVE LIQUID RELEASE SITUATION (IRTS)

-ns : n:.s:-i a' r aste -reatment Sumo (IkTS) and tne Industrial Waste Filter i_: (: 25) 90-I

ollect nonradioactive licuid industrial wa'stes at the

'MI fa:ility.

-ne normal sources of water to these sumps are floor drains and c:ner semps located in facilities which do n:t have radioactive systecs.

-ne IWF5 and IWT5 are periodically discharged to the Susquehanna River by being peaced (approxicately 130 gpm) into the cooling tower blowdown which fic s in o the river at a location just South of the Unit 2 mechanical

a': :::lir.; t: tr The 50,000 gallon per c.inute cooling tower blowdown cilutes he IWF5/IWT5 discharge by a f actor of approximately 500 before it enters tne river.

During the TMI incident, the high concentration of radioactivity in primary systems cross-contacinated normally non-radioactive secondary systems and ccntaminated water eventually ended up in the IWF5/IWTS.

The precise 117 245 s

ti.i.; cf these events is not knowrg.

To precluce overflow :f the IWF5/IVT5

.ne licensee initiated discharge at about 1300 hours0.015 days 0.361 hours 0.00215 weeks 4.9465e-4 months on inersday, March 29.

Log records show that the licensee considered a controlled diluted release a better alternative than letting the-sump overflow with a resulting untiluted release to the. iver.

NRC analysis of water in the IWFS/IWTS at this time indicated the presence of Xe-133 and Xe-135, but results were not recisely known because the radioactivity in the gaseous plume being eleased interfere with radiation counting instruments used 10 analyze the samoles.

H -ever, it was determined that no iodine was present and the Xe

rcentratiers were not considerec significant i:- the reisase pathway.

'er t: tne initial release NRC consulted wit".ne State Of Pennsylvania, Eureau of Rad Health who was in agreement with NR:'s position to allow eleases as long as Technical Specificatiens were met.

The State later, newever, expressed concerns and at approximately 1800 hours0.0208 days 0.5 hours 0.00298 weeks 6.849e-4 months on Thursday,

" arch 29, NRC requested the licensee to stop discharging pending further analysis of the situation.

-f ter consultation with *.he State, NRC and Pennsylvania subseouently authori:ed the continuation of release at 0015 hours1.736111e-4 days 0.00417 hours 2.480159e-5 weeks 5.7075e-6 months on Friday, March 30.

The licensee began caking releases again at 0430 hours0.00498 days 0.119 hours 7.109788e-4 weeks 1.63615e-4 months on Friday, March 30.

Intermittant releases continued until Monday, April 2, when the State of Pennsylvania requested they be discontinued.

Due to a backlog of samples for analysis, NRC did not become aware of, adioicdine in the waste water until the sample counted at 1430 hours0.0166 days 0.397 hours 0.00236 weeks 5.44115e-4 months on Saturday, March 31; this sample had been collected at 0400 hours0.00463 days 0.111 hours 6.613757e-4 weeks 1.522e-4 months that

--ing.

Also, because samples were being split with the licensee's 117 246 centractor, the samplas were not being analyced in the same order in which they were collected.

During suhsequent analysis it was cetermin'ed that iodine was initially present in the discharge on early Friday, March 30,.as identified by a sample collectec at 0200 hours0.00231 days 0.0556 hours 3.306878e-4 weeks 7.61e-5 months on Friday, March 30.

This particular sample was analyzed at 0133 hours0.00154 days 0.0369 hours 2.199074e-4 weeks 5.06065e-5 months on Sunday, April 1.

Releases were again terhinated at 1110 hours0.0128 days 0.308 hours 0.00184 weeks 4.22355e-4 months on Monday, April 2.

Several reasons exist for the approximate two day time frame between identification of adiciocine in the water and cessation of releases.

First, the NRC

'.aboratory was merely processing samples and was not in a position to

'r.cerpret the results.

Second, the feedback of results of sample analyses

th:se who mign; interpret them was hampered.by the overall urgency of the coment.

Third, the majority of samples were below the release limit, thereby making this a low priority matter relative to the other events at the time.

After further review of the matter and additional consultation with both the States of Penr.sylvania and Maryland, joint agreement was reached and the licensee was again authorized to make releases on Thursday morning 4/5.

The licensee began discharging again at about 0300 hours0.00347 days 0.0833 hours 4.960317e-4 weeks 1.1415e-4 months on Friday with no further problems noted.

It should be noted that three organizations have been performing sample analysis.

NRC and the licensee's contractor were performing analysis on the scene and the samples were. then forwardec to the State of Maryland for analysis.

Analyses performed at the scene were considered preliminary because of counting interference caused by the gaseous releases from TMI 117 247

_4 Unit 2.

Obviously, there would be some time delay in receiving Maryland's results:

It should als.o be noted that a State of Pennsylvania representative (Bill Dornsife) was at the scene throughout these events and was frequently receiving the results of all sample results.

This person stated that he had received all information in a timely manner.

Revies of sample analysis indicates that the maximum concentration of

-6 adioicdine released was 2.7 x 10 microcuries per milliliter (pCi/ml) of i ocine-131, af ter cilution; this is approximately nine times the instantaneous release rate limit specified in the plant's Technical Speci-fications; the limits are the concentrations for unrestricted areas listed in Table 2, Appendix B,10 CFR Part 20 a.d whereas Part 20 allows concen-trations to be averaged over a year to act.ieve compliance, the Technical Specifications limit di'scharges to Part 20 concentrations on an instantaneous

-7 casis.

Tne ca.iority of samples averaged approximately 2.4 x 10 pCi/m1 or about 8C%' of the Technical Specification limit.

At no time was any radioicdine identified in any river water samples collected downstream of the release point.

117 248

Resident Inspection Program In May 1977 the NRC cecided to adopt a revised inspection program that, snen fully implemented, will include assignment of resident inspectors to each cperating power reactor site, to selected fuel facilities and to power eactor sites in the later stages of construction.

This decision was based

.pcn the results of a two year trial program of resident inspection which

-as ccrpleted in October 1976.

The trial program demonstrated that the concesc of locating inspectors near reactor sites has the potential for

'ncreases in botn effectiveness and efficiency when compared to the program cf inscections conducted by inspectors based in a regional office which s) be several hundred miles frc: a reactor site.

r May '_977, the Com-ission requested tnat 0"3 approve an amendment to

E's FY 1978 bucget to provide resources needed te begin implementation c f the revised inspection progra A FY 1978 supplemental requ,est was sub-

-itted to the CM3 on Snptember 15, 1977 and was signed by the President en Septemoer 8, 1978,

'he initiel resident inspector under this program arrived onsite in July is78.

Currently, there are resident inspectors assigned to 20 reactor sites.

As a result of the Three Mile Island accident, at eacn of these si^.es with similar Babcock and Wilcox desig.ed reactors, a full-time inspector was-assigned to provide -the equivalent of the resident inspection program.

- cesc-iction of the Revised Inspection Prcgra-for Nuclear Power Plants

-as cuclished as NUREG-C397 (March 1978).

-ne fcu elements cf the revised inspection program prcvide a balanced exarination of the activities of the licensee.

The revised program consists of:

Resident inspectors onsite at all reactors in operation, at reactors in the late stages of construction, and at selected fuel facilities.

Region-based inspectors who will supplement the inspec-tions performed by the residents with highly specialized inspections in such areas as environmental monitoring, physical security and health physics.

117 249

2 Performance appraisal ' inspectors to independently assess licensee performance, the effectiveness of the NRC inspec-tion program and to confirr. the objectivity of inspectors.

Increast4 independent verification of licensee activities.

The specific requirements of resident, specialist, and performance-appraisar inspectors and of the entire program create a need for a com-prehensive approach to training, management of the inspection force and career development.

An expanded training program for all types of inspectors and an enhanced career management plan. assure the performance of all elements of the inspection program by well trained and experienced inspectors.

In May 1977, the ComT.ission requested that OMB approve a budget amendsnent for IE for 125 people and 56,000,000.

These resources were requested to allow IE to begin implementation of the resident inspection program in FY 1978 with full implementation in FY 1981.

In June 1977, the Office of Inspection and Enforcement developed its program plan for implementation of the resident inspection program.

This plan assumed timely approval of the budget amendment request and aimed toward having the first resident inspectors onsite in FY 1978 with full implementa-tion by the end of FY 1981.

The planned schedule was:

FY 78 FY 79 FY 80 FY 51 FY 82 Residents 35 45 111 133 152 In Septcmber 1977, the Dr.3 approved a portion of the May 1977 request for additional resources.

This OM3 approval provided for increasing the NRC full-time personnel cs ling by 75 to allos earlier implementation of the revised program.

Unde; this OMB-approved amendment (submitted to Congress in Janucry 1978), the manning schedule was:

FY 78 FY 75 FY 80 FY 81 FY 82 Residents 22 49 76*

93 98

All operating reactor sites manned.

At full implementation, it was olanned to have at least one inspector at sites with reactors in the later stages of construction, in pre operational test, er in operation.

117 250

3 In September 197E, the FY 1978 supplemental request was signed by the President and the NRC was allocated 61 positions and 52,650,000 for the revised inspection program.

The Office of Inspection and Enforcement, in e-ticication of approval of the FY 1978 supplemental had initiated recruit-cent efforts and was successful in promptly recruiting personnel.

In the planning for the resident inspection program, an integral part of the revised program.was a national level performance appraisal effort.

This is i'ntended to provide for (1) evaluation of NRC licensee performance from a national perspective, (2) evaluation of the effectiveness of the NRC inspection program, and (3) confirmation of the objectivity of NRC inspectors.

The modifications to the revised inspection program from the initial budget amendment recuest to 0MB to the approved FY 1978 supplemental are:

Euccet arendment recuest for 125 additional oecole (May 1977)

Manning Schedule:

(Full Implementation)

F

7_8 FY 79 FY 80 FY 81 FY 82 Residen 35 46 111 133 152 Inspectors Performance 42 78 119 157 157 Appraisai Inspectors Full implementation in FY 1931 includes:

One inspector for each reactor phase (construction, preoperational testing, operations) at a site.

Additional inspectors so that no inspector would cover more than two reactors in any one phase.

117 25i

Accroved FY 1978 succlemental of El additional oecole fianninhScaedule:

(Full It'plementation)

FY 78 FY 79 FY SO FY 81 FY 82 Resident 22 49 76 93 98 Inspectors Performance 10 15 17 28 33 Appraisal Inspectors Full implementation in FY 1951 includes:

One resident at each site with an operating reactor One resident at each site with a reactor in a later stage of construction One resident at each of six selected fuel plants Currently, there are.esident inspectors assigned to 20 reactor sites.

At these 20 sites are:

26 operating reactors 2 reactors in the preoperational test phase 6 reactors under constru: tion As a result of the Three Mile Island accident, at each of three additional sites, an inspector was assigned to provide the equivalent of the resident inspection program.

On these three sites is a raa: tor of Babcock and Wilcox design similar to the Three Mile Island reactor.

The phased implementation of the resident inspection program resulted from the need'to train newly hired inspectors, and the need to maintain a cualified base of inspectors in the regional offices. Currently, the imple-mentation of the program is on schedule.

\\\\7 252

PRELIMINA?.Y EVALUkTION OF HEALTH EFFECTS OF THE THREE MILE ISLAND INCIDENT Radiation monitoring indicates that the exposure of the general popula-tion in the immediate vicinity of the plant was well within the limits of

~

NR: regulations (10 CFR Part 20) for annual doses to members of the general.

occulations.

They did exceed the numerical design objectives for normal eactor operation of 5 millirem per year (Ap,pendix I to 10 CFR Part 50).

Tne sourcas cf exposure were radioactive gases (xenon, r rypton and iodine) na: Jeaked from the plant - primarily from the auxiliary building.

Radio-active iodine (I-131) would be of particular concern be:ause of its concen-traticn in food, particularly in milk.

However, as of April 3,1979, it appears that no more than 3.0 curies of radiciodine were released Iodine levels observed in milk samples are less than one-tenth of those observed in milk following the Chinese nuclear tests in the fall of 1977.' The predomi-nant radioactivity released from Three MilesIsland was the noble cas Xenon-133.

T..e NRC has estimated that as of April 5,1979, approximately 10 million curies of Xe-133 were released.

An independent estimate of Xe-133 releases by Lawrence Livermore Laboratory is 14 to 34 million curies, thus both esti-cates are in agreement considering the extent of the uncertainty in the estimates.

An ad-hoc dose assessment group of representatives from NRC, EPA and HEW have made estimates of the radiation doses to the population around the Three Mile Island plant, based primarily on monitoring of offsite areas 117 2r7 JJ

2 by thermoluminescent dosimeters.

The calculated, total cumulative, 50 mile radius populatien dose from March 28 to April 8,* was approximately 2400 man-rems, which is equivalent to an average dose to incividuals of 1.1 milliree!

The maximum dose to an individual cffsite (hypothetical individual continuously present out-of-dcors at a location 0.7 miles NE of the plant) is still estimates to be less than 200 millirems (85 millirem).

This is within the dose limits reccmmended by the National Council en Radiation Prctection and Measurements for annual doses to a member of the general public (170 millirem per year).

These estimates are whole body gamma doses resulting primarily from the elatively weak gamma radiation from Xenon-133 (SO kev).

The heelth impact of the estimate of maximum individual dose for a hypothetical individual exposed cut-of-doors for entire duration at loca-tion of highest measured offsite dose can be considered in terms of the added risk cf a fatal cancer.

The existing lifetime risk of fatal cancer is approximately one-eighth (0.12).

The estimated risk f rcm natural back-ground is apprcximately one to two percent of this value (0.0017).

The aJded risk delivered to the hypotnetical individual would be 0.16% (0.000019) of the existing risk of a cancer death or about one. percent of the estimated risk from natural radiation (1.1%).

The potential health impact of the estimated ' population dose including fatal and non-fatal cancers and genetic effects to all future generation's is 1.3 health effects; and the number of potential fatal can:c s over the lifetime of the population is 0.45.

This can be compared to the existing cancer death rate of 4,500 per year and

^From April 4tn on, these values have been updated by members of the NRC Staff.

r,5

[

i

3 the estinated incidence from natural background radiation (125 millirem oer year) of 54 per year.

This supports the conclusion that the accident will not produce any detectable cancers within the lifetime of all of the residents in the area.

O e

O s

\\.\\1 255

,

ML19220C884

Text

SUMMARY

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