Text

Forwards Addl Portions of NRC Staff Testimony Re Pumphouse Settlement
	ML19259C462
Person / Time
Site:	North Anna
Issue date:	05/04/1979
From:	Swanson D; NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD)
To:	Buck J, Mike Farrar, Rosenthal A; NRC ATOMIC SAFETY & LICENSING APPEAL PANEL (ASLAP)
References
	NUDOCS 7906220125
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NUCLEAft ilEGULATORY COMMisslON 1

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200M Alan S. Rosenthal, Esq., Chairman Michael C. Farrar, Esq.

Atomic Safety and Licensing Appeal Atomic Safety and Licensing Appeal Board Board U.S. fluclear Regulatory Commission U.S. fluclear Regulatory Commission Washington, D.C.

20555 Washington, D.C.

20555 Dr. John Buck Atomic Safety and Licensing Appeal Board U.S. fluclear Regulatory Corrmission Washington, D.C.

20555 In the Matter of Virginia Electric and Power Company (florth Anna fluclear Pewcr Station, Units 1 and 2)

Docket flos. 50-338 OL and 50-339 OL Gentlemen:

Enclosed are the following additional portions of the "flRC Staff Testimony Regarding Pumphouse Settlement", which was sent to you by letter dated April 27, 1979:

1)

Revised " Table of Contents", which supersedes the original Table; 2)

Section 6 entitled " Stress Analysis";

3)

Section 7 entitled "Other Concerns";

4)

Section 8 entitled " Response to Mrs. Allen's Concerns";

5)

Revised second page of references, which replaces the original second page; 6)

Appendix C which is a letter from J. O'Reilly of Region II of the Office of Inspection and Enforcement to VEPC0 dated April 25, 1979, with Inspection Report No. 50-338/79-13 also attached; 7 906 220/M

, 7)

Professional qualifications of E. Gunter Arndt and Jared S. Werniel; and 8) flotice of Appearance of lienry J. McGurren.

The addition of the above-stated material completes the Staff's prefiled direct written testimony in response to ALAB-529.

Sincerely, 0 mal 7 /Ae Daniel T. Swanson Counsel for flRC Staff

Enclosures:

As stated cc w/encloseres:

Se,rvice List

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING APPEAL BOARD In the Matter of

)

VIRGINIA ELECTRIC AND POWER COMPANY

)

Docket Nos. 50-338 OL

)

50-339 OL (North Anna Nuclear Power Station,

)

Units 1 and 2)

)

CERTIFICATE OF SERVICE I hereby certify that copies of " Notice of Appearance" for Henry J. McGurren and additional portions of the "NRC Staff Testimony Regarding Pumphouse Settlement" which includes:

1) Revised Table of Contents;

2) Section 6 entitled " Stress Analysis";

3) Section 7 entitled "Other Concerns";

4) SeGtion 8 entitled " Response to Mrs. Allen's Concerns";

5) Revised second page of references;

6) Appendix C which is a letter from J. O'Reilly of Region II of the Office of Inspection and Enforcement to VEPC0 dated April 25,1979, with Inspection Report No. 50-338/79-13 also attached; and

7) Professional Qualifications of E. Gunter Arndt and Jared S.

Wermiel all in the above-captioned proceeding have been served on the following by deposit in the United States mail, first class, or, as indicated by an asterisk, through deposit in the Nuclear Regulatory Commission's internal mail system, this 4th day of May,1979:

Alan S. Rosenthal, Esq., Chairman

Dr. Paul W. Purdom, Director Atomic Safety and Licensing Appeal Environmental Studies Institute Board Drexel University U.S. Nuclear Regulatory Commission 32nd & Chestnut Streets Washington, D. C.

20555 Philadelphia, Pennsylvania 19104 Dr John Buck

Mr. R. B. Briggs Atomic Safety and Licensing Appeal 110 Evans Lane Board Oak Ridge, Tennessee 37830 U.S. Nuclear Regulatory Commission Washington, D. C.

20555 Michael W. Maupin, Esq.

Hunton & Williams Michael C. Farrar, Esq.*

P. O. Box 1535 Atomic s a fe ty an l l icensino rmo il Richmond, Virginia 23212 Board U.S. Nuclear Regulatory Commission Washington, DC 20555

Ellyn R. Weiss, Esq.

Richard Foster, Esq.

Sheldon, Harmon, Roisman 1908 A. Lewis Mountain Road

& Weiss Charlottesville, VA 22903 Suite 500 102515th Street, N.W.

Mr. Jamer M. Torson Washington, DC 20005 501 Leroy Socorro, New Mexico 87801 Mrs. James C. Arnold Box 3951 Mr. Dean P. Agee Charlottes, Virginia 22903 Executive Secretary Board of Supervisors John J. Runzer, Esq.

Louisa Courthouse Pepper, Hamilton & Scheetz Louisa, Virginia 23090 123 South br oad Street Philadelphia, Pennsylvania 19109 Atomic Safety and Licensing Board Pa nel

Dr. Venneth A. McCollom.

U.S. Nuclear Regulatory Commission Assistant Dean Washington, DC 20555 College of Engineering Oklahoma State University Atomic Safety and Licensing Appeal Stillwater, Oklahoma 74074 Panel (5)*

U.S. Nuclear Regulatory Commission Anthony Gambardella, Esq.

Washington, DC 20555 Of fice of the Attorney General 11 South 12th Street Room 308 Docketing and Service Section (3)*

Richmond, Virginia 23219 Office of the Secretary U.S. Nuclear Regulatory Commission Mrs. June Allen Washington, DC 20555 412 Owens Drive Huntsville, Alabama 35801 M's. Margaret Dietrich Moute 2, Box 568 Gordonsville, Virginia 22042 William H. Rodgers, Jr., Esq.

Georgetown University Law Center 600 New Jersey Avenue, N.W.

Washington, D. C.

20001 o +.u M.E _.-+ d: % v. 4 Daniel T. Swanson Counsel for NRC Staff

f TABLE OF CONTENTS Page A.

Background and Introduction................

1 B.

Responses to Specific Appeal Board Concerns........

7 1.

Relationship,to Public Safety 8

2.

Settlement History.

li

3. ' Soil Mechanics....................

16 4.

Dewatering...................... 20 5.

Monitoring......................

32 6.

Stress Analysis 35 7.

Other Concerns.................... 43 8.

Response to Mrs. Allen's Concerns 49 C.

Attachments

e

~ '

6.

Stress Analysis ALAB Question: The Appeal Board asked for a discussion of the topic of stress analy.c ss, and to indicate the impact of varying amounts of settlement.

They asked for a description of the types of loads assumed and methodology used in analyz-ing stress limits for service water piping and whether stresses due to the apparently greater settlement of pipes relative to that of the pumphouse are included in the analysis.

They asked the staff to (a) provide a full justification for selecting the differential motion limit of 0.22 feet between corners of the north side of the pumphouse and the expansion joint, and explain how this satisfies the staff's concerns on stress limits in the flexible couplings, (b) explain how li,miting the absolute elevation of the exposed ends of the expansion joints to 0.22 feet (measured from August 3,1978)

~

satisfies the staff's concerns on stress limits in the buried pipes, and (c) set forth the basis for choosing 75% of the limit as the level which triggers the reporting requirement for all established limits.

Response

The Staff reviewed VEPC0's proposed testimony regarding the assumed loads and methodology used in analyzing stress limits for service water piping.

The Staff does not disagree with these aspects of VEPC0's testimony.

The objectives of the staff's evaluation of allowable settlement limits were to assure during the period of plant operation, that the stress levels in the service water piping did not exceed the allowable values defined by the ASME Boiler and Pressure Vessel Code,Section III, and that the movement of the expansion joints in the service water lines did

not exceed the design values of the expansion joints.

The following paragraphs address the Appeal Board's specific questions and contain the staff's explanation of the basis for satisfying the stated objectives.

a)

Justification of Differential Motion Limit In the following discussion, the staff uses the term differential motion to mean differential motion between either corner of the north side of the p_phouse and the exposed ends of the pipes that are buried in the gravel filter portion of the dike fill.

The limiting value for differential settlement after July 1977 (0.22 ft.) was developed in the manner described in this and the following paragraphs. Although VEPC0 has indicated other dates, we have conser-vatively assumed that the flexible joints were installed in December 1975, thereby setting that date as the initial reference point for settlement of the north wall of the pumphouse.

The July 1977 date was chosen as the first measurement of the pipes because this is the date that marks SM-15,16,17, and 18 were established on the pipes; no settlement readings were made on these pipe ends prior to July 1977.

Accordingly, no computations of the differential settlement between SM-7 or 10 and SM-15 through 18, based on direct measurements, could be made for the period December 1975 to July 1977.

The approximate settlement of SM-15 through 18 can be established, however, by assuming that the top of the dike near these markers settled the same amount as the exposed ends of the pipes embedded in the dike.

The settlement values for the top of the dike near tM:e pipes (ASM-5) and for SM-7 and SM-10 are given in Table A.

' During the period December 1975 to July 1977, the top of the dike settled 0.079 feet (the locations of SM-15 through 18 were assumed to have settled the same amount), SM-7 settled 0.046 feet and SM-10 settled 0.089 feet.

Thus, the estimated differential settlement across the joint that occurred during this time period was between 0.033 feet (0.79-0.046) and -0.010 feet (0.079-0.089). A value of 0.03 feet was conservatively chosen to represent the differential settlement of SM-15, 16,17 and 18 with respect to the north side of pumphouse during this period of time.

Information from the flexible coupling manufacturer' indicates that the couplin'g is designed for a lateral movement of one end with respect to the other end of 0.25 feet (neglecting twist about the axis of the coupling and rotation of the ends of the coupling in the axial plane).

(Ref.11, p.4).

The limiting differential settlement between mark'ers SM-7 or SM-10 and any marker SM-15,16,17 and 18, after July 1977 is the joint design limiting differential settlement (0.25 feet) when the flexible joint was installed (December 1975) less the differential settlement estimated to have occurred (0.03 feet) during the period December 1975 to July 1977.

This difference (0.25-0.03) is 0.22 feet.

In summary, then, because the expansion joints were designed to accommodate 0.25 ft. of movement without exceeding stress and fatigue limits in the joints, and because we conservatively estimate 0.03 feet of differential settlen:ent has occurred aince the joints were installed, the staff's

concerns about stress limits in the flexible coupling are satisfied with the differential limit of 0.22 ft.

b)

Stress in Buried Pipes The staff assumes that the Board's question refers to the absolute settle-ment of the exposed ends of the expansion joint rather than their absolute elevation.

On August 2,1978, VEPC0 informed the staff that it had concluded that 0.33 feet of additional settlement since December of 1975 would not overstress the buried pipes (Ref.10, p.10). As a rough check of this conclusion, tie staff made the conservative simplifying assumption l

that the pipes could be modeled as being rigidly anchored in the soil at a point' 60 feet from the exposed ends and that the deflected shape of the pipes due to dike settlement is the same as a cantilever beam with a concentrated load at its end.

For such a model, the maximum moment and deflection are (Ref.18):

M = P1 3

y = P1 /3EI where M = maximum bending moment, lb-in P = concentrated load, lb 1

= length of beam, in y = maximum deflection, in E = modulus of elasticity (Young's modulus), psi 4

I = moment of inertia, in The maximum bending stress is defined by the following (Ref.18, p.513):

c = Mc/I where c- = maximum bending stress, psi c = distance from netural axis to extreme fiber (outer surface), in

Combining the above equations yields an expression for the maximum deflection of a cantilever beam, with a point load at the end, as a function of the maximum bending stress at the section with the maximum bending moment:

2 y = el

/3Ec Although the value of the modulus of elasticity varies with the compo-sition of the material and the temperature, a commonly used value for carbon steel (such as the SA-155 used for 'the service water piping) at 6

normal temperatures is 29 x 10 si.

The distance between the neutral axis and the extreme fiber for 36 inch (3.0 ft.) pipe with a 3/8 inch (0.03 ft. ) wall thickness is 18.375 inch.

Using these values and the 60-foot (720 in.) length of the pipe yields:

y = d~/3084 For the SA-155, Grade C5, material used in the service water pipe, Table I-7.1 and ND-3652.3 of Section III of the ASME Code would permit an allowable stress of 41,100 psi for the effect of any single nonrepeated anchor movement.

Stresses in the pipes due to friction forces of the fill on the p pe were estimated at about 4,000 psi by assuming the pipes were buriei 12 feet deep in a fill with a unit weight of 120 pcf and a friction co-efficient (with steel) of 0.6.

Allowing 4,000 psi for friction loads in t..a pipe leaves a limiting stress of 37,100 psi which equals a maximum deflection of 12.03 inches or 1.00 feet.

The pipe stress caused by the friction forces along the deflected pipe were conservatively neglected in this rough check.

The next step in estimating the limiting additional displacement of the end of the buried pipes was to determine the displacement that had occurred since the pipes were buried in the fill. We conservatively assumed that the pipes were rigidly connected to the pumphouse at the elevation shown in the FSAR (Ref. 8), that this elevation was correct as of August 25, 1972, and that no pumphouse settlement had occurred prior to the time the pipes were connected.

The center line of the horizontal portion of the exposed pipes is at an elevation of 320 ft. - 10 inches (320.83 feet) (Ref. 8).

The elevation of the top of the pipes would be 322.36 ft. (320.83 + 1.50 + 0.03) at the time.they were attached to the pumphouse.

VEPC0 provided the follu -

ing elevations for the pipe ends, as measured on August 3,1978:

SM-15:

321.658 ft.

SM-16:

321.661 ft.

SM-17:

321.778 ft.

SM-18:

321.591 ft.

Settlement of pipe SM-18 (the one that apparently settled the most) between the time it was assumed to be buried and attached to the pumphouse and August 3, 1978 was thus 322.36-321.59 = 0.77 ft.

Thus, settlement of the ends of the pipes at markers SM-15 through 18 necessary to reach code allowable stresses was estimated at about one foot and past settlements accounted for 0.77 ft.

Therefore, the ends could settle an additional 0.23 ft. (1.00-0.77) without exceeding code allowable stresses in that portion of the service water pipes buried in the dike fill just to ue nortn of the service water pumphouse.

she above steps led us to recommend that the allowable absolute settle-ment of the ends of these pipes, after August 3,1978 be limited to 0.22 f t. to keep the buried pipe stresses below code allowable values. The staff believes this value of 0.22 ft. is conservative.

New information in VEPCO's Testimony on Service Water Pump House Settle-ment indicates that the service water lines were embedded in the coarse dike filter on August 27, 1973 (Figure 78).

Therefore, stresses induced in the service water pipes due to settlement of the dike would have started on August 27, 1973 rather than, as we had previously understood, on August 25, 1972. According to information provided by VEPC0 to the Staff in' a letter dated September 8,1978 (Table 1 of Reference 3), the northeast corner of the pumphouse had settled 0.15 ft. by August 23, 1973. Assuming that the dike settled as much as the least settlement recorded on the northeast corner of the pumphouse between August 25, 1972 and August 23, 1973, the allowable settlement of there pipes might be increased to 0.37 ft. (0.22 + 0.15) without exceeding code limits for stress in the service water pipes. Accordingly, the staft

tlieves that there is additional basis to believe that the 0.22 ft. limit is conservative.

In summary, then, we have conservatively estimated the stresses in buried pipes induced by the settlement of the service water reservoir dike. We have found that additional settlement of the dike and embedded pipes in the amount of 0.22 ft. after August 3,1978 can be sustained without exceeding Code Allowable stress values. We believe that the technical specification for el,rt operation, which gives the allowable

limits of settlement of the exposed ends of these buried pipes, is adequate to satisfy staff concerns regarding stress in these pipes.

c) 75 Percent Reporting Requirement The requirement that VEPC0 report to the staff when settlement reaches 75% of the limits set in the techr.ical specifica

'is was proposed by VEPC0.

It was accepted by the staff because it was judged to provide adequate time for remedial safety-related actions prior to reaching settlement values that would affect safety or plant operations.

The staff would probably have accepted reporting values ranging from 60 to 80 percent, because the same objective would have been attained with those limits.

d)

Frequency of Monitoring Settlement of Service Water pumphouse The Technical Specifications for Unit 1 require that the Category I safety related structures be surveyed every six months to assess settle-ment.

VEPC0, however, is continuing to monitor the settlement of the Service Water Pumphouse every month. The staff concurs with VEPC0's practice.

The Unit 1 Technical Specifications for monitoring groundwater elevations near the pumphouse and beneath the service water reservoir dikes call for monitoring every month for the first five years of plant operation.

The staff believes that the frequency of monitoring settle-ment near the puaphouse should be the same as that now prescribed for measuring groundwater levels and drain flow rates. Accordingly, measure-ments on settlement markers SM-7, 8, 9,10,15,16,17,18, H-569, and H-584 should be made at least once every 31 days until Unit 1 has been

in operation at least five years.

Based on the past record of rates of pumphouse settlement and the expectation that the dr'ains will reduce the potential for rapid settlement, a one-month interval is often enough to provide adequate warning that settlement limits given in the Technical Specifications are being approached.

At the end of the 5-year period, an engineering study will be made by VEPC0 to determine the need for and frequency of continued monitoring of settlement, groundwater and drain flow rates.

7.

Other Concerns In its January 9,1979 submittal to the Appeal Board, the staff identified certain items of concern with respect to service water pumphouse settle-ment effects.

These items are addressed in the following sections.

a)

Differential Movement and Tilt of Pumphouse - Effects on Pipes This item is discussed in Section 6 of this testimony.

b)

Tilt of Pumphouse - Effect on Pumps The second concern, pumphouse tilting effects on the service water pumps, is addressed in the response to question P3.6 cf tne Final Safety Analysis Report.

VEPC0 has stated that the pumps will be shimmed, as necessary, to correct for any pumphouse tilt so that the pump alignment is within the 0.011 inches per foot recommended by the pump manufacturer.

This corresponds to a total allowable displacement of 0.29 inches for the 26-foot long vertical pump.

The manufacturer has also indicated that a total divlacemen; or U.5 inches would not adversely affect pump operabili ty.

In addition, VEPC0 is measuring differential pressure, flow rate and vibration amplitude every 30 days as required by Article IWP-3000 of Section XI of the ASME Code.

These pump performance parameters are to be maintained within the tolerances specified in Table IWP 3100-2 of Section XI, except that for the flow rate parameter, a tolerance of +8 percent is acceptable.

If necessary, corrective action will be taken as required by paragraph IWP-3230 to assure the required pump performance.

Maintaining the pump performance parameters within the specified tolerances provides adequate assurance that the pump will maintain its operability and that any effects of tilt will be accounted for.

c)

Stress in Buried Service Water Pipes This matter is also discussed in Section 6 of this testimony.

d)

Leakage of Service Water Through Shears With respect to the fourth concern, the Final Safety Analysis Report indicates that the bottom of the service water reservoir was lined with compacted cohesive soil to impede leakage of reservoir water into the underlying saprolite. The FSAR indicates that the pumphouse foundation is supported by the compacted liner material.

As the pumphouse settles with respect to the liner, it punches into the liner material, as evidence by the past relative movement of the pumphouse with respect to the wingwalls.

A VEPC0 letter to the staff dated September 8,1978, includes an analysis of reservoir leakage potential due 'o bending of the liner.

We have concluded that the lack of potential for leakage has not been

demonstrated and would be difficult to demonstrate and, therefore, have conservatively postulated that leakage will occur during the plant 1i fetime.*

Leakage of the reservoir liner will contribute to the quantity of water collected by the underdrain system and will change groundwater levels measured by piezometers. Technical Specification 3/4.7.13, which gives the present groundwater level monitoring program and limiting ground-water levels in the vicinity of the service water reservoir, is closely related to Technical Specification 3/4.7.12.

Groundwater monitoring as presently required by the Technical Specification is to be conducted monthly'for the first five years after the issuance of the Unit 1 Operat-ing License.

Adequate assurance that leakage will not be undetected and affect safe operation of the plant can be attained by changing Technical Specification 3/4.7.13 to require:

(a) measering and recording the quantity of groundwater flowing from the underdrains on a monthly basis for five years; if flow rates for any month become more than three times the aver ige annual flow rate, an engineering evaluation of the cause of the changed flow rates should be conducted and a report filed with the NRC; (b) monitoring and recording groundwater elevations on a monthly basis for a period of five years; and (c) at the end of the five-year period, requiring an engineering report to be filed by VEPCC to deter.line if further measurements of groundwater levels are needed. A required

As discussed in Section 4 of this testimony, we could not visually confirm the presence of a liner along the sides of the pumphouse (p.29).

However, tecause we have c;;tui tad ledage of the lirar under the pumphouse, the exis tence or w 'i:.ar it not critioi.

. revision to Technical Specification 3/4.7.13 covering the above matters is presented in the proposed technical specifications included as an dttachment to VEPCO's testimony.

e)

Potential for Cracking of pumphouse The potential for significant cracking of the reinforced concrete pumphouse structure due to future differential settlement across the structure is likely to be preceded by warping of the pumphouse foundation. Available measurements and visual inspection by the licenseeindicates that very little, if any, warping has occurred to date and that only nominal cracking is now evident.

Because of the relatively soft foundation provided by the clay liner and underlying saprolite and the stiffness of the pumphouse foundation slab, significant differential settlement across the structure is unlikely.

However, an out-of-plane distortion of any corner of the pumphouse foundation of about 0.06 feet would indicate the onset of additional cracking in the structure. The potential for crack development can be interpreted by analyzing measurements at settlement points SM-7, 8, 9, and 10. We have concluded that the out-of-plane distortion of any corner of the pumphouse foundation should not exceed 0.06 feet in order to limit the width of cracks. A required revision to Table 3.7-5 of the Technical Specification is presented in the proposed technical specifications attached to VEPCO's testimony.

The 75 percent Technical Specification reporting criteria would apply to this limit.

. f)

Effect on Spray Piping Connections The effect on spray piping connections at the service water pumphouse from further settlement of the pumphouse has been reviewed with VEPCO's technical personnel and representatives of the Stone & Webster Engineer-ing Corporation.

The staff understands that one end of the four 35-foot long pipes supplying the spray system was rigidly connected to the pumphouse wall with concrete above the reservoir bottom in the spring of 1975.

During June of 1975, the other end of the 24-inch-diameter pipes was supported above the reservoir bottom by a hanger and footing resting on the clay liner of th'e reservoir.

To reach the American Society of Mechanical Engineers Boiler and Pressure Vessel Code allowable stress in these pipes, the differential settlement (as calculated by VEPC0 and reviewed by the staff) between the southeast corner of the pumphouse and the hanger would need to be 0.175 feet.

Tables A and B, attached to this testimony, show that the differential settlement between marker SM-8 and either H569 or H584 has been essentially zero during the period of time from early August 1976 to late April 1978.

This evidence suggests that the differential settlemen' between the ends of the pipes has been negligible since June of 1975, when the ends of the pipes were tied down.

Accordingly, in order to assure that future pipe stresses will not exceed Code allowable values, the differential settlement between marker SM-8 at the southeast corner of the pumphouse and markers H-569 and H-584 at the pipe support hanger should not become greater than 0.175 feet since the hangers were installed in June 1975.

g)

Inservice Testing of the Auxiliary Water Pumps Our January 9,1979, submittal to the Board indicated'that we had pre-viously granted VEPC0 a 20-month relief from the inservice testing of the auxiliary service water pump for Unit 1.

This relief was based on the fact that:

1) testing would result in untreated (Lake Anna) water being discharged into the service system; 2) four similar pumps (the service water pumps) would be tested monthly; 3) VEPC0 committed to perform a study of methods to permit testing; and 4) the pre-operational testing of the pumps was successful.

We concluded our January 9,1979, presentation to the Board by indicat-ing that the staff would require VEPC0 to provide an acceptable method of inservice testing of the auxiliary service water pumps at the end of the 20-month period of relief.

Subsequent to our presentation, VEPC0 sumitted its inservice testing program for Unit 2.

This program, submitted with their letter of Janu-ary 31,1979, did not request relief for the auxiliary service water pump on Unit 2.

Recent telephone conversations between the Staff and VEPC0 have indicated that they have determined that the chemical content of Lake Anna has changed sufficiently to permit the use of untreated Lake Anna water in the service water system during periods of inservice testing of the auxiliary service water pumps.

It is the staff's under-standing that this information will be confirmed in a forthcoming letter from VEPCO.

Thus, monthly inservice testing of the auxiliary service water pumps appears to be noir fmible for Unit 1, also.

In addition to

49 -

providing the bases for the change in position, VEPC0 will also propose beginning the inservice testing for Unit 1 at the same time as it will begin for Unit 2, i.e. when it is licensed.

The licensing of Unit 2 is currently scheduled for June 1979 and testing will be monthly thereafter.

Coupling the start of the two inservice testing programs will permit an orderly implementation of the procedure and is acceptable to the Staff.

If the issuance of an operating license for Unit 2 is delayed, we will require that r.onthly inservice testing of the Unit 1 auxiliary service water pumps be initiated during the first refueling of Unit 1.

The staff concludes that this resolves the previously noted concern with respect'to the inservice testing of the auxiliary service water pump for both Units 1 and 2.

8.

Response to Mrs. Allen's Concerns ALAB Request: The Appeal Board asked that the testimony pre-pared by the parties contain sufficient information to address the concerns that the North Anna Environmental Coalition (NAEC or Coalition) has posed in its written communications which the parties believe are legitimately significant and relevant to the pumphouse settlement issue (ALAB-529, Slip op.11, n.10).

These concerns as well as the responses to these concerns are set forth below.

Coalition Question: The Coalition has questioned the effectiveness of the drain system as a means of protecting the pumphouse.

Staff Response:

Section 4 of this testimony addresses this question in some detail.

Coalition Question: The Coalition asked whether any other nuclear plant had been required to install a comparable system of remedial drainage and if so, where is it located, and what has been its experience to date?

Staff Response: Some nuclear power plants have proposed ground water con-trol systems for their sites.

For example, a ground water control system was proposed by the application and has been found acceptable for use on the Perry nuclear plant.

We are not aware of the required installation of a groundwater control system at any nuclear plant that is comparable to the one proposed for th,e North Anna Power Station, Units 1 and 2, service water pumphouse.

Horizontal drains, based on the same principles as the proposed North Anna system, have been used for decades to reclaim swampy land for agricultural uses; clay tile is commonly specified for this purpose.

Coali tion __ Question: The NAEC inquired about the length of time the staff specified as an adequate pre-operational testing period for the drainage system at North Anna.

Staff Response: No pre-operational testing period has been specified for the above system because future environmental conditions over any speci-fied time period are not known.

Piezometers will be read at scheduled intervals and used to measure the effectiveness of the system over the life of the plant.

If the system is, or becomes inadequate, it can be replaced or supplemented with negligible risk to the health and safety of the public.

Pre-operational testing is thus unnecessary.

. Coalition Question: The flAEC asked what specific measures will fir.C take if the drainage system fails after the florth Anna operating license is granted.

Staff Response:

If the drain system fails (becomes clogged), the f1RC will require it to be purged or otherwise cleared so that it will again limit groundwater levels.

If the proposed drains transport fines from the saprolite, they can be abandoned and replaced with a redesigned system.

Coalition Question: The Coalition asked if it had been experimentally determined yet at florth Anna whether controlling groundwater levels will prevent settlement or cause settlement beneath the service water pumphouse.

Staff Response: The explicit answer to the Coalition question is no, beca:Jse the groundwater control system has not been in service long enough to predict its effect over the life of the plant (say 40 years).

In theory, if the :.ater table is about 274 feet elevation when the horizontal drains

. are installed, the drains will lower the water table and cause an incre-ment of pumphouse settlement due to increased effective stresses.

However, this increment of settlement would be no more than would be experienced by a natural seasonal decrease in water table elevation to an elevation of 274 feet.

In theory, if tl. water table is at or below 274 feet when the drains are installed the drains would not cause any change in effective stress and no increment of settlement due to the drains would be expected.

The drains should reduce the total settlement of the pumphouse over the li fe of t ho plan t l'ecm mo 1 nuctuation of groundriater levels will be reduced.

. Coalition Question:

Coalition has asked how florth Anna's design can with-stand possible lack of integrity in saprolitic foundation.

Staff Response:

Section 3 of this testimony addresses the Coalition's question in some detail.

As mentioned in Section 3, appropriate engineering tests have been per-formed on the saprolitic soils which exist at the t' orth Anna site.

Labora-tory tests on undisturbed specimens (representative of in-situ foundation materials) and on reconstituted specimens (representative of engineered fill material used to construct the dikes and dams) of these saprolites show that this material has adequate strength to satisfy the design con-ditions imposed by the plant facilities.

The occurrence and compressibility of the in-situ saprolite and weathered rock beneath the pumphouse make future predictions of settlement and differential settlement of these structures complex and possibly imprecise.

Future cettlement, however, will occur slowly and upper bound values of settlement rates and magnitude can be based on past and continuing settle-ment measurements.

We believe that a conscientious, complete and diligent program of settlement monitoring, interpretation, and plan-for remedial action will provide adequate safety from the effects of past and future settlement of the pumphouse.

The design of the groundwater control system is compatible with the properties of the saprolite such that piping of fines from the saprolite should not occur as water drains frca it.

If pping of the fi nc, l ;i: ',

some time in the future, a large increase in the turbidity and suspended

. solids content of the effluent from the system would occur.

As a pre-caution VEPC0 will monitor the effluent for suspended solids and turbidity.

Monitoring will provide sufficient warning on the onset of any piping so that remedial action can be taken before unsafe conditions can develop.

Coalition Question: The Coalition asked on what experiential or experi-mental basis can predictions be made about the future course of settlement at North Anna.

Staff Response: The main basis for predicting the future course of settle-ment at the North Anna Power Station, Units 1 and 2, will be the record of past settlements.

Coalition Question:

The Coalition has asked what studies the NRC has done of the possible relationships between microseismic activity, regional faulting (Neuschel's Lineament, Stafford faulting et al), and the weakness of saprolite as a foundation material.

Staff Response: Microseismic activity, and any regional faulting together with other geologic and tectonic factors have been taken into account in determination of the safe shutdown earthquake.

There is no evidence whatsoever to indicate that an earthquake would more likely occur in saprolites than other materials.

However, any different behavior of saprolite during an earthquake has been taken into account in the design of the North Anna Power Station, Units 1 and 2.

Coalition Question: The Coalition has asked if the North Anna dam is designed to withstand activity on a nearby fault or activity from the point where Neuschel's Lineament transects the reservoir.

Staff Response: The North Anna plant is designed to a reference acceleration o f 0.129 based on an assumed intensity VII (Modified Mercalli).

There are no known active faults near the dam that could localize an earthquake there.

The North Anna dam is expected to survive the ground motion effect of a safe shutdown earthquake with a peak acceleration of 0.129 on rock and 0.18g on saprolite.

We believe our expectations are reasonable in light of the survival of similar California dams that were affected by the 1971 San Fernando earthquake which had a Richter magnitude rating greater than the magnitude of the SSE at North Anna.

Coalition Question:

The Coalition asked for our present day judgments on matters pertaining to laboratory tests and seismic design and foundation engineering that transpired in 1969.

They asked whether we considered the 1969 answers to questions were still accurate and, if not, when changes in soil profiles, bearing capacities, etc., were changed and by whom.

Staff Response: We would consider 1969 answers to questions to be accurate today, but incomplete.

The 1969 answer did not include a bearing value for the highly weathered saprolite (residual soil) nor did it indicate allowable bearing values based on settlement considerations.

On October 6, 1976, we learned that t 2 alla ' hie bearing value used for the design of

foundations on the highly weathered saprolite was about half of the vclue used for foundations on dense saprolite.

The FSAR for Units 1 and 2 hhs been amended by.VEPC0 to include an allowable bearing value for this foundation material.

Our evaluation of the changed bearing value for the saprolite is stated on page 2-5 of Supplement Number 7 to our Safety Evaluation Report dated August 1977, wherein we condluded that the transient bearing value is acceptable.

In light of the limited information available at the time that the 1969 answer was filed, we still judge that the 1969 annter was a reasonable representation for the situation as known at that time. A considerable amount of additional information has been developed and docleted by VEPC0 during the past few years.

In our judgment, the new information provides a better interpretation of foundation conditions and dike stability than that provided by VEPC0 in 1969 in anwer to question 5.

Thus, considering the new information, we would now judge that the margins of stability of the ultimate heat sink reservoir dike and foundation are somewhat less than indicated by the 1969 answer to question 5.

Nonetheless we have con-cluded that, considering the existence of Lake Anna, they possess adequate reliability under seismic conditions.

Our evaluation of the ultimate heat sink reservoir dike and foundation is stated on pages 2-12 and 2-13 of Supplement Number 2 to our Safety Evaluation Report dated August 1976.

Coalition Question: The Coalition has asked what the increased stresses are in the service water pipino and whether these stresses ha*e exceeded or are close to exceeding allowable safety limits.

. Staff Response:

Section 6 of this testimony addresses the Coalition's questions and concerns in some detail.

Coalition Question: The Coalition asked whether we agreed with a statement that "no additional settlement has occurred since the installation of the groundwater control system", and with the statement that "the majority of the recent settlement resulted from the installation of the groundwater control systems"?

Staff Response:

The Coalition's questions can best be answered by referring to settlement data contained in Reference 11 and in Regerence 2.

These letters, indicate that the average pumphouse settlement from December 1975 to October 1976 (10 months), was about 0.025 feet.

From October 1976 to September 1977 (11 months), the period when drains were installed and the reservoir filled three times and emptied twice, the pumphouse settlement increased from about 0.025 to 0.105 feet.

Of the 0.08 feet of additional pumphouse settlement that occurred during this 11 month period, about one third can be attributed to time effects (ordinary expected settlement),

one third due to the influence of drains (causing a drawdown of the water table) and one third due to repeated reservoir fillings (changing loading on soils). More recent settlement amounts are included in VEPC0's' testimony and in Appendices B and C of this testimony. The Staff's interpretation of the recent settlement data would not indicate that the drains have not been a significant cause of settlement.

. Coalition question: The Coalition has asked wP.y there is any necessity to double the allowable pumphouse settlement from 1.8 to 3.96 inches.

Staff Response: According to Technical Specification 3/4.7.12, if the average settlement of the pumphouse exceeds 0.15 feet since December of 1975, the plant would have to be shut down.

The pumphouse settlement is now approaching the specified limits.

The Staff has proposed to increase the allowable settlemert value for the pumphouse.

The bases for the new limits are set forth in Section 6 of this testimony.

Coalition Question: The Coalition has asked the basis for the staff's validation of settlement predictions.

Staff Response: The staff is not attempting to validate predictions of pumphouse settlement as a basis for allowable settlement values.

Rather, we are examining the consequences of increased pumphouse settlement values on the safety functions of service water system components.

Coalition Question:

The Coalition asked how the staff interprets the pattern of settlement reflected in VEPCO's reading of April 25, flay 10, and May 15,(1978) and asked if June and July readings show a similar trend.

Staff Response: The staff would avoid an interpretation of the pattern of average settlement from April 25 to May 15,1978 because the time period is very short and because the change in settlement (0.006 feet) is too wall to tie 3 ; p i i c c.n t can;idering the required sensitivity of

. the measuring system.

The pattern of settlement af.2r May 15,1978 is shown in Figure 7 of VEPCO's testimony.

Coalition Question: The Coalition has asked what remedial actions are being considered beyond those of changing allowable limits.

Staff Response: We will not consider immediate remedial measures until the limits for safe operation of the plant are approached.

If and when that time comes, we view possible remedial actions to include reworking or replacing the expansion joints, addition expansion joints to pipes between the pumphouse and reservoir spray system, and mud jacking the north side of the pumphouse.

Underpinning of the pumphouse foundation is another alternative remedial action.

Coalition Question:

The Coalition has expressed concern that the expansion joints constitute an unreviewed safety question.

Staff Response:

Expansion joints are commonly employed in the piping systems of fossil fuel and petrochemical plants and the technology assoc-iated with the use of expansion joints is well known.

The use of such joints is familiar to staff reviewers and we have reviewed the expansion joint utilized at North Anna.

Thus, we do not feel that their use at North Anna constitutes an unreviewed safety question.

Coalition Question:

The Coalition has asked what caused the pumphouse to settle 0.66 inches in 50 davs in late 1974 and early 1975.

Staf f Response:

This question is addressed in Section 4 (pp. 25-27) of our testimony.

Coalition Question: The Coalition has asied what caused the pumphouse to settle 0.57 inches in 23 days between July 11 and August 2,1977.

Staff Response:

It appears that the uain cause of the settlement was significant lowering of groundwater levels by drain number 4 which was placed below adjacent drains and below the target elevation of 274.0 feet.

Coalition Question: The Coalition ask whether the increased stresses on the service water piping are due to settlement and whether they exceed allowable limits.

Staff Response: This matter was responded to in Section 6 of our testimony.

Coalition Question: The Coalition asked if settlements during December of 1974 and July of 1977 had the same causal mechanism.

Staff Response: We have no data to substantiate that the settlements had the same cause.

Coalition Question: The Coalition asked, if the groundwater level was below the drains during their installation post-drought in the summer of 1977, how were the drains able to significantly affect the groundwater level.

Staff Response:

Previous Piezometer readings from which the groundwater levels were determined are now thought to be erroneous. Because ground-water flowed from the drains when they were installed, we conclude that the drains were placed below the groundwater level.

Coalition Question: The Coalition has asked if it has ever been clearly established that changes in groundwater level were responsible for settle-ment at the North Anna Site.

Staff Response: We are not aware of any direct evidence on the changes in groundwater levels during the period of rapid pumphouse settlement, except for the Nalues reported during the period of drain installation.

The-period of rapid settlement precedad the initiation of periodic monitoring of groundwater levels.

Coalition Question:

The Coalition has asked whethe, or not the causes of rotation and tilt have been clearly established.

Staff Response:

The staff has not made an attempt to establish the reasons for the tilt (rotation is another term for the same phenomenon) of the pumphouse, but it is likely due to the different loads and soil properties under and near the pumphouse.

Coalition Question:

The Coalition has asked for the safety rationale of basing remedial actions and reporting on " average settlement".

" Sta ff Response _: This question is addressed in Section 6 of the staff's testimony. Average settlements are not used as a limiting basis for report-ing in the proposed technical specification.

Coalition Question:

The Coalition asked how the safety of the florth Anna site is protected by changit g the Technical Specifications to double the amount of settlement.

Staff Response: The staff's proposed change to the Technical Specification does not propose doubling of the average settlement.

Staff testimony, Section 6, addresses this question.

Coalition Question: The Coalition has asked about the prompt surveillance and accurate reporting of settlements along with other chronological matters related to pumphouse settlement.

Staff Response:

Settlement measurements and drain installation dates are given in VEPC0's testimony.

The staff's evaluation of VEPC0's surysillance practices are described in ".ection 2 and Appendices B and C of the staff's testimony.

Cor!ition Question: The Coalition asked the baeis for future nredictions of settlement and why the saprolites can be found suitable as foundation material.

Staff Response: The basis for future estimates of settlement will be the record of past se ttleu ent;

t. i k evicence for tne suitability of saprolite

as a foundation for the pumphouse is addressed in the staf f's testimony, Section 3.

Coalition Question:

The Coalition asked, if the causes of the settlement have never been firmly diagnosed, upon what basis can " remedial actions" be taken or a prognosis made regarding the 40-year foundation integrity.

Sta ff Re_sponse: The Technical Specifications for the florth Anna plant prescribe a program of continual diagnostic procedures.

If future symptoms indicate the recurrence of unexpected and unacceptable settle-ment, then appropriate remedies, based on a diagnosis of the new symptoms, will be' implemented to assure that adequate levels of safety are main.tained.

Coalition Question: The Coalition has expressed their belief that the staff has been inconsistent in their attempts to explain the cause of unexpected settlement of the pumphouse.

The Coalition cites the staff's statement that, " settlement has been empirically related to precipitation" and the staff's statement that, "there is no known reason for settlement based on factual data such as infiltration of rainfall and changes in groundwater levels", as evidence of inconsistency.

Staff Response:

Rates of rainfall and rates of settlement are the only available data.

There are no data for changes in groundwater levels during the periods of rapid pumphouse settlement.

An empirical correlation of settlement and rainfall has been observed.

Changes m grotm ' ter 1; ;l-

, c r>e settlo ant, but there is no

data during the period of rapid settlement to prove that such changes actually occurred.

For the above reasons, the staff does not believe the cited statements are contradictory.

Coalition Question:

The Coalition has asked if the change from 1.8 to 3.96 inches of allowable average settlement of the pumphouse is a solution to the problem.

Staf f Response: The s'taff dots not believe that the change is a complete solution.

The staff's proposed Technical Specification change explained in Section 6 of the staff's testimony is considered to be an adequate solution to the problem of pumphouse settlement values that are approaching present Technical Specification limits.

Coalition Question:

The Coalition noted that VEPC0's requested revision to the Technical Specification, allowing 0.33 ft average settlenent since December 1975, when added to the average settlement in December of 1975, when added to the average settlement in December of 1975 (0.37 ft) is nearly the same as the staff's proposed December 22, 1978 specification (superseded) of 0.22 ft of allowable average settlement since July 1977, if one adds to this value the average settlement measured in August of 1977 (0.49 ft.).

. Sta f f Response:

The Staf f's December 22, 1978 proposed specification was superseded by our January 9, 1979 proposal.

In the January 9, 1979 proposed speci fication, the staff proposed a limiting value of 0.22 ft.

of differential settlement, whereas VEPC0 proposed limit of 0.33 ft. of average settlement.

The two figures cannot be compared by simply adding to the Staff's proposed limit the average settlement of the pumphouse prior to July 1977.

D

REFEREf1CES 16.

Terzaghi, K., and Peck, R., (1967) Soil flechanics in Enqineering Practice, 2nd Edition, pages 86,180, Wiley & Sons, flew York 17.

Lambe, T., and Whitman, R., (1969) Soil Mechanics, p.419, Wiley &

Sons, flew York 18.

Eshbach, 0xid W. and Sounders, Mott, Handbook of Enoineering Funda-mentals, John Wiley & Sons, 1975, page 518 e

APPEf1 DIX C NOTE: Appendix C, IE Report flo. 50-338/79-13, is attached since it contains recent settlement figures that were reviewed by IE inspectors. The Summary of Inquiry, which is a part of the Report, is not relevant to this proceeding as it pertains only to the enforcement / compliance aspect of the investigation.

However, it is being included for completeness since it is referred to in the earlier portions of the Report.

UNITED STATES

[p* "f coq'o, NUCLEAR REGULATORY COMMISSION k

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101 M ARlETT A sTRE ET. N.W.

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j-*p//.. r ATLANTA GEORGIA 3o303 APR 2 51979 In Reply Refer To:

RII:JJL 50-338/79-13 Virginia Electric and Power Company ATTN:

W. L. Proffitt Senior Vice President, Power P. O. Box 26666 Richmond, VA 23261 Gentlemen:

This refers to the inspection conducted by J. J. Lenahan of this office on Ma rch 5-15, 1979, of activities authorized by NRC License No. NPF-4 for the North Anna Power Station, Unit I facility, and to the discussion of our findings held with W. R. Cartwright at the conclusion of the inspection.

Areas examined during the inspection and our findings are discussed in the enclosed inspection report. Within these areas, the inspection consisted of selective examinations of procedures and representative records, interviews with personnel, and observations by the inspector.

Within the scope of this inspection, no items of noncompliance were disclosed.

We have examined actions you have taken with regard to previously reported unresolved items. The status of these items is discussed in the enclosed report.

One new unresolved item resulted from this inspection and is discussed in the enclosed report. This item will be examined during subsequent inspections.

In accordance with Section 2.790 of the NRC's " Rules of Practice", Part 2, Title 10, Code of Federal Regulations, a copy of this letter and the enclosed inspection report will be placed in the NRC's Public Document Room. If this report contains any information that you (or your contractor) believe to be proprietary, it is necessary that you make a written application within 20 days to this of fice to withhold such information from public disclosure.

Any such application must include a full statement of the reasons on the basis of which it is claimed that the information is proprietary, and should be prepared so that proprietary information identified in the application is contained in a separate part of the document.

If we do not hear from you in this regard within the specified period, the report will be placed in the Public Doct=ent Room.

a

APR 2 51y9 Virginia Electric and Power Co. Should you have any questions concerning this letter, we will be glad to discuss them with you.

i Sincerely,

.gf O' 1mes P. O'Reilly Di ector

Enclosure:

Inspection Report No.

50-338/79-13 cc w/ enc 1:

W. R. Cartwright, Station Manager Box 402 Minera1,,VA 23117 P. G. Perry Senior Resident Engineer P. O. Box 38 Mineral, VA 23117 4

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o NUCLEAR REGULATORY COMMISSION "f. [*, a 99 [

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ATLANTA, GEORGI A 30303 i

Report No. 50-338/79-13 Licensee: Virginia Electric and Power Company Post Office Box 26666 Richmond, Virginia 23261 Facility Name: North Anna Power Station, Unit 1 Docket No. 50-338 License No. NPF-4 Inspection at North Anna Site near Mineral, Virginia, VEPC0 offices, Richmond, Virginia, and Stone and Webster Engineering Corporation (S&W) offices, Boston, Massachusetts Inspector:

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//5-///

J. 6 Menahan Date Signed Accompanying Personnel:

C. E. Alderson Approved by:

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C. Bryant, Section Chief, RCES Branch Date Signed

SUMMARY

Inspection on March 5, 6, 14 and 15, 1979, at North Anna site; March 7, 1979 at Richmond, Virginia; March 13, 1979 at Boston, Massachusetts A_reas Inspected This special, unannounced inspection involved 21 inspector-hours on-site and 18 inspector-hours in the VEPC0 and Stone and Webster Corporate Offices in the areas of settlement data collected on Units 1 and 2 service water pumphouse, performance of horizontal drains, collection of piezometer data and licensee action on previously identified items concerning settlement surveys.

In addition, an inquiry was conducted concerning handling and review of service water pumphouse settlement data. The inquiry involved 11 hours1.273148e-4 days 0.00306 hours 1.818783e-5 weeks 4.1855e-6 months on-site and 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months in the VEPC0 and Stone and Webster corporate offices by an NRC investigator. The Summary of Inquiry is appended to this inspection report.

Results Of the areas in gected, no apparent items of noncompliance or deviations were identified.

I

0 4

DETAILS 1.

Persons Contacted Licensee Employees C. M. Robinson, Supervisor, Civil Engineering Services

0. Schultz, Supervisor, Survey Services

C.

E. Sorrell, Civil Engineer

J. W. Waddel, Manager, Power Station Engineering P. A. Slater, Resident QA Engineer

E. R. Smith, Jr., Supervisor, Technical Services

J. D. Kellams, Superintendent Station Operations

V. R. Cartwright, Station Manager R. C. Sturgill, Assistant Engineer T. Schreckenghast, Engineering Technician Other Organizations D.'Barry, Resident Engineer, North Anna Site (S&W)

B. McIver, Geotechnical Engineer, Boston (S&W)

NRC Resident Inspector

H. S. Kidd

Attended exit interview.

2.

Exit Interview The inspection scope and findings were summarized on March 15, 1979 with those persons indicated in Paragraph I above.

3.

Licensee Action on Previous Inspection Findings (0 pen) Unresolved Item (338/78-37-04): Settlement of Class I Structures.

Technical Specifications are not clear on settlement survey requirements for reset survey points and baseline dates since several of the points were not required by NRC until after the baseline dates had passed.

Also, though some of the points were in existence prior to the appro-priate baseline dates, survey readings were not made on the baseline date. A typical example of this is point number 117 on the service building. The Technical Spe,cifications specify a limit on the settlement occurring after April 1, 1977. However, settlement surveys were made on March 9, 1977, and not on April 1.

Therefore, it is necessary to extrapolate the post April I settlement for Point 117.

Other examples of the need to clarify baseline dates are settlen:ent points 200 ti.rouch

. 209 on the Boron Recovery Tank Dike.

The technical specifications specify limits on settlement after completion of construction (i.e.,

"as built" settlement).

However, these settlement limits, were not required by NRC and initial settlement readings were not made until May 1976, more than one year after this structure was built.

Six points have been reset since the technical specification baseline date.

This was due either to construction activities which resulted in points being destroyed or erection of permanent facilities which have made points inaccessible to surveying. However, the licensee has a large redundancy in survey monitoring points and, therefore, was able to reconstruct the settlement history of reset points f rom other settlement points on the same structure or from settlement points on adjacent structures which have similar foundation and loading conditions.

A typical example of how missing data were reconstructed for reset points can be illustrated for point number 144 on Unit I containment structure.

In addition to point number 144, the licensee had estab-lished 5 other pointr, numbers 126, 127, 130, 143 and 149 on the Unit I containment structure.

These additional points were surveyed at the same frequency as point number 144. Point number 144 was destroyed between the 10/8/79 and 7/7/77 readings; however, it is possible to reconstruct the missing data for point number 144 from data collected for the other poiuts.

The readings col'.ected for the other 5 points on the structure indicated an average of approximately 0.016 feet of rebound during the period 10/8/76 through 7/7/77.

Since all the points are on the same rigid structure, it is reasonable to conclude that point number 144 also rebounded 0.016 feet during this period.

Point number 144 indicated 0.003 feet of settlement between 5/13/76 and 10/8/76 and 0.005 feet of settlement between 7/7/77 and 10/25/78. Therefore, the net apparent movement of point number 144 since May 1976 is actually.008 feet of rebound, not settlement.

The Unit I containment structure is founded on rock. The inspector concluded, based on the data, that the struc-ture most likely has not moved since May 1976, and the small apparent movements are a result of the limits of accuracy of surveying.

The inspector examined installation of two additional permanent benchmarks which had been established in the main plant area.

These benchmarks had been drilled and grouted into rock. Although the surveys made to date meet the requirements for U. S. Department of Commerce, National Oceanic and Atmospheric Admini.ctration (NOAA) Second Order, Class II accuracy, the survey results will be improved when these benchmarks are used since they are much closer to the plant than the benchmarks presently in use. According to NOAA standards, accuracy in leveling is a function of the square root ot tar distance surveyed. A reduction in the distance

. surveyed will lower the acceptable errors of closure, thus increasing survey accuracy. Also, a reduction in distance surveyed will reduce the number of turning points, which will udd to increased, survey accuracy.

The inspector examined the licensee's revised procedure to be furnished to Moore, Hardee, and Carrouth Associates (MH&C), the engineering firm retained by the licensee to perform the settlement surveys. This procedure lists requirements for collection and reduction of survey data, transmittal of the data to the licensee, and QC requirements.

The time lapse octween completion of the MH&C surveys and evaluation of the data by tLe licensee was up to four months in the past. This revised procedure requires MH&C to transmit survey data to the licensee within seven working days after completion of the survey.

The inspector discussed with licensee management the need to protect settlement points from being disturbed by construction and other activities.

The licensee is still evaluating methods to be used to accomplish this.

Ba' sed on review of the settlement data collected to date, it appears that the licensee has met the intent of Technical Specification 3.7.12.1, i.e., to monitor and evaluate settlement of Class I structures.

The licensee has requested a change to the Technical Specification to clarify baseline dates and reset survey points.

Unresolved item 338/78-37-04 remains open pending revision of the Technical Specifi-cation and NRC review of the licensee's corrective action and final report.

4.

Unresolved Items Unresolved itemt are matters about which more information is required to determine whether they are acceptable or may involve noncompliance or deviations.

New unresolved items identified during this inspection are discussed in Paragraph 7.e.

5.

Independent Inspection Effort The inspector examined the service water reservoir embankment, including slope protection, slope stability, and downstream embankment toe.

No deviations or items of noncompliance were identified.

6.

Scope of Special Inspection On April 28, 1978, the licensee notified NRC Region II that survey readings taken by MH&C on March 30, 1978, indicated that the average settlea.ent of the ;.crvice w ter pump house (S'nTii) exceeded the value

. ~

required for reporting, i.e., 75% of the maximum allowable value of 0.15 feet.

The licensee submitted a special written report regarding the SWPH settlement to NRC Region II on May 31, 1978.

This special inspection was performed to:

a.

Make a comparison of the SWPH settlement data collected by Stone &

Webster (S&W) with that collected by Moore, Hardee and Carrouth Associates (MH&C).

b.

Evaluate MH&C SWPH settlement data collected since November 1978.

c.

Evaluate differential settlement. data between the SWPH and the north side of the service water piping expansion joints, and visually examine the expansion joints.

d.

Determine th.e performance of the horizontal drains.

e.

Review piezometer data.

In' addition, an inquiry was conducted during the inspection by a Regional Investigator concerning the licensee's handling and review of SWPH settlement data. The Summary of Inquiry is appended to this inspection report.

7.

Findings a.

Comparison of S&W and MH&C SWPH Settlement Data - S&W, the plant designer and constructor, monitored settlement of the SWPH during its construction in accordance with standard engineering practice to confirm their design assumptions.

MH&C was retained by the licensee to perform the surveys required by the Technical Specification 3.7.12.1.

The inspector examined the S&W survey field book containing the SWPH data collected by S&W surveyors, reviewed calculations reducing the raw field data collected by S&W and MH&C to the computed SWPH settlement, made an independent check of these calculations, and compared the SWPH settlement calculated from the S&W field data to the settlement calculated from the MH&C data.

A comparison of n}i&C and S&W settlement measurements is shown in the following table:

l

. MH&C DATA S&W DATA Average SWPH Average SWPH Data Settlement (ft.)

Date Settlement (ft.)

i 12/01/75 0.000 12/10/75 0.000 12/17/75 0.001 12/19/75 0.000 8/23/76 0.011 8/21/76 0.020 10/01/76 0.022 10/07/76 0.029 10/06/76 0.027 11/10/76 0.033 11/13/76 0.039 12/01/76 0.038 12/06/76 0.031 12/15/76 0.064 2/24/77 0.061 3/03/77 0.061 3/28/77 0.068 5/23/77 0.066 7/11/77 0.063 8/03/77 0.114 8/29/77 0.112-10/05/77 0.114 10/31/77 0.113 12/12/77 0.103 12/08/77 0.117 1/05/78 0.116

~

3/15/78 0.121 3/01/78 0.112 3/30/78 0.119 3/29/78 0.123 4/25/78 0.107 4/20/78 0.118 5/10/78 0.110 5/12/78 0.132 Notes (1) Settlement shown is in feet (2) S&W settlement values for 8/3/77 through 1/5/78 are based on incomplete data; i.e., no readings were made on settlement point SM-8 during this period. Missing data for SM-8 was interpolated from other data.

The Technical Specifications require that the licensee perform an engineering evaluation to determine the consequences of additional settlement when the average settlement of the SWPH exceeds 75% of 0.15 feet (0.1125 feet). The licensee is required to notify the Commission and submit a special report within 60 days of when this limit is detected.

S&W data indicate that 76% of the allowable SWPH settlement of 0.15. feet occurred by August 3, 1977. However, the MH&C data indicates only 42% of the allowable settlement had d

occurred by July 11,11977, and that 69% had occurred by December 12, 1977..S&W data of December 8, 197/ indicates, for all practical purposes, no change from the August 3 data. The difference, 69%

I:

i

. of 0.15 and 76% of 0.15, is less than 0.01 foot.

MH&C data did not indicate that the allowable settlement (75% of 0.15 ft.) was exceeded until March 15, 1978.

i The S&W data generally indicated approximately 0.01 foot more settlement than MH&C data.

Examination of the data in the S&V survey field book disclosed that survey loop closures were not documented for the period between March 28, 1977 and March 27, 1978.

Since these loop closures are not documented, the accuracy of the S&W surveys for this period is questionable.

In addition, S&W did not make settlement survey readings on settlement point SM-8 (S&W point number 3) from August 3,1977 through January 5, 1978.

The settlement data for point SM-8 was interpolated from the data obtained for point numbers SM-7, SM-9 and SM-10.

Therefore, some of the S&W average settlements shown in the above table are based on suspect and/or incomplete survey data and in any case would not have the same degree of accuracy as the MH&C data.

The MH&C average SWPH settlement shown in the above table is based on complete data obtained from well controlled surveys which were made to Second Order, Class II accuracy.

The MH&C survey loops were closed with acceptable accuracy in all cases.

In cases of conflict between the MH&C data and the S&W data, the inspector concluded that MH&C data would be accepted as correct since it was complete and was obtained from a more accurate and better con-trolled survey than the S&W surveys. A more detailed discussion concerning MH&C and S&W survey procedures is contained in Region II inspection report number 50-338/78-44.

No deviations or items of noncompliance were identified.

b.

Evaluation of MH&C SWPH Data Collected Since November 1977 - The inspector reviewed MH&C SWPH data collected since November 1978.

Selected MH&C data is given below to show trends:

Average SWPH Percent of Allowable Date Settlement (Feet) Settlement (.15 Feet) 12/01/75 0.000 0

7/11/77 0.063 42 12/12/77 0.103 69 3/15/78 0.121 81 3/30/78 0.119 79 4/25/78 0.106 71 5/10/78 0.110 73 8/03/78 0.117 78

.\\

. Average SWPH Percent of Allowable Date Settlement (Feet) Settlement (.15 Feet) t 11/06/78 0.126 84 11/20/78 0.124 83 1/03/79 0.128 85 2/06/79 0.127 84 3/07/79 0.126 84 Notes December 1, 1975 is the baseline date for SWPH settlement in the Technical Specifications.

The data for Spring and early Summer 1978 indicate that average SWPH settlement was approximately 0.115 feet.

Readings made in November 1978 through March 1979 indicate that average SWPH settle-ment was approximately 0.125 feet.

This means that the SWPH settled an additional 0.01 foot between early Summer and early Winter 1978.

The licensee indicated that monitoring of SWPH settlement will con-tinue on a monthly basis until further evaluation indicates the frequency can be reduced.

No deviations or items of noncompliance were identified.

c.

Differential Settlement between SWPH and North Side of Service Water Piping Expansion Joints and Inspection of the Expansion Joints - The inspector reviewed the results of surveys performed by MH&C since November 1978 to measure settlement of the service water lines north of the expansion joints.

Settlement of the service water lines is compared to the settlement of SWPH settlement point SM-7, which is located on the northeast corner of the SWPH where the ser-vice water lines enter the pumphouse. The settlement of point SM-7 versus settlement of point numbers SM-15 and SM-18 on the two outboard service water lines north of the expansion joints is tabulated below.

Data are selected to show trends.

Settlement in Feet Differential Differential Between Between Point Point SM-7 Point SM-7 Date SM-7

,SM-15 and SM-15 SM-18 and SM-18 7/11/77

.000

.000 12/12/77

.039

.051

.012

.058

.019 3/15/73

.053

.071

.012

.081

.022

. Differential Differential Between Between Point Point SM-7 Point SM-7 Date SM-7 SM-15 and SM-15 SM-18

'and SM-18 3/30/78

.057

.072

.015

.077

.020 4/25/78

.045

.060

.015

.066

.021 5/10/78

.043

.063

.020

.071

.028 8/03/78

.051

.066

.015

.069

.018 11/06/78

.058

.081

.023

.082

.024 11/20/78

.057

.083

.026

.083

.026 1/03/79

.063

.095

.032

.090

.027 2/06/79

.061

.101

.040 090

.029 3/06/79

.061

.097

.036

.088

.027 Notes:

(1) July 11, 1977 is date when initial survey was performed on service water lines.

(2) SM-15 is settlement point on east pipe.

(3) SM-18 settlement point on west pipe.

The above data indicate that differential settlements between the service water lines north of the expansion joints and the northeast corner of the SWPH has been approximately 1/2-inch since July, 1977. The data indicate that the service water lines have settled more than the SWPH. The expansion joints in the service water lines are located where the height of fill in the dike is the greatest.

Monitoring of pipe settlement was not initiated until July 1977 while the expansion joints in the service water lines were installed in August and October 1976. However, conservative estimates of the total differential settlement which has occurred brtween the SWPH and the north side of the expansion joint can be made by comparison of SWPH settlement data with available service water line settlement data.

Settlement point SM-7 on the SWPH settled 0.046 feet between December, 1975 and July, 1977.

The maximum differential settlement between SM-7 and the service lines for this magnitude of settlement of SM-7 was 0.028 feet, occuring in May, 1978. Therefore it would be reasonable to conclude that the amount of differential settlement between SM-7 and the service water lines in the time period August 1976 to July, 1977 was approximately 3/8-inch (0.03 feet). This amount, added to ! inch which has necurred since July 1977 would mean that approximately 7/8-inch ci d:f f er-ntial settlement has occurred between the SWPH

(point SM-7) and the service water lines since the expansion joints were installed in August and October 1976.

The expansion joints are designed to tolerate up to three inches of differential settlement between the SWPH and the service water lines.

The inspector examined the expansion joints during the inspection and detected no problem.

No deviations or items of noncompliance were identified.

d.

Performance of the Horizontal Drains - The licensee committed in an amendment to the FSAR to control the ground water level in the vicinity of the SWPH. The licensee had considered the use of deep wells, but this method was ruled out after the results of pumping tests indicated that, due to the low permeability of the insitu soils, large drawdowns and close well spacing would be required.

The licensee,then elected to use drilled horizontal drains.

Drilled horizontal drains to control groundwater have been in use since the 1940's on numerous projects, including dams, highways, railroads, buildings, and other structures.

The initial drain, drain 0 was installed in August, 1976. During installation of this drain the impermeable liner of the reservoir was punctured. The licensee reported this to NRC Region II as a 50.55(e) item.

After repairs to the liner were completed and installation procedures were revised, horizontal drain number 1 was installed at North Anna in October, 1976 as a test drain.

The data gathered from this drain was used to determine drain pipe size, drain spacing, and drain flow characteristics.

Based on the data gathered from drain 1, the licensee determined that five additional drains were needed to control the groundwater level in the vicinity of the SWPH. The additional drains, drains 2 through 6, were installed in July and August of 1977. The drains were installed near the groundwater table elevation existing at time of installation.

The inspector examined field books containing records of the horizontal drain installation and discussed installation techniques with the responsible engineers.

Examination of the records disclosed that after the problems with drain 0 had been resolved, installation of the remaining drains was carefully controlled.

The location of the drains, both horizontal and vertical, was determined during installation using various types of instrumentation. Drain 4 was installed at elevation 272.5.

The remaining drains were installed between elevation 274 and elevation 276.

The inenector exanined records of periodic tests performed by the licer- - to -'v"re tr volume of flow from the horizontal drains and to ceasure the turbidity and suspended solids in the effluent from the horizonpal drains. Recordsexaminedwerethoseo{ tests

. performed on April 7,1978, July 7,1978, and January 4,1979.

Acceptance criteria for measurement and analysis of flow from the horizontal drain are contained in PT-75.6, " Service Water Pump House Drain System - Turbidity - Suspended Solids",+and Technical Specification 3/4.7.7.1., " Service Water System". The required frequency of testing is at least once every six months.

No deviations or items of noncompliance were identified.

Review of Piezometer Data - The inspector examined records of e.

piezometers located in the vicinity of the SWPH to determine the effect of horizontal drain installation on groundwater levels.

Prior to installation of the drains, piezometer number P-14 indicated ground water was at elevation 274.

Piezometer P-14 is angled to a point under the center of the SWPH.

Piezometer P-13 indicated groundwater was at elevation 276 prior to drain instal-lation.

Pi,ezometer number P-13 is a vertica? piezometer which was installed on top of the dike approximately 40 feet west of the SWPH.

After installation of the drains, piezometer P-13 indicated a drop in groundwater from elevation 276 to elevation 274 while piezometer P-14 indicated a drop in groundwater from elevation 274 to elevation 270.5.

Since this is below the level of the horizontal drains, the only explanation that S&W engineers could offer for the behavior of piezometer P-14 after drain installation was that the transducer for this piezometer was installed approximately 4 feet higher than previously believed.

The inspector examined monthly records of piezometer readings taken from June 1978 through February,1979 to determine the ground water level of the service water reservoir. Acceptance criteria far measurement of the groundwater level are contained in PT-75.7, " Service Water Reservoir - Groundwater Level", and Technical Specification 3/4.7.13, " Groundwater Level - Service Water Reservoir-Limiting Condition for Operaton."

Piezometer numbers P-13 and P-14 have indicated drops in ground-water level or approximately 1.5 feet since late November, 1978.

The inspector questioned North Anna site personnel concerning the apparent drop in groundwater level.

These discussions disclosed that site personnel compare the piezometer readings to Technical Specification (TS) requirements and if the data is within the TS limits, no further action is required.

P.esults are then filed in the Document Control Unit (DCU) after distribution of copies of the data to various personnel in the Richmond VEPC0 and Boston S&W offices. Site personnel do not perform and procedures do not require a trend analysis which would disclose variations in data z

from average monthly readings.

Site personnel had no comment concerning the piezometer data, except to state tha; the data were within TS limits.

Discussions in the Richmond VEPC0 offices with the VEPC0 Supervisor of Civil Engineering Services and in Boston with the S&W Geotechnical Engineer disclosed that the apparent drops in groundwater levels in these piezometers are suspected to be either a result of errors by the individual making the readin6s or malfunction of the pore pressure indicator (instrument used to read the piezometers).

The VEPC0 Supervisor of Civil Engineering Services notified the site of the potential problem with the piezometer data in late February, 1979.

Further discussions at the site on March 14 and 15, 1979, with licensee man'agement disclosed that the manufacturer of the pore pressure indicator will be contacted in the near future to send a representative to the site to service and calibrate the instrument, if required, review the procedure being used to read the instrument, and verify that the individual reading the piezometers is doing it correctly.

The inspector expressed concern over the delay in discovery of the potentially incorrect piezometer readings and questioned whether or not a trend analysis should have been performed to detect potential errors in readings.

The apparent lack of adequate procedures to specify corrective action, e.g.,

perform a trend analysis, was identified to the licensee as Unresolved Item 338/79-13-01. This item is being evaluated by NRC to determine if adequate procedures have been established.

NRC will also review the report of the pore pressure indicator manufacturer in evalua-tion of this item.

The most current SWPH settlement survey data at the site on March 6, 1979, were the November 20, 1978, readings.

The inspector verified that these data were the most current available on site on this date by review of DCU files and discussions with the engineer responsible for review and analysis of SWPH settlement data.

During discussions with the VEPC0 Supervisor of Civil Engineering Services and his staf f on March 7,1979, the inspector questioned if any additional SWPH settlement surveys had been made since November 20, 1978.

The inspector was informed that surveys were made in January and February but that this data had not yet been received from MH&C.

During a discussion of the effect of the apparent drop of groundwater table elevation on SWPH settlement, the licens?e's reprer.antative indice.ted that they were not concerned i

I

. that additional SWPil settlement had resulted from a drop in the groundwater table since they assumed the piezometer data was incorrect. At the request of the inspector, the licensee obtained copies of the January 3, 1979, and February 6, 1979, survey data.

The inspector and the licensee reviewed the data and verified that additional SWP11 settlement had not occurred since November 20.

No deviations or items of noncompliance were identified.

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i

SUMMARY

OF INQUIRY

Subject:

Virginia Electric & Power Company (VEPCO)

North Anna Unit 1 Docket No. 50-338 Allegations that VEPC0 had knowledge of significant safety information regarding foundation conditions (Service Water Pump House settlement) at the North Anna site in August 1977 and withheld the informa-tion from the NRC for seven months until April 28, 1978.

Dates of Inquiry:

March 5-13, 1979 Performed by:

_ Q lAlderson_ e J 3-Z7-79 C. E.

Date Regional Investigator Office of the Director Reviewed by:

M/

J-D 7 79 F. J. Long Date Acting Deputy Director Office of the Director 9

34

I.

INTRODUCTION In a letter to the Commissioners dated November 1, 1978, the North Anna Environmental Coalition (NAEC) stated that from information available to the NAEC it appeared that significant safety information regarding foundation conditions at the North Anna site had been withheld from the NRC for a period of seven months and was never reported to the Atomic Safety and Licensing Board (ASLB).

The letter alleged that VEPC0 had been aware of abnormal and differential settlement in August 1977 and had not reported it to the NRC until April 1978. The letter further alleged that the matter was reportable under the Unit 1 Technical Speci-fications and had been reportable under the requirements of 10 CFR 50.55(e) prior to issuance of the Unit 1 operating license.

In a letter to the Advisory Committee on Reactor Safeguards (ACRS) dated November 3, 1978, the NAEC stated that it would appear that VEPC0 under-took no evaluation for months after becoming aware of the excessive settlement.

This letter to the ACRS included a copy of NAEC's November 1st letter to the Commissioners.

This inquiry and a special inspection were initiated under the authority provided by Section 1.64 of Title 10, Code of Regulations and were conducted jointly to:

(1) determine the specific reporting requirements pertaining to the Unit I and 2 Service Water Pump House settlement which were in effect at the various times in question; (2) review Stone and Webster (S&W) and VEPC0 procedures for the accumulation, evaluation and reporting of settlement data; (3) determine the specific handling of the data resulting from the survey performed by Stone and Webster in August 1977; and (4) determine if an investigation into the matter was warranted.

The results of the inquiry are presented below.

Technical evaluation of the North Anna settlement monitoring program, including S&W surveys and Moore, Hardee and Carrouth Associates (MH&C) surveys is addressed in the report of the special inspection (IE Report No. 50-338/79-13) to which this Summary of Inquiry is appended.

II.

SCOPE This inquiry included the following activities:

i a.

Review of 10 CFR 50.55(e) reporting requirements.

b.

Review of North Anna Unit 1 Technical Specification reporting requirements.

c.

Review of:

(1) Correspondence between VEPC0 and the NRC; (2) the transcript of the r.w a 1. earings for the Unit I operating license;

(3) the North Anna Unit I and 2 Safety Analysis Report; and (4) the North Anna Units 1 and 2 Safety Evaluation Report including supple-ments, to determine whether VEPCO had made any commitments beyond the settlement monitoring and reporting requirements of the Unit 1 Technical Specifications.

d.

Review of files related to settlement in the possession of the S&W Construction Group at the North Anna site and discussions with the S&W Site Construction Project Engineer on March 5, 1979.

c.

Review of files related to settlement in the North Anna Station Records (VEPCO) and discussions on March 6, 1979, with the engineer on the North Anna operating staff assigned responsibility to evaluate settlement data.

f.

Review of files in the possession of and interwiews with VEPCO's Supervisor of Civil Engineering Services and the Chief Surveyor at the Corporate Offices in Richmond, Virginia on March 7, 1979.

g.'

Review of files in the possession of and interviews with S&W's Lead Geotechnical Engineer for the North Anna project and a previous Engineering Project Engineer for North Anna Unit I at S&W's Corporate Offices in Boston, Massachusetts on March 13, 1979.

h.

Discussions with the current and prior Licensing Project Managers and the Leader of the Geotechnical Engineering Section in the Office of Nuclear Reactor Regulation.

i.

A telephone discussion with the official of the NAEC who had written the letters to the Commissioners and the ACRS.

III. DETAILS a.

Review of Monitoring and Reporting Requirements and Effective Dates Paragraph 50.55(e) of 10 CFR 50 was reviewed for applicability to the situation.

Based on this review, it would appear that VEPCO's telephone notification to Region II on April 16, 1975 and their subsequent written report to the NRC dated May 15, 1975 concerning settlement of the Unit I and 2 Service Water Pump House satisfied the reporting requirements of 50.55(e).

The purpose of 50.55(e) is to ensure that the NRC is made aware of any significant problems identified during construction of a facility so that the problems can be evaluated and monitored to assure appropriate resolution.

Periodic status reports are not required by 50.55(c) after initial notification is made.

t

. The monitoring and reporting requirements of the North Anna Unit 1 Technical Specifications became operative on November 26, 1977 when the operating license was issued, and therefore, no, report could have been required thereunder, before that date.

The question as to whether a sixty-day report on the S&W survey results of August 1977 would have been due on:

(1) the day the license was issued (since more than sixty days had elapsed since the surveys had been made), (2) sixty days following issuance of the license, or (3) sixty days from the time VEPC0 became aware of the results, requires a legal interpretation of the Technical Specification. Howe /cr, based on the information obtained during this inquiry, the answer to this question does not appear to have any bearing in this matter.

The investigator reviewed VEPCO/NRC correspondence on this issue and discussed at with both the current and prior NRR Licensing Project Managers, and the Geotechnical Engineer who had been involved to determine if any special reporting requirements had been imposed

^

on VEPC0 regarding settlement survey results. The review and discussions did not disclose any special requirements; however, a letter from VEPCO to the NRC dated July 11, 1975 was found to contain the following statement:

" Monitoring of the settlement will be continued on a monthly basis throughout the construction and initial operation of Units 1 and 2.

These observations will be reviewed at that time to deterraine if a less frequent monitoring sequence can be justified.

The staff will be consulted prior to any change in the monitoring schedule."

This statement was contained in VEPCO's response to a question from NRR which requested a discussion of proposed Technical Specification limitations. The investigator was unable to locate any subsequent NRC/VEPC0 correspondence regarding monitoring frequency until the proposed Technical Specification with a six-month surveillance frequency, was submitted in October 1977.

This response was also discussed with the three individuals from NRR and none could recall the letter or a discession of a one-month frequency. They further stated that there was never a requirement that surveys be accom-plished monthly.

It should be noted that between June 11, 1975 and the subeittal of the proposed Technical Specification, additional structures had been identified as requiring monitoring for settlement. The Technical Specification which was eventually issued required a much more extensive program than was being considered when the earlier letter vas written.

. b.

Responsibilities for Performing Surveys The investigator interviewed several individuals to determine the relationship between S&W surveys and those performed by MH&C.

The Supervisor of Civil Engineering Services (VEPCO) stated that monthly settlement measurements were initiated in December 1972 due to the appearance of cracks in the SWPH wing-wall. At that time S&W was instructed by VEPC0 to perform the necessary surveys for what was believed to be a temporary program.

However, the Supervisor said that in 1975 it became apparent to VEPC0 that the NRC would require a long-term monitoring program, possibly lasting the life of the plant. The Supervisor explained that since S&W would eventually leave the site when construction was completed, VEPCO decided that it would be better to hire a local company to perform the surveys.

MH&C had been performing survey work for VEPC0 in other areas since 1967 and VEPC0 decided that they should perform the surveys required by the Settlement Monitoring Program being developed at that time.

The investigator reviewed the "open-ended" service contract between VEPC0 and MH&C and determined that it had been entered into on September 1, 1967. The investigator also reviewed a letter from VEPC0 to MH&C dated September 23, 1975 which authorized MH&C to initiate a survey program to monitor the North Anna Service Water Reservoir dam and pump house under the service contract. The letter specified that upon completion of the original surveys, the alignment-settlement markers were to be monitored when the water-level in the reservoir reached certain specified levels and once each year af ter the reservoir was filled.

The investigator found several S&W and VEPC0 letters in the various files reviewed which clearly establish that S&W was assisting VEPC0 in the development of the Settlement Monitoring Program and the proposed Technical Specification, including the identification of structures and components to be monitored, the frequency of monitoring and the limits on differential settlement. The letters and various internal memoranda also indicate that it was VEPCO's intent to have a single monitoring program which satisfied the informational needs of VEPCO, S&W and the NRC, and that the surveys would be performed by HH&C.

The individuals interviewed were unable to state why the S&W pump house settlement surveys, continued after MH&C was coatracted to perform the settlement surveys; however, it was pointed out to the investigator that S&W surveys did not include but five of the many points required by the Technical Specifications and were never intended to satisfy those requir ments.

1.

1

~ c.

Procedures for Accumulating, Evaluating and Reporting Settlement Data The S&W Project Engineers for Construction (site) an'd Engineering (Boston), and the Lead Geotechnical Engineer were interviewed to determine the normal procedure for handling the settlement survey data within the S&W organization. At VEPCO's Corporate Office the Supervisor of Civil Engineering Services and the Chief Surveyor were interviewed to determine the normal procedure for handling the settlement survey data within the VEPCO organization. Discussions were also held with the engineer on the North Anna operating staff responsible for evaluating the survey data and discussions had been held previously with the S&W survey party chief who had been involved in the August 1977 surveys.

These interviews and records reviews disclosed that prior to October 11, 1977 there were no formal written procedures within S&W or VEPC0 covering this area, but the descriptions provided by these individuals as to how the data was handled were all in general agreement.

With regard to S&W surveys, the S&W surveyors would make the surveys and enter the raw data in a field book. At some later time the survey party chief would transfer the raw data to a form.which was then forwarded to S&W-Boston. The records indicate that from initation of the survey program in late-1972 until late-1975 this form with the raw data was sent only to one individual at S&W-Boston by telecopier.

In late-1975 (around August) a standard transmittal form was introduced and the distribution of the raw data was expanded to include several individuals, including VEPCO employees.

From this point in time on, the data was mailed to the recipients, except for special requests which were sometimes telecopied. The transmittal sheet was revised at least once and the distribution was changed. The transmittal sheets contained no data themselves and merely served as " routing" forms. For this reason, the trans-mittal sheets were not retained with the data sheets, if at all, and the investigator was unable to identify from the records those individuals who received any particular set of raw data or when they received it.

The records available did indicate that between February 1973 and mid-1975 the S&W survey data was being received by S&W-Boston within one to two weeks from the time the survey was made.

After mid-1975, the records indicated a continuing trend of increase in the time between the survey and receipt of the data in Boston.

Beginning in late-1976 it appears that the S&W survey data was forwarded to S&W-Boston and other persons on distribution only af ter a data sheet was full; the time required being dependent on the troquency or a..,

p.

Generally, it appeared that STN-Boston receivea the cata wit.un one to two months af ter the first survey on the data sheet was made.

t

=

e *

=

. Regarding MH&C data, normal flow af the raw survey data was from MHSC to \\TPCO's Chief Surveyor, who passed it on to VEPCO's Supervisor of Civil Engineering Services. The Supervisor of Civil Engineering Services then forwarded copies of the data to S&W-Boston, and following issuance of the operating license, to the operating staff at North Anna.

The various individuals interviewed indicated that prior to licensing of Unit 1, S&W's Lead Geotechnical Engineer was responsible for reducing and evaluating the survey data from both S&W and MH&C.

Within VEPCO, the responsibility for the Settlement Monitoring Program was assigned to the Supervisor of Civil Engineering Services.

Upon issuance of the operating license, responsibility for evaluating the data for compliance to the Technical Specifications was assigned to an engineer on the North Anna operating staff.

This engineer only received and evaluated the MH&C data.

He did not normally receive S&W data.

The Lead Geoternnical Engineer stated that raw S&W data would sometimes be.eceived regularly, but that at other times, no data would be received for quite a while and then several sets of the raw data would be received at one time. He explained that it depended on the workload of the Survey Party Chief and when he could find time to transfer the raw data from the field book to the data sheets. At times, the Lead Geotechnical Engineer would call the S&W Survey Party Chief and request the data be forwarded.

The Lead Geotechnical Engineer further stated that there was no specific schedule established for him to reduce the raw data and determine settlement and that he did it at irregular intervals.

The Supervisor of Civil Engineering Services (VEPCO) stated that he normally received copies of the S&W data, but that he only glanced at it, as S&W was responsible for reducing the data and informing VEPC0 if any problems were encountered.

d.

Handling of S&W Survey Data for August 1977 The Lead Geotechnical Engineer (S&W) stated that he did not believe that he received any S&V survey data from the field between May 1977 and January or February 1978.

He explained that he had requested the data from the S&W Survey Party Chief several times, but that the Survey Party Chief was busy and had not gotten around to sending the data.

He stated that he was out of the office for three weeks in January 1978 and when he came back he started reviewing MH&C data and bringing his settlement plots up to date. He further stated th,t,round the end of February 1978 he was reviewing and plottinr t dna i,r t he ".HF.C pep house survey of December 12, 1977 and noticed a significant change, but did not know if it was

4 an actual settlement or a bad survey.

He then notified VEPCO's Chief Surveyor of the possible problem and requested.that the Survey Party Chief send all S&W survey data not previously received by S&W-Boston from the field. An internal memorandum from the S&W Survey Party Chief to the Lead Geotechnical Engineer indicated that S&W survey data was forwarded to S&W-Boston on February 28, 1978.

A memo from the Lead Geotechnical Engineer back to the Survey Party Chief indicated that S&W surveyors performed an additional survey on March 1, 1978 and that the field books were reviewed to determine the validity of the bench marks. The memo also indicates that the Lead Geotechnical Engineer had reached the conclusion that the MH&C data for December 12, 1977 survey was valid.

The Lead Geotechnical Engineer stated that he prepared a letter to VEPC0 and on March 6, 1978 he notified VEPCO's Supcrvisor of Civil Engineering Services that the MH&C data for December 12, 1977 indicated that the pump house had attained 65 percent of the average ellowable total settlement and that S&W survey data confirmed the validity of the measurement.

VEPC0 subsequently requested NH&C to perform additional surveys.

An MH&C survey performed on March 15, 1978 indicated that the pump house settlement had exceeded the 75 percent limit and a special report to the NRC was required within 60 days. This required report was provided on May 31, 1978; however, the NRC had been notified of the settlement and members of NRR had visited the site as early as April 13, 1978 to review the matter.

A Licensee Event Report was submitted on April 28, 1978.

e.

Discussion With NAEC Official In reviewing the draft of this summary, it was noted that the phrase "from information available to the NAEC" which appeared in the NAEC's letter to the Commissioners dated November 1, 1978, could imply that they had information beyond that which they addressed in the letter and which might not be known to the NRC staff. The NAEC representative who had signed the letter was contacted by telephone on March 28, 1978, and was asked if the NAEC had any information that had not been made available to the NRC.

The it.dividual stated that she did not believe they had any infor-mation beyond that available in the documents in the Public Document Room.

With regard to the allegation that VEPC0 was aware of the settle-cent ct Auru t 3, D77, the indi.' dual stated that this was based on the inforu tiva contained in LtCo's special report dated May 31, 1978.

Regarding reportability of the settlement, she stated that 4

9 the NAEC had contacted the consultant to the ACRS after reading his report to the ACRS dated July 19,1978 and that he ' ad said he felt the settlement should have been reported in August 1977.

IV.

CONCLUSIONS The records available clearly indicate that VEPCO intended that a.

there be one monitoring program and that VEPCO expanded an existing contract with MH&C to accomplish the necessary surveys.

b.

Prior to issuance of an operating license, VEPC0 relied on S&W to evaluate the survey data and forwarded the results of MH&C surveys to S&W.

Subsequent to issuance of the Unit 1 operating license, responsi-c.

bility for evaluating survey data to determine compliance with Technical Siccifications rested with the plant _ operating staff and l

only MH&C data was forwarded for their evaluation. However, VEPCO continues to forward the MH&C results to S&W for further evaluation.

d.

When reduced and evaluated, the results of the surveys performe' by S&W on and af ter August 3,1977 indicated that the service water pump house settlement had exceeded 75 percent of the limit; however the investigator could not conclusively establish the date that S&W-Boston or VEPC0 became aware of the August 3,1977, and subse-quent S&W survey results, but there was no indication that either received the raw data for these surveys until near the end of February 1978.

There did not appear to be any significant differences in the e.

handling and processing of S&W data of August 3, 1977 and later, when compared to the handling and processing of earlier S&W data.

f.

The allegations are not substantiated and no further investigative effort is warranted with regard to this matter.

9

-4

E. GUNTER ARilDT PROFESSIONAL QUALIFICATIONS STRUCTUP.ES & COMPONEllTS STAriDARDS BRAbCH OFFICE OF STAtlDARDS DEVELOPMENT I am a Senior Structural Engineer in the Structures & Component Standards Branch in the TIRC Office of Standards Development.

My responsi-bilities include the development of standards, codes, and criteria relating to the structural engineering aspects of reactor safety, and advising other NRC offices on related reactor safety matters.

In 1960, I received a Bachelor of Science Degree in Civil Engineering from the Tufts University College of Engineering.

My subsequent technical experience has been in the field of structural engineering.

I spent two and one-half years (1960-1963) in service with the U.S.

Navy Civil Enginee' ring Corps.

During~my service my assignments rotated through all phases 'of the Public Works Department of Rota, Spain, including duty as assistant to the Utilities Officer in the base power plant, and cratract administration.

From 1963 to 1968 I was employed in New York City by the structural consulting finn of Lev Zetlin & Associates. The job involved complete structural design, coordination, follow-through and field inspection for commercial and high rise buildings (theatres, apartments, hospitals, offices, etc.), as well as some specialized structures.

_2-In March 1968, I joined the AEC Division of Reactor Licensing in the Containment and Component Technology Branch as a Nuclear Structural Engineer.

From March 1970 until the formation of the NRC in 1974, I served in-the same capacity with the AEC Division of Reactor Standards, in the Structural Engineering Branch.

Since then, I have been in what is now the NRC's Structures & Components Standards Branch.

Codes and standards development participat' ion consists of:

1.

ACI 359, Code for Concrete Reactor Vessels and Containments Member, Subgroup on Inservice Inspection Coordinator of AEC/ REG review of draft Code 2.* ASME Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components.

Member, Working Group on Inservice Inspection for Gas Cooled Reactors.

3.

Various degrees of involvement in reviewing, endorsing or contributing to a variety of structurally related nuclear standards.

4.

IAEA, TRC.on Design & Construction In 1971, I attended a course on Design of Structures to Resist Tornadoes

& Hurricane Winds at the University of Texas at Lubbock.

Jared S. Wermiel Professional Qualifications Auxiliary Systems Branch Division of Systems Safety Office of Nuclear Reactor Regulation I am a Reactor Engineer in the Auxiliary Systems Branch in the Division of Systems Safety, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission.

In this position I perform technical reviews, analyses, and evaluations of reactor plant features pursuznt to the con-struction and operation of reactors.

I received a Bachelor of Science Degree in Chemical Engineering from Drexel University in 1972.

Since 1972 I have taken courses on PWR and BUR System Operation, Reactor Safety, and Fire Protection.

My experience includes seven years with the Bechtel Power Corporation as a Systems Design Engineer engaged in the design of various nuclear power plant auxiliary and balance of plant systems.

These have in-cluded cooling water systems, water treatment systems and fire protec-tion systems.

I joined the Auxiliary Systems Branch of the Commission in March, 1978.

Since joining the Comm'ssion I have performed safety evalua-tions on safety related ccoling water systems for the Virgil C.

Summer Nuclear Station, Palo Verde Nuclear Generating Station Units 4 and 5, Allens Creek. Nuclear Generating Station, Byron /Braidwood Stations and Enrico Fermi Atomic Power Plant Unit 2.

In addition, I have reviewed and commented on the proposed ANSI Standard for

_2 safety related cooling water systems.

I have responsibility for the review of the following nuclear power plant auxiliary systems: new and s;.ent fuel storage, spent fuel pool cooling, fuel handling, ser-Vice water, component cooling water, condensate storage, ultimate heat sink, instrument air, chemical ard volume control, main steam isolation valve leakage control, heating ventilating and air condition-ing, fire protection, portions of the main steam system,and auxiliary feedwater.

~

I am a registered Professional Engineer in the State of Maryland.

I am'an Associate Member of the American Institute of Chemical Engineers.

UNITED STATES OF A.'.! ERICA NUCLEAR REGULATORY CO:.::.11SSION BEFORE Till:. ATOhllC SAFETY A;!J LICEdSING APPEAL BOARD in the L..latter of

)

VIRGINIA ELECTRIC AND POWER CO.\\lPANY )

Docket Nos. 50-338 OL

)

50-339 OL (North Anna Nuclear Power Station,

)

Units 1 and 2)

)

NOTICE OF APPEARANCE dotice is hereby given,that the under igned attorney herewith enters an appearance in the captioned matter. In accordance with s 2.713(a),10 CFR Part 2, the following information is provided:

Name llenry J.1,1cGurren Address U.S. Nuclear Regulatory Commissica Office of the Executive Legal Director Washing ton, D. C. 20555 Telephone Number Area Code 301 - 492-7836 Adraission Supreme Court of the State of Illinois Name of Party NRC Staff U.S. Nuclear Regulatory Commission Washington, D. C. 20555

,If ' - :",

l,'. :y /, L.;'),],_

V' I

,1 lleifry J. ' tcGurren Counsel for NRC Staff Dated at Bethesda,..laryland this 4th day of alay,1979

ML19259C462

Text

Enclosures:

Response

Enclosure:

SUMMARY

SUMMARY

Subject:

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