ML17083B403
| ML17083B403 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 06/14/1984 |
| From: | Yin I NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17083B398 | List: |
| References | |
| NUDOCS 8407060150 | |
| Download: ML17083B403 (12) | |
Text
'Testimony Before Subcommittee on Energy and the Environment Committee on Interior and Insular Affairs U.S.
House. of Representatives on June 14, 1984 Prepared By: I.'. Yin Mr. Chairman and members of the Congress, my name is Isa Yin.
I am a Senior Mechanical Engineer in NRC s Region III, Division of Engineering.
Relative'o the Oiablo Canyon Nucleai Power Plant investigation effort, my assignment was to follow up. on some of the allegations made by Mr. Charles Stokes. 'he specific investigation areas were restricted to site small bore (S/B) pi'ping suspension system design control.
- However, due to hardware deficiencies observed during plant walkdown, the licensee design control measures for large bore (L/B) piping system were also included as a part of the overview inspection and evaluation.
On March 26-27, 1984, during the NRC Commission's meeting held to consider reinstatement of the licensee's low power test Operation License (OL), I brought to the Commission's attention the following issues which had not been
. adequately addressed:
1.
Substantiation of design allegations.
NRC overview inspections concluded" that there had been significant gA program deficiencies in the areas 'of S/B and L/B piping design control.
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2.
A large number of calculat'ional erroi's and deficiencies had not been identified through various reviews and checking stages.
3.
,Diablo Canyon Project Organization's lack of implementation of a sound design control gA program which resulted in violation of NRC re'gulations
'in personnel
- training, document control, audits, design verifications, and raised questions in many,technical and hardware related areas.
4.
Reinspection, and necessary hardware re-work and modification could be performed with less complication prior to reactor criticality.
My testimony contributed to the Commjssioners'ecision to defer the OL reinstatement decision pending review by the ACRS.
Prior to the ACRS meeting held.on April 6,
- 1984, an NRC peer review team was V
formed under the direction of Mr. Dircks, the NRC Executive Director for Operations.
The peer review team reviewed all of the issues and discussed I
them with Pacific Gas and Electric Company (PG&E) representatives and with me.
During the ACRS meeting, the staff presented a consensual view that:
l.
It was acceptable to permit low power operation prior to completing corrective actions.
Such operation would not compromise corrective actions and would not be a risk to the public health.and safety.
2.
Prior to operation above 5X power, the significant issues concluded by the NRC peer review team should be addressed and corrected by PG8E and evaluated and accepted by the staff.
e
The ACRS letter to the Commission, dated April. 9, 1984, concurred with the staff position, and requested further review of staff resolution of the various relevant issues raised by NRC inspectors and others.
The low power OL was subsequently reinstated during the April 13; 1984 Commission hearing.
The'Commission also asked that the peer review team issues be included in a license amendment.
This set forth License Condition 2.c.(11) in an Operating License Modification forwarded to PG8E on April 18, 1984.
'resently, the staff is working toward resolving the License Condition items, as well 'as Independent Oesign Verification Program (IDVP) concerns and programmatic issues raised by me.
1.
The'icense Conditions included:
a.'e-analyses and re-qualification of all S/8 piping support computer calculations.
b.
Evaluation and shimming of closely spaced rigid to rigid restraints and anchors.
c.
Performing additional piping analyses to ensure functionability of snubbers that were installed in close proximity to rigid supports.
d.
Establishment of inservice inspection to maintain required thermal gaps within the rigid support structures thoughout plant life.
e.
iSy~
Staff observation of hot walkdown inspections of Main Steam and Residual Heat Removal Systems to ensure absence of structural interference.
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op Review of "quick fix" s~gnificant design changes; and design criteria that were prescribed in informal "Oiablo Problem" correspondence.
g.
Consideration of additional technical topics raised by allegations.
These issues are presently handled by the NRC staff.
2.
My written concerns on possible inadequate IOVP for L/B and S/B piping stress analyses and support calculations, and seemingly insufficient followup'evaluations after deficiencies had been identified were formally submitted to NRR management on April 25, 1984.
Joint review of these concerns will be conducted by NRR, IE staff, and me.
3.
In addition to the License Conditions, I believe there are other program-matic issues that could affect the quality of ongoing and future project activities.
In my view, the'following changes are warranted:
a.
Improvement of site personnel indoctrination and training program as well as measures to be taken to ensure effective implementation of program requirements.
I b.
More stringent control of site procedures, including removal of outdated documents, and avoidance of procedure revisions by unauthorized means, for example Inter"office memoranda.
c.
Upgrade of procedures to include better control or preliminary design data, design interfaces between site Stress and Support 4
- groups, and PG8E and Westinghouse.
d.
Improvement of timeliness of project responses to site personnel safety concerns, and gA audit findings.
Corrective actions should include identification of underlying causes, and surveillance to prevent recurrence.
- e. 'onducting more extensive gA program audits that will:
(1) include broader scope and more in-depth review during the audit and prior to accepting audit finding corrective actions, and (2) ensure 'all aspects of design control requirements, such as design criteria, assumption, judgement basis,
- review, and approval are imple-mented in accordance with program provisions.
f.
Upgrade of Tolerance Clarification program (TC or commonly called guick Fixes) to ensure that adequate design reviews will be made prior to major hardware modifications.
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I I have discussed these concerns with PG8E management and I am presently reviewing the licensee's actions.
As it stands to date, followup actions are incomplete.
Hr. Chairman, and members of the Congress, I thank you for the opportunity to
- testify, and will truthfully answer any questions that you may wish to ask.