ML17298A886
| ML17298A886 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 02/29/1984 |
| From: | Knighton G Office of Nuclear Reactor Regulation |
| To: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| NUDOCS 8403090149 | |
| Download: ML17298A886 (14) | |
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Docket Nos.:
50-528, 50-529 and 50-530 FEB 29 1984 Mr. E.
E.
Van Brunt, Jr.
Vice President - Nuclear Projects Arizona Publ ic Servi ce Company Post Qffice Box 21666 Phoenix, Arizona 85036
Dear Mr. Van Brunt:
DISTRIBUTION Document=Control=50=528/529/530 NRC PDR L PDR NSIC PRC System LB83 Reading ACRS (16)
JLee EALicitra GLear
Subject:
Request for Additional Information - Palo Verde DER 81-35 The staff is currently reviewing the Final Report, along with the supporting documentation, that you submitted for DER 81-35 relating to the leaks in temporary water lines that disturbed backfill under seismic Category 1
structures at Palo Verde.
As a result of that review, we have determined the need for additional information in order to complete our assessment.
The specific information required is identified in the enclosed request.
We ask that you provide responses to this request and that you inform us within two weeks of receipt of this letter as to when the information will be provided.
If you have any questions regarding this request, you should contact Manny Licitra, the Licensing Project Manager.
Sincerely,
Enclosure:
As stated Odglnal algae'y:.
forgo N. K~tqhtea George W. Knighton, Chief Licensing Branch No.
3 Division of Licensing DL:LB83P/1 EALicitra/yt GLear P /D7/84
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Palo Verde Hr. E.
E.
Van Brunt, Jr.
Vice President - Nuclear Proiects Arizona Public Service Company P. 0.
Box 21666 Phoenix, Arizona 85036 Arthur C. Gehr, Esq.
Snell
& Wilmer 3100 Valley Center Phoenix, Arizona 85073 Mr. James H. Flenner, Chief Counsel Arizona Corporation Commission 1200 West Washington Phoenix, Arizona 85007 Charles R. Kocher, Esq. Assistant Counsel James A. Boeletto, Esq.
Southern California Edison Company P. 0.
Box 800
- Rosemead, Cal ifornia 91770 Ms. Margaret Walker Deputy Director of Energy Programs Economic Planning and Development Office 1700 West Washington Phoenix, Arizona 85007 Hr.
Rand L. Greenfield Assistant Attorney General Bataan Memorial Building Santa Fe, New Mexico 87503 Resident Inspector Palo Verde/NPS U.S. Nuclear Regulatory Commission P. 0.
Box 21324 Phoenix, Arizona 85001 Hs. Patricia Lee Hourihan 6413 S. 26th Street Phoenix, Arizona 85040 Regional Administrator - Region V
U. S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Kenneth Berlin, Esq.
Winston 5 Strawn Suite 500 2550 H Street, NW Washington, DC 20037 Ms. Lynne Bernahei Government Accountability Project of the Institute for Policy Studies 1901 gue Street, NW Washington, DC 20009
Enclosure Palo Verde Nuclear Generating Station, Unit 1 Docket No. 50-528 Request for Additional Geotechnical Information l.
Explain the basis for locating temporary water and other utility lines under Category I structures.
Provide a drawing showing
'ocations of these lines.
2.
Describe the compaction procedures for the backfill and the subgrade that were used around these utilities.
Provide.photographs of the bearing surface of the backfill before the mudmat or foundation>was placed.
3.
Explain the mechanism by which these leaks might have been caused and the sequence of events that lead to the pipe leaks.
Describe the extent of'eakage and show the affected zone{s), using drawings, with an explanation of the basis for your conc'lusions.
4.
In Section 5.4 of Reference 1, you have suggested that, in all probability, the leaks caused quite narrow paths within the backfill along pipes and walls before finding an exit.
You did not provide any logical basis for this hypothesis.
Explain why it is not more probable that the pipe leaks caused saturation and uplift.on almost all the backfill before seepage exited in the seismic gap.
Results of your limited excess grout-take during grouting of the pipelines tend to support the idea that erosion of soi 1 may not be concentrated in the area of the pipe leaks.
5.
In Table 1 of Ref. 2, you indicate that there are only two locations at which a leak is known to exist in the Fire Protection Pipeline.
In
~
. Table 2 of the same reference, you have shown that leakage was observed at many more locations of this pipeline.
Explain
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in this discrepancy.
- Also, CSH 0,
MP a review of Table 2 indicates that you observed leaks in CA, and AR lines as well.
Explain how you considered the effect.of leakage in these lines in your final safety evaluation of the"backfill condition.
"Also explain the mechanism which caused the leaks in these lines.
6.
Provide a listing of the locations and elevations of the safety related buried pipes and utilities essential for plant oper ation (that are not abandoned) that are within 100 ft radius of the known and potential location of pipe breaks and/or leaks.
Give dates of installation of these pipelines and utilities and explain your reasons to believe that these hese utilities will remain safe and functional despite the nearby pipe leaks, consequent backfill erosion, and potential removal of soil from this a
is area and beneath these facilities.
7.
Your settlement data and plots dated October 3 and 6, 1983 (Ref. 3) are not self-explanatory.
Update this information and provide the following additional details.
(a)
On large scale drawings (plans and cross-sections) show the location and dimensions of the Auxiliary Building (inc1uding deep section),
control building, corridor building and the abandoned Fire Protection System pipelines and any other abandoned utility lines.
C1early identify each bvi1ding area and'ocation of pipe lines and known and potential locations of breaks.
Show the'ocation of settlement monuments on the same drawings.
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(b)
Tabulate values of maximum measured total settlements at monuments that are located in the Containment Building, Auxiliary Building, Control Building, Corridor Building, Radwaste Building, and Diesel Generator Building (i) at approximately the time of discovery of pipe leakage
{say August 1981); {ii) in November 1981 (iii) after grouting (in November.1982) and (iv) based on latest settlement readings.
(c)
Tabulate values of the measured maximum differential settlements at the time periods indicated in (b)'above, and show comparisons of the measured data with the anticipated differential settlements assumed in the analysis of these structures and their appurtenances.
Evaluate the 'impact of any differences between the measured and anticipated settlements on the design and performance of these structures and I
appurtenances.
(d)
Large scale time (dates) vs. settlement plots of data between the time period of discovery of pipe leakage and the latest readings at monuments located in the Containment Building, Auxiliary Building, Control Building, Corridor Building, Radwaste Building, and Diesel Generator Building.
Analyze the data to indicate (i) history of total maximum.tilt:of each building (plots of date vs.
maximum tilt) and (ii) history of maximum differential settlement between adjacent buildings (plots of date, vs.
maximum differential settlements).
Discuss the impact of these values on the desigp and performance of the various seismic Category I structures, systems and components.
4
- 8..Ind'te how much settlement of the Auxili y, ar Control and Corridor between structures and buried buildings has occurred since the connections etw f the ast and safety-relate u i i ies d t'I t were made.
Evaluate the effect o p
anticipated.future settlement of these structures o
y n safet related utility connections.
9.
In your report on the engineering evaluaation of conditions of backfill after pipe leaks
{ e
{R f I) you have not provided sufficient analysis details and assump sons use i
t'sed in your analysis of the Auxiliary Huilding.
~Provide the following information in sufficient deta detail so as to enable the
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staff to make an independent evaluation of your analysis.
{a)
Your basis for assuming the extent and location of the non-bearing area under the auxiliary building.
Discuss the effect of possible backfill voids on the stability of the adjoining control building and corridor building.
Explain how you accounted for possible reduced density and reduced strength of the backfill under the structures after the pipe leaks:
{b)
The analytical model used to calculate the changed stresses:after erosion from pipe leaks, and the various material proper ties used in the model.
{c)
The modified properties of the backfill underneath the founaations after pipe leaks.
Compare these properties with the properties of the backfill used in your analysis for conditions existing before the leak.
Justify the basis for your assumptions made in the analysis.
H (d)
The various loads and load combinations used in evaluating the il
.changed stresses.
(e)
Details of the numerical results of analysis, and factors of safety, before and after the assumed erosion occurred.
10.
A review of your grouting program report suggests that the program was only intended to fill the temporary pipelines, and that it apparently 7
did not succeed in filling any ~voids in the backfill caused by leaks.
Your report also indicated that any further grouting of backfill is not considered necessary, in your judgement, as a result of your structural analysis findings.
Explain how you justify this position in view of the potential for future deterioration of support conditions caused'by a change in backfill density due to groundwater effects, an earthquake at the site, or any other unanticipated disturbance or vibratory activity in the vicinity of the plant.
Il.
In the report dated August 25, 1982 by your grouting consultant John King (Appendix E of Ref. 2), it is suggested that "should there be any need to fill remaining voids or consolidate loosened fill material, this can be handled by driving insert pipes into the soil in the gap and pressure grouting through them until the su~face starts to heave.",,
Describe detailed plans and procedures that you would use to grout t
the remaining backfill voids should this action be required to correct foundation defi cienc'i es.
'I 12.
Explain how you would implement a grouting program for potential vo>ds in the backfill under Category I structures, without undue due risk, while the plant is in operation.
Describe possible difficulties and precautions that would be needed,
>f any", in ca e
se the need for this remedial work should arise at a later date.
.References of Conditions of Backfill After Pipe Leaks l.
"Engineering Evaluation of Con i i Verde Huclear Generating Station,
- oenix, Ph Arizona H. 81-35) by Bechtel (Sendzyszyn, (Deficiency Evaluation Re'port o.
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'Mend, Schechter and Bingham), dated Nay 1982.
ar Pi in at the Palo Verde Nuclear 2.
",Grouting for Disposition of Temporary ip g
Generating Stat>on, ni St t'nits 1
2 and 3, Phoenix, Arizona y
ec e
1982.
3.
"Settlement Observation Record Tables and Grap y
hs
" b Bechtel, dated October 3 and 6, 1983.
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