ML20129J669

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Forwards Revised Statement of Conclusions to Be Substituted for Conclusions Contained in Draft Rept Submitted on 810105 Re Notification of State & Federal Officials of Event Details on 790328
ML20129J669
Person / Time
Site: Three Mile Island Constellation icon.png
Issue date: 01/26/1981
From: Udall M
HOUSE OF REP., INTERIOR & INSULAR AFFAIRS
To: Ahearne J
NRC COMMISSION (OCM)
Shared Package
ML20127A105 List:
References
FOIA-84-311 NUDOCS 8507230212
Download: ML20129J669 (10)
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STAFFEilCCTOR DdORRIS M. UDALL. ARIZ CHAIRMAN

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The Honorable John Ahearne .

Chairman, Nuclear Regulatory Commission Washington, D.'C. 20555 ,

Dear Mr. Chairman:

I am enclosing herein a revised statement of conclusions to be substituted for the conclusions contained in the draft staff report transmitted under cover of my letter of January 5, 1981.

Sincarely, ,

M RRIS K. UD).LL nairman Enclosure 8507230212 850506 PDR FOIA PDR DOROSHOO4-311

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1/26/81 247 -

VI. Conclusion -

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The record indicates that in repor~ ting to State and Federal officials on March 28, 1979, TMI managers did not '

commun,1cate information in their p6ssession that they.

s p, understood to be related to the severity of the situation.

The lack of such information prevented State and Federal officials from accurately assessing the condition of the plant. In addition, the record indicates that TMI managers presented State and Federal officials misleading statements (i . e . statements that.were inaccurate and incomplete) that conveyed the impression the accident was substantially less 4 .

severe and the situation more under control than what the managers themselves believed and what was in fact the case.

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Rsvised 1/23/81 *

. 12/1/80 INTRODUCTION At 9: 00 a.m. on March 28, 1979, Inf5rmation available in the TMI-2 control room indicated that the reactor had been. severely damaged and that the plant was in a condition

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? not covere'd by its emergency procedures. Control room

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personnel were aware that a portion of the reactor's cooling Water had been lost via a pressure relief valve that had

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been stuck open for more than two hours.- As a result of the lost water, the main coolant pumps could no longer function as the syst'em became stham bound. Temperature sensing devices indicated that a portion of the reactor core was being coole,d byisteam rather than water and some t . of the temperatures were of such a magnitude as to suggest the production of substantial quantities of gaseous hydrogen .

as a product of a chemical reaction between steam and the j

zirconium tubes which held the uranium fuel pellets. Very i

high radiation levels in the containment building indicated escape of radioactive gases from a significant portion of the fuel rods. ,

The NRC's Special Inquiry Group (SIG) report stated that uncertainties at 9 :00 a.m. on March 28 as to how and whether

, the reactor could be brought to a stable cooling configuration raised the possibility of further degradation leading to melting of the core and a large radiological release.* The SIG stated that the situation was sufficiently serious i

to' warrant a' recommendation to State officials that there be a precautionary evacuation of the first few miles around

  • [SIG,Vol.II,Part3,p.983

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III. Availability and' Comprehension of Information -

A. Awareness of Open PORV as Cause of Low Pressure in Cooling System.

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. At approximately 6:22 a.m., TMI Shif't Supervisor Brian l

-Mehler (who had arrived at the plant about '5:45 a.m.) shut -

the block valve located upstream from the leaking Power Operated Relief Val.ve (PORV) . Following closu',e;of r the PORV, the primary coolingsystempressureincreasedandthIreactorbuilding pressure decreased, indicating that heretofore the system had experienced for more than two hours a loss of coolant accident via the PORV which had not closed as it sliould have following the drop in pressure after the initial pressure increase at about.4:00 a.m'. Some control room supervisors were aware that the' malfunction of the PORV'(sometimes referred to as the 1- -

electromatic valve) explained the low system pressure and high reactor-building pressure, believing therefore that the source of ,

the problem had been found. TMI-l Supervisor Ken Bryan recalled .

(GPU, Bryan, 4/26/79, p. 7) that Supervisor Mike Ross had call'ed hTE~from tli& UniE ControlRoomsaNing, " Hey dummy, you know that electromatic's leaking by? . . . We just isolated it. "

Ross told NRC investigators on April 28, 1979 that prior to closure of the block valve, the operatoEs were not aware the PORV was closed: "I'm under the assumption that they felt (the PORV) was closed, because sometime in that time gap we went ahead and is31ated it, and the reactor coolant pressure started to' drop. ,

So we felt that the electromatic (i.e. the PORV) had in fact been passing." (I&E, Ross,_4/25/79, p. 12).

In'a' subsequent discussion with NRC investigators, Ross' engaged in the following dialogue concerning the leaking PORV, _

the closttre of the block valve, and the inference as to what

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TMI managers failed to clearly inform the NRC and State of Pennsylvar of the ev}nt and its significance as soon as they themselves understood what had, happened. ,

Tne following discussion supports the conclusion that on F#.rch 28, the M station Manager and some of his subordinates were nere likely

. than not aware of the detonation and its potential significance. The

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discussion. that follows is based on ex6:erpts and inferences from the record of the TMI investigations conducted by the President's Commission, the NRC, and the Senate Special Investigation.

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Hydrogen' Combustion (Recognition'that a pressure ~ pulse ~had occurred.,

TC supeLwisors, who have said they did not believe the pressure pulse to have been real, have given a:rf of three er;1anations in support of tie.ir statemr

.as to. sty they.had not recoggized that..the pressure pulse and. associated actuaticr t'

safeguards systems had in fact been an indication of a real increase

,. in containment building pressure. -

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g i e 24 4 Q ~4211, tha reasen ~I a:ked tha question of courso was the !

, i 25jfac that two pecple , ycurself and ane:her ersen, estified that '

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} I j'you weren't there on that day, weren't in If.at office on that 4 .

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}- 2 ,f day. Those two testimonies were taken to discount that the order a

s i 3 jwas given on the 28th. I just want to clarify that it is now

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today your recollection you were in the shift superviscr's effice  :

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i en that day, and I have done thar . ';- .; . .

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l A Yes. ..

.' (Chwastyk, I&I:, 9/4/80 p.~45-46).

On September 4, 1980 Chwastyk engaged in the following' dialogue with NRC investigators wherein he seeks to explain how Mehler might have gotten from hiin the impression that the

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instruction concerning equipment in the containment had not been given on March 28. Chwastyk tells the investigators that it was in fact his recollection that the instruction to not start equipment was given on March 28. .

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BY MR. HOETLING:

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j. A l Q Joe, let me go back to scmething we have already talked i

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. Tnis is the instruction not to start electrical equipment

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10lthat we talked about earlier.

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ne instrue:1cn was given en !! arch 25th by :iiller not to start

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! any electrical equipment in the containment.

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'3 licw , we have talked te Brian ::ahler on this same

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= 1 subject, about the instruction and when it was given. Th'is <s 3 .

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b- hcw that spun out. On October 11:h, ' 7 9 :.xian restif.ied on this u

16 i[ subject and he said basica13y whet ,you have paid ther he recalled

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h. I7 l the instruction having been given by Miller cn the 28th. After -

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Ravised .., .afo.L

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said he found it hard"to .believe that anyone could have' missed it or the ensuing discussi'ons of it.

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(Supra, p. 13 0. ) TMI-2 operator, Ed

  • Frederick said that'dary Miller was particularly interested in

. the pressure spike on the chart recorder. (Id . , p..'.123.)

. Ross said that he was aware of the' pressure pulse

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, and that he was standing,near Miller when the pressure pulse occurred. '(Supra,. p. '130.) Chwastyk

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said that soon after the pressure pulse' occurred,

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he realized that'it had been real, th' a t it was ,

indicative of core damage, that.he explained *.

his conclusions to Gary Miller, and that on the basis ~of these he recommended that they'no longer cycle the PORV because the explosion had appeared coincident with opening of this valve. (Id . , p .13 7-147. )

  • Chwastyk. recalls 'that he was concerned that the contairrnent integrity might have be'en breeched by the pressure pulse;.he recalls. directing that a radiation survey be made outside the' containment to determine

. whether cracks had developed in the concrete 2 containment building. (Supra, p. 148-150.) Chwastyk also told I&E investigators that to the best of

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his recollection that scr:eone (he asstrned Miller) had given a_,. directive,

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on March 28 that equipment in the containment building not be turned on ar.6 the record indicates that the basis for this circe

, was concern that turning on equipment would cause a spark that w-ig'it,e n hydrogen feared t'o be in the bui1 ding. (Supra, p. 166-172.

Meglerrecallshavingbelievedthatthechart e

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recorder had indicated that there had been a real pres'sure pulse in the containment building rather

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than an electrical noise signal. Prior lo October-30, 1979 Mahle:

recalled the instruction not to start equipment in 'he t containment building.

(Id. , p. 158. )

While .

Mehlei said on October 30, 1979 add. subsequently that'he was unsure as to whether this instruction

. l had been issued on March 28, the testimony on l balance indicates that Miller gave the instruction

_. _. , or( it was given in his presence) to Me.hler and Chwastyk in the Shift SW.*r office late in the day on. March 28. (Id . , p . 15 8 , 16 4, 152.) Theodore Illjes, a. TMI operator stated that on Marcht 28 the pressure pulse and a y . ,

possible hydrogen explosion were discussed.

'(Id., p. 182.) M5.11er admits having heard a

  • noise 'at the time the pre'ssure pulse occurred,

.but'he has denied .having been aware on March 28 of a' pressure pulse having been recorded, of the containment sprays having initiated, or c.f. an Engineered Safeguards systems actuation.

In sum, of those seitior personnel present.in. ..

. the control room on March 28, most recollect the-pressure pulse and actuation of containmc.nt .

sprays; Illjes said that on March 28 there was speculation about hydrogent Mehler and Chwastyk

, believed on March 28 that the reactor building pressure cha::t had shown a real increase-in pressure; Chwastyk .

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1 believes 'he told Miller that the pressure pulje was caused by a hydrogen explosion; Mehler and chwastyk recall that

.. someone (the evidence indicates Miller) instructed that , ,, , _

equipment in the contalment building not be started, the record '

indicating tiiis being out of mncern that a s' }qwouldcauseanexplosion of hydrogen; and Miller states that he heard a

, noise but was unaware of the pressure psise and the

. possibility of hydrogen ignition being the source ,

, of the . pressure pulse until two . days latter,' cn March 30 (Id. , p. 9 7.)

t y On balance, consideration of stater.ents made to TMI investigators of the situatien at the time the ignition occurred and in th'e following liours leads to the conclusion that it is likely that Miller's reccliection of not having been

_ . _ . aware of the pressure pulse' and its significance is erroneous.

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