ML19241B073
| ML19241B073 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/14/1976 |
| From: | Shapar H, Shaper H NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | Taft P JUSTICE, DEPT. OF |
| Shared Package | |
| ML19241B068 | List: |
| References | |
| NUDOCS 7907110624 | |
| Download: ML19241B073 (14) | |
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Peter R. Taft, Esquire Assistant Attorney General Land and Itatural Resourra: Division Departaant of Justice Washington, D.C.
20G30 Re:
ATG:PliK 90-G-1-7-220
Dear iir. Taft:
In your letter of Iicrch 1,1970 (by rir. Alfred T. Chierzi) to
?;r. Olnstead of fr.y staff, you requested certain docu5r_nts cnd additional informtion to suppleant t,y letter to you dated Decer: hor 19, 1975.
Responses to your nu:tered questions and the requested doctaents are attached.
Please faci free to contact me if you need additional infomation or
. assistance in this natter.
Sincerely, p_..., C. 7.:.3 D:'
- .? n ;
. A
(-
[bb Nd '. Shapar Executive Legal Director
Enclosures:
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52 Questions and Anst:ers uiti 16 Exhibits attached l
a 307 301 790711 % gy,;
f ir 1 1; In regard to the settling problem at the florth Anna pumphouse, nur n derstanding that the FSAR was amended to allow a total anticipated Llcma.t of 4.3 inches at the pumphouse center.
Although previous settle-
- ts at the pumphouse corners had reached as much as 5.568 inches in the
- ;rthi.est corner, no measurements are indicated in material in our Fossession
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as to the subsidence presently occurring at the pumphouse center.
Please supply us with a copy of the most recent measurements of settlements at the pumphouse center.
Answer 1:
Settlement of the pumphouse center may be calculated from neasure-ments of settlements at the pumphouse corners which are hereby provided.
These measurements were supplied by VEPC0 in a letter dated May i3,1975, to
!!pC Region II.
A copy of that letter is attached as Exhibit A.
At that time VEPC0 stated in part:
"As of April,1975 the following total settlements at the four corners of the SWPH and the alignment-settlcment marker in the dike (marker
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no. 5) have been recorded:
2.40 in'.
SE corner 0.20 ft.
=
4.30 in.
SW Corner 0.36 ft.
=
4.20 in.
IlE Corner 0.35 ft.
=
6.72 in.
IN Corner 0.56 ft.
=
1.68 in."
No. 5 Marker 0.14 ft.
=
Thus the most recent measurements of settlements at the pumphouse show average settlement at the pumphouse center to be' 0.367 ft or approximately 4.4 in.
_ Ques tion _2_:
Approximately what degree of settlement would be unacccptable for the pumphouse at the North Anna site?
Answer 2:
An unacceptable degree of settlement for the Unit 1 and 2 purphouse would be that which would cause an unacceptable risk to the supply of emergency service water to the plant.
The water supply risks include failure of buried piping connected to the pumphouse, malfunctica of pumps due to excessive pump-house tilt, and rupture of the earthen liner for the pond as the pumphouse slowly punches into the liner. (See also Answer 3).
Question 3:
In regard to the rubber connectir.g sectents attached to ~ relieve stress in the fiorth Anna pumphouse pip.ing, approximately how much additional differential settling would be required to rupture or otherwise render in-operative those rub';er segments?
Please provide any calculations or esticates now in your possession either generated by the Cemmission or by VEpCO.
Anster 3:
According to VEPC0's letter of Aunust 21, 1975 to A. Schwencer (tiRC),
their proposed expansion joint design will accommodate 3 inches of additional VEPC0's calculations o-y-
o[
o_
.a ir r letter or o:nust
<t, attached as Exiiibit b.
307 302
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- tion 4
Please provide calculations submitted by VEPC0 as to the o~ticipated feture settling that may occur at the North Anna site.
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VEPC0's calculations of the future settlement of the pun phouse for Antwor 4:
Units 1 and 2 are included in a document entitled, " Report on Geo'.echnical Investigations of Service Hater Reservoir, North Anna Power Station, Units 1 and 2, December 23, 1975" attached as Exhibit C.
_ Question 5:
Why were the measurement reference points changed from the corners of the pumphouse to its center?
Answer 5:
The measurement reference points were 'not changed.
The settlement at the center of the pumphouse can be computed from the tlement at the corners by assuming that the foundation is rigid.
However, the degree of tilt of the pumphouse is not accounted for in a single setticment value at the center of the pumphouse.
Since VEPC0 based their design on average predicted settle-ment, it sought to use the center of the pumphouse. for comparison of predicted to actual settlement.
Question 6:
What fixed reference point will be used to measure future settling of the pumphouse center?
Answer 6:
Presumably, the same reference will be used for the center as for the corners of~the pumphouse.
The settlement at the center of the pumphouse can be computed from the settlement at the corners by assuming that the foundation is rigid.
, question 7:
In a letter from Mr. John G.. Davis, Acting Director, Division of Field Operations, Office of Inspection and Enforcement directed to Mr. Stanley Ragone VEPC0 senior vice-president and dated _ November 14, 1975, (Docket No. 50-333) the Commission notes that VEPCG consultants in April,1975, indicated a maximum bending stress in the North Anna pumphouse piping of 2300 P.S.I. compared to the code-allowed 20,550.
Furthermore, VEPC0 representatives apparently concurred in this evaluaticn and reported to the Region II office en May 15 that no corrective action was planned.
Upon inspection by NRC, however, on August 21, 1975, stresses were measured in the piping system as high as 28,000 P.S. I., approximately 7500 P.S.I. in excess of that allor;ed by the code.
Does this unreported excess constitute.a significant departure frco permitted operation? liad the Commission known of this excess stress earlier, would it have ordered or requested some form of modification in the structure or operation of the North Anna facility?
Answerl:
The stresses on' piping were not measured to the knowledge of NRC.
Tha stroccos in nuestion izere forecast as a result of questions raised at the ip q p st orn a<--
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cn..,.,_ _cuja stresses exceeding code requirements could require modifications in deslu.. or construction and NRC approval would be required.
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> ; tion 8:
Please provide copies of any reports which you may have in your j. session issued by VEPC0 or by any of its consultants or subcentractors 1 N Jrting stress figures on pumphouse piping at North Anna that contradicts those measured by the Conmission.
Answer 8:
There have not been any stress measurements on the pumphouse piping by either VEPC0 or the NRC.
NRC is not aware of any reports by VEPCO, its c'onsultants or contractors which contradict stress calculations made by
-VEPC0 and presented to the NRC.
Question 9:
NRC headquarters concluded in its Movember 14, 1975 Notice of Violation (Docket No. 50-339) that VEPC0 had failed to make a proper cal-culation of the stresses on the piping involved and was thus unaware that a reportable situation existed.
Please describe briefly the stress measurement process.
In particular, what is the likelihood that mere negligence in cal-culating stresses would result in a reported figure that is too low by a factor of ten?
Answer 9:
In April of 1975, VEPCO's consultants calculated (erroneously) pipe bending stresses of 2300 psi per inch of pumphouse settlement cnd concluded (erroneously) that 4 inches of settlemcnt could be tolerated.
Later, VEPCO's consultants recalculated (properly) 28,000 psi pipe bending stresses due to 3 inches of pumphouse settlement and concluded that remedial action and connectic-redesign was necessary to accommodate past and future settlement.
He are ur. aware of any stress measurements.
The calculated stress change was in error by a factor of four.
The error was due to a lack of analytical competence rather than negligence.
Question 10:
Please describe VEPCO's expl'anation as to how the erroneous stress measurement was made and why it was not considered suspect, given that in 1975 it was already known that settlement had occurred that was more than four times that previously predicted?
Answer 10:
The stresses were not measured but were calculated.
The calculaticns were intended to indicate the maximum stresses that the piping would experience over the lifetime of the facility.
The model useJ for the calculations was th3r.
of a pipe supported at each end and apparently the model neglected the soil in:Er-action forces which would cause increased stress levels.
Since the pipe was no:
connected to the pumphouse until June 1974, it was only subjected to the move-ments which took place between June 1974 and February.975, the time of reporti.':
These are tabulated as follows:
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e 307 304
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/,nswer 10 continued:
Pumphouse Settlement June 1974 to February 1975 6/74
_P/ 75 -
A Settlement _
1.416" SE Corner 0.102' O.20' O.098'
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1.68" ilE Corner 0.28' O.42' O.14'
=
1.452" SW Corner 0.242' O.363' O.121'
=
1.632" llW Corner 0.424' O.56' O.136'
=
puestion ll:
Please attach copies of any documents containing the explanation by VEPC0 requested in the previous question.
Answer 11:
The letter and report are attached as Exhibit D.
This report was received as an cnclosure to a letter dated August 1,1975, from VEPC0
~(W. L. Proffitt) v hich was sent to !!RC Region II in Atlanta (Director
!!orman C. I oseley).
~~
Question 12:
The Department is informed that in a letter from Mr. Schwencer of the Commission to Mr. Ragcne of VEPC0, Mr. Schwencer concluded-that the foundation engineering information reviewed as of July 24,1975 was in-sufficient to conclude that the pumphouse would reliably perform its design function.
Please attach a copy of !1r. Schwencer's letter dated July 24, 1975 and any response which VEPC0 may have made to that letter.
Answer 12:
Letters are attached as Exhibit E.
VEPCO's rcsponse ir dated August 15, 1975.
puestion13:
In regard to the problem of reactor vessel supports, at what point in time were VEPCO subcontractors first aware of the existence of Heuschel's lineament?
Answer 13:
As far as we kriow, VEPC0 subcontractors became aware of !!euschel's lineament upon publication of the following
,er in 1970:
fleuschel, S.K.,
1970, Correlation of Aercmacnetic and aerorau cactivity with lithology in the Spotsylvania area, Virginia:
Geol. Soc. Amer. Bull. V. 81, p. 3575-3582.
Question 14:
Here any VEPC0 engineering personnel, as opposed to subcontracters or other individuals, aware that the Mestinghouse design for reactor vessels sup-ports failed to er.ccmpass asymmetric loading?
Ahswer 14:
VEPC0 engineering personnel with project management / liaison duties tiere made aware in late 1973 that the original design loads generated by Westinghouse did not include asymmetric loads and that it had been determined
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w "a rquired that m
.c.
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Answer 14 continued:
desinn basis pipe rupture postulate.
!!owever, these same individuals were assured by their design agent Stone & !!cbster (Stone &
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!!ebster is responsible for the actual design of the reactor vessel supports) that the vessel supports as designec' were capable of sustaining much higher loads than originally specified by !!estinghouse and that Stone & !!ebster's initial judgement was that the additional loads could be accomodated with no change in design.
In f' in the latest analyses performed by Stone & !!ebster usino !!est-inghouse load aata, with alriost all sinp14 fying assumptions removed, demonstra ted that the supports as designed are Rund to l'e atisfactory for service.
The staff is not sched...J to complete its revic, <f these analyses until early 1977.
Question 15:
!!ere any VEPC0 F rsonnei responsible for monitoring or checking the llestinghouse design?
If su what.are'their names?
Answer 15:
l'r. L!. Dennett, the VEPC0 project engineer, is responsible for maintaining general cognizance of the najor subcontractors' efforts.
Stone &
llebster Co. (an architect engineering fira) was hired by the utility to act as their agent and to provide specialized engineering services.
Stone & !!ebster alas responsible for design of the pressure vessel supports to meet the loading conditions specified by '!estinghouse.
Ruestion16:
fir. Shapar's letter of December 19, 1975, directed to this office, indicates that l!estinghouse, as the desicner of the supports, was fully aware in 1971-72 that the design did not account for asymmetric loading.
Although Mr. Shapar indicated that these loads were then thought to be of relatively little significance, fir. Shapar notes that detailed studies were initiated by l!estinghouse.
Did !!estinghouse, at any time prior to April,1974, indicate to
.VEPC0 that such studies viere taking place?
Answer 16:
As indicated in fir. Shapar's letter of Deuember 19, 1975 Stone and ITebster Company, not !!estinghouse, is the party responsible for design of the VEPC0 vessel supports.
l!cstinghouse becane aware in 1971-72 that asyrretric loads uignt occur under certain design basis pipe rupture postulates.
1.'he t h er or not these highly transient loads were of significance to actual structural systems e.g. reactor vessel supports was ccnsidered quite debatable and further studies were instituted to resolve the matter.
The conduct of these studies was published as technical papers and given in seainar format by !!tstinghouse and !!estinghouse employees in 1973 and early 1974.
Stone and I!ebster personnel on the VEPC0 project and cognizant VEPCO personnel were aware that these stud:cs were in progress but no cefinitive informtion was available to indicate the actual loads that night be expected to occur with any specific support design.
Of interest is the fact that the actual load developed in a given support system depends on the interaction between the hydraulic forcing function and the structural response of the support members.
Therefore, it is entirely possible that with a oimo fnreino f"nctinn one sanoort systen design will develop very h i '; h 1. -
1 a
O 307 306
E Uho are the individuals at Uestinghous.e and/or at VEPC0 who
, Question 17:
indicated that VEPC0 had no knowledge of the design problem prior to April, 1974?
Ansver 17:
In discussion with the staff, l'c. H. Cennett of VEPC0 and l'r. N. Goldstein of Stone and Hebe.ter indicated that final results showing that the original design criteria f or the !! orth Anna pressure vessel sup-Both of these individuals ports had been exceeded were available in April 1974.
as well as others in the technical community were aware that studies were under-uay to more accurately characterize the design basis loadings for P!lR coolant systems and that these studies were indicating that asym etric loads may exist.
Because of the transient nature of these loads housver it was inpossible to draw a definitive conclusion as to the significance of the leads until a ccmplete dynamic characterization of the load forcing function (a time history) had been prepared for all loadings and a detailed dynamic model of the reactor coolant system had been prepared and analyzed us ag the time history forcing functions.
~ Question 18: Uas VEPC0 aua n at any time prior April 23,1975 that a support design problem existed? Cn what evidence is the answer to the immediately pre-ceding question based?
VEPCO engineering personnel, with project management / liaison duties, Answer 18:
were made aware by Uestinghouse in late 1973 that the original design loads generated by Uestinghouse did not include asynmetric loads and that it had beco determined that asynaetric lo2ds of some aagnitude would be present under the required design basis pipe rupture postulate.
However, these sane individuals
'were assured by their design agent Stone & Uebster (Stone & Uebster is responsibh for the actual design of the reactor vessel supports) that the vessel supports as designed were capable of sustainina much higher loads than originally spec-ified by Westinghouse and that Stone & Uebster's initial judgement was that the In fact the additional loads could be accommodated with no change in design.
latest analyses performed by Stone & Uebster using Ucstinghouse load data, (with almost all simplifying assunptions rcmoved) deronstrate that the supports The NRC staff has not yet completed as designed are heid to be satisfactory.
its review of these analyses.
NRC staff expects to complete its review in early 1977.
This answer is basco on statements made to the NRC staff by VEPC0 and Stone and Uebster personnel during the course or follcu-up meetings on the North Anna docket.
If any VEPCO, Stone and Uebster, and/or Uestinghouse employees, Question 19:
agents, of ficers or directors stated that VEPCO had no knculedge of the desim nr%, nrior tn A,ril 23. 1975. nicase qive their names.
307 307
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- r 19:
lio such statements were made to the iiRC technical staff.
C
> tion 20:
Did Mr. Ragone from VEPC0 write a letter to 11r. iMelty of the i
tt iission dated i'ay 15, 1975, or there about, indicating that external piping to the pumphouse had not been overstressed, that the structure was not expected to becoma overstressed and that the structure was fully capable of service as a "si.fety grade" system?
Answer 20:
!!RC received a letter dated May 15, 1975 from VEPC0 signed './
lir. Ragone.
_qu_es tion 21 :
If so, please attach a copy of that letter.
Answer 21:
A copy of that letter is attached at Exhibit A.
In this connection note page 4 of the referenced letter which states in part:
"lionitoring indicates that, since the lines were connected to this S!!PH, the S!!Pil and the dike are settling at the same rate ( See Figure 1).
Thus, there would t:e no differential settlement between the pipe and the Sl!Pil, and therefore no sheer stresses at the penetration.
After leaving the SWPH, the service water lines travel down the slope to<tard the power station.
The setticment of the S'.lPH and the dike will result in ninor stresses in the pipe.
Calculations indicate that one inch of deflection at the SUPli and dike will result in at most 2300 psi of bending stress in the pipe if deflection is considered limited to only the first one hundred ft.
Two inches of settlement have occurred since the attachment of the pipe.
Conservatively, at least three additicnal inctes (figure 0.25 ft.)
of settlement could occur before stresses in the pipe reached the point that additional investigation would be required."
"The settlement of the SMPH is not considered significant with regard to safety of operation of the !! orth Anna power station, nor are the settle-ments enough to require extensive e/aluation, redesign, or repair.
The structure is adequately designed to preclude structural damage due to the settlement, and the external piping has not been overstressed due to rotational movement."
_ Question 22_:
Did fir. Ragone write te Mr "nuth of the !!RC cn or about May 16, 1975, indicating that settlement at liorth Anna at that time was not considered to be a reportable event pursuant to paragraph 50.55(e)(1)?
If so, please attach a copy of that letter.
Answer 22:
Dr. Knuth, Director, Office of Inspection and Enforcement, fluclear Regulatory Ccc.nission, received a letter dated I;ay 16, 1975, from VEPCO signed A" "r.
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- - N r m rubility of the L' orth f.nna pumphouse settle-nn t.
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Ruer. tion 23:
On or about July 24, 1975, did f'r. Sciuencer urite a letter t0 iir. Ragone at VEPC0 to the ef fect that foundation engineering inforeation '
revicued as of that date would not support a conclusion that the reservoir,
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dike, and puuphouse trould reliably perform their design function?
If so, please attach a' copy of that letter.
Ansuer 23:
Yes.
A copy of ~the letter is attached as Exhibit F-1.
Question 24:
On or about August 1,1975, did fir. proffitt from VEPC0 urite a letter to fir. Sciniencer indicating that VEPC0 could not locate the original calculations for the estimated 1.44-inch settlement at !! orth Anna?
If so, please attach a copy of that letter.
Answer 24: A copy of the referenced letter is attached as Exhibit G.
Ruestion 25:
On what date did VEPC0 cmployees or personnel first becone aware of the existcnce of fleuschel'c lineament?
Anstler 25:
Although i;RC does not known uhm VtPC0 employees or personnel first became aware of l'euschel's linearcent, the company knt t of the publication of the following paper in 1970:
fleuNhel, S.K.,1970, f ;rre lation-of Aero-magnetic and Aeroradicactivity with ii.hology in Spotsylvanic area, Virginia:
Geol. Soc. Amer. Bull., v. 81, p. 35,5-3582.
Ruestion 26:
At any time prior t-At>
st 15, 1975, was VEPC0 asked to provide information to substantiate the stability of the I: orth Anna pumphouse?
If so, when were they so asked?
If thcy complied, please attach a copy of their response.
Answer 26:
On April 29, 1975, flRC inspectors requested VEPC0 to submit a lettar describing the events and actions that VEPC0 prcposed to take relative to the pumphouse setticmant.
This request is documented in IE Inspection Report I!os.
50-330/75-5 and 50-339/75-5, which were transmitted to VEPC0 on I:ay 20,1975.
(FxhibitH)
YEPCO responded by letter dated ltay 22, 1975.
(Exhibit I) Also see a letter from Stanley Ragone dated liay 15, 1975 to the f!RC Region II discuss--
the pumphouse settlement.
(Refer to Question 1)
A copy of this report uas als:
sent to f!RC Headquarters by I'r. Ragone as an attachment to a letter dated Itay 16, 1975 (see Questien 22).
Ruestion27_:
Please describe in full the technique Stone and Hebster used to evaluate the soil under the pumphouse and dike prior to August 15, 1975.
Plea 52 indicate the name of the civil engineer primarily responsible for the soils analysis.
Answer 27:
fiRC is uncertain whether or not a certified civil engineer was
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represented Stone arid IIcbster as soils engineer during
. i n.1 ;tiO G n April 29, 1975.
!!e understand that several engineers been designated responsibility for the soils analysis during the design
< onstruction of the dike and pumphouse.
fv", tion 28:
If no certified civil engineer was responsible for soil analysis et leli6rith Anna pumphouse site, please give the name and position of the
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VEI'C0 coployee or any other person primarily responsible for soils analysis at the l' orth Ar.na pumphouse site prior to August 15, 1975.
Answer 28:
Responsibility for soils analyses rests with the ficad of the Geotechnical Capartment, Stone and llebster Engineering Corporation.
Presently, this position is held by Stan Rossier.
_questica 29:
On or about August 15,1975, did f1r. Ragone or another'enployee of VEPC0 write to Mr. Schwencer indicating that the soils under the pumphouse were complex, irratic and anisotropic?
If so, please attach a copy of that letter.
Answer 29.
A copy of that letter is attacheo as Exhibit I-l.
Ruestion 30:
In regard to the settling problem at the Surry nuclear power station. by whom and on what date was llRC first made aware that settling had occurred at the Surry site?
Answer 3rJ.
(Deleted - contains reference to Exhibit J)
Question 31:
On what date war differential settling first observed at the site?
Anstier 31:
The letter referenced in response to question 30 above indicates thet the measurements of settlement were made on February 2,1971.
Subsequent measurc-ments were made on April 20, 1972.
llhether early measurements were made which also revealed settling is not known to llRC.
Question 32:
'lho first observed it, and by whom and in what form was it first reparted to NRC?
Answer 32:
See answers ta questions 30 and 31 above.
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.Y Ounstion 33:
tihen did VEPC0 first report differential settling at the Surry site?
I Answer 33:
following
}iiiC iiiiTiated an investigation on llay 3,1975.
At that time VEPC0 provided the
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inspectors with information confirming Mr. Ilaite's allc3ations.
Question 34:
In what document was it reported? Please attach a copy.
Answer 34:
The results of the l'RC investigation are reported in Investigatien Report Mos. 50-200/75-1 and 50-281/75-1.
Copies of these reports are attached (Exhibit K).
Inspection report has protected the identity of specific individuf:
A code identifying these individuals is gi.ven in response to question 35.
Luestion 35:
In a document entitled Regulatory Investigation Report Office of Inspection and Enforcement, Region II of VEPCO, Surry I and II Site, Reoorts No. 50-280/75-1 and 50-281/75-1, a copy of which was mde available to our office, we note that page 2 thereof indicates that VEPC0 managemnt was aware
.of reactor building settler.ent in excess of those estimat,es shown in the FSAR three years prior to discovery by URC.
Please attach a copy of any document in your possessien which indicate such knowledge on VEPC0's part.
Answer 35:
Investigation Report Nos. 50-2E0/75-1 and 50-281/75-1 (referenced above in aaswer 24) and ralated correspondence indicate that certain individuals in the VEPC0 organization were aware of the settiement at the Surry nuclear station.
The names and titles of indi-.uals identified in the forcgoing re-ports have been kept confidencial.
A code which identifies these individuals
,is attached as Exhibit L.
Question 36:
At page 3 of the aforementioned report, the writer states VEPC0 "llas not in a position to determine what aaditional settlement had taken place or what the differential setticment was, up to the time of the investigation or what may have taken place since the 1972 sur"ey."
Please explain that statcment.
lias it beccuse VEPC0 had not taken any measurements or sufficient measurements after it was aware of the excessive settlem:nt thac the above conclusion was drawn?
Ar$ suer 36:
The MRC investication revealed no settlement measurcnents taken during the period April 20, 1972 through May 8,1975, tne 4 ate on vthich the NRC investigation co menced.
The Stone and llebster findir.gs in the structural settlement study dated September 25,1974 (refer to answer 34 and Exhibit 9 of the referenced investigation reperd are used to support the position that the settlement indicated by the April 20, 9, -.
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,"-li-were oduic.anai se m e.._ns
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.,c stucy.
Const#.ntly, it was not possible at the tiue of the HRC investigation to determine hiiat total structural settlements had occurred.
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i n 37:
Uhat were the original FSAR settlement estimates allowed for ft burry i and 2 plants respectively?
i sLr 37:
There were none.
NRC has not considered settlement at the Surry site to be a problem.
Question 38:
In the NRC's view, is there a reliable r2thod for projecting future settlements at Surry?
Answer 38:
NRC believes that then2 are reliable methods for predicting future settlements at the Surry site.
9uestion 39_:
What total level of settlenant would the agency now consider unacceptable at the Surry Site?
Answer 39:
If total settlement at Surry 1 and 2 should increase from present values o' about 1 1/2 inches to a future value of 21/.2 inches, we would consider this unacceptable.
Question 40:
Uas any Surry FSAR amended to account for excessive settling?
Answer 40:
ilo.
NRC is not in possession of evidence of excessive settlement at Surry.
Question 41; On or about flay 6,1975, did llRC Region II receive a phone call from a " confidential infomant" regarding abnonnal satling at Surry?
Answer 41:
Yes.
(Seeanswer30.)
Question 4?;:
If there was such a phone call frcin a " confidential informant",
was this the first knowledge that NRC had-received regarding settling at Surry?
Answer 42:
Yes.
Question 43:
Please describe the Richmond Fall Line and explain how it is rclated to the problem of settling at Surry.
Answer 43:
The Rich-1 Fall Line is an unfamiliar tenn.
The Fall Line is the boundary between t : ancient and sesistent crystalline rocks of the Pied cnt Plateau and younger and softer sedir.:ents of the Atlantic Cor.stal Plain in the eastern United States.
The Fall Line would have no relatica to the problem of settling at Surry.
Questien _44_:
Can the Richmond Fall Line be properly described as a " hinge i...e An_swer 44:
No, the Fall Line cannot be geologicaily described as a " hinge
.line."
307 312
r, Please define the term " hinge line."
.ign45:,
.rkS:
A hinge line (struc geol) is defined as a line or bcundary nvu ent.
':Ec'n a stable region and a region undergoing upuard or down'.:.rd lIn Pleistocene geology, it is the boundary between regions undcrgoim.; post glacial uplift anu those of no uplift.
Question 46:
In regard to the Iorth hina site, are there any nining activities contemplated?
Ar.:wcr 46:
The Piedmont Mineral Associate is interested in an area near Ioute 522 and Contrary Crcok approximately 4 miles from the site.
The Associate is prospecting for zinc.
Question 47:
Do you have a copy of a Stone & Uebster report entitled POIE!!ili.L RLSERVOIR LEAVAGE DUE 10 tiltill:C EXCAVATIGil Af!D DEEP UELLS --
IMPS /VEPCO?
If so please foruard a copy of that report.
Answer 47:
A copy of the recuested report is attached as Exhibit M.
Questien 40:
If mining and/or excavation is contemplated at the site, uhat geological analyscs and precautions have becn taken to establish that no adverse effect will accure to any fiorth Anna reactors?
Answer 40:
Ths exclusion area of the I: orth Anna site is "4,427 feet to the cast of the center of the Unit 1 containment structure and 5,000 feet to tu vest of the center of containr.ent of a Unit 4", and "The applicant owns in fee sinple all the land in the exclusion area."
(FSAR, Units 1 and 2).
Thus, the applicant can prevent uny mining activity from being performed within the exclusion area.
Question 49:
Do you have documentation in the form of an AEC compliance re;crt datcd June 1970 describing unstable strata at the Iorth Anna Unit 1 excavation site?
If so, please forward a copy of that report.
Answer 49:
A search of f!RC files does not reveal any compliance report regardiTj unstable strata in Jur.e of 1970.
A refercnce to unstable strata was 1 in Compliance Report Nos. 50-333, 339/70-1 which was forwarded to headquarters on !! arch 26, 1970.
That report is attached as Exhibit ff.
etail the factual basis, including a.
Question 50:
Please describe in d
~~Te Egical testing aad results, up. which a conclusion raay have been reached g
by f;RC or its predecessor that mining in the area would not be hazardous.
Answer 50:
The seismologist contacted Picd:ront to determine the maximum
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This turned out to be 400
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indicated that the resulting ground motion at the reactor site would be several orders of magnitude smaller than those for which the units are designed.
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1.'as there a hearing of the Atomic Safety and Licensing Board
- m. Ler of 1970 regarding I: orth Anna or Surry?
.: r 51:
A Prehearing Conference was held In the Matter of Vir jinia i...tric~and Po'.ler Company (l:$rth Anna Power Station, l' nits 1 & 2) on N r. weber 4,1970 followed by hearings on llovember 23-25, 1970.
0:estion 52:
If so, please attach a transcript of. that hearing.
Ans'.er 52:
Pursuant to agreement bettieen A~Ifred T. Chiorzi, Chief, Pollution Control Section, l.and and Iatural Pesources Division, Department of Justice and llilliam J. Olmstead, Of fice of the Executive Legal Direct ( r, l'uclear regulatory Conmission on April 12, 1975, the transcript will be made available for inspection on request.
Hor:ever, due to the bulk of the transcript, it will not be reproduced for transmittal as an attachment to these responses.
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AFR 2 6 G?B Docket Io. 50-338
!!EMOPJdDUlf FOR:
J. Carl Stepp, Chief Geoscience:, Branch, DSE FRO'!:
L. W. liclier, i.cader Geotechnical Engineering Section
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Ceosciences Branch, DSE VISIT TO I;0RTil ANNA - GEOTECHNICAL ENGINEERlflG
SUBJECT:
On April 13, 1978, Mr. Daaiel !!. C111cn and the undersigned visited the 1 and 2 subject plant to check on roported (1) settlements of'the Unit service water pond pumphouse, (2) silt clogged dewatering pumps, and to get an up-dato on (3) pienometer readings (4) performance of horizontal drains (5) settlenent of spray pond piping, and (6) rock anchor on units 3 and 4.
An attendance list is attached.
VEPCO's technical specificaticus for settlement nonitoring require reuedial, :,ns whenever actual set rienent beco.:es 75 percent of the allewabic se tiement. (License Authority, License and Technical File 1, Volume 1, pages 3/4 7-70, -71, -72,.and Specifications, pages B 3/4 7-7, -8).
The punphouse settlement has nou reached 75 percent of the value predicted in Decenber of 1975 and VEPCO is beginning to prepare remediat plans.
The total settler.cnt, however, is less than half the limi'. or the flexibic (.onnection (3 inches),
and the differential settlement is much less than hcif this limit.
The pumpheuse cont?r.ucs to tilt in the northwest direction.
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reasons for the silt clogged reactor mat dewatering punps remains Th2 indeterminant at this time. VEPCO expects their investigations will take another month or so before conclusive evidence of the source of the silt can be gathered.
Pienemeter readings on 4/4/78 are as follows:
No. 11 - less than 273.4 ft, No. 12 - 272.8 ft, No. 13 - 275.3 ft, and No. 14 - 271.6 ft.
Although from these piezameters are doubtful, they exact groundwater elevations appear consistent and relicabic enough to detect any malfunction of the The horizontal drains have been in p] ace for puuphouse drain system.
nearly 8 nonths and ire perforning satis fact >rily; soce routine cheutcal cicaning may be scheduled in the future.
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t Ic _nt of piping in the spray nond due to loads imposed by
If ng t he pond varied from -0.02 (a rf se or rebound) to 0.14 ft. as of February 15, 1978.
The nm<imum settlement gradient g rears to be on the order of 0.004 f t/f t.
ihe rock anchors for units 3 and 4 are used to tie foundations to the uaderly!ng rock.
The anchors prevent homering of one building on another during an carthquake.
The anri ors are not accded or desic.ned to resist uplif t on structures caused by groundeater beneath the nats.
lU. ),f
< u. u Ly aan W. IIeller, Leader Geotechnicol Engineering Section Geosciences Branch Division of Site Safety and Environmental Analysis cc:
- 11. Denton R. Boyd W. Cammill J. Knight J. Stepp R. Bornak K. Desi L'.
lieller D. Gillen O. Parr D. Vassallo A. Droncrick PDR 307 316
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All Et'D3.'U l.151 i,
i Vf.I CO !!f EI!!:G 4/ I 3/73 AT f utIli A' '!A FA' E AfFILiAT10!{
01 SC IPL li;E TEL FriiO!!E t:0.
Lyr:un licI ler U. S. t!!<C Geofech. Engr.
301-492-7973 Daniel M. Gillen U. S. i;l(C Geofech. Engr.
301-492-7972 Carroll G. Chewning VEPCO Ass t. Project Engr.
804-771-3374 Surendra II. Furohit-S&W Lead Engineer (Engineering l'echanics)
R. B. Drodbury S&W Project Engr.
C. f4. Robinson,.f r.
VEPCO Civi! Engineer.
804-771-3894 Rrbert f4. f!cil VEPCO Licensing Engineer 804-771-4494 E. f.. Brown VEPCO Civil Engineer 804-771-3736 Ch:ef Geofech. Engr.
A. S. Lucks S&W B. fl. MacIver S&W Senior Soils Engineer W. B. Dodson S&W Project Engr.
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t 307 317
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