ML20083J582
| ML20083J582 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/06/1984 |
| From: | Pollard R, Weiss E UNION OF CONCERNED SCIENTISTS |
| To: | NRC COMMISSION (OCM) |
| References | |
| NUDOCS 8401100200 | |
| Download: ML20083J582 (15) | |
Text
..
00CKETED UwRC
'84 J1'-9 All :09 UCS 1/0/84 UNITED STATES OF At' ERICA
~-
NUCLEAR PEGULATORY COMrilSSION BEFORE THE C(HMISSION In the Eattor of
)
)
METRnDOLITAN EDISON COFPANY
)
Docket f!n. 50-289
)
(Pestart)
(Threo Mile Island Nuclear
)
Station, Unit No. 1)
)
UCS REDUTTAL TO LICENSEE'S PEPLY REGARLING EFU FLOW INSTRUMENTATION Introduction On Dec+nber 6, 1983, counsel for GPU transmitted to the Ccomi s sior a document which it characterized as "potentially rel ev a r.t and material to matters under acjudicatior in the plant design and proceduros ph<ise" of the TMI-l restart proceecino.
The docunent is a letter from H.
D.
- Hukill, Director of TMI-1, to J.
F.
Stolz, PRC Staf f, dated Naverber 23, 1983.
The letter disclosed that the emergency feedwater (EFW) flow instruments instailed at TitI-l to comply wi th the short-term " lessens learned" requirements do not meet NRC's criteria or GPU's commitment in the restart proceedinc.
On December 9,
1983, UCS filed with the Commission, " Union of Concerned Scientists Response to GPU Letter of December 6, 1983, Regarcing Energency Feedwater Flow Instrunentation." (Hereinafter, "UC5 Response") On December 23, 1983, GPU filed with the Commission, " Licensee's Reply to UCS Response to GPU Letter of December 6,
- 1983, Pecardina Eneroency Fredwater Flow 8401100200 840106 PDR ADOC,'. 05000289 C
PDR y>
, Instrumentation."
(Hereinafter, " Licensee's Reply")
Licensee's counsel claimed that its reply was submitted "in order to correct the serious factual errors in the UCS pleadino, which miaht otherwise be overlooked because of the extent and exaccerated nature of the nisplaced arguments which are bailt upon them."1I UCS has evaluated Licensee's arcuments and submits tFis rebuttal to demonstrate that UCS made no factual errors and that the evidence supports our arguments.
Discussion GPU's first defense is that +10't accuracy is not "a perforr'ance criterion which is part of the
' lessons learned' recuirement for EFW flow i ns t rumenta tion. "U Licensee claims unecuivocally that "there is absolutely no basis for the UCS characterization of +101 accurecy as a 'reauirement' for EFW flow instrurnentation." !
Perhaps the Licensee has not read all of the pertinent material.
In fact. durina the THI-l restart hearino. the requirerent for EFW flow indicationwasasfollows:b P0s! TION Consistent with satisfyina the recuirements set forth in GDC 13 to provide the capability in the control room to ascertain the actual performance of the AFWS when it is called to perform its intended function. the following requirements shall be implemented:
1/ Licensee's Reply at 1-2.
2/
Id. at 2.
3/
Id. at 2-3.
-4/ Staf f Ex.1, f UREG-06PO. "TMI-l Restart." June 1980, p. C8-38, emphasis added.
. 1.
Safety-grade indication of auxiliary feedwater flow to each steam generator shall be provided in the control roon.
2.
The auxiliary feedwater flow instrument channels shall be powered from the emernency buses consistent with satisfying the energency pcwer diversity reouirenents of the auxiliary feedwater system set forth in Auxiliary Systems Branch Technical Position 10-1 of the Standard Review Plan. Section 10.4.9.
CLARIFICATI0l' l.
Auxiliary feecreater flow indication to each stean cenerator shall satisfy the single failure criterien.
2.
Testability of the auxiliary feedwater flew instrument channels shall be a feature of the design.
3.
Auxiliary feedwater flow instrument channels shall be powered from the vital instrument buses.
4 f,uxiliary feedwater flow indication to each steam generator shall satisfy safety-grade reouirements.
S.
For itens 1-3, the flow indication channels should by themselves satisfy the sinole f ailure criterion for each steam generator. As a fall-back position, ore auxiliary feedwater flow channel may be backed up by a steam cenerator level channel.
6.
Each auxiliary feedwater flow chaneel should provide an analoa indication cf teer flow with an accuracy on the order of +10.
Thus, a
+10*.
accuracy criterion was clearly in effect.
The NRC Staff testified that the licensee had committed to installing two safety grade sonic flow devices on each of the two EFW supply lines to the stram acnerators and that the licensee " indicated that the new flow device.s have an accurac; of bettor than +S?,, which is acceptable to the staf f."b Based on its review and evaluation of this i n f o rma ti on, the Staft concluded that TMI-l was
'in compliance with all the requirements of NUREG-0578 i tem 2.1. 7.b, subj e c t to S/
Id., p CC-39.
Actually, the Staff exaggerated Licensee's claim. GPU only raid that the EFU flow instruments would have an " accuracy of better than or equal to 5%."
See Lic. Ex. 1, Am. 22, p. 2.1-23.
l
. submittal of the vendor environmental cualification certificntion."b/
The Licensing Board relied upon the in forma tion provided by GPU and the Staf f's cenclusion "that Licensee is in compliance with the NUREG-0578 recommendation, in item
?.l.7.b, for emeroency feedwater flow indication to the steam generators."1/
r in November 1%0, after the licensee and staff te s ti n'ony on which the Licensing Board relied was submitted. NUREG-0737 was published.
With respect to EFW flow instrumentation, the most pertinent part of t'UREG-0737 is t h'e following:$/
Clarification The intent of this recommennation is to assure a reliable indication of AFWS performance.
This objective can be met by providina an overall indication system that neets the followirq appropriate design principles:
(1) For Babcock and Wilcox Plants (a) To satisfy these renuirements, BAW plants nust provide as a minimum two auxiliary feedwater flowrate indicators for each stcam generator.
(b) The flow indication system should conform to the followino salient paraaraphs of IEEE 779-1971:
IEEE 279-1971, PAPAGRAPH 4.l*
General Functionel Reauirements 4.P*
Single Failure 4
4.3 & 4.4 Oualification 4.6 Channel Independence 4.7 Control and Protection System Interaction 4.9* 8 4.10*
Capability for Testing
- These recuirements were part of the short-term control-grade requirements.
6/
Id., p. C8-40.
The Staff subseauently addressed the environmental qualification of the sonic flow devices.
See Staff Ex. 14, NUREG-0680, Supp. No. 3, April 1981, pp. 38-39.
7/ Metropolitan Edison Co., (Three Mile Island Nuclear Station, Unit 1),
LOP-81-59, 14 NRC 1211, 1362, December 14, 1981.
8/ NUREG-0737 at 3 3-83.
l'
. In ef fect, the' earlier " Clarification" items listed in NUREG-0680 were folded into. the " Clarification" in NUREG-0737 that the EFW flow instruments should meet the listed portions of IEEE 279-1971.
One of the pertinent IEEE 279-1971 sections cited provides as follows:
4.1 General Functional Requirement. The nuclear power generating station protection system shall, with precision and reliability, automatically initiate appropriate protective action whenever a. condition monitored.by the system reaches a preset level. This recuirement applies for the full range of conditions and performance enunerated in j5ections 3(?), 3(8),
and 3(9).
[In turn, Section 3(9) provides as follows:)
- 3. Design Basis A specific protection system design basis shall be provided for each '1uclear power generating station. The information thus provided shall be available, as needed, for making judgments on system functional adecuacy.
The design basis shall document as a mininum, the following:
(9) minimum performance reouirements including the following:
(a) system' response times;
. (b) system accuracies; (c) ranges (normal, abnormal, and accinent conditions) nf the magnitudes and rates of change of sensed variables to be accommodated until proper conclusion of the protective action is assured.
fEmphasis added.]
Since the only accuracy figure reported-by GPU itself was +5% (See n.
5, supra), one could conclude that if NUREG-0737 is applied rather than
'NUREG-0680, the +5% criterion rather than the +10% criterion is in effect.
NUREG-0737 surely provides no "out" for GPU.
Moreover, in reporting to the NRC Staff six weeks ago, GPU itself stater 1 'he following:
Recent tests performed on the EFW systen in conjunction with OTSG testing indicateo oscillations at low flow conditions (less than approximately 100 gpm) outside the +10; criteria.
9/
H. D. Hukill, Director of TMI-1, to J. f. Stolz, NRC Stat f, "EFW Flow
~
Devices (D/P) Testing", November 23, 1983, p. 1, emphasis added.
. lhus, there seems to have been no ouestion in GPU's mind until very recently that a +10% criterion existed for EFW flow instrumentation accuracy.
In summary. GPU's denial that +10% accuracy is a reouirement f or EFW flow Hstrumentation is inaccurate.
GPU's second argument is that UC5 " ignores tne limited ficw regime for which the oscilllations occur, dnd proceeds to postulate the complete absence of EFW flow indication."El To begin wi th, UCS die not postulate " complete absence" of flow indication (whatever that may nean).
We postuiated "the lack of reliable flow indication."SI GPU seems to be arauing that the inability to reliably measure EFW flow at low flow rates is insionificant because "f Mn a TNI-2 accident condition, full EFW flow would be desired
. "E!
It is of course true that full EFW flow would be desired at the outset.
- However, once the water level in the steam cenerators reaches the desired level and decay heat diminishes, flow would 'b e tnrottled to a low flow condition to safely cool the plant down.
This is precisely the condition when the EFW flow a
instruments are said to be inaccurate and the condition UCS referrred to when we postulated that the lack of reliable fl ow indication could af fect proper operator action.
In addition, it is worth noting that GPU's Novenber 23, 1983, letter to the NRC Staff does not precisely indicate for what flow range the instruments are reliable.
Mr. Hukill states that t sting at flows less than approximately 100 opn " indicated" that the +101 criterion was not met and that tests 10/ Licensee's Reply at 3.
M / UCS Response at 4.
12/ Licensee's Reply at 3.
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-7
" indicate" that above 400 ppm the instruments are within +10%.S/
He also states that "during the Power Escalation testing data will be collected' and used to assist the operators in uncerstandina how the EFW flow devices are expec ted to perform under various EFW flow conditions."E Thus, it appears that it is not known how the instruments will nerform under a variety of flow conditions.
GPU's third argument relat.es to UCS's point that the EFW pumps are cooled by flow through the pumps and that, ther'efore, "f ailure of the recirculation flow paths could recuire prompt oper.itor Action to nrevent failure of the EFW pumps."$/
GPU responded by statino that "UCS apparently is not aware that Licensee has committed to lock open the EFW pump recirculation line valves."5/ GPU is correct that, as of. December 9, 1083, UCS was unaware that the recirculatien valves are supposed to be locked open.
This was subsecuently announced at a NRC Staff /GPU meeting on Decenber 16, 19fs 3.
However, this does not affect UCS's observation that tailure of the recirculation flew paths could recuire prompt operator action because: 1) GPU has demonstrated a proclivity _ for. f ailing to have valves in their correct positions; 2) there are other valves ip the recirculation flow paths which, if.
closed, could block, recirculation flow; and 3) locking cpen the EFW pump reci rcul a tion line valves creates an. additional sa fe ty hazard.
We explain each of these seriatim.
--13/
H. D. Hukill, Director of TMI-1, to J. F. Stolz, NRL Staff, "EFW Flow Devices (0/P) Testino", Noverber 23,19L3, p.1.
14/
Id. at 2.
15/ UCS Response at 5-6.
16/ Licensee's Reply at 3.
- The accouacy of the plant design features and administaative controls provided to assure that valves are in their correct positions was a subject of the restart hearing.
In response to a centention first advanced by UCS and later adopted as a Licensina Board question, the ASLB found "that the EFW systea is important to safety whether or not it was classitied as a safety systen at the time of the accident."
The Board also found that "It]he existino autcr'atic indicators in coniunction with the additional acministrative control being innlementcd by Licensee will serve to verify the operational readiness of systems ic portant to safety."b Despite these predictions by tbc Licensing Board. GPU has continued to demonstrate its inability to ensure that important valves are in their correct positions.
For example, when containrient integrity was recuired, a conflict between plant procedures caused a containment isolation valve to be partially open.
In another instance, two independent verifications of valve position failed to identify a valve in the " stuck"' open position.
Finally, the Staff identitied "three apparent violations durir.g hot functional testing in which valves were inadvertently left open or were misoperated, that resultec in safety components being inoperable for chort periods of time."E l lhus, in view of GPU's history of mispositioning valves both prior and subsequent to the TMI-2 accident, CPU's clair that the EFW recirculation line valves will be locked open provides little assurance that recirculation flow will be available.
Therefore, the availability of EFW flow instumentation 17/ Metropolitan Edison Co., (Three File Island Nuclear Station, Ur.it 1),
LBP-bl-59, 14 NRC 1211, 1313, Dec erbc r 14, 1981.
See also aenerally paracraphs 887-906 at pp. 1312-1317.
'8/ See Richard W. Starostecki, IE, to H. D. Hukill, Director, TMI-1, October 28, 1983, and enclosed Inspection Reports 50-289/83-25 and 50-289/83-26.
l.
1
! which is accurate at low flows is reouired so that, among other things, prompt operator action might be taken to prevent damage to the ' EFW pumps if the recirculation flow path is blocked.
Second, UCS is aware from attendino NRC Staff /GPU meetinos that GPU's
. promise to lock open the EFW recirculation lire valves applies specifically to valves EF-V-HA, EF-V-8B and EF-V-FC.
However. the recirculation lines also contain check valves (EF-V-19A, EF-V-19B and EF-V-21) and t hrottle valves (EF-V20A,EF-V20BandEF-V22).$/ Even it these valves were added to the list of those which are supposed to be locked open (in the case of the check valves, this might not be possible), the above discussion iagardino GPU's
~ history of mispositioning valves would still apply.
Finally, even if all EFW recirculation line valves were actually locked open, this would create another safety problem, narrely: the loss of excessive
-water from the condensate storage tank following an earthquake.
The recirculation lines are not seismically aualified and have not even been shown to be capable of remaining intact during the very mild Operating Basis Earthouake.El As CPU has noted, the combination of the loss of water from the broken recirculation lines and the CST "B" de-ice line "would present a safety concern".since there would be not be sufficient water in the Condensate
. Stcrace Tanks to cool down the plant.SI If the recirculation line valves are locked open, the operator would be unable to close them promptly to halt the water loss.
(Of' course, since the recirculation line valves are not presently 19/ Lic. Ex.1, " Restart Report," Figure C-302-081, Pev.17.
-20/
H. D. Hukill, Director, TMI-1, to Darrell G. Eisenhut, ARC Staff, Seismic Qualification of Auxiliary Feedwater System, September 29, 1981, p. 1.
-21/ H;- D. Hukill, Director, TMI-1, to J. F. Stolz, NRC Staf f, July 7,1982,
' Encl. 2. " Evaluation of TMI-1 Condensate Supply for Emeraency Feedwater,"
- p. 4.
. seismically cualified either,22/ the operator might not be able to close them even if they were not locked open.
This is only one aspect of the dilenma CPU faces in tryinq to justify operation with an EFW systen that is not safety grade.)
In sunea ry. locking open the EFW recirculation line valves is not a viable alternative to providina EFW flow indicatien which is accurate at low fl ows.
Another argunent advanced by GPU in its attempt to justify operation of TMI-1 wi th inaccurate EFW flow instrumentat,oi is that during manual takeover of the emeroency feedwater system, "the operator would not control flow based upon this indication alone."b!
Mr. Hukill also made this point, stating that
" Emergency Feedwater continues to be controlled based on the OTSG level and pressure (level to prevent over/under-filling and pressure to prevent over-coolina).
Tre operator's attention is focused on these instruments wnen reculatina flow."El First of all, the reauirement for safety crade EFW flow inoication was adopted by HRC with full recognition of the existence of steam aenerator level indication.NI However, the utility of steam generator pressure in
-22/
H. O. Hukill, Director, TMI-1, to D. G. Eisent ut, NRC Staf f, February It,
1982, enclosure, Table A.
23/ Licensee's Repl.y at 4.
-24/
H. D. Hukill, Director of TMI-1, to J. F. Stolz, NRC, "EFW Flow Devices (0/P) Testing," November 23, 1983, p. 2.
-25/ During the TMl-1 restart hearing, the requirement for two flow indicators for each steam generator was clarified as follows: "As a fall-back position, one auxiliary feedwater flow channel may be bocked up by a steam generator level channel." Staf f Ex.1, NUREG-0680, "TM1-1 Restart," June 1980, p. 08-38, emphasis added.
6__
. controllina EFW flow is not explained by GPU nor is it apparent.
In any event, the TMI-l emergency procedures focus on venting of the steam generators (usina the turbine bypass or atmospheric dump valves) as the principal means the operator should use to control steam generator pressure.
A review of the TMI-l emeroency procedures in UCS's possession indicates that the operator does not use steam generator pressure to control EFW tiow rate and we have r,0where previously heard this asserted.
In addition, cavitatina venturis in the EFW discharae lines nininize the potential for overcooling as a result of excessive EFW flow, a condition in which tne EFW flow instruments are allegedly accurate anyway.
Secondly, the requirement f or EFW flow indication was anopted to provide the capability in the control room to ascertain the octual perfornance of the EFW system.
This requirement was relaxed, for Westinchouse and Combustion E_ncineering plants, to the extent that only one EFW flow indicator for each steam cenerator is required "for PKPs with U-tube steam generators because flow i'ndication is of secondary importance in assurino steam cenerator cooling capability for steam generators of this desion."U Pecause TM1-1 uses a once-through steam generator design, EFW flow indication is of primary importance.
Finally, GPU's arouments ignore the TMI-2 accident lessons learned in another respect.
During the accident, the operators focussed their attention on pressurizer level and shut off the emergency core coolina systen to the detriment of core integrity.
The operators then ionered indications of ex tremely. hi ch temperatures in the core because they knew inn incore thermo-26/ NUREG-0737, "Clarificatio.n of TMI Action Plan Recuirements," November 1080, p.
II.E. 1.2-4.
~
. couples were not safety grade and thus potentially unreliable.b flow GPU proposes to have the operaters focus their attention on the steam generator level and pressure instruments and assist the operators in understanding how the EFil flow instruments perform, i.e.,
inaccurately at low flows.
It is unlikely that such an approach can meet the requirement that the EFW flow instruments"notincreasethepotentialforoperatorerrrnr."b GPU's final response is related to our rcint that GPU has turned its back on the experience of the TMI-2 acciden by puttinq the operators in a position where they have to take important actions on the basis of unreliable instruments.
We noted that during the TMI-2 accident, the operators ionored the thermocouple readings showing extrer'ely biah core temperatures because they knew the instruments were not safety arade and thus potentially unreliable.EI GPU's breathtaking response is that the "EFW flow instrumen-tation at TMI-1, however, is safety grade."b/ This response is remarkable on several l evel s.
First, an instrument without reasonable accuracy cannot be said to be safety grade.
Secondly, these instrunents are not reliable and cannot theretere be relied upon by the operators.
Inct is precisely what the fundamental problem was with the thermocouples.
GPU has nissed the forest for the trees -- whatever the cause of the unreliability, the result is that the i
operators cannot be assured that the informatie:7 they need to safely operate the plant is accurate.
~27/ ?!RC Special incuiry Group, "Three faile Islanc. A Peport to the Comnissioners and to the Public," January 1090, Vol.1, p.
126; Vol.II, Part 3, pp. 898, 901.
28/ tJUP.EG-0737, p. II.E.1.2-5.
29/ UCS Response at 5.
30/ t.icensee's Reply at 4.
. In summary, the lessons learned from the TM1-2 accident specifically require what THI-l does not have emergency feedwater flow instruments meetino strict, detailed performance criteria to ensure that operators can rely on them.
Faced with the reality that it lacks sufficient technical competence to design accurate EFW flow instruments despite two attempts, GPU essentially attempts to arque that accurate instruments are unnecessary.
Such an argument was not advanced by GPU during the restart hea ri ng.
Its advancement at this late date does not cure its fundamental defect -- it has no merit.
Conclusion The root cause of most of the dif ficulties di. cussed above-is that GPU is attempting to patch bandaids over a fundamentally deficient EFW system.
If the EFW system were truly safety grade, each of its component parts could be relied upon to perform. its function and not to fall in ways. that compromise sa fety.
Instead, each time GPU tries to jury rig a temporary " cure" for one part of the system's deficiencies, it causes or accentuates others.
UCS' urges the Corrmi ssion at the least to reject GPU's _ attempt to circumvent the short-term lessons-learned reouirements for EFW flow instrumentation.
Respectfully submitteo, 4
{t -
n ET1yn<R. weiss -_
General Counsel
//$
{
. N/
Robert i>. Pol 1ard nuclear Safety Enaineer
' Dated: January 6, 1984
\\
- O UNITED STATES OF AMERICA FUCLEAR REGULATORY COMMISSION In the Matter of
)
)
METROP0LITAN EDISON COMPANY
)
Docket ho. 50-289
)
(Restart)
(Three Mile Island Nuclear
)
Station, Unit No. 1)
)
CERTIFICATE OF SERVICE I hereby certify that copies of "UCS REBUTTAL TO LICENSEE'S REPLY REGARDING EFV FLOW INSTRUMENTATION" have been served on the followinn persens by depcsit in-the United States mail, first class postace prepaid, this 6th day of January 1984, except as noted by an asterisk.
Nunzio Palladino, Chairman Gary J. Edles, Chairnan U.S. Nuclear Regulatory Commission Atomic Safety and Licensino Appeal Board Washington, D.C. 20555 U.S. Nuclear Reaulatory Cormission Washinaton, D.C. 20555 Victor Gilinsky, Conmissioner U.S. Nuclear Regulatory Connission Dr. John H. Buck Washinoton, D.C. 20555 Atenic Safety ano Licensina Appeal Board U.S. Nuclear Reaulatory Commission James Asselstine, Cemnissioner Washington D.C. 20555 U.S. Nuclear Reculatory Commission Washinqton, D.C. 20555 Dr. Reginald L. Gotcny Atomic Safety and Licensina Appeal Board Frederick Bernthal, Commissioner U.S. Nucicar Regulatory Commission U.S. Nuclear Regulatory Commission Washington D.C. 20555 Washington, D.C. 20555 Judge Christine N. Kohl Thomas Roberts, Commissioner Atomic Safety and L,icensino Appeal Board U.S. Nuclear Reculatory Cornission U.S. Nuclear Reculatory Connission Bashinoton, D.C. 20555 Washinaton, D.C. 20555 Docketino ana 5(rvice Section Ivan W. Snith, Chairman Office of the Secretary Atomic Safety and Licensino Feare U.S. Nuclear Reculatory Commission U.S. Nuclear Regulatery Ccnnissicn Washington, D.C. 20555 Washinoton, D.C. 20555
Sheldon J. Wol fe, Al ternate Chairman
- William S. Jordan, III Atomic Safety and Licensing Board Harmon & Weiss U.S. Nuclear Regulatory Commission 1725 1 Street, N.W.
Washington, D.C. 20555 Suite 506 Washington, D.C. 20006 Professor Gary L. Milhollin 4412 Greenwich Parkway John A. Levin, Assistant Counsel Washington, D.C. 20007 Pennsylvania Public Utility Conmission P.O. Box 3265 Mrs. Mariorie Aamodt Harrisburo, Pennsylvania 17120 R.D. A5 Coatsville, PA 19320 ANGRY /TNI P!RC 1037 Maclay Street Douglas R. Blazey, Chief Counsel Harrisburo, PA 17103 Department of Environmental Resources 514 Executive House, P.O. Box 2357-
- 'ateven C. Sholly Harrisburg, PA 17120 Union of Concerned Scientists 1346 Connecticut-Ave., N.W., Suite 1101 Ms. Louise Cradford Washington, D.C. 20036 Three Mile Island Alert 1011 Green Street Richard J. Rawson Harrisburg, PA 1/102 Of fice of Executive Leoal Director U.S. Nuclear Regulatory Commission Dr. Judith H. Johnsrud Washinaton, D.C. 20555 Dr. Chauncey Kepford Environmental Coalition on Thoras A. Baxter, Esq.
Nuclear Power Shaw, Pittman, Potts & Trowbridge 433 Orlando Avenue 1F00 M Street, N.W.
State College, PA 16801 Woshinoton, D.C. 20036 f
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- Hand delivered.
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