ML20132D126
| ML20132D126 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Davis Besse |
| Issue date: | 06/17/1985 |
| From: | Markey E HOUSE OF REP., ENERGY & COMMERCE |
| To: | Palladino N NRC COMMISSION (OCM) |
| Shared Package | |
| ML20132B273 | List:
|
| References | |
| TAC-57932, NUDOCS 8506260600 | |
| Download: ML20132D126 (9) | |
Text
. -, Lc,. ~
" " C l *a
- M T. " ' _
- o. - ~
@fyya_
((c -3',6 U.S. HOUSE OF REPRESENTATIVES Ea".'u"."=I"O "dN'.".'o*k"'% camoun.
SUBCOMMITTEE ON ENERGY CONSERVATION AND POWER
"'""'L'",,*,,,",,,,,
CF THE q o y==c=Gaa COMMITTEE ON ENERGY AND COMMERCE u-,,,,,,,
WASHINGTON. DC 20515 June 17, 1965 The Bonorable Nunzio J. Palladino Chairman Nuclear Regulatory Commission 1717 H Street, NW Washington, D. C.
20555
Dear Mr. Chairman:
The June 9, 1985 incident at the Davis-Besse reactor near Toledo, Ohio is one of the most serious since the 1979 accident at Three Mile Island.
The large number of failures and the similarity to the accident at Three Mile Island raise significant concerns.
I am particularly troubled by the fact that NRC had previously recommended improvements to the auxiliary feedwater system and had previously identified serious management deficiencies at Davis-Besse.
Hence, it appears that there may have been opportunities to prevent such a close call.
The Commission must devote the same degree of scrutiny to itself as it does to the licensee.
It is important to determine the extent to which NRC is responsible for allowing Davis-Besse to suffer a major degradation of essential safety related equipment.
I would like to request that the Subcommittee be briefed on the Davis-Besse incident and other related matters on Friday, June 21, 1985 at 9:30 a.m. by the NRC Staff.
In addition to a representative of the Task Force investigating the incident, I would also request that William Dircks, Harold Denton and James Keppler be in attendence to brief Members of the Subcommittee.
As the briefing will be open to the public, the Commission is certainly welcome to attend, although this is not required.
Xh 856624%b@
The Honorable Nunzio J. Palladino June 17, 1985 Page 2 Additionally, I request your response to the attached questions within ten working days.
Some of these questions may arise at the briefing on Friday.
While I understand that your analysis of the incident is continuing, and that some of your answers may necessarily be subject to change, your preliminary response should be provided by June 28, 1985 at the latest.
A complete response should be provided to the Subcommittee prior to any restart of Davis-Besse.
Thank you for your attention to this important matter.
Sincerely, kN h
(
Edward J. Markey Chairman EJM:mw i
Attachment
Questions for the Nuclear Rsgulatory Commincion 1.
List each failure that occurred during the Davis-Besse incident including:
(a) the cause (s) of each failure; and (b) the intended function of the system or component that failed.
2.
Based on probabalistic risk analyses and precursor data prior to the Davis-Besse incident what was the estimated probability of the following:
a.
loss of main feedwater; b.
loss of main feedwater and loss of auxiliary feedwater; c.
failure of PORV to close; d.
each other failure that occurred during the incident; e.
the combination of all the failures that occurred during the incident.
i 1
3.
Had the electric driven startup pump not manually started during the Davis-Besse incident, and had the auxiliary feedwater system not been restored, would there have been a severe core damage accident?
If yes, how long would it have taken before fuel damage occurred?
4.
According to preliminary information provided by the NRC Staff, the Emergency Core Cooling System (ECCS) at Davis-Besse is unable to function properly when the primary cooling system is pressurized in excess of 1,600 pounds per s
square inch.
If this is true, why did the operators initiate l
the ECCS during the Davis-Besse incident and why did they terminate ECCS?
What other pressurized Water Reactors (PWR) have High Pressure Injection pumps whose shutoff head is below the set point of the code safety valves?
5.
According to preliminary information provided by the NRC staff, Davis-Besse is not capable of cooling the reactor using the " feed and bleed" process.
What is the technical basis for not requiring Davis-Besse to be capable of cooling the reactor using this process?
Identify all PWR's for which feed and bleed has been demonstrated -- using safety evaluations performed in accordance with establish NRC requirements -- to be an adequate method of core cooling.
6.
Does the failure of the PORV during the Davis-Besse incident raise questions about the adequacy of testing done in accordance with the TMI Action Plan?
Additionally, please provide the following informations (a) was the specific PORV model used at Davis-Besse tested as part of the TMI Action Plan; (b) how many other plants have the same model PORV; and
2 (c) how many PORV failures have occurred during operation or testing since the accident at Three Mile Island?
7.
Does the auxiliary feedwater system at Davis-Besse provide greater, equal or smaller margin of safety than the auxiliary feedwater system ct other pressurized water reactors?
8.
Provide a history of any previously noted difficulties observed with the main or auxiliary feedwater systems at Davis-Besse since 1979 and any actions taken in response.
9.
What are the generic implications and lessons learned from the Davis-Besse incident?
10.
In light of the Davis-Besse incident, is there any information of which the Commission is aware that would lead it to reconsider any of the positions taken by the NRC Staf f, or in any of its own decisions, in the TMI restart proceeding?
For example, in the TMI restart proceeding, the NRC Staff contended that a total loss of feedwater was beyond the design basis and therefore, capability to accomplish feed and bleed was not required.
11.
List those TMI Action Plan items directly relevant to the Davis-Besse incident and provide the current status of compliance.
Specifically included in your response should be a detailed explanation of what actions were taken and when in response to those TMI Action Plan items concerning the auxiliary feedwater system and pilot operated relief valve.
Your response should clearly identify those relevant Action Plan items that have not been fully implemented and explain when each item was originally scheduled to have been completed and the reason it remains outstanding.
12.
In NUREG-0667, Transient Response of Babcock &
Wilcox-Designed Reactors (May 1980), the NRC-specifically recommended that Davis-Besse improve saf ety by installing a diverse drive auxiliary feedwater pump.
Acccording to preliminary information provided by the NRC Staff, this I
I recommendation was suspended and is now pending for the next refueling outage in 1986.
Please provide a detailed history of all actions taken in response to this recommendation and all actions since 1979 taken concerning the auxiliary j
feedwater system at Davis-Besse.
Your response should I
include a listing of all meetings, copies of all correspondence between NRC and the licensee and all documents concerning the auxiliary feedwater system since 1979.
13.
In terms of configuration, reliability, diversity and capacity how, if at all, does the auxiliary feed water system at Davis-Besse differ from the system in place on March 28, 1979?
14.
According to preliminary information provided by the NRC
3 Staf f, the licansae has resisted NRC recommendations to improve the reliability and capacity of the auxiliary feedwater system at Davis-Besse.
Is this true and if so, why i
did NRC not require that improvements be made?
15.
The Commission was provided with a preliminary sequence of events which occured at Davis-Besse in a June 12, 1985 memorandum from William J. Dircks, Executive Director for i
Operations that appears not to include several important details of the incident.
For example, the preliminary i
chronology fails to note that the PORV stuck open, that ECCS was initiated and turned off, and that one of the auxilary i
feedwater pumps could not be returned to operation from the control room.
When did the Commission first become aware of this information and why was it not transmitted to the Commission in the June 12, 1985 memorandum?
j a
16.
According to a June 13, 1985 memorandum from William J.
li Dircks, Executive Director for Operations, to the Commission i
the licensee failed to provide accurate info:mation to the I
NRC about the Davis-Besse incident.
The memorandum states:
"It became clear the the initial written description of tha event was incomplete and that a number of potentially important details were not included."
What information was incomplete and what details were not included in the licensee's initial report to NRC?
What is the reason for this failure and what, if any, reporting requirements were violated?
i i
17.
What actions will NRC require prior to restart of Davis-Besse.
Specifically, will NRC require that the January 4
i 1985 license condition committing to an additional auxiliary i
feedwater pump be fulfilled prict to restart.
In not, please explain why.
18.
List all pending requirements and licensing actions relating to systems and components involved in the Davis-Besse I
incident.
19.
According to a June 13, 1985 memorandum from William J.
Dircks, Executive Director for Operations, to the Commission, j
the NRC Task Force investigating the incident has allowed a j
lawyer representing the licensee to be present during interviews with workers at the plant.
This practice was used l
during the investigation of the accident at Three Mile Island where some believe it resulted in less than candid testimony from workers and enabled the company to coordinate testimony.
Practices such as this were also harshly criticized by the i
Department of Justice in a March 25, 1983 letter.
Why is this practice being allowed at Davis-Besst when the NRC has already noted that information originally provided was less than complete?
What, if any, policy does NRC have on third j
party attendence during investigations?
l l
4
- 20. - Please provide the following information for ecch year since 1980:
j a.
the number 10 CFR 50.72 reports; b.
the total number of Licensee Event Reports, specifying i
the number attributable to personnel error, equipment l
failures, and design or fabrication errors; l
c.
the number of unusual events, alerts and abnormal occurrences; d.
the number and cause of reactor trips; and i
e.
the number of all enforcement actions including a brief descriptioa of the issur., the severity classification and any fine levied.
21.
NRC's most recent Systematic Assessment of Licensee Performance report on Davis-Besse noted that improvment was i
needed in 5 of 11 areas.
The report concluded that " strong i
steps are needed to raise the performance. level at the Davis-Besse facility."
Specifically what actions has NRC taken?
22.
What are the root causes of management problems noted by NRC at Davis-Besse?
What steps should be taken to correct these problems?
Provide any documents including internal memoranda that relate to NRC concerns about Davis-Besse's regulatory performance.
i 23.
Please provide all documents including internal NRC staff memoranda which relate to the Davis-Besse incident.
Your i
response should provide all documents generated by the NRC Task Force investigating this matter including transcripts of interviews with employees of Tolede Edison.
I 24.
At the Subcommittee's April 17, 1985 budget authorization hearing, the Commission testified that some plants dominate the probability of a severe accident as reported in the Commission's 45 percent estimate of a core meltdown at a U.S.
reactor in the next 20 years.
Is Davis-Besse one of those plants? What factors are important in identifying those plants most likely to have a severe accident?
What facilities has the Commission identified as most likely to have a severe accident and what actions has the Commission taken at each?
l
- ~.
-