ML19263F222
| ML19263F222 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/13/1972 |
| From: | US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML19263F223 | List: |
| References | |
| NUDOCS 8001100646 | |
| Download: ML19263F222 (17) | |
Text
s UNITED STATES OF AMERICA fiUCLEAR REGULATURY COMMISSION OFFICE OF f;UCLEAR REACTOR REGULATION HAROLD R. DENTON, DIRECTOR in the Matter of
)
)
PHILADELPHI A ELECTRIC COMPANY
)
Docket f;os. 50-352 (Limerick Nuclear Generating
)
and 50-353 Station, Units 1 & 2)
)
DIRECTOR'S DECISION UNDER 10 CFR 2.206 By letter dated April 12, 1979, Frank Romano of Ambler, Pennsyl.'ania, reosysted that the Commission investigate whether blasting at a quarry near the site of the Philadelphia Electric Company's (PECO) Limerick Generating Station has a deleterious effect on the site. Mr. Romano's letter has been treated as a request under 10 CFR 2.205 of the Comission's regulati:ns.
lutice of receipt of Mr. Romano's April 12th letterplas published in the Federal Register 44 Fed. Reg. 33987 (June 13,1979).
In letters dated May 14 crd June 12, 1979, Mr. Romano also raised concerns related to (1) concrete void / honeycomb in a structure at the Limerick facility, (2) the computer analysis used in the seismic design of safety-related piping, (3) the dis-covery of insufficient gaps between seismic Category I structures, and (4) a request for information from the NRC sent to PECO on April 14, 1978,
.regarding the design of safety-related components in the containment building.
Mr. Romano requested that repair of concrete void /honeyccmb be included in his request for an investigation of blasting near the Limerick site.
While the subject of the blasting was covered during the preparation of the Safety Evaluation Report on the preliminary design, it is not clear that two particular issues were adequately treated.
One issue is whether the design 2211 029 8001100 l-f6
s ground motino adopted for the Limerick plant is adequate to enveloo the spectra rnation that includes the effect of blasting.
The second issue is the potential for displacement along the faults under the facility due to the blasting.
Before the Staff can affirm its previous conclusion that the nearby blasting would not have a detrimental effect on the facility, the Staff must investigate these ratters.-1/
Thus, I have determined that an investigation should be ccnducted of the effects of blasting at the quarry near the site of the Limerick facility.
A geotechnical engineer was sent to the site arer in May 1979 and discussed this concern with personnel from tiRC's Office of Inspection and Enforcement.
In addition 1.ne fiRC staff has enlisted'the assistance of technical experts f rem the U. 5. Geological Survey.
The U. S. Geological Survey has been requested to e.aluate the two specific items described above:
(1) whether the present seismic design bases (ground motions) are adequate to account for the effects of the r.earby blasting and (2) the likelihood that the nearby blasting will reactivate old faults at the site.
The fiRC staff requested that the U. S. Geological Survey complete its evaluation by December 31, 1979.
However, completion by this date is depend-ent on the availability of U. S. Geological Survey reviewers and possible need for acquisition of required data from the applicant.
1/
In this respect the Staff disagrees with the applicar.t's position in this ratter.
In a letter of August 22, 1979, from its counsel, Troy S. Conner, Jr., the licensee stated that the record concerning the issuance of the c = truction permits indicated that the potential effects of blasting had been fully explored.
2211 030 The other concerns expressed in Pr. Romano's April 12, 1979 letter relcting to site geology, fracture zones and the adequacy of the foundations have been addressed in the Safety Evaluation Report issued in fiovember 1971 and in the staff's evaluation of f aulting in the excavation issued January 23, 1975.
In these previous reviews of faulting at the Limerick site the staf f ccncicded that (1) the f aults were not capable faults and (2) the methods used to repair the fracture zones were acceptable.
At this time I fir no reason to alter these conclusions.
In any event, review of the Limcrick Final Safety Analysis Report will again consider these issues as part of our consideration of PECC's application for operating licenses.
I have determined that a further investigation of concrete void / honey-conb at the Limerick facility is not warranted at this time.
Certain concrete vi d/ honeyc omb 'ere discovered in the Unit f.o. I containment building while the structure was being built in 1976.
These defects in the concrete were
_;ated in seven areas around the personnel air lock penetration and the con-1;el rod drive mechanism penetrations.
The voids were caused in part by the tcngestion of reinforcing steel around these penetrations which made it difficult to place the concrete.
The locations of the defects are listed in (IE Inspection Report tio. 50-352/77-01).
In repairing the con-tainment wall, the defective concrete was removed; the steel reinforcing and sound concrete were left in the area.
The overriding criteria for repairing the concrete are proper placement and strength. Grout, a mixture of sand, water and cement, was the material chosen for the repairs. By design the grout did not contain coarse aggregates (stones) that are normally a part of concrete. The use of coarse aggregates 2211 031
4 in concrete reduces the amount of cement required; this nakes concrete a rcre economical building material when used in large quantities. However, the onission of the coarse aggregates enhances the grout's ability to penetrate the crevices in the surfaces to which the grout is applied. Al so, the onis-sion of the coarse aggregates does not lead to a material that has a lower ccapressive strength than that of the concrete used for the containnent walls.
To verify that the grout achieved the requi ed compre' 3ive strength, test samples were made at the time of grout placement. Tre samples were allowec to cure and were subsequently tested by PECO.
The compressive strength of the samples was equal to or greater than that required.
'F.e f;RC's.0ffice of Inspection and Enforcement investigated the matter of the cencrete void /honeycenb at the Limerick plant.
Inspection personnel followed the matter frcm the discovery of the voids /honeyccmb to tne repair of the containment walls. The inspection efforts on this matter are documented in Inspection Reports 50-352 /76-08, 50-352 /76-09, 50-352 /77-01 and 50-352 /77-15, copies of which are enclosed as Enclosure 1.
In summary, the Of fice of Inspec-tion and Enforcement 1oncluded that PEC0's resolution of the problem was acceptable; therefore, I find that further investigation at this tine is not warranted. Of course, should new information become available concerning additional honeycombing in concrete at the Limerick facility, the Commission will not hestitate to investigate such problems or take appropriate action to assure that such deficiencies, if any, are corrected.
Although specific action was not requested with respect to the other con-cerns raised by Mr. Romano in his letters, the remainder of this decision addresses those concerns.
Each of these items involves matters subject to 1!
032
' either ongoing or future review by the 'GL.
The item regarding computer analysis and the seismic design of piping systems is the subject of IE Eulle-tin 79-14 (Enclosure 2).
This bulletin requested that PEC0, ancng other licensees, take certain actions and report the results to NRC within 120 days of the bulletin.
PECO's response was submitted on August 1,1979.
I n addi-tion to PEC0's response to the bulletin, we will review the seismic design of safety-related piping systems during our review of
.e Final Safety Analysis (FSAR) for the Limerick plant.
We expect the FSAR to be submitted by PEC0 during the spring of 1980, and our review of that document will prob-ably start shortly thereafter.
The NRC requested information on Arril 14, 1978, related to dynamic ~ioeds on the containment that were not explicitly considered with the seismic loads at the preliminary design stage.
This request for additional information was sent out to all plants under constrJCtion that utilize the Mark 11 pressure suppression containment.
The request is a part of our reassestment of the Mark 11 containment design which began in 1975.
In 1975, new pool dynamic loads on the containment were discovered by General Electric (the originator of the Mark 11 containment). Our reassessment also covers the operation of safety / relief valves.
Experienct at several operating reactors with pressure suppression containment had shown that damage to wetwall interval structures occurred during steam blowdown through the safety / relief valves.
This bicadown produces a dynamic load on components in or attached to the suppression pool.
In the FSAR for the Limerick plant, PEC? must show that the Limerick design can withstand the effects of combinations of setnic loads and each of the dynamic loads.
2211 033
Mr. D~ nano's final concern dealt with the separation gaps between struc-tures at the Limerick plant.
In the Preliminary Safety Analysis Report (PSAr:),
PECO corriitted to make the separation gaps between seismic Category I structures twice the distance determined by seismic analysis of the structures. However, during construction PECO found that some of the separation gaps did not neet this commitment; PECO reported this matter to the NRC in cogliance with 10 CFR
- 50. 55 ( e).
During PECO's study of this matter, a rear lysis of the seismic design was performed. As described in PEC0's final r eport dated June 13,197C, (Enclosure 3) this reanalysis included " realistic consideration of temperature and pressure transients; structural material and soil properties; soil-structure interaction; and structural and soil dampir.g." Based on the reanalysis, PECO four.d that some of the gaps which would be unacceptable under the original analysis were acceptable; the balance of the insufficient gaps were increased to meet the PSAR comaitment.
Mr. Romano's May 14th letter suggested that the reanalysis to justify the as-built gaps resulted in an unacceptable removal of conservatism. This is not necessarily the case. When an applicant uses realistic or "as built': parameters, conservative analysis technicues, and factors of safety applied to the results of the analysis, an acceptable result can be obtained. Again, our review of the FSAR for the Limerick plant must conclude that the design of the plant is acceptable before the plant can go into operation.
A copy of this decision will be placed in the Commission's Public Document Room at 1717 H Street, N. W., Washington, D. C.
20555, and the local public document rocn for the Limerick Nuclear Generating Station at the Pottstow1 Public Library, 500 High Street, Pottstown, Pennsylvania 19464.
A copy of 2211 034
s.
this cecision will also be filed with.he Secretary of the Ccruissicn for us review in accordance with 10 CFR 2.20(.(c) of the Cornission's regt,lations.
As provided in 10 CFR 2.206(c) this decision will constitute the fir,al action of the Conmission 20 days after the date of issuance, unless the Cor-mission on its own notion institutes review of this decisicn v.ithin that time.
FOR THE NUCLEAR REGULATORY CCPMISSIC',
l
/fim
/
fia rol d R. Denton, Di rector
( Office of Nuclear Reactor Regulation 6 d,yland Dated at Bethesda Mar 7
this fLday of 1979
Enclosures:
1.
IE Inspection Reports:
50-352 /76-08, 76-09, 77-01 and 77-15 2.
IE Bulletin 79-14 and Revision No.1; Suppl ement Nos. I and 2 PECO Report (6/14/78) 2211 035
s utilTED STATE 5 0F AMERICA f;UCLEAR REGULATORY COMMISSION Pl!!LALELPHI A LLECTRIC CC: PAfiY
)
Docket ho s. ' - 1..
(Lir crit k f:t:cl.cor 'irr.crat ir:c
_4 d t i on,
a nt: SC-E3 Units I coo 2)
)
( 11
". J j
!:0TICE OF ISSUMCE OF DIRECTOR'S DECISICf:
UtiDER 10 CFR 2.206 By letter dated April 12, 1979, Frank Romano of M ber, Pennsylvar.ia, requested that the Commission investigate the effects of blasting a' a nearby quarry on the site of the Philadelphia Electric Company's Linerick !;uclear Generating Station. flotice of receipt of Mr. Romano's April 12th letter was published in the Federal Register, 44 Fed. Reg. 33987 (June 13,1979).
In letters dated May 14 and June 12, 1979, Mr. Romano raised additional concerns regarding the Limerick facility and further requested that repair of cencrete voids in structures be investigated.
On review of the information presented by Mr. Romano, I have determined that the effects of blasting on the Limerick site should be conducted.
Because deficiencies associated with concrete voids and their repair have been pre-viously investigated and resolved, I have also detennined that a further inves-tigation into this matter is not warranted at this time.
2211 036 F
79/DD6 206 8M
s
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A copy of the decision in the matter will be placec in he Corr.issior's Public Document Rocm at 1717 H Street, ii. W., Washing or., C. C.
20555 ar.: i-the local public' document room for the Limerick Ge,erating Station at the Potts-town Public Library, 500 High Street, Pottstown, Pennsylvania 19464.
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Dated at Bethesda,, Maryland thi s 9 H-d ay of LL ach,vs W 2211 037
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